ZOOL 2403 Boros Exam 3 TTU fully solved & updated

5 cranial senses - answer-olfaction, taste, vision, hearing and equilibrium Olfactory pathway - answer-odor-olfactory receptors-olfactory nerves-olfactory bulbs-olfactory tracts-olfactory cortex Gustatory Pathway - answer-Taste buds are on the dorsal surface of the tongue taste-receptors- cranial nerves-medulla-gustatory cortex 6 primary taste sensations - answer-sweet salty bitter sour umami water Cranial Nerves - answer-Facial nerve(CN VII)- anterior 2/3s on tongue Glossopharyngeal (CN IX)- posterior 1/3 on tongue 3 Layers of the eyeball - answer-Outer layer Middle Layer Inner Layer Outer Layer of the Eye - answer-Dense connective tissue 1. The Sclera- White sheath protecting eyeball. 2. The Cornea- Transparent anterior continuation of the sclera that protects the lens. The cornea is avascular and can be transplanted. Middle Layer of the Eye - answer-Loose connective tissue 1. Choroid- Contains blood vessels that supply oxygenated nutrients to the tissue of the eye. 2. Ciliary Body- Anterior continuation of the choroid, contains smooth muscle called ciliary muscles to control the shape of the lens for focusing on an object 3. Iris- Gives the eye color, it is composed of smooth muscle which change the size of the pupil to regulate the amount of light entering the eye. Inner Layer - answer-Nervous tissue layer 1. Retina- contains photoreceptors associated with optic nerve(CN II) Rods and Cones are here Rods - answer-Receptors activated by dim light Used for night vision Black and White vision Used for peripheral vision Cones - answer-Receipts activated by bright light Used for daylight vision Color Vision Used for central vision Posterior Cavity - answer-Transparent Gel(99% Water) Fills 80% of the eyeball Helps keep the retina in place Not produced until you are 4-5 Yrs old Only 1/2 full by the time you're 70 Yrs old It is not replaced. Visual Pathways - answer-Light-Optic Receptors-Optic Nerves- Optic Chiasm-Thalamus-Visual Cortex Inferior Rectus - answer-Eye looking down- Oculomotor nerve(III) Medial Rectus - answer-Eye looking medially- Oculomotor nerve (III) Superior Rectus - answer-Eyes looking Up- Oculomotor nerve (III) Lateral Rectus - answer-Eye Looking laterally- abducens nerve (VI) Inferior Oblique - answer-Eye rolls, looking up, and laterally out-oculomotor nerve(III) Superior Oblique - answer-Eye rolls, looking down, and laterally out- trochlear nerve(IV) The 5 steps of the hearing process - answer-1.Sound waves travel along the external ear canal 2. Sound waves arrive at tympanic membrane 3. Vibrations of tympanic membrane causes ossicles to move 4.Movement of stapes at oval window generates pressure waves in the fluid filled cochlea of the inner ear 5. Pressure waves in the inner ear finally travel to the round window Cochlea - answer-It contains 3 circular chambers that create vibrations along the floor of the middle chamber called the basilar membrane. Hair Cells - answer-Bending hair cells open an ion channel in the hair cells membranes, this causes ions to rush into hair cells, this activates hair cells, and stimulates CN VIII Vestibular Apparatus - answer-Also in the inner ear and it is connected to CN VIII, associated with equilibrium and balance, is composed of semi-circular canals and saccule and utricle Semi-circular canals - answer-Contains a structure calles a cupola filled with a gelatinous substance, receptors called hair cells embedded on it, are simulated by head rotation. The cells bend, opening ion channels, this activates hair cells and stimulates CN VIII, this also helps you maintain your balance during head rotation Saccule and Utricle - answer-Contains recepters called hair cells stimulated by gravity and linear acceleration/deceleration. Hair cells are embedded in a gelatinous material containing calcium carbonate crystals called otolith that bend hair cells when moved Sensory Pathway - answer-1.Originates at receptors in the periphery 2. Ascends on axons of sensory neuron in the white matter of spinal cord 3. Is relayed to cell bodies of a sensory neuron in the gray matter of cerebral cortex(CNS), where it becomes conscious Spinal Reflex - answer-A motor response produced when a sensory neuron synapses on a spinal cord motor neuron. Its very fast and occurs before the information reaches the brain, it is also involuntary. Two types are monosynaptic and polysynaptic Monosynaptic - answer-Stretch reflex, a sensory neuron synapses directly on cell body of a spinal cord motor neuron The stretch reflex occurs constantly to help you maintain an upright position Step in a stretch reflex - answer-1.A stretch stimulates muscle spindle 2. Axons in a dorsal root send info to sensory neurons in dorsal root ganglion 3. Sensory neuron synapses with motor neuron 4.Axons in a ventral root send info out from activated Somatic Nervous System - answer-Innervates skeletal muscles It is a voluntary system Initiates skeletal muscle contraction 1-neuron system Autonomic Nervous System - answer-Innervates smooth and cardiac muscle Is involuntary Coordinates smooth or cardiac muscle contraction 2-neuron system The somatomotor system - answer-Somatomotor neuron cell bodies are located in the CNS Their axons synapse directly on skeletal muscles in the periphery ANS: a 2-neuron system - answer-Neuron #1 is called the pre-ganglionic neuron whose cell bodies in the CNS synapse on neurons #2 Neuron #2 is called the post-ganglionic neuron, whose cell bodies located in ganglia in the PNS, synapse on smooth or cardiac muscles in the periphery This allows the signal to be amplified or weakened or otherwise modified between its source and its targets 2 Divisions of the ANS - answer-Sympathetic(fight-or-flight(stimulating effect on the body)) and the parasympathetic(rest-and-digest(relax)) take turns, when one is up-regulated, the other is down regulated. Important difference between the 2 Divisions - answer-Sympathetics innervate mainly vascular smooth muscle, therefore sympathetics are everywhere in the body Parasympathetics innervate only visceral smooth muscle . Sympathetic Nervous System - answer-Pre-ganglionic neuron cell bodies are located in the spinal cord Post-ganglionic neuron cell bodies are located in ganglia, located mainly in the sympathetic trunk Sympathetics: Fight or flight. - answer-Readies the body for crisis: Increase respiratory rate Increase heart rate and blood pressure Increase metabolism Increase alertness Increase sweating Decrease digestive and urinary functions Parasympathetic nervous system - answer-Preganglionic neuron cell bodies are located in the brain stem and spinal cord Postganglionic neuron cell bodies are located in ganglia in the head or in the walls of the viscera Parasympathetic nerves - answer-From the brain stem travel with cranial nerves to reach their targets in the head, thorax, and abdomen From the spinal cord travels with spinal nerve to reach their targets in the pelvis Parasympathetics: rest and digest - answer-The parasympathetic division stimulates visceral activity and conserves energy reserves. An increase in parasympathetic activity equals a decrease in heart rate and drop in blood pressure decrease in metabolic rate increase in glandular secretions increase in digestive tract motility increase in the urge to urinate and defecate Epithelial tissue function - answer-lines all body surfaces including cavities and tubes Serves as a barrier Provides protection for the deeper tissue layers Regulates exchange for substances for these deeper tissue layers Preforms absorption and secretion Epithelial tissue characteristics - answer-Composed only of epithelial cells Forms a continuous sheet of cells Therefore there is almost no extracellular space between adjacent cells Therefore it is avascular Receives its nutrients from diffusion IT is connected to the underlying connective tissue layer by a basement membrane that enables epithelial cells to attach to connective, divide when necessary and migrate to close a wound Epithelial Cells characteristics - answer-The exhibit polarity, that is, each surface has a unique function, each cell has a apical surface furtherest from the basement membrane and may contain microvilli or cilia. Each cell has a lateral surface and contains specializations such as junctions, each cell has a basal surface closest to the basement membrane. They also undergo frequent mitosis Type 1A - answer-Simple Squamous Lines blood vessel and body cavities Regulates diffusion across this layer Type 1B - answer-Simple Cuboidal Lines ducts Provides moderate amounts of secretion and absorption Type 1C - answer-Simple columnar Lines intestine Provides vast amounts of secretion and absorption Type 1D - answer-Psuedostratified AKA respiratory epithelium Lines respiratory tract Provide secretion and movement along the surface Stratified Epithelium - answer-Composed of more than one layer of cells Type 2A - answer-Stratified unkeratinized epithelium lines internal surfaces of tubes such as esophagus Type 2B - answer-Stratified keratinized epithelium Lines the skin Superficial-most layers of cells are flat, dead, filled with keratin Type 2C - answer-transitional epithelium AKA urothelium lines urinary bladders and ureters Glandular Epithelium - answer-From the invagination of surface epithelium Exocrine glands release saliva, swear, and buffer onto a surface through ducts Endocrine glands release hormones into the surrounding connective tissue and blood stream, no ducts. The endocrine system - answer-Regulates long term processes development, growth, and reproduction Regulated by negative feedback Goal is to provide homeostasis Endocrine Glands - answer-Secretory units composed of epithelial cells 1. Begin as invagination of surface epithelium- lose their duct 2. Release secretory products into the bloodstream for distribution Hormones - answer-Chemicals that are released from endocrine organs, are distributed by the blood, change the rate of activity preformed by the body: smooth muscle cells increase or decrease activity, epithelial cells secrete more or less secretory product Homeostasis - answer-Defines as a stable internal environment All body systems work together to maintain homeostasis and to prevent potentially dangerous changes. Body systems must function within a normal range Failure to function within a normal range results in disease or death Homeostasis is necessary for your survival How your body maintains homeostasis - answer-It has receptors that sense a stimulus It has a control center that receives and processes this information from receptors It has effects that respond commands by the control center Hypothalamus - answer-As a nervous tissue it controls the ANS As the integrator between the nervous and endocrine systems it secretes regulatory hormones that control endocrine cell secretion in the pituitary gland As an endocrine organ it secretes the hormone ADH and oxytocin Pituitary Gland - answer-Major endocrine gland Connects nervous and endocrine systems Connected to the hypothalamus via the infundibulum Anterior lobe - answer-Glandular Developed from epithelium Composed of endocrine cells Posterior lobe - answer-Developed from nervous tissue Part of the CNS Composed of axons whose cell bodies are in the hypothalamus How the hypothalamus communicates with the anterior lobe of the pituitary gland - answer-Releasing hormones RH and inhibiting hormones IH from neurons in the hypothalamus, enters blood vessels called a portal system, and are released into endocrine cells in the anterior lobe of the pituitary gland The pituitary portal system - answer-This portal system is composed of capillaries in both the hypothalamus and the anterior pituitary gland connected by portal veins in the infundibulum advantage of the portal system - answer-Allows cells in the hypothalamus to secrete very small amounts of hormones into the first set of capillaries Allows these hormones to reach their target cells in the anterior pituitary vis the second set of capillaries, very rapidly, without being diluted in the general circulation F(L)AT PIG - answer-The anterior lobe of the pituitary releases 6 hormones These hormones in turn stimulate other endocrine glands in the body FSH(follicle stimuli-zing hormone) LH(luteinizing hormone) ACTH(adrenocorticotropic hormone) TSH(thyroid-stimulating hormone) PRL(prolactin) GH(growth hormone) FSH - answer-stimulates follicle development in female ovaries stimulates maturation of sperm in male testes LH - answer-Stimulates progesterone production in females Stimulates testosterone production in males Stimulates GnRH from hypothalamus Regulates activities of gonads ACTH - answer-Stimulates the release of steroids hormones by the adrenal cortex Stimulated by CRH from the hypothalamus TSH - answer-Also called thyrotropin Stimulates the release of thyroid hormones from the thyroid gland Stimulated by TRH from the hypothalamus Hypothalamic Regulatory Hormones for (F(L)AT) - answer-Hypothalamus secretes only releasing (+) hormones for these 4 pituitary hormones Secretion is controlled by negative feedback Posterior Pituitary hormones - answer-contains 2 hormones that are synthesized in nerve cell bodies located in the hypothalamus and are released from axon terminals in the posterior pituitary and then taken up by the bloodstream Hormones include - answer-AHD(antidiuretic hormone) that restrict water loss from the kidneys and promotes thirst Oxytocin, stimulates smooth muscle contractions in the mammary glands, uterus, and prostate gland Adrenal Glands - answer-Located along the superior border of each kidney, they are subdivided into an outer cortex and an inner medulla Adrenal Cortex - answer-Synthesizes steroid hormones: Mineralocorticoids for the kidneys which increase sodium and water retention Glucocorticoids which increase blood glucose Sex steroids which stimulate the onset of puberty CRH release from the hypothalamus stimulates ACTH release form the pituitary which stimulates release of these steroids from the adrenal gland Adrenal Medulla - answer-Its secretory activities are controlled by the sympathetic nervous system Its cells produce epinephrine and norepinephrine-increases heart rate and blood pressure Unlike the immediate changes produced by these chemicals when released by nerves, these metabolic changes persist for several minutes Thyroid Gland - answer-Lies inferior to the thyroid cartilage of the larynx and superficial to the trachea Consists of 2 lobes Thyroid follicle - answer-Hollow balls lined by eithelial tissues, they synthesize hormones T3(triiodothyronine) and T4(thyroxine) Thyroid hormones - answer-Are stored in the cavities of the follicles until needed Thyroid gland functions - answer-Thyroid hormones increase your basal metabolic rate by increasing oxygen and energy consumption and increasing heart rate and contraction strength TRH release stimulates - answer-TSH release from the pituitary which stimulates thyroxin release from the thyroid gland The thyroid gland also contains - answer-C(clear) cells C cells produce hormone calcitonin, causes a decrease in blood calcium Parathyroid gland - answer-Its cells produce parathyroid hormone(PTH) and causes an increase in blood calcium Calcitonin - answer-Produced by the thyroid gland High blood calcium leads to increase of calcitonin release which decrease blood calcium by increasing calcium excretion and decrease osteoclast activity. Parathyroid hormone - answer-parathyroid gland,low blood calcium leads to increase in parathyroid hormone release which increases blood calcium by decreasing calcium excretion and increasing osteoclast activity Pancreas - answer-Lies between the spleen and the small intestines Contains exocrine and endocrine cells Endocrine cells form clusters called islets of langerhans or pancreatic islets 2 major types of endocrine cells in pancreatic islets - answer-Alpha and beta cells Alpha Cells - answer-Secrete glucagon which increases blood glucose. Increases the rates if glycogen breakdown and glucose manufactured by the liver Beta Cells - answer-Secretes the hormone insulin which decreases blood glucose and increases the rate of glucose uptake and utilization Insulin - answer-Known as the building hormone Thyroxin, cortisol and adrenaline are known as - answer-the breaking down or using up hormones, A proper balance between these vital hormones is crucial for proper metabolism, which affects every aspect of your conscious and unconscious life Stress - answer-Any condition that threatens homeostasis General adaptation syndrome(GAS) - answer-Is our bodies response to stress causing factors and is also called stress response. 1. Alarm Phase- immediate fight or flight system. 2. Resistance Phase- dominated by hormones, your body is fighting(glucocorticoids) 3. Exhaustion Phase- organ failure Alarm Phase - answer-An immediate response to stress Is directed by ANS Energy reserves mobilized Fight or flight responses Dominant hormone is epinephrine Resistance Phase - answer-Entered if stress lasts longer than a few hours Dominant hormones are glucocorticoids Conserves salt, water, loss of potassium and hydrogen Energy demands remain high, 1. Glycogen reserves are nearly exhausted after several hours of stress 2. Lipid reserves mobilize to support body systems for years 3. Protein reserves mobilize to support body systems for years, e.g. muscles and other structural proteins Exhaustion Phase - answer-Begins with homeostatic regulation breaks down Failure of 1 or more organ systems, will be fatal Mineral Imbalance Respiratory System - answer-Consists of a conduction portion, from nasal cavity though bronchioles Consists of a respiratory portion, alveoli in the lungs, and where O2 and CO2 exchange occurs Pleural Sacs and gross anatomy - answer-Each lung becomes surrounded by a pleural sac, 2 of 3 sacs within the thoracic cavity( the 3rd is for the heart). Each lung extends from the diaphragm to the clavicle. Functions of the respiratory system - answer-1. Will move air to and form alveoli surfaces 2. Provides a gas exchange surface between air and blood. O2 is obtained from air during breathing by diffusion across membranes of the lungs. O2 is carried to cells of the body by the cardiovascular system. The cardiovascular system also returns CO2 to the lungs to be eliminated 3. Produce Sounds 4. Contribute to olfaction Amazing tasks of the respiratory system - answer-Prevent contaminants in the air from plugging the airway or getting into the blood Get enough air close enough to blood for O2-CO2 exchange without a substantial water loss Accomplish these tasks in a fairly compact space Respiratory tract lining - answer-Composed of a surface layer of epithelium, pseudo stratified epithelium AKA respiratory epithelium Also of a deeper layer of connective tissue, loose and dense connective tissue called lamina propr.. Also contains cartilage, smooth muscle, elastic fibers, mucous glands that secrete mucus onto the epithelial surface. Respiratory Epithelium - answer-Composed of goblet cells, ciliated cells, stem cells Functions of the respiratory epithelium - answer-Mucous from goblet cells catches inhaled debris Cilia of ciliated cells move mucous towards oropharynx Stem cells divide and replace old goblet and ciliated cells Nasal Cavity - answer-Conchae produce air turbulence, warms the air, associated with paranasal sinuses Nasal Hairs- filter the air of particulate matter Mucous Glands- moisten the air with mucous secretions Breathing through the mouth bypasses these important steps The pharynx - answer-A chamber shared by the digestive and respiratory systems Extends from the nasal cavity to entrances of larynx and esophagus Divisions of the pharynx: Nasopharynx, Oropharynx, laryngopharynx Nasopharynx - answer-Posterior to the nasal cavity Contains pharyngeal tonsils and opening to the auditory tubes Oropharynx - answer-Posterior to the oral cavity Contain palatine tonsils Laryngopharynx - answer-Posterior to the larynx Extends to the opening of the esophagus The Larynx - answer-Thyroid Cartilage Cricoid Cartilage Arytenoid Cartilage Epiglottis Thyroid Cartilage - answer-"Shield" For protection Attachment site for vocal cords Cricoid Cartilage - answer-For protection A complete ring of cartilage Arytenoid Cartilage - answer-Attached to the cricoid cartilage Attachment site for vocal cords Epiglottis - answer-"Above the glottis" Fold over glottis during swallowing Prevents the entry of food and liquids into respiratory tract Glottis - answer-Floor of the larynx Entrance for the trachea Composition: The vocal cord ligaments are attached to the arytenoid cartilages and the thyroid cartilage , skeletal muscles close the cartilage Must be open to breathe Must be closed to speak The trachea - answer-Extends from cricoid cartilage to primary bronchi, contains 15-20 cartilage rings to strengthen and protect airways The bronchi - answer-A series of tubes decreasing diameter Primary bronchi, right and left, each primary bronchi supplies one lung Primary bronchi branch into secondary bronchi, each secondary bronchus supplies one lobe of lung Secondary bronchi in to tertiary bronchi, each tertiary bronchi supplies a bronchopulmonary segment of a lobe, each lung has about 10 of these segments Walls of the primary, secondary and tertiary bronchi - answer-contain progressively less cartilage and more smooth muscle and elastic fibers, this means that smooth muscle has more control over airway constriction in a tertiary crunches than in a primary bronchus Bronchodilation - answer-Dilation of bronchial airways, caused by the sympathetic nervous system, it allows smooth muscle to relax, and reduces resistance of air flow Bronchioconstriction - answer-Constriction of the bronchial airways, caused by parasympathetic nervous system, causes muscles to contract, increases resistance of air flow Asthma - answer-Excessive bronchoconstriction, due to an allergic reaction and inflammation Results in severely restricted airflow The bronchioles - answer-Each tertiary bronchus branches into multiple bronchioles; they are lined by simple epithelium, no longer the respiratory epithelium Have no cartilage in the lamina propria, only smooth muscle and elastic fibers have control over diameter of bronchioles and control air flow in lungs Gross Anatomy of the lungs - answer-Right lung: 3 Lobes, superior, middle and inferior and is separated by 2 fissures, horizontal an oblique Left lung: superior and inferior, separated by 1 fissure, oblique fissure. Microscopic anatomy of the lungs - answer-Bronchioles give rise to alveoli, where gas exchange takes place, air-filled balls, make up most of the lungs. give lungs its spongy qualities, 500 million alveoli/ lung Alveolus - answer-Its epithelial lining, simple squamous epithelium Type I cells: O2- CO2 exchange Type II Cells: produce surfactant, an oily secretion much like soap Its connective tissue layer contains capillaries, elastic fibers, and no more smooth muscle Surfactant - answer-Coats alveolar surfaces Reduces surface tension, which is the attraction between water molecules, if surfaces tension is too high the alveoli collapse Respiratory distress syndrome - answer-Difficult respiration- due to alveolar collapse Caused when type II cells do nor produce enough surfactant Surfactant is not synthesized until 8 months of fetal development Premature babies born prior to this have difficulty breathing 3 Components of the respiratory membrane - answer-1.Epithelial cell(Type I cell) lining the alveolus 2. Thin Layer of connective tissue in between 3. Endothelial cell lining a capillary Pneumonia - answer-Alveolar walls become inflamed Alveoli become full of fluid O2 from the air cannot reach the bloodstream Pneumothorax - answer-From the knife wound, broken rib, spontaneous in some individuals The "Vacuum" between 2 layers of the pleural sac is compromised 1 layer is attached to the lungs, 1 layer is attached to the thoracic wall, this is what hold the lungs against the thoracic wall Air enters the pleural sac The elastic component of the lungs causes them to collapse With each attempt to take a breathe, more air fills the space between the lungs and the thoracic wall, further collapsing the lungs due to the pressure Abdominal Cavity - answer-bordered superiorly by the diaphragm, bordered inferiorly by the pelvic cavity Lined by the peritoneum, serous membrane Functions of the digestive system - answer-Ingestion Mechanical processing Secretion Digestion Absorption Excretion Ingestion - answer-Occurs when materials enter the digestive tract via the mouth Mechanical Processesing - answer-Chewing,churning, makes materials easier to propel along digestive tract Secretion - answer-The release of water, acids, enzymes and buffers by cells of epithelial lining and by glandular organs Digestion - answer-The chemical breakdown of food into smaller fragments Absorption - answer-Movement of organic substrates, ions, vitamins, and water from lumen, across the cells of the epithelial lining, into interstitial fluid Excretion - answer-Removal of waste products form the body Impressive lining of the Digestive Tract - answer-The epithelial lining of the digestive tract is continuous, at the mouth and at the anus, with external environment It must accommodate these transitions at either end while remain moist It must also be very thin to accomplish both digestion and absorption It must handle the paid turnover of its epithelial cells due to mechanical and chemical insults while protecting deeper tissues against chemical stresses, mechanical stresses,and pathogenic bacteria General Organization of the Digestive Tract - answer-Mucosa Submucosa Muscularis Serosa Mucosa - answer-Inner lining of the digestive tract Consists of its own three layers, epithelium, lamina propria(loose CT) and muscularis mucosa( a thin smooth muscle layer) Surface Epithelium - answer-Epithelium is either stratified or simple columnar depending on location, function and stresses. Oral cavity, pharynx, esophagus, and anus - answer-Function: ingestion, and transport along the length of the tube, are lined with simple columnar epithelium fro rapid transport across the epithelial lining Lamina Propria - answer-Deep to epithelial layer Loose connective tissue Contains small blood vessels, small lymphatic vessels and lymphoid tissue, small sensory and motor nerves. Muscularis Mucosa - answer-Deep to the lamina propria A thin layer of smooth muscle cells Muscle contraction causes movement of the mucosa Submucosa - answer-Deep to the mucosa Dense irregular connective tissue contains large blood vessels, large lymphatic vessels and large nerves. Submucosal Nerve Plexus - answer-Contains sensory neurons that sense chemical changes in the lumen Motor neurons innervate the muscularis mucosa Muscularis - answer-2 Layers of smooth muscles Inner circular Outer longitudinal Involved in Peristalsis, wave-like muscular contractions that move materials along digestive tract Contains a nerve plexus Mesenteric Nerve Plexus - answer-Contains sensory neuron that sense muscle stretch and motor neurons that coordinate peristalsis Innervates this muscular layer Interesting facts - answer-There are more neurons in the gut than in the spinal cord The only organ with more neurons is the brain Many neurotransmitters found in the brain are also used by the neurons in the gut This is one reason why stress, for example, leads to GI complications Many causes are unknown, quite a few are autoimmune diseases Peristalsis - answer-Waves of muscular contractions 1.Circular smooth muscle layer contracts behind bolus 2. Longitudinal smooth muscle layer ahead of bolus contracts shortening adjacent segments 3. Waves of contractions in circular muscles forces bolus forward Serosa - answer-The outer kinging of the digestive tract composed of simple squamous, and loose connective tissue Functions of the Oral Cavity - answer-Mechanical processing- through actions of teeth and tongue Lubrication- mixing with salivary gland secretions Some digestion contains saliva amylase(enzyme that breaks down starches) and lipase( enzyme that breaks down lipids) The Pharynx - answer-A common passageway for solid foods, liquids and air shared by digestive and respiratory systems, food passes through the pharynx to the esophagus Esophagus - answer-A hollow muscular tube, transports solid food and liquids to the stomach, passes through the diaphragm muscle to get from the thorax to the abdomen functions of stomach - answer-Storage of ingested food Sterilization of ingested food Some digestion, mechanical breakdown of ingested food by churning, and chemical breakdown of food material by acids and enzymes Lining of the stomach - answer-Simple columnar epithelium invaginated to form gastric glands Epithelial cells of the gastric glands - answer-Mucous cells Parietal cells Chief cells Endocrine cells Stem cells Mucous Cells - answer-Secrete mucous and are used for protection, stops acid from burning through the stomach Parietal Cells - answer-Secretes HCL, aka gastric acids Chief Cells - answer-Secrete pepsinogen, converted to pepsin by gastric acid Endocrine Cells - answer-G cells, release the hormone gastrin, stimulates by parietal and chief cells Functions of the Small intestine - answer-plays a key role in digestion and absorption of nutrients Regions of the small intestine - answer-Duodenum Jejunum Ilium Duodenum - answer-First segment of the small intestine, begins at pylori sphincter, controls flow from the stomach into the duodenum, its about 1 foot long. Its receive chyme from the stomach and digestive enzymes and buffers from the pancreas and liver Jejunum - answer-Middle segment of Small intestine 8 Feet long and its the site of most digestion and absorption Ileum - answer-Last segment of the small intestine About 12 feet long Ends at iliocecal valve, controls flow form small intestines into the large How the small intestine increases surface area - answer-Plicae- folds in the intestinal lining, increasing surface area, covered with villli Villi-Fingerlike projection, increase surface area The columnar epithelial cells lining the villi contain microvilli Epithelial Cells Lining the Small intestine - answer-Absorptive cells Goblet cells Endocrine cells Stem cells Absorptive cells - answer-Contain microvilli to increase surface are for absorption goblet cells - answer-secrete mucous for protection Small Intestine Endocrine Cells - answer-CCK cells- secrete cholecystokinin S cells- secrete secretin GIP cells- secrete gastric inhibitory peptide CCK cells - answer-secrete cholecystokinin stimulates secretion of pancreatic enzymes from the pancreas bile from the liver via the gall bladder in to the small intestine S cells - answer-Stimulates secretion of buffer form the pancreas into the small intestines to neutralize the acidic chyme GIP cells - answer-cells secrete gastric inhibitory peptide, inhibits gastric secretions Functions of large intestine - answer-Extends from end of ileum to anus, its about 5 feet long and functions to absorb water, vitamins produced by bacteria and bile, also to compact feces, and storage of feces prior to defecation Cecum - answer-Expanded pouch like first portion, receives material arriving from the ileum Colon - answer-largest portion, walls form a series of pouches Rectum - answer-last 6 inches of digestive tract Appendix - answer-Attached to posterior surface of the cecum A slender hollow vestigal, appendage A lymphoid organ composed of lymphoid nodules Ascending colon - answer-Begins at cecum, ascends on right side of the abdomen Transverse colon - answer-Crosses abdomen left to right Descending colon - answer-Descends along left side of the abdomen Sigmoid colon - answer-S shaped segment about 6 inches long, empties into the rectum Epithelial Cells lining the colon - answer-Main cell type of its simple columnar epithelial lining is the goblet cell, produces vast amounts of mucous for lubrication of feces. It also contains absorptive cells The colon has no villi, does not need as much surface are for absorption The Anus - answer-Inferior to the rectum, lined by stratified squamous keratinized epithelium Location of the pancreas - answer-Inferior and posterior to the stomach, extends from duodenum to the spleen Exocrine pancreas - answer-99% pancreatic cells secrete pancreatic enzymes into ducts Secretions reach duodenum via pancreatic duct, enter the duodenum at duodenal papilla. release is controlled by hormones from the duedenum Pancreatic Enzymes - answer-Pancreatic Amylase- breaks down carbohydrates into di- and tri- saccharides Pancreatic lipase- breaks down complex lipids into fatty acids Pancreatic proteases- break down proteins into peptides The liver - answer-Largest visceral organ, divided into lobes, right, left, caudate and quadrate. Preforms many essential functions Functions of the liver - answer-Removes and stores nutrients and toxins from the blood, synthesizes nutrients when necessary, regulates blood glucose, lipid an amino acid levels Phagocytes of old or damages RBCs Synthesizes bile, bile breaks lipid droplets apart, creates tiny droplets, this increase surface area for lipid digestion by pancreatic lipase which itself is water-soluble Liver disease - answer-you cannot liver without your liver Liver cirrhosis- Hepacytes die, are replaced by scar tissue, cannot be reserved, one ultimately dies if a liver transplant is not available, causes alcoholism and chronic hepatitis Liver Histology - answer-Liver Lobule is the functional unit of the liver Composition of a lobule: Hepatocytes Bile Canaliculi Sinusoids Hepatocytes - answer-Liver cells Form walls of cells Bile Canaliculi - answer-Spaces between hepatocytes within a wall Drain bile, synthesized by hepatocytes into bile duct Sinusoids - answer-Capillary-like vessels Spaces between hepatocytes between walls Drain blood from hepatic portal vein and hepatic artery into the central vein Hepatic Blood Supply - answer-1/3 of blood supplied to the liver is P2 rich blood from hepatic artery 2/3 is nutrient rich but O2 poor blood from the hepatic portal vein Carries blood from the stomach, small intestine and large intestine Sinusoids in the liver brain blood from both hepatic A and hepatic portal veins to the central veins of hepatic lobules then via the hepatic vein and then inferior vena cava and back to the heart and general circulation. Liver Drainage - answer-Blood drains out of the liver via the hepatic veins into the inferior vena cava an don to the heart Bile drains out of the liver via the hepatic ducts an don to the gall bladder Gall bladder and the bile duct system - answer-Bile travels from the hepatic duct via the cysts duct to the gall bladder Where it is stored and concentrated In responses to CCK a hormone is released by the duodenum The gall bladder contracts, releases bile via the common bile duct into the duodenum through the duodenal papilla