BIOMD101 Urinary & Reproductive Systems

Afferent Arteriole

In the kidney, an afferent arteriole carries blood to each glomerulus. Afferent means directed to or toward a point of reference.

Aldosterone

Hormone produced by the adrenal cortex that regulates sodium reabsorption.

Antidiurectic Hormone (ADH)

Hormone produced by the hypothalamus and released by the posterior pituitary. Stimulates the kidneys to reabsorb more water, reducing urine volume.

Dialysis

General term for several techniques that attempt to take the place of kidney function in patients whose kidneys have failed by letting the patient's blood exchange waste materials with artificial fluids.

Efferent Arteriole

In the kidney, an efferent arteriole carries blood away from each glomerulus. Efferent means directed from or away from a point of reference.

Glomerular Filtration

The process of filtering protein-free plasma fluid from the glomerular capillaries into Bowman's capsule.

Glomerulus

Cluster or tuft of capillaries inside the glomerular capsule in a kidney. The glomerulus is involved in the formation of the glomerular filtrate.

Loop of Henle

Hairpin-shaped tubular structure that extends into the medulla of a nephron. The loop of Henle (also called the loop of the nephron) is important in the ability of the kidney to form either concentrated or dilute urine.

Nephron

Structural and functional unit of the kidney. A nephron consists of the renal tubule and the blood vessels that supply it.

Peritubular Capillaries

Capillaries that form a network surrounding the proximal and distal tubules in the cortex of a nephron.

Proximal Tubule

Segment of a nephron that starts at Bowman's capsule and extends to the renal medulla.

Renin

An enzyme secreted into the bloodstream by the kidneys that leads to an increase in blood pressure and the secretion of aldosterone.

Tubular Reabsorption

The movement of fluid and solutes (primarily nutrients) from the renal tubules into the blood.

Tubular Secretion

The movement of solutes (primarily undesirable substances such as drugs, metabolic wastes, and excess ions) from the blood into the renal tubules.

Urea

Main nitrogen-containing waste excreted in urine.

Ureter

One of two tubes that transport urine from the kidneys to the urinary bladder.

Urethra

Tube through which urine passes from the bladder to the outside of the body.

Vasa Recta

Long, straight capillaries that perfuse the inner (medullary) portion of the kidney, supplying the loops of Henle and collecting ducts.

Estrogen

Female sex hormone that stimulates the development of female secondary sex characteristics, helps oocytes mature, and affects the uterine lining during the menstrual cycle and pregnancy.

Follicle

Ovarian structure consisting of a developing egg surrounded by one or more layers of granulosa cells.

Gamete

Haploid sex or germ cell. Sperm and eggs are gametes.

Menstrual Cycle

Pattern of changes in the ovaries and uterus. The menstrual cycle lasts about 28 days and is controlled by hormones.

Menstruation

Process in which the endometrial lining disintegrates, its small blood vessels rupture, and the tissue and blood are shed through the vagina.

Orgasm

A brief, intensely pleasurable reflex event consisting of rhythmic, involuntary muscular contractions.

Ovarian Cycle

Monthly cycle of follicle development, ovulation, and corpus luteum formation in an ovary.

Ovaries

The two female sex organs (gonads) in which ova (eggs) are produced.

Oviduct

Tube that leads from an ovary to the uterus, also called the Fallopian tube or uterine tube.

Ovulation

Ejection of an immature egg (oocyte) from the ovary.

Progesterone

Hormone partly responsible for preparing the uterus for the fertilised ovum. Progesterone is secreted by the corpus luteum of the ovary and by the placenta.

Semen

Thick, whitish fluid mixture containing sperm and the secretions of the male accessory reproductive glands.

Sperm

Male reproductive cell (gamete).

Testosterone

Male sex hormone produced primarily by the testes. (The adrenal cortex produces a small amount of testosterone in both sexes). Testosterone promotes the development of secondary sexual characteristics and is necessary for normal sperm production.

Uterine Cycle

A series of changes that occur in the uterus in preparation for the arrival of a fertilised egg. A complete cycle generally takes about 28 days.

Uterus

Hollow, thick-walled organ that receives, retains, and nourishes the fertilised egg. The uterus is the site of embryonic/fetal development.