cardiovascular biology Flashcards
what does cardiovascular system consist of?
heart and the blood vessels
where is the heart located?
the heart is located behind sternum
1/3 of heart lies to the right of the midline
2/3 lies to the left
part of heart is covered by lungs
how many pumps does the heart do ?
2 pumps which distribute blood around
RHS - pumps blood to lung
LHS - pumps blood to body
how many layers are in the wall of heart?
the walls of the heart are divided into 3 layers
what are the 3 layers that make up walls of the heart?
. epicardium - external layer - tough outer protective composed of connective tissue
. myocardium - bulk of the heart - cardiac muscle tissue - responsible for pumping oxygenated blood around body cardiac muscle
. endocardium- inner layer - smooth endothelium , simple squamous epithelium ,continuous with major blood vessels entering and leaving the heart which ensures frictionless flow of blood
protect valves and heart chambers
what is pericardial cavity/pericardium ?
. outer coat of heart which protects the heart and big blood vessels
what is the space between pericardial cavity and epicardium ?
space between pericardial cavity and epicardium is filled with pericardial fluid which is formed by pericardium
what is the function of pericardial fluid?
. lubrication to reduce friction between the heart and the surrounding structures , and minimises the friction generated by heart as it contracts
-If cavity dries up- pericarditis- acquired defects.
what is pericardium?
the heart is enclosed by pericardium
pericardium produces pericardial fluid
-There to anchor the heart is place but still give it freedom to move
what does inflammation of pericardium result in?
decreased secretion
this is example of acquired defect
what is the lining of heart made of ?
simple endothelium
what are the four chambers of heart?
. right atrium
. right ventricle
. left atrium
. left ventricle
function of right atrium?
.receives deoxygenated blood from body via 2 vessels superior and inferior vena cava and pumps to right ventricle
what is the function of right ventricle?
. pumps deoxygenated blood back to lungs
what is the function of left atrium?
. receives oxygenated blood from lungs and pumps it to left ventricle
what is the function of left ventricle?
. pumps oxygenated blood to body
describe what happens in the circulatory system?
- heart has 4 chambers
- right atrium receives deoxygenated blood from body and pumps to right ventricle
- right ventricle contracts and pushes blood out pulmonary arteries and deoxygenated blood goes to the lungs
- lung pick oxygenated blood and oxygenated blood goes to left side of heart
- left atrium receives oxygenated blood from lungs and pumps it to left ventricle
- left ventricle contracts and pumps oxygenated blood to the body
what are the 3 openings of the heart?
superior vena cava
inferior vena cava
fossa ovalis ( coronary sinus )
what is the function of superior vena cava?
The superior vena cava is the large vein which returns
deoxygenated blood to the heart from the head and neck
what is the function of inferior vena cava ?
the inferior vena cava returns deoxygenated blood to the heart from lower body
what is the function of fossa ovalis / coronary sinus?
brings deoxygenated blood from heart to right atrium via fossa ovalis
how does blood leave the heart via the aorta to the rest of body?
- deoxygenated blood arrives at the right atrium
- deoxygenated blood from heart comes to right atrium via fossa ovalis
- when right atrium is full of deoxygenated blood , tricuspid valve opens and lets blood into right ventricle
- right ventricle contracts and closes this valve
- another valve opens ( semi lunar valve)
- blood is pushed out pulmonary artery and pulmonary artery takes blood to lung
7.blood goes to lung and picks new oxygen - new oxygen comes back to left atrium through pulmonary veins
- there are 4 openings from lungs to right atrium
2 left and 2 right - left atrium contracts when full and opens bicuspid valve
- blood goes lo left ventricle
- left ventricle contracts and open aorta
- oxygenated blood rushes out the aorta
why is the left side of heart stronger than the right?
the left ventricle is much more developed than the one on the right.
this corresponds to the greater force needed to push blood through the systemic circulation
what is the function of the right and left coronary arteries?
they supply the heart muscle with blood
they branch off the aorta where it emerges from the heart taking about 5% of the heart’s daily output
where do the right and left coronary artery branch from?
the left and right coronary artery branch off the aorta
what is the function of aorta?
the main artery that carries oxygenated blood from left ventricle to the body
what are the two main types of valve in the heart?
. atrioventricular (AV) ( associated with opening between atria and ventricles -
bicuspid (left )and tricuspid ( right )
. semi lunar ( associated with exit from heart )- pulmonary and aortic