Excretion Vocab

Antidiuretic Hormone (ADH)

• substances that reduce urine production, cause more water to be absorbed by nephron

• Made in hypothalamus, stored and released by posterior pituitary gland in response to low blood volume (dehydration)

• promotes additional water removal from urine

adrenal cortex

• outer layer of adrenal gland (on top of kidney)

• produces hormones that regulate bodily functions

Afferent arteriole

small artery that delivers blood to glomerulus, associated with urine formation

Efferent arteriole

• small artery, takes blood away from glomerulus

• pressure is higher due to pressure filtration

Aldosterone

• hormone produced by adrenal cortex under influence of anterior pituitary gland

• Increases amount of Sodium absorbed from urine at the distal convoluted tubule along with an increase in the excretion of Potassium

• Increasess water retntion from urine which increases urine concentration

Bowman’s capsule

• ending of nephron tube

• porous inner surface, envelops glomerulus

• recipient of fluid material forced by blood pressure out of plasma during plasma filtration

collecting duct

• final region of a nephron that urine flows through to enter renal pelvis

• level of ADH in blood affects it

  • More ADH = increased water reabsorbtion leading to more concentrated urine

Glomerulus

• capillaries between afferent and efferent arterioles in renal cortex

• Fluid forced from glomerulus into Bowman’s capsule during urine formation (pressure filtration)

Homeostasis

• Set of process that functions to maintain a constant internal environment

Hypothalamus

• part of lower portion of midbrain

• responsive to many blood conditions and produces chemical substances to affect the homeostasis of these conditions

• Produces ADH and oxytocin (released through posterior pituitary gland)

• prodocues other substances that affect the release of hormones from the anterior pituitary

Kidney

• oblong, bean shaped organ in dorsal, posterior region of abdominal cavity

• supplied with blood from renal artery

• contains nephrons which remove and concentrate urine for excretion

Loop of Henle

• V-shaped portion of nephron between proximal and distal tubules

• Filtrate entering has good stuff removed

• Role: recovery of water and sodium chloride from urine

Metabolic waste

• waste products from cellular metabolic activity (eg. CO2, O2, NH3)

Nephron

• functional unit of kidney (millions)

• miscroscopic tubular structure (begins with Bowman’s capsule)

• produces urine

Nitrogenous waste

• metabolic waste product containing Nitrogen

• Cells produve ammonia, NH3, a toxic waste product through removal of Amino Acids

Osmotic gradient

difference in water concentration between 2 regions

Peritubular Capillary Network

• the capillary bed that surrounds the nephron of the kidneys

• millions of nephrons = millions of peritubular capillary beds