Digestive, Urinary & Reproductive Systems – Exam 3 Review

A curated set of Q&A flashcards covering key concepts from the digestive, urinary, and reproductive system lecture notes to aid in Exam 3 preparation.

What are the six primary functions of the digestive system?

Ingestion, propulsion, mechanical digestion, chemical digestion, absorption, defecation.

Into which two main groups is the digestive system divided?

Alimentary canal (GI tract) and accessory digestive organs.

Name three organs that belong to the alimentary canal.

Examples: mouth, esophagus, stomach, small intestine, large intestine, rectum, anus.

Give two examples of accessory digestive organs and their roles.

Pancreas – secretes digestive enzymes and bicarbonate; liver – produces bile for fat emulsification.

How does catabolism differ from anabolism?

Catabolism breaks large molecules into smaller ones (releasing energy); anabolism builds larger molecules from smaller ones (requiring energy).

Define mechanical digestion and list its four main processes.

Physical breakdown of food; includes chewing (mastication), mixing/churning, segmentation, and swallowing.

Define chemical digestion and list the three major enzyme classes involved.

Enzymatic breakdown of macromolecules; key enzymes: amylases (carbohydrates), proteases (proteins), lipases (lipids).

What is hydrolysis with respect to digestion?

Chemical process that splits molecules by adding water, central to enzymatic digestion.

The esophagus is part of the , whereas the pancreas is an digestive organ.

Alimentary canal; accessory.

List the four tissue layers of the GI tract (deep to superficial).

Mucosa, submucosa, muscularis externa, serosa (or adventitia in the esophagus).

Which GI plexus is found in the muscularis externa and what is its function?

Myenteric nerve plexus; coordinates GI motility (peristalsis and segmentation).

Differentiate short vs. long GI reflexes.

Short reflexes involve enteric neurons only; long reflexes involve CNS integration via vagus or sympathetic pathways.

Parasympathetic stimulation generally has what effect on GI activity?

Stimulatory – increases secretion and motility.

Sympathetic stimulation generally has what effect on GI activity?

Inhibitory – decreases secretion and motility.

Define the peritoneum and name five major peritoneal folds.

Serous membrane lining abdominal cavity; folds: greater omentum, lesser omentum, mesentery, mesocolon, falciform ligament.

Name and briefly describe the three phases of gastric secretion.

Cephalic (sight/thought of food stimulates vagus), gastric (food in stomach triggers stretch/chemo-receptors & gastrin), intestinal (chyme in duodenum initially excitatory then inhibitory).

Which two enzymes in saliva begin chemical digestion and what do they act on?

Salivary amylase – starch; lingual lipase – triglycerides (activated in stomach).

Why does your mouth feel dry before public speaking?

Sympathetic activation inhibits salivary secretion.

What tissue makes up the tongue and what is its digestive role?

Skeletal muscle; manipulates food into bolus, initiates swallowing, houses taste buds, secretes lingual lipase.

Define deglutition and list its three stages.

Swallowing; oral (voluntary), pharyngeal (involuntary), esophageal (involuntary peristalsis).

What are the two sphincters of the esophagus and their functions?

Upper esophageal sphincter – prevents air entry; lower esophageal (cardiac) sphincter – prevents reflux of gastric contents.

List the four anatomical regions of the stomach.

Cardia, fundus, body, pylorus.

What are the three major components of gastric juice?

Hydrochloric acid, pepsinogen/pepsin, intrinsic factor (plus mucus and water).

What do parietal cells secrete and why is each product important?

HCl – activates pepsinogen & kills microbes; intrinsic factor – required for vitamin B₁₂ absorption.

Name three primary stimulators of HCl secretion.

Acetylcholine (parasympathetic), gastrin (G cells), histamine (ECL cells).

What two factors inhibit gastric HCl secretion?

Low stomach pH (negative feedback) and intestinal hormones such as secretin/CCK.

Describe the pancreas’ dual roles in digestion.

Exocrine pancreas produces pancreatic juice (enzymes + bicarbonate) delivered to duodenum; endocrine pancreas secretes hormones (insulin, glucagon).

What do pancreatic ducts empty into and via which openings?

Duodenum; via main pancreatic duct (with hepatopancreatic ampulla) and accessory pancreatic duct.

List at least four functions of the liver.

Produces bile, stores glycogen, detoxifies blood, makes plasma proteins, metabolizes nutrients, stores fat-soluble vitamins, converts ammonia to urea, participates in hematopoiesis in fetus.

What are Kupffer cells and where are they located?

Hepatic macrophages in liver sinusoids; they phagocytize debris and pathogens.

What is bile and what is the function of bile salts in the intestine?

Yellow-green alkaline solution from liver; bile salts emulsify fats to aid lipase action—without them fat absorption would be minimal.

What hormone triggers gallbladder contraction and pancreatic secretion?

Cholecystokinin (CCK), released from duodenal mucosa in response to fatty chyme.

Name the three regions of the small intestine in order and their approximate lengths.

Duodenum (~25 cm), jejunum (~2.5 m), ileum (~3.5 m).

What are plicae circulares and their purpose?

Permanent circular folds of mucosa/submucosa that slow chyme and increase surface area for absorption.

Match the small-intestine cell type: Goblet cells vs. Paneth cells vs. Enterocytes.

Goblet – secrete mucus; Paneth – secrete lysozyme & defensins (antimicrobial); Enterocytes (absorptive cells) – absorb nutrients via microvilli.

List three enteroendocrine hormones produced by the small intestine.

Secretin, cholecystokinin (CCK), gastric inhibitory peptide (GIP/GLP-1).

Name the four main parts of the large intestine.

Cecum, appendix, colon, rectum (plus anal canal).

What are the four sections of the colon, in order?

Ascending, transverse, descending, sigmoid.

State four homeostatic functions of the urinary system.

Regulates blood volume/pressure, ion concentrations, pH, and removes metabolic wastes/toxins.

Describe the two major kidney regions and their functions.

Renal cortex – houses glomeruli and cortical nephrons; renal medulla – contains pyramids with loops of Henle & collecting ducts for urine concentration.

Put these urine-flow structures in order starting at collecting duct.

Collecting duct → Minor calyx → Major calyx → Renal pelvis → Ureter → Urinary bladder.

What structures form the renal corpuscle?

Glomerulus (capillary tuft) and Bowman’s (glomerular) capsule.

Name the three segments of the renal tubule.

Proximal convoluted tubule (PCT), nephron loop (loop of Henle), distal convoluted tubule (DCT).

Which segment of the nephron has dense microvilli for reabsorption?

Proximal convoluted tubule.

Define the juxtaglomerular complex (JGC) and its primary function.

Contact point between DCT and afferent arteriole; regulates blood pressure & GFR via renin and tubuloglomerular feedback.

Differentiate cortical and juxtamedullary nephrons.

Cortical – short loops, mostly in cortex, bulk of filtration; juxtamedullary – long loops deep into medulla, crucial for concentrating urine.

List the three basic processes of urine formation.

Glomerular filtration, tubular reabsorption, tubular secretion.

What is the main force that promotes glomerular filtration and its typical value?

Blood hydrostatic (glomerular) pressure; ~55 mmHg.

Provide the formula for Net Filtration Pressure (NFP).

NFP = BHP – (BOP + CHP).

Calculate NFP when BHP = 55, BOP = 30, CHP = 15 mmHg.

NFP = 55 – (30 + 15) = 10 mmHg (filtration occurs).

Define glomerular filtration rate (GFR) and normal average values.

Volume of filtrate formed per minute by both kidneys; ~125 mL/min in males, ~105 mL/min in females.

What happens if GFR is too high?

Insufficient time for reabsorption → excessive urine output → dehydration & electrolyte loss.

Name the two intrinsic mechanisms of renal autoregulation.

Myogenic mechanism and tubuloglomerular feedback.

Which hormone is released by JG cells in response to low BP and what is its effect?

Renin; activates angiotensin II → constricts arterioles, increases aldosterone, raising BP and GFR.

Define renal clearance.

Volume of plasma from which a substance is completely removed by kidneys per unit time (mL/min).

State two clinical uses of renal clearance tests.

Estimate GFR (e.g. inulin/creatinine clearance) and adjust drug dosing based on kidney function.

Define sexual reproduction.

Process in which two gametes (sperm & oocyte) fuse to form a zygote, enabling genetic diversity.

What are primary sex organs and give examples.

Gonads that produce gametes and hormones; testes in males, ovaries in females.

Which five hormones constitute the HPG axis signaling cascade?

GnRH, FSH, LH, sex steroids (testosterone/estrogen), inhibin.

List the structures of the male reproductive duct system in order (SEVEN UP mnemonic).

Seminiferous tubules → Epididymis → Vas deferens → Ejaculatory duct → (Nothing) → Urethra → Penis.

What is the scrotum’s primary function?

Houses testes and maintains them ~3 °C below core body temperature for optimal spermatogenesis.

Define spermatogenesis.

Process by which spermatogonia develop into mature spermatozoa within seminiferous tubules.

Name the four stages of spermatogenesis.

Mitosis of spermatogonia, meiosis I (primary → secondary spermatocytes), meiosis II (spermatids), spermiogenesis (spermatids → spermatozoa).

What two major parts make up a sperm cell?

Head (with acrosome & nucleus) and tail (flagellum with midpiece motor).

How does semen differ from sperm?

Semen = sperm plus seminal fluid (secretions from seminal vesicles, prostate, bulbourethral glands).

Which autonomic division mediates penile erection?

Parasympathetic (nitric oxide release → vasodilation of corpora cavernosa).

List the six main organs of the female reproductive system.

Ovaries, uterine tubes, uterus, cervix, vagina, external genitalia (vulva).

State the two primary functions of the ovaries.

Produce ova (oogenesis) and secrete sex hormones (estrogen & progesterone).

Define oogenesis and where it occurs.

Formation of female gametes; occurs within ovarian follicles in the cortex of the ovaries.

What are primordial follicles?

Earliest stage of ovarian follicles containing primary oocytes arrested in prophase I until puberty.

Identify the usual site of fertilization in the female tract.

Ampulla of the uterine (fallopian) tube.

Name the three layers of the uterine wall.

Endometrium (mucosa), myometrium (smooth muscle), perimetrium (serosa).

List four components of the vulva.

Mons pubis, labia majora, labia minora, clitoris (plus vestibule, urethral & vaginal openings, bulbs of vestibule).

Which glands in the female external genitalia are homologous to the male bulbourethral glands?

Greater vestibular (Bartholin’s) glands.

Explain the role of the clitoris during sexual response.

Erectile tissue that becomes engorged with blood, contributing to female sexual arousal and orgasm.

What is folliculogenesis?

Maturation of the ovarian follicle surrounding the developing oocyte, culminating in ovulation.

State four key steps in folliculogenesis.

Primordial → primary (unilaminar) → secondary (multilaminar) → tertiary (Graafian) follicle leading to ovulation.

Describe the function of the uterine tubes.

Transport ovulated oocyte toward uterus; site of fertilization; ciliated epithelium & peristalsis move gametes/zygote.

Which layer of the uterus is shed during menstruation?

Functional layer of the endometrium.

What hormone primarily drives milk production after childbirth?

Prolactin (from anterior pituitary).

Which two posterior-pituitary hormones are critical for labor and lactation, respectively?

Oxytocin – uterine contractions and milk ejection; (Note: ADH unrelated to lactation).

What is the function of inhibin in both sexes?

Provides negative feedback to anterior pituitary to decrease FSH secretion, regulating gametogenesis.