Transport to and from exchange surfaces Flashcards
What are the two circulatory systems
Open circulatory and closed circulatory system
What are the two circulatory systems
Open circulatory and closed circulatory system
What is the open circulatory system
It is where heart pumps blood via vessels into the fluid-filled cavity
where tissues bathe in the blood directly and exchange of materials take place
What is the closed circulatory system
the blood is transported in tubes called blood vessels. Blood is pumped by muscular heart at high pressure resulting in rapid flow.
The tissues are not in direct contact with the blood but bathe in tissue fluid which can exit out of the walls of capillaries.
There are two types of closed circulatory system, what are they?
The single circulatory system
- blood goes through the heart once for each circuit around the body (e.g fish)
The double circulatory system
- blood passes twice through the heart because of two circuits (pulmonary - lungs (low pressure) and systemic - rest of body (high pressure))
for each complete circuit of the body. (e.g humans)
What is an advantage of having double circulatory systems
Blood leaving lungs will be fully oxygenated and blood entering lungs can enter at a lower pressure (high pressure will damage lungs).
What is the general structure of a blood vessel (from outside to inside)
1 - TUNICA EXTERNA - strong fibrous protein, helps vessel withstand high pressure
2 - TUNICA MEDIA - smooth muscle - for contractions and constrictions of vessel. Elastic tissue - allows stretch and recoil of vessel. This layer helps sustain blood pressure.
3 - TUNICA INTIMA - single layer of endothelial cells. smooth and flat to reduce friction of the flowing blood
4 - LUMEN - cavity where the blood flows through.
What does the artery do
Takes high pressure blood away from the heart to other regions of the body
What does the vein do
returns low pressure blood to the heart from the lung to the body
What does the capillary do
connects small arteries with small veins and allows exchange of materials with the tissues.
Description of the artery
Thick walls made of collagen (Tunica Externa) which provides resistance against high pressured blood, traveling away from heart.
Lots of elastic tissue (tunica media) allowing blood vessels to stretch and accommodate surge of blood from ventricles and recoil to maintain the pressure
Smooth muscle - allows vasoconstriction to reduce diameters of lumen = reducing blood supply to organs.
Description of vein
elastic tissue is less (tunica media) - blood travels at low pressure = less need for these structures.
Large diameter of lumen - helps in returning low-pressure blood to heart.
Valves - prevent backflow of blood.
What is the open circulatory system
It is where heart pumps blood via vessels into the fluid-filled cavity
where tissues bathe in the blood directly and exchange of materials take place
What is the closed circulatory system
the blood is transported in tubes called blood vessels. Blood is pumped by muscular heart at high pressure resulting in rapid flow.
The tissues are not in direct contact with the blood but bathe in tissue fluid which can exit out of the walls of capillaries.
There are two types of closed circulatory system, what are they?
The single circulatory system
- blood goes through the heart once for each circuit around the body (e.g fish)
The double circulatory system
- blood passes twice through the heart because of two circuits (pulmonary - lungs (low pressure) and systemic - rest of body (high pressure))
for each complete circuit of the body. (e.g humans)
What is an advantage of having double circulatory systems
Blood leaving lungs will be fully oxygenated and blood entering lungs can enter at a lower pressure (high pressure will damage lungs).
What is the general structure of a blood vessel (from outside to inside)
1 - TUNICA EXTERNA - strong fibrous protein, helps vessel withstand high pressure
2 - TUNICA MEDIA - smooth muscle - for contractions and constrictions of vessel. Elastic tissue - allows stretch and recoil of vessel. This layer helps sustain blood pressure.
3 - TUNICA INTIMA - single layer of endothelial cells. smooth and flat to reduce friction of the flowing blood
4 - LUMEN - cavity where the blood flows through.
What does the artery do
Takes high pressure blood away from the heart to other regions of the body
What does the vein do
returns low pressure blood to the heart from the lung to the body
What does the capillary do
connects small arteries with small veins and allows exchange of materials with the tissues.
Description of the artery
Thick walls made of collagen (Tunica Externa) which provides resistance against high pressured blood, traveling away from heart.
Lots of elastic tissue (tunica media) allowing blood vessels to stretch and accommodate surge of blood from ventricles and recoil to maintain the pressure
Smooth muscle - allows vasoconstriction to reduce diameters of lumen = reducing blood supply to organs.
description of capillary
single endothelium cell wall is thick, no elastic tissue - provides short diffusion path for exchange of molecules.
small diameter of lumen - slow blood flow, cause friction with walls. low speed of flow enhances ability to exchange materials by diffusion.
Large numbers of capillaries in body - large surface area for exchange of molecules.
Description of vein
elastic tissue is less (tunica media) - blood travels at low pressure = less need for these structures.
Large diameter of lumen - helps in returning low-pressure blood to heart.
Valves - prevent backflow of blood.
function of vena cava
Returns blood from organs except lungs
function of pulmonary vein
returns blood from lungs
function of left atrium
receives blood from lungs and pushes it to left ventricle.
function of atrioventricular valve (bicuspid)
stops blood from flowing back to atrium
function of left ventricle
receives blood from left atrium and pushes it to the body. has the highest pressure because it has to pump blood through the aorta to the rest of body. meaning muscle wall is thick (3 times thicker than right ventricle)
function of the aortic valve
stops blood flowing into ventricles
Function of the aorta
distributes blood to all organs except lungs
when the atriventricular valve and the semilunar valve close what sound does it make
lub-dub
function of pulmonary artery
distributes blood to lungs
function of pulmonary valve
stops blood flowing back to ventricle
function of right ventricle
receives blood from right atrium and pushes to lung. Higher pressure than the atria.
function of atrioventricular tricuspid valve
stops blood flowing back into atrium
Function of the right atrium
receives blood from body organs and pushes into ventricles.
functions of the atria
exerts small pressure to push blood into ventricle - has thing muscle wall.
when does the atrioventricular valves open
they open when the pressure in the atrium is greater than the pressure in the ventricle.
When does the atrioventricular valves close
when the pressure in the atrium is less than the pressure in the ventricle.
when does the semi lunar valves open
when the pressure is greater in the ventricle than in the artery.
when does the semi lunar valves shut
when the pressure is less in the ventricle than in the artery
