OPT 114: Blood Vessels - Overview

plasma, red blood cells, white blood cells, platelets

4 main components of blood

plasma

liquid component of blood, 91% water, 7% protein, 2% other

red blood cells

most abundant cell in the blood; shape is diconcave disk with a flattened center; does not have a nucleus; contain special protein called hemoglobin

hematocrit

percentage of blood volume that is made up of RBCs (measure of RBC levels)

Why do red blood cells not have a nucleus?

allows them to change shape easily, which helps them fit through blood vessels and limits the life of the cell

Average life span of a cell

120 days

hemoglobin

carries oxygen from the lungs to the rest of the body; returns carbon dioxide from the body to the lungs so it can be exhaled; gives RBCs its' red color

white blood cells

protect the body from infection

platelets

small fragments of cells; helps the blood clotting process (coagulation)

the way platelets help in the blood clotting process

gather at the site of an injury; stick to the lining of the injured blood vessel; cover the wound and prevent blood from leaking out; form the scaffolding upon which new tissue forms

function of blood

transport nutrients and oxygen to cells; remove waste products from cells and deliver it to the kidneys and liver, which filter and clean the blood; transport hormones (messages) from one part of the body to another; protect the body from infection and foreign bodies; form blood clots to prevent excess blood loss and initiate wound healing; regulate body temperature and pH levels

arteries, capillaries, veins

blood travels through...

components of blood

arteries

transport oxygenated blood away from the heart and deliver it to tissues in the body

large vessels

arteries are...

small vessels

arterioles are...

capillaries

arterioles become...

capillaries

location for exchange of gases, fluids, and nutrients between blood and tissues; where cells can deposit waste and carbon dioxide to the blood

venules

capillaries become...

veins

drain the capillary beds (venules); return deoxygenated blood to the heart

veins

venules become larger vessels called....

arteries -> arterioles (smaller) -> capillaries -> venules -> veins

progression of blood movement structures