Chapter 5 Circulatory System Flashcards
(11 cards)
What is the cardiovascular system?
Includes the heart and blood vessels
Brings nutrients to cells and helps get rid of waste
Blood is refreshed in the lung, kidneys, intestines, and liver
What are the functions of cardiovascular system?
- Generate blood pressure
- Transport blood
- Exchange of nutrients and wastes at the capillaries
- Regulate blood flow as needed
What is the main pathway of blood in the body?
Heart –> arteries –> arterioles –> capillaries –> venules –> veins –> back to the heart
Arteries and arterioles
Carry blood away from the heart
Arterioles are small arteries that regulate blood pressure
Composed of 3 layers: Thin inner epithelium, thick smooth muscle layer, outer connective tissue
Capillaries
Microscopic vessels between arterioles and venules
Made of one layer of epithelial tissue
Exchange of oxygen occurs at capillary beds
Combined large surface area
Exchange at the capillary beds is primarily a result of
Osmotic pressure, blood pressure, and diffusion
In the arterial end of capillary:
Arterial blood is bright red, nutrient rich
BP (30 mmHg) > osmotic pressure (21 mmHg)
Contains water and small molecules that form tissue fluid
In the midsection capillary:
Concentration of oxygen and nutrients is much higher here than at the arterial end; low concentrations of carbon dioxide
In the Venous end of capillary:
BP = 15 mmHg (less than osmotic pressure)
Size of capillary is largest at venous end
Water enters capillaries, bringing along waste
Metarteriole
capillary that connects veins to arterioles
Sphincter
Function: They constrict to prevent blood from flowing through certain capillaries in the body; this is because the human body does not contain enough blood to be everywhere at once, so this controls where the blood flows and where it doesn’t
