Unit 8a - Urinary System

excretion

Removal of metabolic wastes from the body

(carbon dioxide by the lungs and nitrogenous wastes by the kidneys)

urine

A fluid produced by the kidneys that contains water, urea and other waste materials

metabolic wastes

The wastes produced as a result of metabolism, including carbon dioxide, water, nitrogenous wastes and salts

nitrogenous wastes

products of cellular metabolism that contain nitrogen

urea

Form of nitrogenous waste in humans. It is less toxic and more soluble than ammonia.

ammonium

Waste product NH4+

creatinine

Waste product resulting from the breakdown of a high-energy phosphate reserve molecule in muscles.

uric acid

Waste product resulting from the breakdown of nucleotides.

kidney

Organ that removes urea, excess water, and other waste products from the blood and passes them to the ureter

renal artery

Blood vessel that carries blood to the kidneys

renal vein

Blood vessel that carries blood away from the kidneys

ureter

tube that carries urine from the kidney to the urinary bladder

urinary bladder

elastic, muscular organ that holds urine until it leaves the body

urethra

tube leading from the urinary bladder to the outside of the body

renal cortex

Outer, granulated later of the kidney.

renal medulla

Inner layer of the kidney that consists of cone-shaped masses called renal pyramids.

renal pelvis

Central space, or cavity, of the kidney that is continuous with the ureter

nephron

Functional unit of the kidney

afferent arteriole

Vessel that carries blood from the renal artery to the glomerulus

glomerulus

A knot of capillaries that acts at the site of pressure filtration

efferent arteriole

Vessel that carries blood from the glomerulus to the rest of the peritubular capillary network.

peritubular capillary network

Surrounds most of the nephron and functions in reabsorption during urine formation

Bowman's capsule

cup-shaped strucutre of the nephron of a kidney which encloses the glomerulus and which filtration takes place.

proximal convoluted tubule

Part of nephron that reabsorbs greater variety of chemicals than other parts of nephron

loop of Henle

Section of the nephron tubule located in the renal medulla that minimizes the volume of urine by reabsorbing water.

distal convoluted tubule

Part of the rephron where larger waste products are actively transported from the blood through tubular secretion.

collecting duct

Final portion of the nephron, many of these carry urine to the renal pelvis.

glomerular filtration

Process where water and small molecules move from the blood into the nephron.

filtrate

Cell-free fluid extracted from the body fluid by the excretory system.

tubular reabsorption

Movement of water, sugar and salt are returned to the bloodstream in the capillaries after waste are removed

tubular secretion

Some wastes are actively secreted into the fluid in the distal convoluted tubule

aldosterone

Hormone secreted by the adrenal cortex and promotes the reabsorption of sodium ions.

adrenal cortex

Outer portion of the adrenal gland that secretes aldosterone.

osmotic gradient

the difference in concentration between solutions on opposite sides of a semipermeable membrane

reabsorption of water

what is the descending loop of henles major function?

antidiuretic hormone (ADH)

Hormone that promotes retention of water by kidneys

posterior pituitary

ADH and oxytocin are produced in the hypothalamus and stored here until needed

hypothalamus

A structure found near the base of the forebrain that is involved in the regulation of basic biological needs.

gout

Accumulation of uric acid in joints

kidney stones

Collection of solid material that may block the kidneys, ureters, or bladder.

renal failure

Failure of the kidneys to perform their essential functions.

hemodialysis

Use of an artificial kidney machine that filters the blood of a person to remove waste products

urinary tract infection

Bacterial infection of the urethra, bladder, ureters, or kidneys