Blood Vessels Flashcards
(13 cards)
Arteries & arterioles (red)
Carry blood away from heart ❤️
Blood content is oxygenated
pressure high
Veins and venules (blue)
Carry blood towards heart ❤️
Blood content deoxygenated
Pressie is low
Where does the exchange of substances between blood & cells/tissues take place?
In the capillaries
Which are small blood vessels connecting arterioles and venules.
1 cell thick allows easier passing of substances allowing exchange of
Water - osmosis
Nutrients - facilitated diffusion & active transport
Gases - co2 and o2 - diffusion down gradient
Describe the the three layers of blood vessels?
Tunica externa - outer layer made up of collagen and fibres
Tunica media - layer of smooth muscle controls vasoconstriction and vasodilation
Tunica interna - innermost layer made of endothelium
Describe one key difference between the layers of blood vessels between arteries and veins.
In arteries and arterioles the tunica media is thicker.
In veins and venules it generally has thin walls and the the thickest layer is tunica externa
Capillaries only have endothelium
What substance is relases in the body and causes vasodilation?
Nitrous oxide.
Causes muscles to relax which means blood pressure drops.
How do veins prevent back flow of blood?
Valves.
Varicose veins are incompetent valves
What is hepatic first pass?
Venous blood passes from the digestive system, the spleen & pancreas to the liver.
In this way, blood with a high concentration of nutrients goes to the liver first, supplying it with rich source of nutrients for its metabolic activities. Ensures unwanted and/or toxic materials are eliminated before blood is returned for general circulation.
Name the three heart layers and their function?
Pericardium - outer layer
Contains fibrous pericardium and serous pericardium
Function to keep the heart in the mediastinum and allow free movement during contractions
Myocardium - middle layer
Consists of cardiac music
Function to pump blood out of heart
Endocardium - innermost layer
Layer of endothelium
Function is to provide a smooth lining for the heart champers
The heart chambers.
What is the function of the right atrium?
Right side of heart pumps blood to the heart and back
Right atrium received deoxygenated blood from superior & inferior vena cava. Pumps blood into the right ventricle through the tricuspid valve
The heart chambers.
What is the function of the right ventricle?
Receives deoxygenated blood from right atrium
Pumps blood to the lungs through the pulmonary valve.
The heart chambers
Describe the function of the left atrium!
3mm thick
Received oxygenated blood from lungs via pulmonary vein
Pumps blood to the left ventricle through the mitral/bicuspid valve.
The heart chambers
Describe the function of the left ventricle?
10-15mm thick
Receives oxygenated blood from the left atrium.
Pumps blood through the aortic valve into ascending aorta
The 11 stages of the heart chambers
- Deoxygenated blood enters superior and inferior vena cava
- Blood enters right atrium
- Right atrium pumps blood into right ventricle through tricuspid valve
- Pumps blood into lungs though pulmonary valve. divides into pulmonary arteries
- Blood enters lungs
- Left atrium recieves oxygenated blood through Pulmonary vein
- Left atrium pumps blood to left ventricle through he mitral/bicuspid valve
8.left ventricle receives oxygenated blood - Left ventricle pumps blood into aortic valve into aorta
10 enters body - Returns to vena cava
