Anatomy and Physiology: Digestive, Urinary, and Reproductive Systems Practice Flashcards

A collection of vocabulary-based flashcards covering the major topics of the digestive, urinary, and reproductive systems, as well as fluid balance and human development.

Mechanical digestion

The physical breaking down of large pieces of food into smaller ones without changing their chemical composition, occurring in the mouth, stomach, and small intestine.

Chemical digestion

The process of using specific chemicals and enzymes to break chemical bonds of large nutrient molecules into simpler chemical building blocks such as monosaccharides and amino acids.

Mastication

The process of chewing food in the mouth to physically break it down for digestion.

Salivary amylase

An enzyme in human saliva that begins the chemical digestion of starches by breaking them down into disaccharides.

Chyme

A semi-fluid paste created in the stomach by mixing food with gastric juices.

Segmentation

Rhythmic local contractions in the small intestine that move contents back and forth to mix chyme with digestive juices.

Bile salts

Components of bile produced by the liver that perform emulsification, breaking large fat globules into smaller droplets to increase surface area for enzymes.

Pancreatic juice

A complex mixture produced by the pancreas containing enzymes like amylase, lipase, and nucleases, as well as bicarbonate ions to neutralize acidic chyme.

Mucosa

The innermost layer surrounding the lumen of the digestive tube, responsible for protection, secretion, and absorption.

Peristalsis

A wavelike motion produced by smooth muscles in the wall of the digestive tube that pushes food or chyme forward through the canal.

Incisors

Chisel-shaped teeth used to bite off pieces of food; there are $8$ total in the secondary set.

Cardia

A small region of the stomach located near the opening where the esophagus enters.

Rugae

Thick folds of the mucosa and submucosa in the stomach lining that allow the organ to distend as it fills.

Chief cells

Secretory cells in the stomach that secrete pepsinogen, the inactive form of the enzyme pepsin.

Parietal cells

Secretory cells in the stomach that secrete hydrochloric acid ($HCl$) and intrinsic factor.

Intestinal villi

Finger-like projections in the inner lining of the small intestine that vastly increase the surface area for nutrient absorption.

Lacteals

Specialized lymphatic capillaries within the intestinal villi that absorb digested fats encased in protein as chylomicrons.

Teniae coli

Three distinct bands of longitudinal muscle fibers that run the length of the colon in the large intestine.

Haustra

A series of pouches along the wall of the large intestine created by the tension of the teniae coli.

Nephron

The functional unit of the kidney, consisting of a renal corpuscle and a renal tubule, responsible for urine formation.

Glomerulus

A tangled cluster of blood capillaries in the renal corpuscle that filters water and small dissolved substances from the plasma.

Juxtaglomerular Apparatus (JGA)

A specialized structure that monitors blood pressure and electrolyte levels and secretes renin to regulate them.

Antidiuretic hormone (ADH)

Also known as vasopressin, it increases the permeability of the distal convoluted tubules and collecting ducts to water to facilitate reabsorption.

Micturition

The process of urination, where the detrusor muscle contracts and the internal and external urethral sphincters relax.

Extracellular Fluid Compartment (ECF)

The fluid compartment containing approximately $37\%$ of total body water, including interstitial fluid, blood plasma, lymph, and transcellular fluid.

Intracellular Fluid Compartment (ICF)

The largest fluid compartment, containing approximately $63\%$ of the total body water located within the cells.

Acidosis

A condition that occurs when blood pH drops below $7.35$.

Alkalosis

A condition that occurs when blood pH rises above $7.45$.

Gonad

A primary reproductive organ (the testes in males and ovaries in females) responsible for producing sex cells and hormones.

Gamete

A haploid sex cell (sperm in males and oocytes in females) produced through the process of meiosis.

Spermatogenesis

The biological process in males that begins at puberty and produces four haploid sperm cells from one primary spermatocyte.

Oogenesis

The biological process in females that begins prenatally and results in one viable secondary oocyte and non-functional polar bodies.

Capacitation

A process sperm undergo within the female reproductive tract that weakens their acrosomal membranes to allow for fertilization.

Zygote

The diploid cell formed by the union of a sperm nucleus and an egg nucleus during fertilization.

Blastocyst

A hollow ball of cells that develops from a morula and eventually implants into the uterine endometrium by the end of the first week.

Parturition

The formal term for the birth process.

Neonatal Period

The stage of human development from birth to the end of the fourth week.

Senescence

The process of growing old, characterized by degenerative changes and a reduced ability to maintain homeostasis.