B9 (Human transport) Flashcards
(85 cards)
Function of the circulatory system
supplies oxygen and nutrients to the different parts of the body and removes carbon dioxide and other waste material
What is the circulatory system
A system of blood vessels with a pump and valves that ensure one way flow
What does the circulatory system consist of?
A pump (the heart)
blood vessels to carry blood
valves to make sure that the blood flows in one direction only
what do veins do?
carry blood towards the heart
What are the three main blood vessels
arteries
veins
capillaries
what do arteries do?
carry blood away from the heart
What do capillaries do?
connect to the veins and arteries
site of exchange of oxygen, nutrients and waste products
What is blood that is low in oxygen called
deoxygenated (usually denoted w/ colour blue)
What is blood that is high in oxygen called
oxygenated (usually denoted w/ red)
features of veins
-cell layers have less muscle
-fairly thin outer wall
-lumen is wide
-blood pressure is lower
-contains valves (prevent back flow)
features of arteries
-artery wall made of many cell layers (thick)
-lumen is narrow- guarantees high blood pressure
-thick layers of muscle
-muscle cells contract & relax
features of capillaries
-wall made of a single layer of cells
-lumen wide enough to fit ONE RBC
What does single circulation mean?
Single circulation is a type of blood flow where blood passes through the heart only once during each complete circuit of the body.
e.g fish
what does double circulation mean?
blood flows through the heart twice and follows two circuits
e.g humans and other mammals
what are the two circuits that are followed
in the first circuit, the blood flows from the heart to the lungs for oxygenation and then back to the heart
in the second circuit, the blood flows from the heart to the other parts of the body and then back to the heart.
whats the pathway taken by the blood in double circulation?
oxygen diffuses into the blood->
oxygenated blood is carried to all cells in body from the left side of the heart->
oxygen diffuses from the blood to the cells->
Deoxygenated blood is returned to the right side of the heart->
deoxygenated blood is carried to the lungs
what is the pulmonary circuit
the part of the circulatory system that carries blood from the heart to the lungs and back, for gas exchange (oxygen in, carbon dioxide out).
in single circulation, blood flows from the ______ to the _______ to the tissues and cells of the body
heart
gills
what are some structures in the mammalian heart
Muscular wall
Septum
Left ventricle
Right ventricle
Right atrium
Left atrium
One-way valve
Coronary artery
Vena cava
Pulmonary artery
Pulmonary vein
advantages of double circulatory system
-the higher the pressure, the greater the flow of blood and the further the blood can travel in the body
-oxygen and glucose for respiration are supplied rapidly to the cells in the body and waste is removed quickly from them
-blood can be supplied to distant parts of the animals
-near constant body temperature (flow of warm blood)
What are the right and left atrium?
Upper chambers of the heart
What are the right and left ventricles?
Lower chambers of the heart
What do the walls of the heart consist of?
muscle
What is the heart separated by?
The septum