Lecture Exam 4 - Respiratory & Digestive Systems PDF

LECTURE EXAM 4 RESPIRATORY SYSTEM RESPIRATORY SYSTEM - PARTS Nose Only visible part Nares are entrance to nasal cavity Pharynx Nasopharynx – superior area just behind nose Oropharynx – middle area just behind mouth Laryngopharynx – inferior area attached to larynx  L...

LECTURE EXAM 4 RESPIRATORY SYSTEM RESPIRATORY SYSTEM - PARTS Nose Only visible part Nares are entrance to nasal cavity Pharynx Nasopharynx – superior area just behind nose Oropharynx – middle area just behind mouth Laryngopharynx – inferior area attached to larynx  Larynx Routes food and air into proper channels Role in speech Epiglottis - protects opening of larynx during swallow, so food is routed to esophagus, prevents food from entering vestibule of larynx Vocal folds – true vocal cords  Trachea Lined with cilia that move in opposite direction of flow of air Expels mucus loaded with dust/debris away from lungs Bronchi Formed by division of trachea Primary bronchi supply one lung (right bronchus – right lung, left bronchus – left lung) Continue dividing into smaller and smaller bronchi and bronchioles  Lungs Each lung contained by a pleural cavity Each lung is divided into lobes by deep fissures Alveoli Actual sites of gas exchange in the lungs RESPIRATORY SYSTEM - FUNCTION Normal air flow into lungs: Nares> nasopharynx> larynx> trachea> primary bronchi> bronchioles> alveoli Movement of air into and out of the lungs = pulmonary ventilation Hypoxia – condition of low tissue oxygen level RESPIRATORY SYSTEM - FUNCTION Inhalation As the diaphragm and external intercostal muscles contract, the diaphragm descends and the rib cage rises. This results in increase in volume of lungs Air moves into the lungs because the gas pressure in the lungs is less than outside pressure Exhalation Mostly passive process Diaphragm and external intercostal muscles relax, diaphragm ascends and rib cage lowers. This results in decrease in volume of lungs Air moves out of the lungs because the gas pressure in the lungs is higher than outside pressure RESPIRATORY VOLUMES A= Inspiratory reserve volume Amount of air that can be forcibly taken in above tidal volume B=Tidal volume Normal quiet breathing, ~500 mL of air C=Expiratory reserve volume Amount of air that can be forcibly expelled after tidal expiration D=Residual volume Does not participate in exchange of gases Air remaining in lung after expiration Keeps alveoli inflated DIGESTIVE SYSTEM DIGESTIVE SYTEM Two major divisions: Alimentary canal (gastrointestinal or GI tract) Accessory digestive organs ALIMENTARY CANAL – MOUTH (oral cavity) First site of mechanical processing of food Mastication = the act of chewing Teeth Enamel covers dentin of a tooth root 32 permanent teeth, wisdom teeth last to emerge Saliva contains enzymes that begin the breakdown of carbohydrates moistens food and aids in compacting of the bolus cleanses mouth Not acidic (not involved in chemical digestion) ALIMENTARY CANAL PARTS Oropharynx Laryngopharynx Epiglottis protects airway to keep food from entering trachea Esophagus Enlarges and connects to stomach at the cardiac sphincter Food bolus propelled down esophagus by peristalsis (wave-like muscular contractions) ALIMENTARY CANAL PARTS - STOMACH Stomach Can be considered both a digestive and endocrine organ because it has cells that secrete enzymes as well as that secrete hormones Anatomical features/landmarks Lesser/Greater curvature Distal portion of stomach = pylorus Rugae = internal folds within stomach Cellular/chemical features Parietal cells – produce and excrete stomach acid; largely affected by antacid drugs that block histamine receptors Gastric intrinsic factor – necessary for absorption of vitamin B12 ALIMENTARY CANAL Small intestine – three divisions Duodenum – proximal portion of small intestine Jejunum – middle segment of small intestine Ileum – distal portion of small intestine Large intestine Dehydrates indigestible materials Cecum & appendix just after junction of small intestine and large intestine Ascending, transverse, and descending colon Sigmoid colon ALIMENTARY CANAL Rectum Anus ACCESSORY DIGESTIVE ORGANS Salivary glands Parotid, sublingual, submandibular glands Salivation is controlled by: Food entering mouth Anything chewed (gum, rubber band) Emotional stimuli (just think of your favorite food!) Parasympathetic fibers in cranial nerves VII (7) and IX (9) Pancreas Retroperitoneal Produces enzymes used in digestive tract that digest starches, fats, proteins, and nucleic acids Secretes enzymes into duodenum ACCESSORY DIGESTIVE ORGANS Liver Largest gland in body Four lobes – right, left, caudate, quadrate Produces bile Bile travels through common hepatic duct and through the bile duct to enter the duodenum Hepatic portal circulation - collects absorbed nutrients for metabolic processing in the liver Gall bladder Storage site for bile when food digestion is not occurring When needed, bile released from gall bladder travels through the cystic duct and through the bile duct to enter the duodenum Common hepatic duct fuses with cystic duct to form the common bile duct DIGESTION Release of water, acids, enzymes, and buffers by the digestive epithelium Breakdown of food into nutrient molecules for body’s use DIGESTION – “Start to finish” Intake of food item into oral cavity Teeth and tongue mechanically break apart food in mouth Saliva moistens and binds food into bolus Salivary amylase begins starch digestion Bread chewed for a long time would become sweeter as the sugars are released by the starch breakdown that begins with salivary amylase and mechanical breakdown Bolus propelled through pharynx to esophagus to stomach by peristalsis Stomach acids activate pepsin to begin protein digestion Chyme moves from stomach to small intestine DIGESTION – “Start to finish” In small intestine, pancreatic juice and bile added to chyme mixture, begins fat digestion Small intestine enzymes Secretin & cholecystokinin (CCK) BOTH stimulate pancreas to release enzyme products BOTH influence activity in the small intestine Secretin– increases liver output of bile Cholecystokinin (CCK) – gall bladder contraction to spurt stored bile DIGESTION – “Start to finish” Large intestine Produces no digestive enzymes Resident bacteria further metabolize some nutrients Large intestine absorbs vitamins, water Feces forms Feces is eliminated from body Mechanoreceptors throughout GI tract respond to distension URINARY SYSTEM URINARY SYSTEM - ORGANS Kidneys Ureters Urinary bladder Urethra KIDNEYS Functions Dispose of waste products in urine Produce renin (maintains blood pressure, production of renin is stimulated by a decrease in blood pressure) Produce erythropoietin (EPO) to stimulate red blood cell production Converts vitamin D to its active form Maintaining water balance of blood Maintaining electrolyte balance of blood Ensuring proper blood pH  Nephrons = functional units of kidneys Nephrons made up of Renal corpuscle Renal tubule  Renal corpuscle consists of two parts: Glomerulus Responsible for filtration Filtration rate controlled by: Renal autoregulation Hormonal regulation Neural regulation Bowman’s capsule  Renal tubule Proximal convoluted tubule Cells of the proximal convoluted tubule (PCT) contain many mitochondria because a great deal of active transport takes place in the PCT Nephron loop (Loop of Henle) thin segment of nephron loop's descending limb aids in the passive movement of water out of the tubule Distal convoluted tubule URETERS Slender tubes connecting kidneys to bladder Run behind the peritoneum, retroperitoneal Retroperitoneal organs are posterior to the peritoneal cavity URINARY BLADDER Smooth, collapsible, muscular sac Composed of transitional epithelium Micturition = voiding the bladder URETHRA Thin-walled tube that transports urine from bladder to outside the body Function Females – carries urine only Males – carries urine and sperm URINARY SYSTEM - HORMONES Antidiuretic hormone (ADH) Causes collecting ducts to become more permeable to water Prevents excessive water loss in the urine and increases water reabsorption Aldosterone Signaled to release from adrenal glands by plasma potassium concentration and Angiotensin II For each sodium ion reabsorbed, a chloride ion follows, and a potassium ion is secreted into the filtrate Water follows salt: when sodium is reabsorbed, water follows it passively back into the blood URINARY SYSTEM - HORMONES Lipid-soluble (steroid) hormones have a relatively long half-life compared to water-soluble hormones. This is in part due to the way these hormone pass into the filtrate from the glomerular capillaries. Steroid hormones travel in the plasma on large transport proteins that cannot pass through the filtration membrane. Because steroid hormones cannot be filtered as easily as water-soluble hormones, their action duration is prolonged (half-life is longer). URINARY SYSTEM – ELECTROLYTE BALANCE Renin-Angiotensin mechanism Most important trigger for aldosterone release Low blood pressure>juxtaglomerular apparatus releases renin Renin>triggers reactions to produce angiotensin II Angiotensin II > vasoconstriction, aldosterone release Increases blood pressure & blood volume Diuretics Promote dehydration URINE PRODUCTION > ELIMINATION Nephron Collecting duct Minor calyx Major calyx Ureter Urethra REPRODUCTIVE SYSTEM REPRODUCTIVE SYSTEM Gonads (primary sex organs) Testes (male) Ovaries (female) Gametes (sex cells) Sperm (male) Ova (ovum singular) or egg (female) MALE Testes Connected to trunk via spermatic cord Duct system Transports sperm from body Epididymus Ductus deferens Urethra MALE Accessory glands Seminal vesicles – produce seminal fluid Prostate gland – NOT PROSTRATE – fluid activates sperm Bulbourethral glands- fluid cleanses urethra of urine prior to ejaculation Semen Milky white, sticky mixture of sperm and accessory gland secretions Sperm Head – nucleus, contains DNA Acrosome – similar to lysosome – releases enzyme to help penetrate egg for fertilization Filaments A word about prostate vs prostrate Prostate: NOUN - Part of the male reproductive system Prostrate: ADJECTIVE -lying stretched out on the ground with one's face downward VERB -lay oneself flat on the ground face downward, especially in reverence or submission Prostate and prostrate ARE NOT the same thing or interchangeable. If you encounter a question in which you must write “prostate” as part of the response, and you write “prostrate,” you will not receive credit for that answer – consider yourself warned! MALE External genitalia Scrotum Divided sac of skin external to the body containing the testes Penis Shaft Glans penis (enlarged tip) Prepuce or foreskin (frequently removed by circumcision) FEMALE Ovaries Follicles contain immature eggs Ovulation occurs when eggs mature and follicle ruptures Suspended within pelvis by suspensory ligaments and to uterus by broad ligament Duct System Uterine tubes Uterus Suspended in pelvis by broad ligament and anchored by round ligament and uterosacral ligament Vagina FEMALE Uterus Thick wall of uterus is composed of three layers Endometrium Inner layer (mucosa) Site of implantation of a fertilized egg Sloughs off with menstruation Myometrium Middle layer of uterine wall Composed of smooth muscle Active in childbirth (responsible for contractions) Perimetrium Outermost serous layer (visceral peritoneum) FEMALE External genitalia Mons pubis – fatty area over pubic symphysis Labia – skin folds covering vestibule (space where urethral and vaginal openings are) Clitoris – sensitive erectile tissue Urethral opening Vaginal opening Greater vestibular glands – flank vagina and excretes lubricating secretions LECTURE EXAM 3 REVIEW BLOOD BLOOD A blood sample is normally collected from a vein A blood sample will be a sample of whole blood Whole blood is the combination of plasma and formed elements Blood can be separated Plasma = ~55% of blood volume Formed elements = ~45% of blood volume Buffy coat =