Human Physio Blood and Blood Flow

Endothelium

thin layer, inner lining of all blood vessels

blood vessels

Surrounded by layers of smooth muscle, elastic and fibrous connective tissue

veins

____ are larger in diameter and thinner walls

pressure gradient

P at one end of a blood vessel - P at the other end of a blood vessel

Flow resistance

tendency of cardiovascular system to oppose blood flow

radius (most important), length, blood viscosity

Factors affecting resistance in blood vessels

Lymphatic system

____ return fluid and proteins filtered out capillaries to circulatory system

____ pick up fat absorbed at small intestine and transfer back to circulatory system

serve as filter to help capture and destroy pathogens

plasma, erythrocytes, leukocytes, and platelets

Composition of blood

Erythrocytes

Transport O2 from lung to tissues and CO2 from tissues to lungs

Lymphocytes

____ help your body's immune system fight cancer and foreign viruses and bacteria (antigens

Monocytes

____ exit bloodstream and become macrophages

Neutrophils

____ phagocyte for bacteria & secretes cytokines

Eosinophils

____ phagocyte for parasites & cytokines related to allergies

Basophils

____ mediate inflammation & allergies via cytokine release (histamine)

Platelets

coagulates blood to prevent blood loss

Hematopoeisis

___ is controlled by cytokines

Erythropoeisis

EPO made in kidney cells, released in response to low O2 levels in tissues

White blood cell production

CSFs (colony-stimulating factors) made by endothelial cells and white blood cells

Platelet production

thrombopoietin (TPO) regulate growth and maturation of megakaryocytes

TPO produced in liver primarily and kidney

nucleus

RBCs lack ____ or organelles

cytoplasmic fragments

Platelets are _________ derived from megakaryocytes

platelets

Since _____ are cell fragments, they do not contain a nucleus nor organelles

Platelet plug formation

Vasoconstriction → ________ → Coagulation (formation of a blood clot)

4 steps of platelet plug formation

Exposed collagen binds and activates platelets

Platelet factors are released.

Factors attract more plateleets.

Platelets aggregate into platelet plug.