The circulatory system Flashcards
What is the function of the circulatory system?
To pump blood around the body
What are the 4 chambers the heart is divided into?
Right atrium(RA), Left atrium(LA), Right ventricle(RV), Left ventricle(LV)
What are the two upper chambers of the heart called?
The atria
What are the two lower chambers of the heart called?
The ventricles
What is the function of the atria?
They receive blood returning to the heart from other areas of the body
What does the right atrium do?
-Receives blood returning to the heart from the superior and inferior venae cavae.
-The superior vena cava returns de-oxygenated blood from the head, neck, arm and chest regions of the body
to the right atrium.
-The inferior vena cava returns de-oxygenated blood from the lower body regions(legs, back, abdomen and pelvis) to the right atrium
What does the left atrium do?
-Receives blood returning to the heart from the pulmonary veins.
-The pulmonary veins extend from the left atrium to the lungs and bring oxygen-rich blood back to the heart.
What is the function of the ventricles?
To pump blood to the entire body
What does the right ventricle do?
Receives blood from the right atrium and pumps it to the main pulmonary artery
What does the left ventricle do?
Receives blood from the left atrium and pumps it to the aorta
What is the twin layered sac the heart is surrounded by?
Pericardium. The cavity between the layers is call pericardial fluid
What are the three layers of the heart called?
epicardium (the outer layer), the myocardium
(the strong middle layer that forms most of the heart wall) and the endocardium (the
inner layer).
What are the coronary arteries?
the blood vessels supplying oxygenated blood to the heart
muscle. There are two coronary arteries, the left and right
What is the bicuspid valve?
One of the four valves in the heart- between the
left atrium and the left ventricle- allows the blood to flow in one direction only- from the left atrium to the left ventricle
What is the tricuspid valve?
Located between the right atrium and the right ventricle-allows blood to flow from the right atrium to the right ventricle and prevents blood from flowing backwards
What are the semilunar valves(aortic valve and pulmonary valve)?
Between the left ventricle and the aorta- prevent backflow from the aorta into the left ventricle- also situated between the right ventricle and pulmonary artery
What are the chordae tendineae?
Chord-like tendons connected to the bicuspid and tricuspid
valves to prevent valves turning inside out
what are red blood cells
carry oxygen to all living
tissue. They contain a protein called haemoglobin, g. They are round, flattened discs
with an indented shape giving them a large surface area
white blood cells
the components of
blood that protect the body from infections,They originate in bone marrow
plasma
the straw-coloured liquid in which all
blood cells are suspended.
platelets
disc-shaped cell fragments
produced in the bone marrow. Their primary function is
clotting to prevent blood loss, sticking to the damaged
area to form a temporary plug to seal the break.
what is the lymphatic system
it is a drainage system. responsible for the transport of a clear fluid known as lymph
what does the cardiovascular system do
- key function is to supply nutrients and oxygen to the tissues via the blood stream
- carries waste products from the tissues to the kidney and livers.
what is systolic pressure
the pressure exerted on your artery
walls when your heart contracts and forces blood out of
the heart and into the body
distolic pressure
– the pressure on the blood vessel
walls when the heart is relaxed between beats and is
filling with blood.
Sinoatrial node (SAN)
located within the walls of the
right atrium. The SAN sends an signal from the
right atrium through the walls of the atria which causes
the muscular walls to contract. This contraction forces
the blood within the atria down into the ventricles.
Atrioventricular node (AVN)
located in the centre
of the heart between the atria and the ventricles, and
acts as a buffer or gate that slows down the signal from
the SAN. By slowing down the signal, the atria are able
to contract before the ventricles which means the
ventricles are relaxed (or open) ready to receive the
blood from the atria at the top of the heart.
Bundle of His and Purkinje fibres
muscle responsible for transporting the eletctical impulses from avn and found in ventricles and septum. at the end of bundles of his are purkinje fibres which allow the ventricle to contract at regular intervals.
