Section 3 "Circulation, Endocrine, & Hemorrhage"

What is open circulation?

Blood not always in vessels

What is closed circulation?

Blood stays in vessels

What is plasma?

Liquid part of blood

What do RBCs do?

Carry oxygen

What do platelets do?

Clotting

What do arteries do?

Carry blood away

What do veins do?

Carry blood toward

What do capillaries do?

Exchange

What does vasodilation do?

Decreases resistance, increases flow

What does vasoconstriction do?

Increases resistance and BP

What is the function of the trachea?

Air passage

What are bronchi?

Lung branches

What are bronchioles?

Smaller branches

What are alveoli?

Gas exchange

What is the main nitrogen waste in humans?

Urea

What do kidneys regulate?

Water, ions, pH

What does the renal corpuscle do?

Filtration

What does the proximal tubule do?

Reabsorption

What does the loop of Henle do?

Concentrates urine

What does the distal tubule do?

Secretion

What does the collecting duct do?

Final urine concentration

What are water‑soluble hormones?

Fast, surface receptors

What are lipid‑soluble hormones?

Slow, intracellular

What does ADH do?

Increases water reabsorption

What does aldosterone do?

Increases sodium retention

What happens during hemorrhage?

Increased HR, vasoconstriction, hormone response

What is the body's goal during hemorrhage?

Maintain blood