Bio216 exam 4 digestive & reproduction

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functions and major physiological processes of the digestive system
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functions and major physiological processes of the digestive system
processes food, extracts nutrients and eliminates residue. Five stages: Ingestion, Digestion, Absorption, Compaction, Defaction
Distinguish between mechanical and chemical digestion.
Mechanical digestion: mastication(chewing), stomach and small intestinal churning. Chemical digestion: Series of hydrolysis reactions that breaks dietary macromolecules into their monomers
Describe the basic chemical process underlying all chemical digestion, and name the major substrates and products of this process.
Digestive enzymes produced by salivary glands, stomach, pancreas, and small intestine
- Results
• Polysaccharides into monosaccharides • Proteins into amino acids
• Fats into monoglycerides and fatty acids • Nucleic acids into nucleotides
List the regions of the digestive tract
Digestive Tract:
mouth-site of mechanical and chemical processing (tongue manipulates food so teeth can chew) (saliva digests carbs)
esophagus-transports food
stomach- site of mechanical and chemical processing (digests protein)
small intestine- site of chemical processing and absorption (digests proteins, fats, carbs, absorbs nutrients and h20)
large intestine- absorbs water and forms feces; contains symbiotic bacteria
appendix- contains immune tissue and harbors symbiotic bacteria
anus- eliminates feces
Identify the layers of the digestive tract and describe its relationship to the peritoneum.*****
mucosa- innermost layer; contains stratified squamous epithelium, lamina propria, muscularis mucosa
submucosa- above mucosa; contains esophageal gland
muscularis externa- inner circular layer and outer longitudinal layer
serosa- outtermost
Describe the general neural and chemical controls over digestive function.
The digestive system function is controlled by the autonomic nervous system. there are sympathetic and parasympathetic pathways.

the enteric nervous system is two networks of neurons that controls local motility and secretion in the gastrointestinal tract. It is independent of the ANS, but is regulated by the ANS activity.
The two enteric nerve networks are:
•the submucosal plexus - secretion
•the myenteric plexus - peristalsis
Describe the gross anatomy of the digestive tract from the mouth through the esophagus.
-Mouth: site for chewing, bolus created and pushed back into pharyx
-Pharynx: muscular funnel that connects oral cavity to esophagus
-Esophagus: muscular tube that carries food into stomach
Describe the composition and functions of saliva.
saliva: begins starch and fat digestion
cleanses teeth
inhibits bacterial growth
dissolves molecules so they can stimulate the taste buds
moistens food and binds food together into bolus to aid in swallowing
Composition: fluid rich in electrolytes and enzymes
Describe the neural control of salivation and swallowing.
Saliva is produced by the salivary glands of body - the parotid, submandibular and sublingual glands. Within the glands, the acinar cells are responsible for the volume of saliva secreted, and the duct cells are responsible for the composition of saliva.
Describe the gross and microscopic anatomy of the stomach.
gross anatomy-------- microscopic anatomy
fundic region----------gastric pit
cardiac region-------- gastric gland
body ------------------lymphatic nodule
pyloric region --------oblique layer of muscle
gastric ruggae
State the function of each type of epithelial cell in the gastric mucosa.1. Mucous cells - Secrete mucus 2. Parietal cells - Secrete hydrochloric acid, intrinsic factor, and ghrelin 3. Chief cells—most numerous - Secrete gastric lipase and pepsinogen - Gastric gland only 4. Enteroendocrine cells (G cells)— - Secrete hormones and paracrine messengers that regulate digestion 5. Regenerative cellsIdentify the secretions of the stomach and state their functions.-Hydrochloric acid: activates pepsin, converts dietary iron to form body can absorb and use, breaks up connective tissues and plant cells helping to liquefy food and form chyme, contributes to non-specific disease resistance by destroying most ingested pathogens -Pepsin: digests proteins to shorter chains -Gastric lipase: digests small amount of dietary fat -Intrinsic factor: essential for absorption of vitamin B12 -Hormones and local chemical messengers: aid digestion and appetite regulationExplain how the stomach produces hydrochloric acid and pepsin.1. HCl activates pepsin and lingual lipase 2. Breaks up connective tissues and plant cell walls - Chyme 3. Converts ingested ferric ions (Fe3+) to ferrous ions (Fe2+) (used for hemoglobin Parietal cells contain carbonic anhydrase (CAH) Hydrochloric Acid synthesis) CAH 4. Destroying most ingested pathogensDescribe the contractile responses of the stomach to food.-after the stomach has relaxed to hold the max amount of food, stomach shows a rhythm of peristaltic contractions(gentle ripple every 20sec mixes food w/ gastric juices, after 30min contractions become very strong. -only small amount of chime go into small intestine and allow for neutralization of stomach acid & digest nutrients little by little -typical meat emptied from stomach after 4hrsDescribe the three phases of gastric function and how gastric activity is activated and inhibited.cephalic stage: Stomach responds to sight, smell, taste, or thought of food gastric phase:Ingested food stimulates gastric activity in two ways: By stretching the stomach By increasing the pH of its contents intestinal phase: Enterogastric reflex—duodenum sends inhibitory signals to theDescribe the digestive secretions and functions of the liversecretes bile and stores glucose, aids in absorption of nutrientsExplain how hormones regulate secretion by the liver and pancreas.cholecyctokinin - released from duodenum in respond to arrival of acid and fat. contracts gall bladder, secretions of pancreas, relaxation of hepatopancreatic sphincter secretion - released from duodenum in response to acidic chyme. secretions of bicarbonate neutralises chyme gastrin - from stomach and duodenum stimulates galls bladder contraction and pancreatic enzyme secretionDescribe the gross and microscopic anatomy of the small intestine.Duodenum - 25cm - liver empties neutralises acids Jejunum - 2.5 metres - most digestion occurs here Ilieum - 3.6metres - clusters of lymphatic nodules Surface area- •circular folds/pilae circularis 10mm tall •vili project 1mm outwards for absorption •microvilli cover surface Crypts- •pore exist between villi secrete intestinal juices (1-2L daily)State how the mucosa of the small intestine differs from that of the stomach, and explain the functional significance of the differences.The mucosae of the small intestine involves the submucosa and form the plicae circulars that effectively increase the surface area of the intestines.Define contact digestion and describe where it occurs.Contact digestion: chyme must contact the brush border for digestion to occur. It occurs in the microscopic of the illeum.Describe the types of movement that occur in the small intestine.intestinal motility includes: •mixing of chyme - segmentation •churning of chyme - segmentation •movement of residue - peristalsisDescribe how each major class of nutrients is chemically digested, name the enzymes involved, and discuss the functional differences among these enzymes.Carbohydrates - digested by amylase starting in mouth and ceases in stomach. Pancreatic amylae digest it further in small intestine. Proteins - digested by pepsin in the stomach and ceases in the small intestine, but pancreas release trypsin and chymotrypsin. Fats - Lecithin emulsifies fate with bile. then acted upon by lipaseDescribe how each type of nutrient is absorbed by the small intestine.Glucose - transported then diffused fructose - diffused entirely galactose - transported then diffused proteins - diffused entirely fats - diffused entirelyLipase breaks down whatfat into glycerol and fatty acidprotease breaks down whatprotein into amino acidsamylase breaks down whatstarches into sugarslist the regions of the accessory tractsalivary glands- secrete enzymes that digest carbs and they supply lubricating mucous liver- secretes molecules that aid in fat digestion gallbladder- stores secretions from liver and empties into small intestine pancreas- secretes enzymes and other materials into the small intestinewhich is not normally found in the saliva?proteasesaliva contains-Salivary amylase: enzyme that begins starch digestion in the mouth - Lingual lipase: enzyme that is activated by stomach acid and digests fat after food is swallowed - Mucus: binds and lubricates a mass of food and aids in swallowing - Lysozyme: enzyme that kills bacteria - Immunoglobulin A (IgA): an antibody that inhibits bacterial growth - Electrolytes: Na+, K+, Cl−, phosphate, and bicarbonateDescribe the gross and microscopic anatomy of the gallbladderStores and concentrates bile by absorbing water and electrolytesDescribe the gross and microscopic anatomy of the bile duct systemBile acids aid in fat digestion and absorption • 80% of bile acids are recycled and sent back to the liver • 20% of the bile acids are excreted in the feces - Body's only way of eliminating excess cholesterol - Liver synthesizes new bile acids from cholesterol to replace those lost in fecesDescribe the gross and microscopic anatomy of the liverHepatic lobules—tiny cylinders that fill the interior of the liver • After a meal, - Hepatocytes absorb glucose, amino acids, iron, vitamins, and other nutrients from the blood • Between meals - Hepatocytes break down stored glycogen and release glucose into the blood • Remove and degrade - Hormones, toxins, bile pigments, and drugs • Secrete into the blood - Albumin, lipoproteins, clotting factors, angiotensinogen, and other productsDescribe the gross and microscopic anatomy of the pancreasanatomy: Retroperitoneal gland posterior to stomach has Endocrine and exocrine gland Ducts from acinar cells converge on pancreatic duct purpose: delivers pancreatic juice to duodenum accessory duct opens independently on duodenum pancreatic juice released without bilewhat does the liver do that the pancreas doesn't?store glucosethe ______ stores excess glucose and releases it into the blood when neededliverThe ____ phase is associated with food stretching the stomach and activating myenteric and vagovagal reflexes, which in turn stimulate gastric secretionsgastricdescribe the structure of the ovary; trace the female reproductive tract and describe the gross anatomy and histology of each organ;-ovary- female gonads that produce egg cells and sex hormones -outer cortex, inner medulla -each egg develops in its own fluid- filled follicleidentify the ligaments that support the female reproductive organsbroad ligament-sides of uterus to walls and floor of pelvic cavity ovarian ligament- attaches ovary to uterus suspensory ligament- connects ovary to body walldescribe the blood supply to the female reproductive tract-to the ovaries: Arteries: the ovarian artery arises from the abdominal aorta at the level of L1. Veins: the ovarian vein drains into the inferior vena cava on the right side and into the left renal vein on the left side. -to the uterine tubes: Arteries: the uterine artery from the internal iliac artery and the ovarian artery from the abdominal aorta supply the uterine tube. Veins: correspond to arteries. -to the uterus: Arteries: mainly from the uterine artery which is a branch of the internal iliac artery. Also anastomosing with the ovarian artery. A small descending branch supplies the cervix and vagina. Veins: the uterine vein follows the artery and drains into the internal iliac vein. -to the vagina: the vaginal artery, a branch of the internal iliac artery, and the vaginal branch of the uterine artery. Veins: the vaginal veins form a pluxux around the vagina that drains into the internal iliac vein.identify the external genitalia of the femaleclitoris: labium minus: labium majus:describe the structure of the nonlactating breast- adipose collagenous tissue - 2 parts, body and axillary tail (extension towards tail)name the hormones that regulate female reproductive function, and state their rolesGnRH: releases FSH and LH FSH: is produced by the pituitary gland during the first half of the menstrual cycle. It stimulates development of the maturing ovarian follicle and controls ovum production in the female, and sperm production in the male. LH: is also produced by the pituitary gland in the brain. It stimulates the ovaries to produce oestrogen and progesterone. It triggers ovulation (the release of a mature ovum from the ovary), and it promotes the development of the corpus luteum. progesterone: is produced by the corpus luteum in the ovary; its function is to prepare the endometrium (lining of the uterus) for the reception and development of the fertilised ovum. It also suppresses the production of oestrogen after ovulation has occurred.describe the principal signs of puberty-begins at age 8-10 for most girls -Estradiol stimulates many changes in puberty Stimulates vaginal metaplasia Stimulates growth of ovaries and secondary sex organs Stimulates growth hormone secretion Increase in height and widening of pelvis Stimulates fat depositiondescribe the hormonal changes of female climacteric and their effectsclimacteric - drop in estrogen levels and rise in FSH and LH levels over timedefine and describe menopause, and distinguish menopause from climacteric.- menopause - ovarian function ceases - cessation of menstruation b/t ages 45 - 55 - symptoms such has hot flashes, mood swings, depression, headachesdescribe the process of egg production (oogenesis)1) during fetal development, germ cells from yolk sacs gather at gonadal ridge, becoming primordial follicles (diploid cells) 2) primordial follicles replicate via mitosis, creating 6 - 7 million primordial follicles 3) before birth, some become primary follicles, while some degenerate, until only 400,000 primary follicles are left at puberty 4) W/ puberty, GnRH stimulates release of FSH, stimulating several primary follicles to complete meiosis I, producing oocyte (haploid), discarding first polar body leaving cell w/ cytoplasm of 4 cells needed for cell reproduction, nutrients stores, etc to sustain itself for 7 days of ovulation 5) One follicle self-selects each month to become ovulated follicle due to most estrogen secretion 6) Selected follicle releases mature oocyte (egg) through process of ovulation by bursting on edge of ovary 7) Remnant of cells from selected follicle become corpus luteum 8) Corpus luteum, under influence of LH produces progesterone 9) if fertilization doesn't happen, oocyte dies, and corpus luteum becomes corpus albicans 10) if fertilization does happen, oocyte goes through meiosis II, creating zygote, discarding second polar body, leaving zygoteDescribe the resulting changes in the male body due to testosteronefacial hair, coarse and visible hair on torso and limbs, relatively muscular physique.Define and describe male climacteric and the effect of aging on male reproductive function.Describe the stages of meiosis and contrast meiosis with mitosis.mitosis:daughter cells identical, asexual, diploid and ends with diploid, 2 daughter cells, # of chromosomes stay the same, produces most cells in body meiosis:don't make identical copies, sexual reproduction, diploid ends with haploid, 4 daughter cells, # chromosomes splits in half, produces gametes, daughter cells uniqueDescribe the sequence of cell types in spermatogenesis, and relate these to the stages of meiosis.Describe the role of nurse cells in spermatogenesis.Describe or draw and label a sperm cell.Describe the composition of semen and functions of its components.60% vesical fluid, 30% prostatic fluid, and 10% sperm and spermatic duct secretions. -Prostate produces a thin milky white fluid, which contains clotting enzyme and serine protease -seminal vesical contribute yellowish fluid which contain fructose an other carbohydrates, citrate, prostaglandins, and a protein called proseminogelin.describe the hormonal events that regulate the ovarian cycle1. Maturing follicile secretes estradiol 2. Estradiol stimulates hypothalamus an anterior pituitary 3. Hypothalmus secrets GnRH 4. GnRH and estradiol stimulate pituitary to secrete LH and FSH 5. OOcyte completes meiosis 1; folllicile rapidly enlarges and then ovulatesidentify the physical and chemical stimuli that increase uterine contractility in late pregnancyname and describe the three stages of labor1. Dilation (vagina begins to dilate and baby starts crowning) 2. Expulsion (expells babay) 3. Placenta stage (afterbirth)describe the shifting hormonal balance that regulates the onset and continuation of lactationdescribe the mechanism of milk ejectioncontrast colostrum with breast milkdiscuss the benefits of breast-feedingdescribe development of the breasts in pregnancydescribe the mechanism of labor contractionslist the major hormones that regulate pregnancy and explain their rolesconstruct a chart of the phases of the monthly sexual cycle showing the hormonal, ovarian, and uterine events of each phase.describe a woman' s bodily adaptations to pregnancydescribe how the uterus changes during the menstrual cycledescribe changes in the ovarian follicles (folliculogenesis) in relation to oogenesisDescribe the hormonal control of puberty.Identify the most fundamental biological distinction between male and female.State the names, locations, and functions of the male accessory reproductive glands.Describe the anatomy of the scrotum, testes, and penis.Describe the pathway taken by a sperm cell from its formation to its ejaculation, naming all the passages it travels.Define primary sex organs, secondary sex organs, and secondary sex characteristics.Explain the role of the sex chromosomes in determining sex.Describe the descent of the gonads and explain why it is important.Explain how the Y chromosome determines the response of the fetal gonad to prenatal hormones.Identify which of the male and female external genitalia are homologous to each other.Whats the infants only source of nutrition during the first 2-3 days of postpartum?colostrumWhat does the term "menstrual cycle" specifically refer to?The cyclic changes in the uterus determined by shifting hormonal changesWhen does an ovum finish meioses II?during fertilization