fourth test lectures

* Please note: these notes are not "all you need" to prepare for the test, but will give an outline of the material that was covered
in lecture
 
 

Chapter 22 Digestive System Digestive System Organs • Mouth  • Pharynx • Esophagus • Stomach • Small intestine • Large intestine • Anus • Accessory organs Digestive System Organs • Function – Breaks food into smaller parts – Absorption of nutrients into blood Coverings of Digestive Organs • Visceral peritoneum – External surface • Parietal peritoneum – Lines walls of abdominal cavity • Peritoneal cavity – Filled with serous fluid • Messentary – Connects visceral & parietal peritoneum – Provides routes for blood vessels, nerves, lymphatics • Blood supply = splanchnic circulation – Holds organs in place Histology • Four tunics – Mucosa  • Lines lumen from mouth to anus • Secretes mucus, enzymes, hormones • Absorbs digestive products • Protects against disease • Layers  – Surface epithelium » Simple columnar – Lamina propria » Areolar connective » Capillaries » Lymphatics  – Muscularis mucosae » Smooth muscle – Submucosa • Dense connective tissue with elastic fibers – Muscularis externa • Responsible for peristalsis • Layers – Inner circular – Outer longitudinal – Serosa • Areolar connective • Outer layer of squamous epithelium Mouth • = oral cavity = buccal cavity • Slightly keratinized • Lips & cheeks – Skeletal muscles – Skin covering • Vestibule = area between cheek & gums • Lips – Extend from nose to chin – Red margin • Transition between karatinized & oral mucosae – Labial frenulum • Median fold that attaches lip to gum • Palate – Roof of mouth – Hard palate • Underlain by bone • Tongue forces food against it during chewing – Soft palate • Mostly skeletal muscle • Rises to nasopharynx during swallowing • Contains palatine tonsils • Tongue – Movements mix food with saliva – Initiates swallowing – Intrinsic muscles • At tip • Allows shape change – Extrinsic muscles • Alters tongue position – Lingual frenulum  • Secures tongue to floor of mouth • Salivary glands – Many different glands • Parotid - anterior to ear – Infected in mumps • Submandibular  – Next to mandible • Sublingual – Anterior to mandible • Buccal glands – Small intrinsic salivary glands – Serous cells • Watery secretions (97-99.5%)containing enzymes – Mucous cells • Mucus – Some saliva is always produced – Increase caused by parasympathetic • Functions of saliva – Cleanses mouth – Dissolves food • Allows for taste – Aids compaction of food into bolus – Begins breakdown of food with enzymes • Teeth – Humans have 2 sets • Deciduous = milk teeth – Start at 6 months – Pairs at 1-2 month intervals – All 20 by 24 months • Permanent – Milk teeth roots are reabsorbed – Full set is 32, unless wisdom are absent • Types of teeth – Incisors • Chisel shaped • Cutting  – Canines  • Conical • Tear & pierce – Premolars (bicuspid) & molars (broad crowns) • Grinding & crushing • Tooth structure – Crown exposed part • Enamel layer – Mineralized calcium salts – No cellular repair • Gingiva = gum – Surrounds tooth • Tooth structure – Root • Embeded in bone • Peridontal ligament – Anchors tooth to bone • Cementum – Calcified connective tissue – Attaches tooth to peridontal ligament • Tooth structure – Dentin • Underlies enamel • Produced by odontoblast • Bone-like material – Pulp • Connective tissue • Blood vessels • Nerve fibers Pharynx • Digestive system uses two parts – Oropharynx  – Laryngopharynx  • Movement is mostly gravity Esophagus • Muscular tube • Collapsed when not in use • Straight route to the stomach • Mucosa changes from stratified squamous to simple columnar • Muscularis externa is part skeletal muscle, part smooth muscle Swallowing  • Coordinated movement – Tongue – Soft palate – Pharynx – Esophagus – Over 22 muscle groups • Voluntary = buccal phase • Involuntary = pharyngeal & esophogeal phase Stomach • Storage tank – Left side of abdomen – Can extend to 1 gallon – Collapses into rugae = longitudinal folds • Chemical breakdown of protein begins • Food is converted to chyme – Creamy paste • Regions of stomach – Cardiac – entry of food, near heart – Fundulus – Body  – Pyloric region • Ends in pyloric sphincter – Controls stomach emptying • Features  – Greater curvature – Lesser curvature – Omentum • Messentary • Greater omentum – From greater curvature over small intestine • Lesser omentum – From liver to lesser curvature • Modification of tunics – Muscularis external • Three muscle layers – Inner oblique – Middle circular – Outer longitudinal • Allows for churning of food • Modification of tunics – Mucosa • Simple columnar is entirely goblet cells • Gastric pits – Secretory cells that produce gastric juice • Secretory cells – Mucous neck cells • Different type of mucus – Parietal cells • Secrete HCl • Gives stomach pH 1.5-3.5 • Kills bacteria – Chief cells • Produces pepsin – Enteroendocrine cells • Release hormones • Mucosal barrier – Prevents stomach from digesting itself – Thick alkaline mucus – Epithelial cells with tight junctions – Epithelial cells replaced in 3-6 days – Gastric ulcers • Damage to tissue • Hypersecretion of HCl • Hyposecretion of mucus • Pain 1-3 hours after meal • Gastric motility – Peristalsis at about 3/min. • Pacemaker cells in smooth muscle along greater curvature – Pyloric valve only allows liquid & small particles to pass – Empties completely in about 4 hours Small Intestine • Major digestive organ • Site of nutrient absorption • Site of most chemical digestion • Regions of small intestine – Duodenum – Jejunum – Ileum  • Villi – Finger-like projections of mucosa – Absorptive columnar cells – Lacteal capillaries – Pulsate using small amounts of smooth muscle • Increase contact with nutrient soup • Milks fat through lacteal • Microvilli  – Tiny projections of the plasma membrane – Have enzymes • Histology differences – Mucosa is simple columnar • Have goblet cells – Submucosa has Peyer’s patches • Lymphoid tissue • Digestive processes – Materials pass through in 3-6 hours – Depends on slow measured delivery of chyme – True peristalsis only after most nutrients are absorbed Accessory Organs • Liver – Largest gland in body – 4 primary lobes – Under diaphragm on right side – Falciform ligament • Mesentary that suspends liver from diaphragm – Round ligament • Fibrous remnant of fetal umbilical vein • Liver microscopic anatomy – Plates of liver cells  • Hepatocytes – Produce bile – Process blood borne nutrients » Glucose to glycogen – Store fat – Play role in detoxification • Radiate around central vein • Liver microscopic anatomy – Liver sinusoids • Leaky capillaries – Kupffer cells • Macrophages  – Bile canaliculi • Small canals for bile – Composition of bile • Bile salts – Emulsify fats • Bilirubin – Waste product of hemi portion of hemoglobin – Gives feces a brown color Accessory Organs • Gallbladder  – Thin walled muscular green sack – At inferior margin of liver • Gallbladder  – Stores bile – Gallstones = crystallized cholesterol Accessory Organs • Pancreas – Produces a broad spectrum of enzymes – Delivers to duodenum – Acini  • Secretory cells of pancreas – Islets of Langerhans • Endocrine gland Large Intestine • Frames small intestine on 3 sides • Major function – Absorption of water – Elimination of solid waste • Anatomy – Muscularis is reduced, except at end • Teniae coli – 3 bands of smooth muscle – Forms haustra = sack like areas • Subdivisions  – Cecum • Sack-like first part – Vermiform appendix • Masses of lymphoid tissue – Colon  – Rectum  • 3 internal transverse folds = rectal valves – Separate feces from flatus – Anus • Has two sphincters – Internal anal sphincter » Involuntary » Smooth muscle – External anal sphincter » Skeletal muscle • Microscopic anatomy – Mucosa is simple columnar epithelium • Thicker than in other parts of digestive system • Tremendous numbers of goblet cells • Anus has stratified squamous epithelium

Chapter 23 Urinary System Urinary System Organs • Kidneys – Major excretory organ • Ureters • Urinary bladder • Urethra  Kidney Anatomy • Between dorsal body wall & parietal peritoneum • Right kidney is slightly lower than left • Between dorsal body Renal hilus – Entry area for blood vessels, nerves, lymphatics, ureters – On inner, concave side • On top of kidney is the adrenal gland Tissue Surrounding Kidney • Renal capsule – Surface of kidney – Barrier to infection • Adipose capsule – Middle layer – Cushions kidney • Renal fascia – Outer most layer – Fibrous connective tissue – Also surrounds renal gland Internal Kidney Anatomy • Renal cortex – Superficial region – Contains nephrons • Renal medulla – Deep to cortex – Has renal pyramids – Urine collecting tubes • Renal pelvis – Continuous with ureter – Walls have smooth muscle to move urine Kidney Blood & Nerves • Renal artery – ¼ of total systemic blood – Divides into segmental arteries, lobar arteries, interlobar arteries… – Veins are similarly named • Nerve supply to kidney is by renal plexus – Autonomic nerve fibers and ganglia Nephrons • Blood processing units – Over 1 million in each kidney – Carry out processes that form urine • Location  – 85% are cortical – 15% are juxtamedullary • Allow kidney to produce concentrated urine • At cortex-medulla boundary  Nephron Anatomy • Glomerulus  – Tuft of capillaries associated with renal tubule • Bowman’s capsule – Blind, enlarged, cup-shaped structure – Surrounds glomerulus • Renal corpuscle = glomerulus + Bowman’s capsule • Renal tubule – Proximal convoluted tubule • Leaves Bowman’s capsule – Loop of Henle • Hairpin loop – Distal convoluted tubule • Attaches to collecting duct • Collecting tubule – Recieves urine from nephrons Nephron Capillary Beds • Glomerulus  – Specialized for filtration – Fed & drained by arteries – Keeps capillary bed pressure high • Peritubular capillaries – Arise from efferent arterioles – Empty into veinules – Typical capillaries – Reclaim materials  Juxtamedullary Apparatus • Region in each nephron • Have enlarged smooth muscle cells in granules containing renin • Contain macula densa – Chemoreceptors – Osmoregulators – Respond to changes in solute content Ureters • Transfer urine from kidney to bladder • Arrangement prevents backflow • Active transport helps urine movement – Distension causes contraction Ureter Histology • Mucosa – Transitional epithelium – Continuous with kidney pelvis – Lamina propria layer • Muscularis – 2 smooth muscle sheets • Adventia  – Fibrous connective tissue Kidney Stones  • Crystallized urine formed in renal pelvis • Large enough to obstruct ureter • Increases pressure on kidney • Pain from contracting ureter walls Urinary Bladder • Smooth collapsible sac • Stores urine temporarily • Empties into urethra • Three openings – 2 attached to ureter – 1 attached to urethra • Linings similar to ureter, except muscularis – Different muscle arrangement • Distends to hold about a quart – Can burst if over distended Urethra • Thin walled muscular tube • External end changes to stratified squamous epithelium • Two muscle control voiding – Internal urethral sphincter • Involuntary – External urethral sphincter • Voluntary • Skeletal muscles • Gender differences – Female •  1.5 inches long • Tightly bound to anterior vaginal wall • Easily infected – Male • 8 inches long • Runs through prostate gland • Carries urine and sperm Developmental Aspects • Newborn kidneys can not concentrate urine – Bladder is small – Voiding is frequent • Neuromuscular maturation begins at 18 months • Nephrons are lost with age • Renal failure is uncommon but very serious • Bladder capacity and tone decrease with age

Chapter 24 Reproductive System Female Reproductive System • Organs – Ovaries • Main female reproductive organ – Uterine tube – Uterus – Vagina – External genitalia Ovaries • Anchored by ligaments – Ovarian ligament • Attached to uterus – Suspensory ligament • Attached to pelvic wall – Broad ligament • Several attachments • Blood circulation – Ovarian arteries and veins • Tunica albuginea – Connective tissue covering the ovary • Ovarian follicles – Each has an oocyte – Surrounded by follicle cells – Enlarges as it matures – Ruptures to release a mature oocyte – Ruptured follicle becomes corpus luteum Uterine Tube • = Fallopian tubes • = Oviducts • Three distinct regions • Infundibulum  – Finger-like extensions – Nearest ovary – Not in contact with ovary • Ampulla – Middle region • Isthmus – Passage to uterus • Infundibulum is ciliated – Recieves & moves egg • Fertilization is in the ampulla • Oocyte, or zygote, is carried toward uterus by cilia & peristalsis Uterus • Hollow, thick walled organ • Receive, retain, & nourish zygote • Areas of uterus – Fundus – Body – Isthmus  – Cervix • Cancer is common between age 30 & 50 • Pap smear is test for this slow growing cancer • Supports for uterus – Mesometrium  • Messentary – Lateral cervical ligaments • Attach cervix to vagina – Uterosacral ligaments • Attach to sacrum – Round ligaments • Attach to labia majora of vulva • Uterine wall – Outer layer = perimetrium • Visceral peritoneum – Middle = myometrium • Smooth muscle • Contracts during childbirth – Inside = endometrium • Mucosal lining • Simple columnar epithelium • Area where embryo imbeds • Two layers – Stratum functionalis – Stratum basalis Vagina • Two functions – Copulatory organ – Birth canal • Lubrication provided by cervical mucous glands External Genitalia • Vulva  – Labia • Skin folds – Clitoris • Erectile tissue Mammary Glands • Accessory reproductive organ • Modified sweat glands that produce milk – 15-25 lobes – Lobes radiate around opening at nipple  • When not lactating, breast size is mostly due to adiposte tissue • Breast Cancer – 2nd leading cause of death in American women – Usually starts in epithelial cells of ducts – Risk factors • Early menses or late menopause • No pregnancy or late life pregnancy • Overexposure to X-rays • Cigarette smoking • Excess alcohol intake • High fat diet • Advanced age • Family history of breast cancer Male Reproductive System • Testes • Epididymis  • Vas deferens • Ejaculatory duct • Urethra • Accessory organs – Seminal vesicles – Prostrate – Bulbourethral gland Testes • Paired oval glands • Sperm cells produced in seminiferous tubules • Sertoli cells – Nourish sperm cells • Leydig cells – Produce testosterone Coverings Of Testes • Tunica albuginea – Covering testicle • Tunica vaginalis – Lines scrotum • Scrotal cavity  • Scrotum Scrotum • Muscular sack – Muscles allow for position of testes – Sperm production requires temp of 3o C below body temp • Covered by skin Rete Testis • Seminiferous tubules converge into rete testis • Transfers sperm cells to epididymis  Epididymis • Single coiled tube • On top of testicle • Allow sperm to mature – 10-14 days • Store sperm cells • Sperm movement in epididymis – Sperm are not yet motile – Smooth muscle – Pseudostratified epithelium  Vas Deferens • = ductus deferens • = seminal duct • = part of spermatic cord • Transfers sperm cells – From epididymis  – Around bladder Ejaculatory Duct • Entry point of seminal vesicle • Within prostate gland • Area of addition of accessory materials Seminal Vesicle • Accessory gland • Supplies more than half of semen – Fructose • Energy source for sperm – Prostaglandins • Stimulate smooth muscle – Fibrinogen • “clots” semen to keep it in female reproductive tract Prostate • Large single gland • Provides materials for semen – Alkaline fluid • Neutralizes acidic vaginal secretions – Clotting enzymes • Release motile sperm form clot • Common male cancer site Bulbourethral Glands • Drain into urethra • Secrete mucous like substance Relationship of Accessory Glands Urethra • Common passage – Urine – Semen • Contains mucous secreting glands Penis • Copulatory organ • Contains erectile tissue – 3 cylindrical masses – Able to engorge with blood

Chapter 25 Endocrine System • Second major controlling system of the body • Some interaction with the nervous system • Influences metabolic activity with hormones • Actions take seconds to days • Responses are prolonged • Endocrine glands are ductless – Organs are small and scattered in the body Pituitary Gland • = hypophysis • Rests within sella turcica – Depression of sphenoid bone • Attached to brain by infundibulum • Encircled by dural sheath Pituitary Gland Lobes • Posterior lobe • Neural tissue • Releases 2 hormones • Anterior lobe – True endocrine gland – Growth hormone • Targets all cells – Thyroid stimulating hormone • Causes thyroid to release hormones – Adrenocorticotropic hormone • Release of hormones from adrenal cortex – Gonadotropins  • Folicle stimulating hormone – Sperm production – Stimulates follicle cells of ovaries for development & estrogen secretion • Luteinizing hormone – Ovulation – Formation of corpus luteum – Prolactin  • Milk production Thyroid Gland • Located in anterior neck – Anterior surface of trachea • Two lateral lobes connected by median tissue (isthmus) • Largest pure endocrine gland • Internally composed of spherical follicles – Follicle cells • Surround follicles • Usually cuboidal • Produce thyroid hormone • Produce protein thyroglobulin – Parafollicular cells • Produce calcitonin Thyroid Problems • Hypothyroid – = myxedema – Low metabolic rate • Chills • Constipation • Dry skin • Edema • Lethargy  • Mental sluggishness • Cretinism – Hypothyroidism in infants • Short disproportionate body • Mental retardation • Hyperthyroid – Grave’s disease – Elevated metabolism – Sweating – Rapid heart rate • Goiter – Abnormal enlargement of thyroid – Often from lack of iodine • Needed for proper formation of thyroid hormone Parathyroid Glands • Usually 2 pair of glands – Can be up to 8 • On posterior of thyroid gland • Made of 2 cell types – Oxyphil cells • Function unknwon – Chief cells • Secrete parathyroid hormone Thymus • Deep to sternum • Large in children – Diminishes in size • Produces thymosins – Develop and mature the immune response Adrenal Glands • = suprarenal glands • Pyramid glands on top of kidney • Actually 2 glands – Adrenal Cortex • Outer – Adrenal medulla • Inner  Adrenal Cortex • Yellow color due to stored lipids • Produces over 2 dozen steroid hormones • Cells are in 3 distinct zones • Zona glomerulosa – Outer – Mineralocorticosteroids • Control balance of minerals & H2O in blood • Zona fasiculata – Glucosteroids • Metabolic hormones • Zona reticularis – Produces androgens • Some contribute to the onset of puberty Adrenal Medulla • Spherical chromaffin cells – Secrete epinephrine and norepinephrine Kidneys • Small amounts of endocrine tissue • Release several hormones and renin Hormones of Kidneys • Calcitrol – Steroid hormone – Stimulates calcium & phosphate absorption • Erythropoietin – Peptide hormone – Stimulates production of red blood cells Heart • Contains endocrine cells – Atrial natriuretic peptide • Helps control blood pressure & volume Pancreas • Behind stomach • Mixed gland – Endocrine & exocrine • Mostly made of acinar cells – Exocrine – Produce alkaline enzyme • Digestive enzymes • Islets of Langerhans – Endocrine pancreas – Produce pancreatic hormones • Insulin • Glucagon – Regulates blood sugar level Diabetes mellitus • Hyposecretion or hypoactivity of insulin • Glucose is unable to enter cells • More fats are mobalized • Blood sugar level increases • Two types – Type I = juvenile diabetes • No insulin activity • Insulin dependent – Type II  • Insulin is produced • Receptors do not respond • Occurs mostly after age 40 Hypoglycemia • Hyperinsulinsim • Low blood sugar • Symptoms – Anxiety – Nervousness – Tremors – weakness Testes • Male gonads • Secrete androgens – Steroid hormones – Produced in interstitial cells – Sperm maturation – Protein synthesis in muscles – Male secondary characters Ovaries • Steroid sex hormones – Estrogen • Produced by follicular cells • Female secondary characteristics • Follicle stimulation – Inhibin • Produced by follicular cells • Inhibits FHS production by pituitary – Progestins • Produced by corpus luteum • Prepares uterus for implantation • Prepares mammary glands for secretion – Relaxins • Produced by corpus luteum • Relaxes uterine muscles • Stimulates mammary development Pineal Gland • Hangs from 3rd ventricle of diencephalon • Part of epithalamus • Pinealocytes – Secretory cells – Prodoce many peptides & amines – Produces melatonin • Sets biological clock • Mostly released at night Stomach • Some endrocrine cells – Gastrin • Stimulates HCl release – Serotonin • Contractions of stomach muscles Duodenum • Intestinal gastrin • Secretin – Increases bile release – Inhibits secretions of stomach Placenta • Produces steroid & protein hormones • Influence the course of pregnancy Skin • Produces cholecalciferol – Inactive form of vitamin D – Activated by kidney