Cardiovascular 1 Flashcards
What does the cardiovascular system transport?
oxygen, carbon dioxide, waste products, nutrients, hormones, and immune system cells
What is homeostasis?
Plays a central role in maintaining temperature, pH balance, water, electrolyte levels
What are arteries?
They carry blood away from the heart
What does the endothelium consist of in a blood vessel wall?
the thin, inner epithelium
How many layers do artery walls have?
3
What does the middle layer of the blood vessel wall consist of?
smooth muscle and elastic tissue
What does the middle layer of the blood vessel wall help with?
Allowing the arteries to expand and recoil
What are the outer layer of artery walls made of?
connective tissue
What are arterioles?
small arteries
What does the smooth muscle do in artery walls?
contracts to restrict the vessel, reducing blood flow and raising blood pressure. relaxes, dilating the vessel, increasing blood flow and reducing blood pressure
What are capillaries?
microscopic vessels between arterioles and venules
What are the walls of capillaries made of?
endothelium only one cell thick
What happens at capillary beds?
gas, nutrient, and waste exchange occur
What do precapillary sphincters do?
control blood flow through the capillary bed
What is blood pressure?
the pressure that blood exerts against a blood vessel wall
What does blood pressure do?
moves blood in the arteries
systolic pressure
the highest pressure; when blood is ejected from the heart
diastolic pressure
the lowest pressure; when the ventricles relax
What is the average blood pressure?
120/80 mmHg - systolic/diastolic
What are the two forces that drive fluid in and out of the capillaries?
blood pressure and osmotic pressure