Physiology- Study of HOW body and parts work/function (both micro and macro level)
o Cells- Smallest living unit
o Tissues- Collection of same type of cells
o Organs- Collection of 2 or more types of cells which perform specific function
o Organ systems- Collection of organs working together to accomplish a task
Blood- Ties together all organ systems
o Air in lungs, food in GI, fluid in renal tubules are not in the body.
Must enter blood stream, be in cells, lymph or interstitial fluid to be “in”
the body
Immune/Lymphatic- Forms interstitial fluid. Cleanses fluid to protect from pathogens.
Performs housekeeping.
o Biggest single factor in diversity
Homeostasis (Steady State: Dynamic state of equlibrium)- Maintaining stable internal
environment to stay alive
o 37 degress C, blood plasma 7.4 pH, also maintains things like water, sugar levels,
weight, and blood pressure.
o Reproductive system only one not needed for homeostasis
o Homeostatic imbalance- Disturbance in homeostasis causing disease
o Can be external or internal i.e. hot outside or working out causing sweat
Negative feedback is the main guy working
Neural and hormone control of homeostasis
o Receptor (sensors) responds to changes in the environment (stimuli)
o Control center- Analyzes info. Determines appropriate response and sends output
to effectors.
Effectors are the means for response to the stimulus
o 1. Stimulus causes imbalance, 2. Receptor detects the imbalance, 3. Input-
Information sent to control center through afferent path, 4. Output-info sent to
effector (any muscle, gland, or organ) through efferent path 5. Response of
effector to maintain homeostasis
Negative Feedback Control
o Main way to control homeostasis
o Cancels out original stimulus
o The body is opposing the stimulus i.e. if body gets hot, sweat released to cool
down body.
Trying to return to normal parameters known as SET POINT
Positive Feedback Loop
o Uncommon
, o Increases the original stimulus, pushing variable further
The increased response ends only when the stimulus ends (done by outside
factor)
Example: Female produces oxytocin during child birth to cause uterine
contractions. The positive feedback stimulates uterine contractions as long
as baby is in the birth canal to make sure baby gets out.
o Angiogenesis- Formation of new blood vessels
o Heart attack results in heart tissue dying. Remaining muscle pumps harder to
compensate (increased heart rate). Working harder means need more oxygen.
Heart pumps harder to increase own demand for oxygen. Working harder causes
the muscle tissue of the heart to grow (more mass means need more oxygen).
Back to working harder for oxygen demands.
Lecture 2 Blood
Blood- Only fluid tissue of body. Considered connective tissue because comes from bone
marrow. Vehicle of transport. Red due to hemoglobin, dull red if low oxygen. pH=7.4.
Blood transfers heat so slightly warmer than body (38 C)
o The 2 components of Blood
Living Cells- Formed Elements
Erythrocytes- Red blood cells transporting oxygen and CO2
Leukocytes- White blood cells defending against pathogens: in
order of most to least abundant (never let monkeys eat bananas)
o Neutrophils
o Lymphocytes
o Monocytes
o Eosinophils
o Basophils
Platelets- Cell fragments of megakaryocytes used to clot blood
Non-Living matrix- Plasma
The fluid and solutes
o Water, ions, organic molecules, vitamins, gases
Centrifuge blood to separate densities
Hematocrit- Percent of erythrocytes (RBC)
o 45% of blood
Buffy coat- Contains leukocytes and platelets
o Less than 1 % of blood, Whitish layer in the middle.
o Greater amount if there is an infection, leukemia aka blood cancer, anemia aka
lack of blood
Plasma- Top layer. 55% of blood.
, o Kwashiorkor (extreme starvation)- Stomach is bulging out. The body uses
proteins of body to survive which causes blood to be watery, this watery blood
causes swelling.
Blood plasma is 90% water (A lot of this seems like extra info)
o 6-8% proteins which increases osmotic pressure, acts as buffer, provide fuel
o Classes of plasma proteins
Albumins- Carriers
Globulins- Carriers, clotting factor, protein angiotensinogen,
immunoglobulins
Fibrogen- Blood clotting
o Nutrients- Glucose, amino acids, lipids
o Wastes- Urea, creatinine
o Gases- Oxygen and CO2
o Hormones
o Electrolytes
High Na and Cl. Low H, HCO3, K, and Ca
Buffered Ringer’s Solution
o Solution of distilled water and electrolytes (same concentration as body)
o Iso-osmotic to blood and tissue (iso means same). Need about 300 mOsm/L.
o If given low amounts, the people will swell up because of the hypotonic solution
(the high water concentration moves to low concentration of water in blood).
Need to pee it out (those with kidney failure die cause can’t pee)
Given high amounts would cause hypertonic blood
Osmosis- Water (the solvent) diffuses down the concentration gradient
o Water moves from high solvent to low solvent
o Water moves from low solute to high solute
If low solvent (water) then the water will shift there cause it’s roomy
If high solute (electrolytes) then the water will shift there cause it’s roomy
o Pure water=0 solute
Blood plasma continued
o Acidosis- Acidic blood, less than 7.35 pH
Due to CO2 dissolving in blood plasma to form carbonic acid
o Alkalosis- Basic blood, greater than 7.45
o Kidney restores pH
o Base accepts hydrogen
Strong dissociates and ties up H+
Weak (bicarbonate and ammonia) slower to accept H
o Acid donates hydrogen
Strong dissociates completely losing all H+
Weak (carbonic acid) dissociate partially