TRANSPORT IN ANIMALS
Human circulatory system
The heart
EXTERNAL STRUCTURE:
CHARACTERISTICS:
surrounded by pericardium= 2 inelastic membranes -1 attached
to heart the heart is a pump that
fluid secreted between membranes = prevent friction applies pressure to force
coronary arteries = supply the heart with oxygen blood around the body
have deposits of fat middle of the chest/ thorax
in hallow space between the
lungs= mediastinum
protected by ribs and
sternum
Date: 16 October
INTERNALLY:
divided into 4 chambers
2 upper = atria = small + thin walls = receiving chamber = collect blood
from veins + pushing into the ventricles
2 lower = ventricles = thick walls, contract and push blood out
walls of left ventricle = super thick = have to pump blood to body
right ventricle = thinner = only need to pump to lungs
myocardium = layer of heart wall made of special muscle - cardiac
muscle = contracts rhythmically
heart divided into right & left sides by septum
heart lined with smooth membrane = endocardium made of endothelial
tissue
ventricles have papillary muscles = tendinous cords extend to the
atrioventricular valves
, TRANSPORT IN ANIMALS
Human circulatory system
The heart valves
VALVES:
1. Atrioventricular valves (AV valves)
between atria and ventricles
right A and right V= 3 flaps= tricuspid valve
left A and left V = 2 flaps = mitral valve
valves only allow blood to flow from atria to ventricle
tendinous cords attached to each flap = anchor them and
prevent them being pushed inside out by contraction of V
2. Semilunar Valves
@ base of vessels leaving heart & pulmonary A and aorta
pulmonary and aortic semilunar valves respectively
Date: 16 October
3 = half moon shaped membranous flaps = attached to internal
VALVES:
2. Semilunar Valves
ventricles contract = pressure of blood flattens the flaps
ventricles relax = blood flow back towards the ventricles & fill the
pouches = pushes flaps together and closing them
INTERNALLY:
Human circulatory system
The heart
EXTERNAL STRUCTURE:
CHARACTERISTICS:
surrounded by pericardium= 2 inelastic membranes -1 attached
to heart the heart is a pump that
fluid secreted between membranes = prevent friction applies pressure to force
coronary arteries = supply the heart with oxygen blood around the body
have deposits of fat middle of the chest/ thorax
in hallow space between the
lungs= mediastinum
protected by ribs and
sternum
Date: 16 October
INTERNALLY:
divided into 4 chambers
2 upper = atria = small + thin walls = receiving chamber = collect blood
from veins + pushing into the ventricles
2 lower = ventricles = thick walls, contract and push blood out
walls of left ventricle = super thick = have to pump blood to body
right ventricle = thinner = only need to pump to lungs
myocardium = layer of heart wall made of special muscle - cardiac
muscle = contracts rhythmically
heart divided into right & left sides by septum
heart lined with smooth membrane = endocardium made of endothelial
tissue
ventricles have papillary muscles = tendinous cords extend to the
atrioventricular valves
, TRANSPORT IN ANIMALS
Human circulatory system
The heart valves
VALVES:
1. Atrioventricular valves (AV valves)
between atria and ventricles
right A and right V= 3 flaps= tricuspid valve
left A and left V = 2 flaps = mitral valve
valves only allow blood to flow from atria to ventricle
tendinous cords attached to each flap = anchor them and
prevent them being pushed inside out by contraction of V
2. Semilunar Valves
@ base of vessels leaving heart & pulmonary A and aorta
pulmonary and aortic semilunar valves respectively
Date: 16 October
3 = half moon shaped membranous flaps = attached to internal
VALVES:
2. Semilunar Valves
ventricles contract = pressure of blood flattens the flaps
ventricles relax = blood flow back towards the ventricles & fill the
pouches = pushes flaps together and closing them
INTERNALLY:
