BIO-202 Final Exam Clinical Case Studies with Graded A+ Answers | GCU Human Anatomy & Physiology II

Final exam cases 1. Mary had one kidney removed due to cancer. Five weeks later, she was taken into the emergency room with severe fatigue and muscle weakness. Her heart rhythm is abnormal and her blood pressure is 160/100. Blood tests reveal that her remaining kidney is not functioning normally and that renal failure is a real possibility. Her breathing rate has increased and she has peripheral edema. The results of her blood tests are as follows: Hyperkalemia Hypernatremia Anemia – low hematocrit pH 7.32 (normal 7.35-7.45) PCO2 – 30 mmHg ( normal 35 - 45 mmHg) HCO3 – 15mEq (normal 22-26 mEq) Urinary system structure and function (filtration, reabsorption, and secretion, hormones released by the kidneys) a. Hormones released by the kidneys: vitamin D, renin, aldosterone, and erythropoietin b. Function: eliminate wastes from the body, regulate blood volume and pressure, control levels of metabolites and regulate pH c. Structure: kidneys, ureters, bladder, urethra, and nephron loop system d. Filtration: 1st step in making urine; process that kidneys used to filter excess fluid and waste products out of blood into the urinary collecting tubules of kidneys (glomerulus) e. Reabsorption: solutes reabsorbed across wall of nephron by osmosis (PCT) f. Secretion: solutes are secreted across wall of nephron into the filtrate (PCT) Acid base balance – diagnosis of type and level of compensation happening sequence of systems involved in resolving and how they work – compensation a. Metabolic acidosis with partial respiratory compensation Fluid/electrolyte balance – how kidney helps to regulate each electrolyte – specifically Na+ & K+ a. Kidneys stimulate the adrenal gland to secrete aldosterone, which causes the kidneys to retain sodium and excrete potassium b. When sodium is retained, the amount of urine produced is lessened, and blood volume increases Na+/K+ pump - Role of electrolytes in maintaining normal cell functioning – like resting membrane potential a. Sodium potassium pump maintains the internal concentration of potassium ions higher than surrounding blood, body fluid, and water; it also maintains the internal concentration of sodium ions lower than the surrounding medium RBC – structure/function – relate to symptoms a. Structure: flexible, bell shape; no nucleus, contains hemoglobin, has a membrane with lipids and proteins b. Function: they have a viscoelastic characteristic, and the shape helps maximize the overall surface area required for oxygen absorption c. Kidneys help to make red blood cells by making a hormone called EPO. EPO sends a signal to the body to make more red blood cells, but if the kidneys are not working properly, there won’t be enough EPO to be made d. Hematocrit: Mary has anemia which results in low hematocrit levels; hard time receiving oxygen in blood and CO2 remains in her blood Erythropoietin – how/where released and function a. Produced and released into the blood by the kidneys in response to low blood oxygen levels. b. Function: prime regulator of red blood cell production; promotes differentiation and development of RBCs to initiate hemoglobin production Transport of gases in blood – oxygen and CO2 a. Oxygen is transported in 2 ways: a. Small amount of oxygen carried in the plasma as a dissolved gas b. Most oxygen carried in the blood is bound to the protein hemoglobin in RBCs b. Carbon dioxide is transported in 3 ways: a. Directly in the blood b. Bound to plasma proteins or hemoglobin c. Converted into bicarbonate (majority) Define hypernatremia and hyperkalemia a. Hypernatremia: too much sodium in the blood b. Hyperkalemia: too much potassium in the blood BP – definitions and regulation a. Blood pressure: pressure of blood in circulatory system that pushes against the walls of the arteries3 b. Regulated by baroreceptors that act in order to influence the nervous system and endocrine systems; long-term regulation by arterial blood pressure; healthy lifestyle and diet; exercise; reduce stress ECG (EKG) – normal reading – what do peaks stand for? Relate to what is happening in the heart (cardiac cycle). a. P wave: first small peak; atrial depolarization (contraction of atrial musculature) b. QRS complex: ventricular depolarization (begins at apex; ventricular contraction) c. T wave: final small peak; ventricular repolarization (ventricles begin to relax and ventricular pressure drops) Action potential of cardiac autorhythmic and contractile cells – normal and how affected by Na+/K+ imbalances a. Normal action potential of cardiac autorhythmic cells: pacemaker potential; depolarization and reversal of membrane potential; repolarization a. If potassium levels increase, action potential decreases b. Inward flow of sodium increases concentration of positively charged ions which causes depolarization, where potential of the cell is higher than the cell’s resting potential b. Normal Action potential of cardiac contractile cells: depolarization, plateau, repolarization Capillary beds – normal functioning – NFP – osmotic and hydrostatic pressure a. Capillary beds: network of capillaries that connect the arterioles to venules; ideal place for exchange of gases, nutrients, hormones, and wastes between the blood and tissue cells b. NFP: interaction of hydrostatic and osmotic pressures that drive fluid out of the capillary c. Osmotic Pressure: pressure that exactly opposes a given concentration gradient; pressure caused by water at different concentrations due to the solution of water by dissolved molecules (salts and nutrients) d. Hydrostatic Pressure: pressure exerted by a stationary column of fluid in a tube 2. Fiona is a 20 year old student seeking medical attention for severe nausea, vomiting, and diarrhea and confusion. Past History: Four days before, she began to experience nausea, lethargy, and malaise. During the first day of illness, her appetite was diminished, but she was able take small meals. During the second day of illness, however, she experienced vomiting with diarrhea every several hours and was unable to keep either food or liquid in her stomach. The excessive vomiting and anorexia have persisted, and her father brought her to their family doctor. Physical Exam: The following were significant physical findings: oral temperature 37.6º C eyes sunken with dark circles skin cool and gray heart rate 110 (80-100 beats/minute) blood pressure 90/60 (110/70) respirations 10 breaths per minute (15-20 breaths/min) Current Status: Fiona was admitted to the hospital for treatment of gastroenteritis with dehydration. An intravenous catheter was inserted for the purpose of fluid replacement. Significant laboratory findings were: arterial blood gases: pH 7.47 (7.35-7.45) alkalosis PaCO2 48 mmHg (35-45) acidosis HCO - 29 mEq/L (22-26) alkalosis electrolytes: sodium 140 mEq/L (135 -145 mEq/L) potassium 3.6 mEq/L (3.5-5.0 mEq/L) Fiona improved rapidly and by the second day was able to tolerate an oral liquid diet. Her heart rate decreased to 80 and her respirations increased to 15. Blood pressure was 110/70. She was discharged from the hospital on the third hospital day. The cause of the acute vomiting was diagnosed as viral gastroenteritis. acid base balance – classification and compensation – role of various systems in compensation a. Metabolic alkalosis with partial respiratory compensation electrolyte and fluid balance – how maintained in the body a. Kidneys help maintain electrolyte concentrations by filtering electrolytes and water from the blood, returning some to the blood, and excreting excess into the urine b. Water balance achieved by the body by ensuring that the amount of water consumed in food and drink equals the amount of water excreted digestive system – stomach structure (including cells) and function, regulation of gastric emptying, a. Three layers of muscle (outer longitudinal, middle circular, inner oblique) a. Inner lining has 4 layers: serosa, muscularis, submucosa, mucosab. Mucous and parietal cells c. Function: aids in digestion; temporary storage of food d. Regulation of gastric emptying: presence of fat in meals results in stimulation of cholecystokinin secretion in the duodenum; this inhibits antral mobility, stimulates pyloric tone, and delays the process of gastric emptying BP –definitions– how body monitors and then steps to correct for low BP (nervous involvement and then hormone involvement). a. Body monitors blood pressure by using baroreceptors (send impulses to the cardiovascular center to regulate blood pressure b. Steps to correct for low blood pressure i. Increase salt intake ii. Increase fluid intake iii. Increase in heart rate and forcefulness of the heart’s contractions increase iv. Pump more blood through the heart Heart rate – effect of sympathetic and parasympathetic NS on HR (specifics on how it creates changes). a. Effects of sympathetic NS on heart rate: releases hormones (catecholamines) to accelerate heart rate a. Involves SA and AV nodes b. Effects of parasympathetic NS on heart rate: releases hormone acetylcholine to slow heart rate a. Involves vagus nerve Urinary system – effect of low BP on NFP and GFR – how do kidneys maintain normal GFR if BP is low? (autoregulation, Renin angiotensin aldosterone pathway, and nervous system). a. Low blood pressure = decreased GFR and NFP b. Autoregulation: protects kidneys from elevations in arterial pressure that would be transmitted to the glomerular capillaries and cause injury; ability of a tissue to automatically adjust its own blood flow to match its metabolic demand for oxygen and nutrients supply and removal of wastes c. Renin angiotensin aldosterone pathway: when blood pressure falls, kidneys release renin into the bloodstream d. Nervous system: sympathetic nervous system regulates arterial pressure e. When blood pressure is low, the afferent arteriole relaxes, which increases the vessel’s radius and increases blood flow. Location and role of sodium and potassium in the body a. Sodium: located in the blood and in fluid around cells a. Helps body to keep fluids in a normal balance b. Potassium: muscle cells, bones, liver, and red blood cells a. Helps nerve’s function and muscles to contract b. Helps regulation of heartbeat c. Helps move nutrients into cells and waste products out of cells Transport of gases – oxygen and carbon dioxide Pulmonary ventilation – what 3 factors are monitored by the body to know when it is time to breathe? a. Blood oxygen levels b. CO2 levels c. Partial pressure d. Respiratory rate 3. Dolores Welborn is a 28-year-old attorney living in Portland, Oregon. Dolores is in the second trimester of pregnancy with her first child, and though her pregnancy had been progressing normally, recently she has noticed that she tires very easily and is short of breath from even the slightest exertion. She also has experienced periods of light-headedness, though not to the point of fainting. Other changes she has noticed are cramping in her legs, a desire to crunch on ice, and the fact that her tongue is sore. She doubts that all of these symptoms are related to one another, but she is concerned, and she makes an appointment to see her physician. Upon examining Dolores, her physician finds that she has tachycardia, pale gums and nail beds, and her tongue is swollen. Given her history and the findings on her physical exam, the physician suspects that Dolores is anemic and orders a sample of her blood for examination. The results are shown below: RBC count = 30.5 million/mm3 (normal = 3.6-5.0 million/mm3) Hemoglobin (Hb) = 7g/dl (normal = 11.6-15 g/dL) Hematocrit (Hct) = 30% (normal = 35.5-44.9%) Serum Iron = lowMean corpuscular volume (MCV) = low Mean corpuscular hemoglobin concentration = low Total iron binding capacity in the blood = high A diagnosis of anemia due to iron deficiency is made and oral iron supplements prescribed. Dolores’ symptoms are eliminated within a couple of weeks and the remainder of her pregnancy progresses without difficulty. Structure/function of reproductive system a. Primary organs: gonads (produce gametes and hormones) b. External structures: a. Labia majora and minora b. Bartholin’s glands c. Clitoris d. Penis e. Testicles c. Internal Structures: a. Vagina b. Uterus (womb) c. Ovaries d. Fallopian tubes e. Epididymis and vas deferens f. Seminal vesicles g. Ejaculatory ducts h. urethra d. Function: a. to produce egg and sperm cells b. to transport and sustain these cells c. to nurture developing offspring d. to produce hormones Female hormones and cycle – role of pituitary gland a. estrogen: helps control menstrual cycle and is important for childbearing; keeps cholesterol in control; protects bone health for both women and men b. progesterone: prepares the endometrium for the potential of pregnancy after ovulation; triggers lining to thicken in order to accept a fertilized egg; prohibits the muscle contraction in the uterus that cause body to reject an egg c. Menstrual Cycle: cycles of hormonal activity that repeat about every month; periodic shedding of the uterine lining a. Phases: follicular (development of egg); ovulatory (release of egg); luteal (hormone levels decrease if egg does not implant) b. 4 main hormones: FSH, luteinizing hormone, estrogen, progesterone i. FSH: controls menstrual cycle and stimulates growth of eggs in the ovaries 1. Highest level just before an egg is released by the ovary ii. Luteinizing Hormone: triggers the release of an egg from the ovary Hormones – types, how cell knows it is target of hormone, and how monitored/released (in general) a. Three Types of Hormones in the Body: a. Lipid derived b. Amino acid-derived: c. Peptide b. Hormones are released into body fluids that carry chemicals to target cells a. Target cells: cells that have a receptor for a signal or ligand from a signal cell i. Hormones elicit a response c. Hormone production and release are primarily controlled by negative feedback a. Stimulus elicits release of a substance, and once the substance reaches a certain level, a signal is sent to stop the further release of a substance RBC – structure and function, hemoglobin saturation curve a. Tool for how blood transports and releases oxygen b. Hemoglobin: primary protein molecule that carries oxygen throughout the body c. Oxygen Saturation: percentage of hemoglobin bound to oxygen d. Partial Pressure of Oxygen in Blood: amount of oxygen dissolved in the blood e. Right Shift: hemoglobin has a decreased affinity for oxygen (oxygen actively unloads)f. Left Shift: increased hemoglobin affinity for oxygen (increase reluctance to release oxygen) Transport of gases in blood Blood volume - blood pressure regulation (nervous system and hormonal) a. Hormonal: renin-angiotensin-aldosterone system a. Hormones send messages that control the heart’s output of blood, stiffness of arteries, and changes in blood volume b. Epinephrine and Norepinephrine: raise blood pressure by increasing heart rate and contractility of the heart muscles; cause vasoconstriction of arteries and veins; part of fight-or-flight response c. ADH: raises blood pressure by stimulating the kidneys to retain water d. ANP: lowers blood pressure by causing vasodilation and by stimulating the kidneys to excrete more water and sodium Urinary system – effect of low BP on NFP and GFR – how do kidneys maintain normal GFR if BP is low? (autoregulation, Renin angiotensin aldosterone pathway, and nervous system). Would you expect this person to have an increased respiratory rate due to the anemia (no – why?) a. Blood cells carry oxygen to various parts of the body. Oxygen attaches to hemoglobin to that the blood can carry it through the circulation. However, if someone is anemic, the capacity to carry oxygen may be compromised because the healthy red blood cell count is much lower which decreases the ability for adequate oxygen to be carried to body tissues. 4. Mary and Bill adopted a good-natured and very inquisitive three-year-old toddler named Sam. Typically, before the finalization of an adoption, children are required to undergo a routine examination by a physician. However, the required examination is not meant to be a complete health screening, and many conditions are not even checked. Therefore, Mary and Bill are bringing Sam to Trinity Medical Center for a standard physical examination by a pediatrician to assess his health status after his adoption. Very little information was known about Sam’s parents except that they died in an automobile accident when Sam’s father suffered a massive heart attack. Sam has had all the proper immunizations for his age. Mary and Bill, have noticed some greasy/oily stools in his diaper. In addition, they are concerned about his wheezing (when breathing) and green/viscid sputum when he coughs. Physical Examination #1 Vital Signs • Weight: 28 lbs. (lower 10%-tile) • Height: 3 ft. 1 inch • Pulse: 115 beats/minute (normal = 65-110) • Respirations: 30 breaths/minute (normal = 20-30 breaths/minute) • Blood Pressure: 95/60 (systolic/diastolic) mmHg (normal = 95-107/60-71) General Appearance • Happy, energetic child • Runny nose but his ears are clear of fluid • Cracking sounds are present in lungs • Coughing and wheezing are noticeable • Normal reflexes The day of the follow up appointment is very hot and humid, which makes it almost unbearable to be outside. Mary and Bill were happy to be in the air-conditioned clinic. While talking with Mary and Bill about Sam’s sputum, the pediatrician looked over at Sam and noticed a white “frosting” on his face (the “frosting” is an indication of salty buildup on the drying edge of sweat). The pediatrician asked Mary and Bill if they had noticed this salty build-up before. They had not. The pediatrician then went over the blood count and chest x-ray results (described below) with Mary and Bill.Blood Lab Results • White blood cell count: values within normal limits. • White blood cell differential: lymphocytes, monocytes, eosinophils, and basophils are within normal limits. There is a slight elevation in neutrophils. • Red blood cell count: values within normal limits • Hematocrit: values within normal limits • Platelet count: values within normal limits Chest x-ray Results • Some hyperinflation and bronchial wall thickening is apparent. Anatomy and basic functions of respiratory system/organs a. Respiratory system: network of organs and tissues that help you to breathe a. Lungs b. Airways c. Blood vessels b. Nose/Nasal Cavity: provide airways for respiration; swirl air around to allow air to humidify, warm, and be cleaned before entering the lungs c. Mouth: used to supplement or replace nasal cavity’s functions when needed; pulls air from outside of the body into the respiratory system d. Throat (pharynx): allows air to pass through the respiratory tract to the lungs e. Larynx (voice box): prevents passage of food and other foreign substances into the lower respiratory tracts; essential role in human speech; air passes through here on the way to the lungs f. Trachea: moistens and warms air while it passes into the lungs; protects respiratory surface from an accumulation of foreign particles g. Bronchi (large airways): passageways that bring air into and out of the lungs h. Bronchioles (small airways): deliver air to a diffuse network of alveoli in the lungs a. As you inhale, oxygenated air is pulled into the bronchioles b. As you exhale, CO2 collected by the alveoli is expelled from the lungs i. Lungs: inspiration and expiration; allow gas exchange (respiration); allow body to take in oxygen from air and help remove CO2 from the body Pulmonary ventilation and external respiration a. Pulmonary Ventilation: referred to as breathing (process of air flowing into the lungs during inhalation and out of the lungs during expiration) b. External Respiration: formal term for gas exchange; bulk flow of air into and out of the lungs and the transfer of oxygen and carbon dioxide into the bloodstream through diffusion; gas exchange between lung and blood (transport); interchange of gases between environment and body’s cells Spirometry terms – definitions a. Spirometry: common office test used to assess how well lungs work by measuring how much air is inhaled, how much is exhaled, and how quickly exhalation occurs a. Used to diagnose asthma, chronic obstructive pulmonary disease, and other diseases that affect breathing b. Forced (Expiratory) Vital Capacity: total volume exhaled forcefully from the point of maximal inhalation c. FEV1: forced expiratory volume during first second of test d. FEV1%: ration of FEV1 to FVC; identifies the percentage of total FVC exhaled during the first second of the test e. FEF25-75: average flow rate between the 25% level and 75% level of the observed FVC. eg, with an observed FVC of 4.0 liters the 25% level is at 1.0 liter and the 75% level is at 3.0 liters. A line drawn through these points on the time-volume FVC curve will display this average liters-per-second flow rate.f. Simple diffusion and Fick’s law a. Simple diffusion: movement of a solute from an area of high concentration to an area of low concentration (no energy needed) b. Fick’s Law: i. According to Fick’s Law, the rate of gas transfer across a tissue plane or membrane is directly proportional to the difference in partial pressures of the gas on the 2 sides of the membrane in the membrane’s diffusing capacity Structure/function of the blood cells a. Small size and large surface area allow for rapid diffusion of oxygen and CO2 across the plasma membrane How oxygen/carbon dioxide carried in blood a. Inside air sacs, oxygen moves across paper-thin walls to capillaries into the blood; hemoglobin then carries oxygen around the body b. CO2 is transported in the blood from the tissue to the lungs in a dissolved solution, buffered with water as carbonic acid, or bound to hemoglobin Oxygen saturation curveVentilation/perfusion coupling - Matching blood flow to air flow - how? a. Matching the amount of gas reaching the alveoli to the blood flow in pulmonary capillaries b. Ventilation rate: volume of gas inhaled and exhaled from the lungs in a given time period (tidal volume x respiratory rate) c. Perfusion: total volume of blood reaching the pulmonary capillaries in a given time period 5. In the disease diabetes mellitus, the pancreatic islets do not secrete enough insulin. Symptoms include excessive thirst, excessive urine output, excessive hunger, metabolic acidosis, and increased respiratory rate. Hormones – types, how cell knows it is target of hormone, and how monitored/released (in general) a. Insulin: hormone released from the pancreas that controls the amount of glucose in the blood b. Somatostatin: inhibits secretion of glucagon and insulin Hormones of pancreas – where made and why? a. Insulin: feasting hormone, decreases blood glucose a. Produced by beta cells (located in the islets of Langerhans) b. Glucagon: fasting hormone; increases blood glucose a. Produced by alpha cells (located in the islets of Langerhans) Relate symptoms to what is happening in body with lack of insulin. a. Insulin helps body use sugar for energy, and when you do not have enough insulin, excess sugar (glucose) builds up in the blood b. Kidneys are used as a backup, and they work extra hard to absorb and filter the excess glucose a. They may pass some of the sugar of the body through urine i. This pulls fluids from tissues b. Process leaves the patient dehydrates and thirsty c. Excessive urine occurs when there is an excess amount of sugar in the blood a. In normal patients, when kidneys create urine, they will reabsorb all of the sugar and redirect it back to the blood stream i. However, with type 1 diabetes, excess glucose ends up in the urine, where it pulls more water and results in more urine output d. Excessive hunger occurs happens in uncontrolled diabetes where glucose levels remain abnormally high and glucose from blood cannot enter cells due to lack of insulin. a. The body can no longer convert the food into energy, and this lack of energy cause an increase in hunger e. If diabetes is not controlled and there is an insufficient amount of insulin, diabetic acidosis can occur a. Develops when substances called ketone bodies (acidic) build up during uncontrolled diabetes f. Kussmaul breathing: deep, labored breathing pattern that indicated that the body/organs have become too acidic Fluid balance – thirst reflex, role of kidneys a. Thirst reflex: craving of potable fluids, resulting in the basic instinct of animals to drink i. Essential mechanism of fluid balance. ii. Arises from lack of fluids or increasing in the concentration of sodium b. Kidneys regulate water levels in the body i. Conserve water if dehydrates ii. Make urine more dilute to expel excess water if necessary Urinary system structure and function (filtration, reabsorption, and secretion) a. Structure: a. Kidneys b. Renal pelvis c. Ureters d. Bladder e. Urethra b. Function: a. Filtration: first step in making urine; process used by the kidneys filter excess fluid and waste products out of blood into the urine collecting tubules in the kidneys, so they may be eliminated from body (glomerulus) b. Reabsorption: absorption of molecules, ions, and water that are necessary for the body to maintain homeostasis from the glomerular filtrate back into the blood (PCT); solutes reabsorbed across the wall of the nephron by osmosis c. Secretion: transfer of hydrogen ions, creatinine, drugs, and urea from the blood into the collecting duct, and is primarily made of water (in PCT)acid base balance – classification and compensation – role of various systems in compensation a. Body’s balance between acidity and alkalinity b. Diabetes: metabolic acidosis with partial respiratory compensation c. Classification: a. Respiratory acidosis b. Respiratory alkalosis c. Metabolic acidosis d. Metabolic alkalosis d. Compensation: a. Full compensation (pH returns to normal) b. Partial compensation (HCO3 or pCO2 level is out of the normal range) c. No compensation: if HCO3 or pCO2 is within the normal range e. Respiratory System a. maintains normal blood pH levels through the regulation of carbon dioxide, an acid that exits the body through exhalation f. Renal System a. assists in regulating blood acidity and alkalinity through the excretion of hydrogen ions (H+) and bicarbonate-the latter expressed as HCO3. Bicarbonate is a base that acts as a buffer in the blood. Glucose reabsorption in nephron a. 180 g/day of glucose is filtered by the renal glomerulus and all of it is reabsorbed in the proximal convoluted tubule b. Reabsorption is affected by 2 sodium-dependent glucose cotransporter proteins c. Retrieval of filtered glucose preventing it from disappearing from the body through the urine GRF – formula and regulation a. Test used to check how well the kidneys are working b. Estimates how much blood passes through the glomeruli each minute c. Formula: 140 – age d. The kidney can adjust the dilation or constriction of the afferent arterioles, which counteracts the changes in the blood pressure 6. Maggie Symes, age 52, inherited Andie’s Tavern from her father 30 years ago (it has been in her family since 1870). Maggie manages the bar and grill alone, since her husband died 2 years ago. She also takes care of her 4-year-old twin granddaughters during the day while the tavern is closed. The twins have just gone back to pre-school after being home for a week with colds. Maggie has caught the cold and now has a fever with a productive cough. She goes to a walkin clinic on her way to pick up the girls from pre-school. History: Female, age 52 – Widow Height 5’5” Weight: 148lbs. Non-smoker Non-drinker No use of prescription meds Uses acetaminophen for pain, fever Temp: 102 F Pulse: 92 BP: 139/86 Productive cough with green sputum 2 prior diagnoses of bronchitis in previous years Dyspnea when walking When the nurse practitioner sees the reading as: pulse: 86 SpO2: 88% (normal is 95-100%), she sends Maggie to get a spirometry evaluation. Maggie is given albuterol (a beta 2 agonist bronchodilator) before performing the spirometry testing. Topics to study: Anatomy and basic functions of respiratory system/organs Spirometry terms – definitions - what might be different in her considering her situation a. Maggie Symes, age 52, inherited Andie’s Tavern from her father 30 years ago (it has been in her family since 1870). Maggie manages the bar and grill alone, since her husband died 2 years ago. She also takes care of her4-year-old twin granddaughters during the day while the tavern is closed. The twins have just gone back to pre-school after being home for a week with colds. Maggie has caught the cold and now has a fever with a productive cough. She goes to a walk-in clinic on her way to pick up the girls from pre-school. b. Maggie has poor hemoglobin oxygen saturation as indicated by the SpO2 reading of 88%. Readings below 90% are especially dangerous. c. Spirometry: measures the amount and speed of air inhaled and exhaled Parts of respiration and how they work– pulmonary ventilation, external and internal respiration (gas exchange) a. Pulmonary ventilation: process of air flowing into and out of the lungs b. External Respiration: exchanges of gasses with the external environment (occurs in the alveoli of the lungs) c. Internal Respiration: gas exchange between the blood and tissues Diffusion – Ficks law of diffusion in relation to this case a. Diffusion: oxygen and carbon dioxide move back and forth across the alveolar capillary membrane by diffusion. b. Diffusion always occurs from higher concentration to lower concentration that is oxygen moves from alveolar gas in to arterial blood and co2 from arterial blood into alveolar gas c. Diffusion continues up to equilibrium reached. Gas transport in blood Oxygen saturation curve Ventilation/perfusion coupling a. Ventilation: air that reaches the alveoli b. Perfusion: blood that reaches the alveoli c. V/Q Ratio: measurement that assesses the efficiency and adequacy of the matching 2 variables a. Ratio of the amount of air reaching the alveoli to the amount of blood reaching alveoli, measured via ventilation perfusion scan b. V and Q are the main determinants of blood oxygen and CO2 c. Oxygen provided by the ventilation is just enough to saturate the blood thoroughly Fever, inflammation– non-specific defenses a. Neutrophils are the most common type of leukocyte and increase dramatically in # in response to infection and inflammation a. Kill invading organisms but can also damage host tissues when there are too many b. Fever: initiated by circulation substances (pyrogens), which affect the brain’s hypothalamus and cause the latter to raise the temperature a. Slows the growth of temperature-sensitive microorganisms, and it increases the metabolism of body cells while stimulating the immune reaction and the process of phagocytosis c. Inflammation: controlled by nervous stimulation and cytokines a. Mobilizes components of the immune system, sets into motion repair mechanisms, and encourages phagocytes to come to the area to destroy any microorganisms present Specific defenses – B and T cells – function and how activated a. B cells fight bacteria and viruses by making Y-shaped proteins (antibodies), which are specific to each pathogen and are able to lock onto surface of invading cell and mark it for destruction by other immune cells a. Activated when bound to the antigen b. Helper T cells: stimulate B cells to make antibodies and help killer cells to develop c. Killer T Cells: directly kill cells that have already been infected by a foreign invader d. T cells: use cytokines as messenger molecules to send chemical instructions to the rest of the immune system to ramp up its response a. Activated by antigen presentation at site of infection Alpha and beta receptors – where located and what neurotransmitter associated with each d. Alpha Receptors: arteries; neurotransmitter: norepinephrine e. Beta Receptors: heart, kidney, and fat cells; neurotransmitter: catecholamines (norepinephrine and epinephrine) 7. Mark is a 24 year old man who works as a physical education teacher in high school. Within the past two months, he has noticed that he is more fatigued. He feels unwell and looks pale. He has also had an increasing number of infections and notices that he bruises more easily and wound healing is slow. He has noticed that his breathing rate has increasedand his heart feels like it is pounding. He finally goes to the doctor who does blood test on him. The blood test reveals a high white blood cell (WBC) count, low red blood cell (RBC) count and low platelet count. The doctor is very concerned and orders a bone marrow biopsy. The results reveal that Joe has acute myeloid leukemia. This is a bone marrow cancer where there is overproduction of abnormal WBCs that do not function normally. The increased numbers of WBCs cause overcrowding in the bone marrow, which leads to the interference of production of other blood components like RBCs and platelets. Blood cells structure and function f. Plasma: liquid component of blood (mixture of water, sugar, fat, protein, and salts) ▪ Function: transports blood cells through body along with nutrients, waste products, antibodies, clotting proteins, chemical messengers (hormone), and proteins that help maintain body’s fluid balance g. Red Blood Cells (Erythrocytes): most abundant cell in blood ▪ Shape: biconcave disk with a flattened center; can easily change shape ▪ No nucleus more flexibility but limits life of the cell as it travels through the smallest blood vessels (survives 120 days) ▪ Start as immature cells in bone marrow and then mature for 7 days and are released into bloodstream ▪ Hemoglobin: protein in RBCs that helps carry oxygen from the lungs to the rest of the body and then returns carbon dioxide from body to lungs so it can be exhaled ▪ Gives RBCs its bright red color h. White Blood Cells: various types (monocytes, lymphocytes, neutrophils, eosinophils, basophils, and macrophages) ▪ Function: protect body from infection ▪ Neutrophil: most common type of WBC; “immediate response” cell ▪ Each lives less than a day, so bone marrow constantly makes new ones to maintain protection against infection ▪ Lymphocytes 2 types ▪ T lymphocytes: help regulate the function of other immune cells and directly attack various infected cells and tumors ▪ B lymphocytes: make antibodies i. Platelets: small fragments of cells ▪ Function: blood clotting process (coagulation) by gathering at site of injury, stick to lining of injured blood vessel, and form a platform on which blood coagulation occurs ▪ Results in fibrin clot (covers wound and prevents blood from leaking out) ▪ Fibrin: forms initial scaffolding upon which new tissue forms which promotes healing ▪ A higher-than-normal number of platelets causes unnecessary clotting which leads to strokes and heart attacks Differentiate between cells a. b. Neutrophils: first to respond to bacteria or virus c. Lymphocytes: fight infection by producing antibodies d. Eosinophils: role in allergy symptoms e. Monocytes: clean up dead cells f. Basophils: role in asthma Control of breathing – center location in brain and factors monitored a. Medulla: directs spinal cord to maintain breathing b. Pons: provides further smoothing of the respiration pattern c. Autonomic, involuntary, and continuous controld. Factors Monitored: blood oxygen levels, heart rate, respiratory rate, blood pressure, brain activity, and volume of air that is inhaled and exhaled Erythropoietin and RBC production a. Erythropoietin: hormone produced primarily by the kidneys and small amounts by the liver that play a key role in RBC production a. Function: controls RBC production and is necessary for adequate supply of oxygen to organs and tissues b. Erythropoiesis: process by which RBCs are produced; triggered by erythropoietin a. Location: bone marrow b. Hemopoietic stem cells proerythroblast early erythroblast late erythroblast normoblast reticulocyte erythrocyte Hemostasis – all three steps a. Hemostasis: natural process that stops blood loss when an injury occurs a. Vascular spasm (vasoconstriction): brief, intense contraction of blood vessels b. Platelet plug formation: aggregation of platelets that are formed during early stage of hemostasis in response to blood vessel wall injury; helps to stop the bleeding c. Coagulation: blood clotting that reinforces the platelet plug with fibrin mesh that acts as a glue to hold the clot together Relate symptoms to functions a. Low RBC: body lacks iron it needs to make hemoglobin, which carries oxygen around body a. Causes fatigue and a decrease in energy; difficulty breathing so you breathe deeper and quicker b. High WBC: rapid production of abnormal white blood cells that are not able to fight infections and impair the ability of bone marrow to produce RBCs and platelets a. Slow wound healing c. Low Platelets: body cannot form clots a. More bleeding (causes bruises) Viscosity/resistance/ and BP b. Blood viscosity: measurement of thickness and stickiness of blood i. Direct measure of the ability of blood to flow through the blood vessels ii. Viscosity increases = blood pressure increases c. Resistance: force that opposes flow of blood due to vessel diameter i. Vessel diameter decreases = resistance increases/blood flow decreases ii. Resistance increases = blood pressure increases Gas transport in blood a. Oxygen: carried in plasma as a dissolved gas; (mainly) bound to hemoglobin b. CO2: carried in plasma as a dissolved gas; binds to hemoglobin in RBCs; (mainly) transported as dissolved bicarbonate ions BP regulation – short term vs. long term a. Short term BP regulation of rising BP a. Stretch of arterial walls b. Stimulation of baroreceptors in carotid sinus, aortic arch, and other large arteries of neck and thorax c. Increased impulses to the brain b. Short Term BP regulation of falling BP a. Baroreceptors inhibited b. Decreases brain impulses c. Decreased parasympathetic activity, increased sympathetic activity i. Increased heart rate and contractility ii. Increased vasoconstriction iii. Release of epinephrine and norepinephrine (enhances heart rate, contractility, and vasoconstriction) iv. Increased blood pressure c. Long Term Regulation of BP a. Primarily accomplished by altering blood volume b. Loss of blood through various reasons will lower blood pressure and trigger processes to restore blood volume and help blood pressure return to normal c. Promote conservation of body fluids via renal mechanisms and stimulate intake of water to normalize blood volume and BP8. Mr. Jones, age 77, is a retired middle school history teacher. He has been brought to the ER from a nearby casino – he began having difficulty breathing after only 20 minutes playing the slots. He had taken a bus to the casino (3 hour drive) and had taken Benadryl so he could sleep on the bus. He has a history of “heart failure” and “COPD” but he did not bring any of his medications with him. His dyspnea responded to oxygen, an inhaled beta 2 agonist (albuterol), and inhaled Atrovent (a short acting anti-cholinergic drug). His arterial blood gas values were: PO255 mmHg (normal – 75-100) Oxygen saturation = 88% (normal = 94-98%) PCO2= 46 mmHg (normal = 35-45 mmHg) - acidosis pH = 7.30 (normal = 7.35-7.45) - acidosis HCO3 = 30 (normal = 22-26 mEq/L) -alkalosis He has pitting edema of his feet. An ECG (EKG) is taken and he has non-specific T wave abnormalities and a prolonged PR interval. (See book for ECG visuals). He has an echocardiogram which determines he has left ventricular hypertrophy and ventricular ejection value of less than 60%. He is given Lasix (a diuretic medicine that reduces sodium and water reabsorption from the loop of Henle). Heart structure and function – ECG – cardiac cell membrane potentials a. Structure: 2 atria and 2 ventricles ▪ 2 atria: separated by interatrial septum ▪ Right: receives deoxygenated blood from inferior and superior vena cavas; pumps blood to right ventricle ▪ Blood is oxygenated in lungs and carried by pulmonary vein to left atrium ▪ Left atrium pumps blood into left ventricle ▪ 2 ventricles: separated by interventricular septum ▪ Interventricular septum: Discontinuous at tricuspid valve and bicuspid valve through which blood flows from atrium to ventricle ▪ Right: contracts to push blood into pulmonary artery which carries blood to the lungs ▪ Left: pumps blood into aorta, and aorta carries blood to all parts of body b. ECG: record the electrical activities during this cardiac cycle ▪ P wave: atrial depolarization ▪ QRS complex: ventricular depolarization; masks the wave of atrial repolarization ▪ T wave: ventricular repolarization c. Ventricular cell resting membrane potential is around -90 mV; SA and AV nodes are much less Cardiac cycle and output a. Cardiac cycle: sequence of alternation contraction and relaxation of atria and ventricles in order to pump blood throughout the body a. Systole and diastole b. Cardiac Output: volume of blood pumped by heart each minute a. CO= stroke volume x heart rate i. Depends on heart rate, force of contraction, stroke volume, and venous return Synapses and receptors– adrenergic vs. cholinergic a. Synapse: junction between axon of one neuron and dendrites of another; separated by synaptic cleft a. 2 types: chemical and electrical i. Chemical: more common; neuron is released in synaptic cleft Cholinergic and adrenergic receptors a. Cholinergic: acetylcholine as ligand ii. Muscarinic: present in CNS, blood vessels, eye, etc. iii. Nicotinic: present in CNS and ganglia b. Adrenergic: adrenaline and noradrenaline as ligands iv. Alpha: 1) in heart v. Beta: 1) in heart; 2) in heart; 3) adipocytes Arterial blood gas – acid/ base balance and compensation a. Respiratory acidosis with partial metabolic compensation Transport of gases in the blood Oxygen saturation curve – how oxygen is carried in the blood a. Oxygen: carried in plasma as a dissolved gas; (mainly) bound to hemoglobin Capillary structure and function – net filtration pressure a. Smallest and most numerous of blood vessels; form connection between: a. Arteries: carry blood away from the heartb. Veins: return blood to heart b. Function: exchange of materials between blood and tissues; connect arteries and veins c. Structure: very thin and have two layers (inner layer of endothelial cells and outer layer of epithelial cells) d. Net filtration pressure: pressure needed to push urine and molecules through filtration membrane Urinary system – nephron function, filtration, reabsorption a. Nephron: microscopic tubule that is the functional unit of kidney i. Function: produces urine in the process of removing waste and excess substances from blood ii. Filtration: glomerulus filters the blood iii. Reabsorption: tubule returns needed substances to blood and removes wastes and excess acid from blood 1. Blood vessel reabsorbs almost all of the water along with minerals and nutrients that the body needs ADH/ aldosterone a. ADH: hormone that helps to control blood pressure by acting on the kidneys and blood vessels; conserved the fluid volume of body by reducing amount of water passed out in the urine (promotes reabsorption of water to maintain proper water balance) b. Aldosterone: steroid hormone that regulates salt and water in the body, which has an effect on blood pressure (maintains proper water balance by enhancing sodium reabsorption and potassium secretion from extracellular fluid of the cells in the kidney tubules) Respiratory system – pulmonary ventilation and gas exchange, perfusion ventilation coupling a. Gas exchange: oxygen moves from lungs to bloodstream a. Simultaneously, CO2 passes from blood to lungs b. Location: between alveoli and capillaries (located in the walls of the alveoli) b. Pulmonary ventilation: volume of air moved in and out of the lungs c. Perfusion Ventilation Coupling: matching the amount of gas reaching the alveoli to the blood flow in the pulmonary capillaries Structure and function of cardiac muscle a. Structure: single nucleus (centrally located); branched; joined together by intercalated disks; rectangular b. Striations present c. Myosin and actin filaments d. Have gap junction e. Function: performs coordinated contractions that allow heart to pump blood through circulatory system Contraction of cardiac muscle a. Occurs due to the binding of the myosin head to ATP, which then pulls actin filaments to the center of the sarcomere, which is the mechanical force of contraction b. Sliding filament model c. Process a. An action potential, induced by the pacemaker cells in the sinoatrial (SA) and atrioventricular (AV) nodes, is conducted to contractile cardiomyocytes through gap junctions. b. As the action potential travels between sarcomeres, it activates the calcium channels in the Ttubules, resulting in an influx of calcium ions into the cardiomyocyte. c. Calcium in the cytoplasm then binds to cardiac troponin-C, which moves the troponin complex away from the actin binding site. This removal of the troponin complex frees the actin to be bound by myosin and initiates contraction. d. The myosin head binds to ATP and pulls the actin filaments toward the center of the sarcomere, contracting the muscle. e. Intracellular calcium is then removed by the sarcoplasmic reticulum, dropping intracellular calcium concentration, returning the troponin complex to its inhibiting position on the active site of actin, and effectively ending contraction as the actin filaments return to their initial position, relaxing the muscle. 9. John Gower – 76 year old man – goes to the dentist for a root canal. While undergoing anesthetic John complains that the room is stuffy so the nurse opens the window. However a burst of wind blows some freshly laid mulch into the surgery room so she closes it but not completely. The surgery goes well and John attributes the light headiness he feels to the Novocain he received to numb his mouth. Novocain is a Na+ channel blocker.The next day John feels a lot of pain in his jaw and feels faint. His wife takes his BP and finds that it is 100/60. The dentist recommends drinking fluids, Tylenol and rest. John agrees and goes to bed. Day 2 after surgery John has a fever and his face muscles are frozen in a grimace. At the ER the doctor diagnoses John with a Clostridium tetani (a bacterium that lives in soil) infection. This bacterium causes “lock jaw”. He is given penicillin, muscle relaxers, and anti-toxin. Skeletal muscle structure and function – contraction and how it works a. Composed of muscle fibers; multinucleated; many mitochondria, T-tubules, myofibrils and sarcomeres, sarcolemma, sarcoplasm, sarcoplasmic reticulum; striations present and voluntary b. Levels: ▪ Molecular: actin and myosin ▪ Microscopic: sarcomere and myofibrils ▪ Cell: myoblasts and myofibers ▪ Tissue: neuromuscular junctions and fascicles ▪ Organ: major skeletal muscles of body c. A band: dark region (contains myosin thick filaments) d. I band: light region (contains actin thin filaments) e. H zone: region of sarcomere with only thick filaments f. Z disc: sarcomere proteins to which actin filaments attach g. Sarcomere: contractile unit of myofibril h. Function of Skeletal Muscle: helps in locomotion; stores and moves substances, mainly calcium, within the body Muscle contraction – comparison of muscle types and at the fiber level vs. whole muscle level a. Shortening of muscle b. Sliding filament mechanism a. Skeletal muscle shortens during contraction because thin and thick filaments slide over one another during contraction b. Myosin heads attach to & walk along the actin filaments at ends of sarcomere which in turn pulls the thin filaments towards the M line i. thin filament slide inwards towards the center of the sarcomere ii. I band and H zone narrow iii. A band and length of thin and thick filaments remain the same iv. when the thin filament slide inwards, the Z disc come close together which in turn shortens sarcomere c. shortening of sarcomere = shortening of muscle fiber = shortens whole muscle Neuromuscular junction – synapse function a. synapse formed between skeletal muscle fiber and somatic motor neuron b. Muscle action potential which stimulates contraction of a muscle arise at neuromuscular junctions c. Neuromuscular junction consists of synaptic end bulbs on one side, motor end plates of muscle cells on the other side & the synaptic cleft between the two. d. At neuromuscular Junction, the axon terminals divide into number of synaptic end bulbs. within each synaptic end bulbs are hundreds of membrane enclosed sacs known as synaptic vesicles. i. the synaptic vesicle contains acetylcholine, which is the neurotransmitter released at neuromuscular junction. e. Synapses: small gaps between two neurons i. Nerve impulses are relayed by a neurotransmitter from the axon of a presynaptic neuron to the dendrite of a postsynaptic neuron Action potentials and graded potentials (membrane potential and nervous system vocab sheet) a. Action Potential: change in electrical potential associated with the passage of an impulse along the membrane of a muscle or nerve cell a. Results in depolarization of membrane and reversal of membrane potential b. Graded Potential: changes in membrane potential that vary in size a. Depolarizing or hyperpolarizing depending upon the stimulus Structure, function and location of voltage gated Na+ and K+ channels a. Voltage Gated Na+ channels a. Structure: alpha subunit that forms an ion conduction pore; 2 beta subunits that have several functions b. Function: open and close sodium ion channel in response to membrane changesc. Location: cell membrane of a neuron and muscle; axon b. Voltage Gates K+ channels a. Structure: tetramers of 4 identical subunits arranged as a ring; each subunit has 6 membrane spanning hydrophobic alpha helix sequences and a voltage sensor b. Function: returning the depolarized cell to a resting state after each nerve impulse; modulate neuronal excitability in CNS and PNS c. Location: axon Voltage regulated vs. ligand regulated channels a. Voltage regulated channels: class of transmembrane proteins that form ion channels that are activated by changes in electrical membrane potential near the channel b. Ligand regulated channels: bind neurotransmitters and open in response to ligand binding; control synaptic transmission between 2 neurons or between a neuron and a muscle Motor units – gradations of muscle contraction a. Made up of a motor neuron and the skeletal muscle fibers innervated by the motor neuron’s axon terminals b. Basic functional units of skeletal muscle c. Activity represents the final output of the CNS and has a role in motor control Water balance – blood volume – blood pressure regulation a. Water balance: amount of water entering organism through ingestion of liquids and food and the total output of water lost from body by way of the kidneys, bowels, lungs, and skin a. Depends on thirst b. Blood volume regulation: regulated by renal system (kidneys); adjustment of amount of water and sodium lost into the urine c. Blood pressure regulation: kidneys produce aldosterone which helps body to regulate BP Renin – angiotensin – aldosterone – ADH a. RAAS plays an important role in regulation of blood systemic vascular resistance, which influences cardiac output and arterial pressure i. Renin: released by kidneys; stimulated formation of angiotensin in blood and tissues stimulates release of aldosterone from adrenal cortex 1. A reduction in afferent arteriole pressure causes the release of renin from the JG cells, whereas increased pressure inhibits renin release. 2. When renin is released into the blood, it acts upon a circulating substrate, angiotensinogen, that undergoes proteolytic cleavage to form the decapeptide angiotensin I. Vascular endothelium, particularly in the lungs, has an enzyme, angiotensin converting enzyme, that cleaves off 2 amino acids to form angiotensin II Fever – non-specific defenses a. Develops in response to various traumas b. Initiated by pyrogens, which affect hypothalamus and cause the latter to raise the temperature c. Slows growth of temperature-sensitive microorganisms and increases metabolism of body cells while stimulating the immune reaction and process of phagocytosis d. Other nonspecific defenses: a. Mechanical barriers b. Chemical defenses c. Genetic barriers d. Inflammation e. Interferon B-cell and T- cell functioning a. T cells: cell-mediated immunity; circulate until they encounter an antigen; respond to infections and boost immune function of other cells b. B cells: humoral immunity; mediate production of antigen-specific immunoglobulin directed against invasive pathogens (antibodies); fight bacterial infections 10. Shayna is a 25 year old African American female. Shayna has been experiencing lower back pain that has become progressively worse over the last 3 months. After participating in a 3 days walk for charity, she discovered she had difficulty walking. She noticed that her legs would “give out”, initially starting on the right side, then progressing to include both legs. She tried massage therapy, and when that did not work, she sought medical attention. Her doctor ordered a full medical workup, including magnetic resonance imaging of the brain and entire spine. A detailed history revealed symptoms of proximal weakness and autonomic dysfunction. She showed no signs of muscleatrophy, and had full range of motion and function in all major muscles and joints in her upper and lower extremities. However, the results of electrodiagnostic tests were consistent with presynaptic neuromuscular junction disorder, specifically Lambert–Eaton myasthenic syndrome (LEMS). LEMS is an autoimmune disease in which the patient’s own antibodies attack presynaptic calcium channels at the neuromusclular junction, decreasing the ability of these calcium channels to open when stimulated. Immune cells - B cell and T cell functioning a. T cells: cell-mediated immunity; circulate until they encounter an antigen; respond to infections and boost immune function of other cells b. B cells: humoral immunity; mediate production of antigen-specific immunoglobulin directed against invasive pathogens (antibodies); fight bacterial infections Antibody structure, classes, production, and functions a. Y-shaped structure with 4 polypeptides (two heavy chains and two light chains) b. 5 classes: a. IgM: involved in ABO blood group antigens on surface of RBCs; enhances ingestions of cells by Phagocytosis; produced first upon antigen invasion b. IgG: long term protection against bacteria, viruses, toxins; trigger compliment protein system; bind antigens to enhance effect of phagocytosis; highest opsonization and neutralization activities c. IgA: bind antigens to microbes before they invade tissues; first defense for mucosal surfaces (intestines, nose, lungs) d. IgD: present on surface of B cells; role in the induction of antibody production e. IgE: bind to mast cells and basophils which participate in immune response; involved in allergy c. Antibody production: produced by specialized white blood cells (B lymphocytes) a. When an antigen binds to B cell surface, it stimulates B cell to divide and mature into a clone. Mature B cells (plasma cells) secrete millions of antibodies into the bloodstream and lymphatic system. d. Functions: bind to antigens and act as opsonins to enhance phagocytosis for phagocytes; occupy binding sites of antigens inhibiting them from binding onto other cells; activate complements; participate in the antibody-dependent-cell-mediated-cytotoxicity (ADCC) Primary vs. secondary response a. Primary Response: reaction of the immune system when it contacts antigen for first time a. Consists of a lag phase in which no antibody is produced b. Antibody production is relatively low b. Secondary Response: reaction of the immune system when it contacts an antigen for the second and subsequent times a. Quicker and more effective than the primary response b. Antibody level remains higher for longer Antigen vs. antibody a. Antigen: molecule (toxin or foreign substance) that stimulates an immune response b. Antibody: protein made in response to an antigen; binds to antigen and helps to ward off future occurrences by the same infections Neuromuscular junction structure and function (steps of how impulse transmitted across synapse) a. Structure: presynaptic terminal, synaptic cleft, and postsynaptic membrane or cell b. Definition: chemical synapse between the motor neuron and skeletal muscle fiber c. Function: site for transmission of action potential from nerve to muscle; site for many diseases; site of action for many pharmacological drugsd. Cholinergic synapse and receptors a. Cholinergic synapses: chemical synapses that use acetylcholine molecules as neurotransmitter; junction between 2 different times of neurons b. Cholinergic receptors: receptors on surface of cells that get activated when they bind a type of neurotransmitter (acetylcholine) i. Muscarinic: present in CNS, blood vessels, eye, etc. ii. Nicotinic: present in CNS and ganglia Role of calcium in all muscle contraction and in neuromuscular junction a. Calcium exposes the site on actin which interacts with myosin, in order for myosin head to bind and stimulate a muscle contraction ▪ Ca ions and proteins bond to action and play a crucial role in muscle cell contraction b. Calcium ions bind to sensor proteins on synaptic vesicles, triggering vesicle fusion with cell membrane and subsequent neurotransmitter release from motor neuron into synaptic cleft Structure of muscle – from organ to sarcomere a. Largest to smallest a. Muscle b. Fascicle c. Muscle fiber d. Myofibril e. Sarcomere f. myofilament Steps in muscle contraction – for all muscle types a. depolarization and calcium ion release b. actin and myosin cross-bridge formation c. sliding mechanism of actin and myosin filaments d. sarcomere shortening (muscle contraction) a. Action potential generated, which stimulates muscle b. Calcium is released c. Calcium binds to troponin, shifting the actin filaments, which exposes binding sites d. Myosin cross bridges attach and detach, pulling actin filaments toward center (ATP required) e. Muscle contracts f. Calcium is removed, which shifts actin filaments to original position, and blocks binding sites g. Muscle contraction stops Location of calcium (for contraction) for all muscle types a. Remains in sarcoplasmic reticulum until released by a stimulus b. Then binds to troponin Motor unit – recruitment a. Process by which the number of active motor units in a given muscle are increased Muscle twitch and summation a. Muscle twitch: single contraction/relaxation cycle that lasts only for a fraction of a second b. Summation: increases the force of contraction by increasing the frequency of stimulus of muscle fibers Graded potential (IPSP or EPSP) vs action potential a. Graded Potential: small deviation from resting membrane potential that makes a membrane more or less polarized a. IPSP: hyperpolarization and chloride or potassium channels openb. EPSP: depolarizes and sodium channels open b. Action Potential: rapid and uniform electrical signal conducted down a cell membrane Voltage regulated vs. ligand (chemically) regulated channels a. Chemically gated channels: gated channel whose gate is controlled by binding to a chemical ligand b. Voltage gated channel: gated channel that opens or closes in response to a change in membrane potential Example of old questions: John is suffering from severe hypertension (high blood pressure). His clothes feel tight and his lower extremities are swollen. He feels tired and weakness with any muscle activity. John’s diet is high in salt and cholesterol and this had led to the narrowing of his arteries due to atherosclerosis. He goes to his doctor who does a full blood analysis on him. The results indicate that his kidneys are not functioning normally and he has hyperkalemia and hypernatremia. 61. What is hyperkalemia? a. Excess amounts of sodium in the blood b. Excess amounts of sodium in the cell c. Excess amounts of potassium in the blood d. Excess amounts of potassium in the cell e. Excess amounts of calcium in the blood 62. What is the effect of atherosclerosis on afterload? a. Increase b. Decrease c. No effect 63. What is the effect (if uncompensated) on cardiac output? a. Increase b. Decrease c. No effect 64. Cardiac output = a. heart rate + stroke volume b. peripheral resistance x heart rate c. stroke volume x resistance d. heart rate x stroke volume e. diameter x stroke volume 65. Eventually chronic elevated blood pressure causes heart failure (inability of the cardiac output to meet the demands of the body). This leads to decreased venous return and contractility of the heart. It can eventually lead to edema. Why does he have swelling (edema) in his lower extremities? a. Increased blood in the veins means more nutrients diffuse out and water follows. b. Increased hydrostatic pressure in the veins causes more fluid to enter the tissues. c. Increased osmotic pressure in the veins causes more fluid to enter the tissues. a. Decreased osmotic pressure in the tissues causes more fluid to enter the tissues.