test 4 vocab

chapters 13, 14, 15, & 16

Adrenal cortex

The outer region of the adrenal gland that secretes steroid hormones, including aldosterone and cortisol.

Adrenal medulla

The inner core of the adrenal gland that secretes the catecholamines epinephrine and norepinephrine in response to stress.

Hormones

Chemical messengers secreted by endocrine glands directly into the bloodstream to regulate the physiological activity of target cells.

Pinal gland

An endocrine gland located in the brain that secretes melatonin to regulate sleep-wake cycles and circadian rhythms.

Pituitary gland

The master endocrine gland located at the base of the brain that produces hormones controlling growth, reproduction, and other endocrine glands.

Thymus

A lymphoid and endocrine organ in the chest that secretes hormones involved in the maturation and differentiation of T lymphocytes.

Thyroid

An endocrine gland in the neck that secretes metabolic hormones that regulate basal metabolic rate, growth, and calcium balance.

Adrenocorticotropic

An anterior pituitary hormone (ACTH) that stimulates the adrenal cortex to produce and release glucocorticoids.

Aldosterone

A mineralocorticoid hormone synthesized by the adrenal cortex that promotes sodium reabsorption and potassium excretion in the kidneys.

Antidiuretic hormone

A hormone released by the posterior pituitary (ADH) that promotes water reabsorption in the collecting ducts of the kidneys to concentrate urine.

Epinephrine

A hormone produced by the adrenal medulla that initiates the body's acute 'fight-or-flight' stress response.

Follicle stimulating

An anterior pituitary gonadotropin (FSH) that stimulates gamete development, inducing ovarian follicle growth in females and spermatogenesis in males.

Glucagon

A hormone produced by alpha cells in the pancreatic islets that raises blood glucose levels by triggering glycogen breakdown in the liver.

Growth

An anterior pituitary hormone (GH) that stimulates cellular growth, protein synthesis, and tissue elongation throughout the body.

Insulin

A hormone produced by beta cells in the pancreatic islets that lowers blood glucose levels by facilitating glucose uptake into body cells.

Luteinizing

An anterior pituitary hormone (LH) that triggers ovulation and corpus luteum formation in females and stimulates testosterone synthesis in males.

Oxytocin

A posterior pituitary hormone that stimulates uterine contractions during labor and induces milk ejection during lactation.

Parathyroid hormone

A hormone released by the parathyroid glands (PTH) that elevates blood calcium levels by stimulating bone resorption and kidney calcium retention.

Prolactin

An anterior pituitary hormone that stimulates the development of mammary glands and promotes milk production following childbirth.

Thyroid-stimulating

An anterior pituitary hormone (TSH) that stimulates the thyroid gland to synthesize and release thyroid hormones.

Anorexia nervosa

An eating disorder characterized by extreme food restriction, severe weight loss, an intense fear of gaining weight, and a distorted body image.

Basal metabolic rate

The baseline rate of energy expenditure by the body at rest while maintaining essential physiological functions (BMR).

Bile

A digestive fluid synthesized by the liver and stored in the gallbladder that emulsifies dietary fats in the small intestine.

Chyme

The acidic, semifluid mixture of partially digested food and gastric secretions formed in the stomach and passed into the duodenum.

Colon

The large intestine, responsible primarily for absorbing water and electrolytes and compacting indigestible material into feces.

Esophagus

A muscular tube that propels swallowed food from the pharynx down into the stomach using coordinated peristaltic contractions.

Gallbladder

A small sac located beneath the liver that stores, concentrates, and releases bile into the duodenum.

Hepatic portal system

A specialized venous pathway that carries nutrient-rich blood directly from the digestive organs to the liver for metabolic processing and detoxification.

Pancreas

An accessory digestive and endocrine organ that produces digestive enzymes, bicarbonate juice, and the metabolic hormones insulin and glucagon.

Peptic ulcer

A localized erosion or sore on the mucous membrane lining of the stomach or duodenum, often aggravated by gastric acid.

Peristalsis

Rhythmic, involuntary waves of smooth muscle contraction and relaxation that propel contents along the gastrointestinal tract.

Polyps

Small, abnormal tissue growths that project outward from the mucosal surface lining the colon or other parts of the gastrointestinal tract.

Segmentation

Localized, alternating smooth muscle contractions in the small intestine that thoroughly slosh and mix chyme with digestive enzymes.

Afferent arteriole

The specialized renal blood vessel that brings blood directly into the glomerulus for filtration.

Collecting duct

A renal tube that collects filtrate from multiple nephrons and carries out the final regulation of water and solutes under ADH influence.

Dialysis

A medical procedure that artificially filters and cleans metabolic wastes and excess fluid from the blood when kidneys are impaired.

Efferent arteriole

The renal blood vessel that carries filtered blood away from the glomerulus and supplies the peritubular capillaries.

Excretion

The biological process of eliminating metabolic wastes, excess water, and harmful substances from the body.

Glomerular capsule

The double-walled cup-shaped sac (Bowman's capsule) encasing the glomerulus that receives the initial fluid filtrate.

Glomerulus

A specialized knot or tuft of fenestrated capillaries inside the renal corpuscle where plasma is filtered under high hydrostatic pressure.

Loop of Henle

A hairpin-shaped U-turn in the nephron tubule that sets up an osmotic gradient in the renal medulla to concentrate urine and conserve water.

Nephron

The microscopic structural and functional filtering unit of the kidney responsible for filtering blood and producing urine.

Peritubular capillaries

A low-pressure capillary network surrounding the renal tubules that permits tubular reabsorption and secretion.

proximal tubule

The initial coiled segment of the renal tubule where the vast majority of water, electrolytes, and vital nutrients are reabsorbed from the filtrate.

renal cortex

The outer layer of the kidney containing the renal corpuscles and convoluted tubules of nephrons.

renal medulla

The inner zone of the kidney organized into renal pyramids containing the loops of Henle and collecting ducts.

tubular reabsorption

The selective movement of water and useful solutes from the renal filtrate inside the tubules back into the peritubular capillaries.

tubular secretion

The active transport of excess ions, drugs, and waste products from peritubular capillary blood into the renal tubule filtrate.

urea

The primary nitrogenous waste product formed by the liver from ammonia during amino acid breakdown, excreted by the kidneys.

ureter

A muscular duct that transports urine from the renal pelvis of each kidney down to the urinary bladder.

urethra

The muscular canal through which urine is discharged from the urinary bladder to the exterior of the body.

Scrotum

An external sac of skin and muscle that holds and protects the testes at a cooler temperature necessary for viable sperm production.

Seminiferous tubules

Tightly coiled microscopic tubules located within the testes where spermatogenesis (sperm production) takes place.

Epididymis

A tightly coiled, comma-shaped structure situated on the posterior surface of the testis where sperm mature, develop motility, and are stored.

Ductus deferens

A muscular duct (vas deferens) that carries mature sperm from the epididymis toward the ejaculatory duct during ejaculation.

Seminal vesicles

Male accessory glands that secrete an alkaline, fructose-rich fluid that provides energy for sperm and constitutes the bulk of semen volume.

Prostate gland

A chestnut-sized male gland encircling the urethra that produces an alkaline fluid to nourish sperm and enhance their motility.

Bulbourethral gland

A pair of small glands (Cowper's glands) that secrete a clear, alkaline pre-ejaculatory fluid that lubricates and neutralizes residual acid in the urethra.

Oocytes

Immature female gametes or egg cells that develop inside ovarian follicles prior to ovulation.

Oviduct

A fallopian tube that transports an ovulated egg from the ovary toward the uterus and serves as the usual site of fertilization.

Cervix

The narrow inferior neck or lower portion of the uterus that connects the uterine body to the vagina.

Endometrium

The inner vascular mucosal lining of the uterus that thickens each cycle and sheds during menstruation if pregnancy does not occur.

myometrium

The thick middle muscular layer of the uterine wall composed of smooth muscle that contracts forcefully during labor.

Clitoris

A small, highly sensitive female erectile organ rich in sensory nerve endings, situated anterior to the external urethral orifice.

Human chorionic gonadotropin

A hormone (hCG) secreted by the early blastocyst and placenta that sustains the corpus luteum and its progesterone secretion during early pregnancy.

Rhythm

A natural family planning contraceptive method that relies on abstaining from sexual intercourse during the fertile window around ovulation.

Vasectomy

A surgical sterilization procedure in males involving the cutting and sealing of the ductus (vas) deferens to prevent sperm from entering ejaculate.

Tubal ligation

A surgical sterilization procedure in females where the oviducts are severed or blocked to prevent the egg and sperm from uniting.

Intrauterine Devices

Small, T-shaped contraceptive devices inserted into the uterine cavity to prevent fertilization or embryo implantation (IUDs).

Diaphragms

Shallow, dome-shaped silicone cups inserted into the vagina over the cervix prior to intercourse to physically block sperm from entering the uterus.

Vaginal ring

A flexible hormonal contraceptive ring placed in the vagina that continuously releases estrogen and progestin to prevent ovulation.

Hormone patch

A transdermal contraceptive patch worn on the skin that continuously delivers estrogen and progestin to suppress ovulation.

Condoms

Sheath barrier devices worn over an erect penis (or placed internally) that catch semen to prevent fertilization and reduce transmission of STDs.

Emergency Contraception

A high-dose hormonal contraceptive taken shortly after unprotected sexual intercourse to inhibit or delay ovulation and prevent pregnancy.

In-vitro fertilization

An assisted reproductive procedure (IVF) where mature eggs are fertilized by sperm outside the body in a laboratory dish before embryo transfer into the uterus.