Anatomy of CVS 1 Flashcards
Function of arteries
distribute blood from the heart
function of lymphatic system
drain excess extracellular fluid from tissues
where is the heart located
in the middle of the mediastinum
where are blood vessels found?
everywhere other than in cartilage
what is the hepatic portal circulation?
part of the lymphatic system
what makes up the base of the heart
Left atrium
what is the mediastinum
area of thoracic cavity between pleural sacs
The heart lies between which vertebrae in recumbent position (lying down)?
T5-T8
where is the apex
Left ventricle: 5th left intercostal space in the midclavicular line
what happens to the heart as you breath
it moves up and down
what is important to know about the heart in children in comparison with adults
it sits higher in children and lies more horizontal
what 3 layers make up the heart wall
endocardium - nnermost
myocardium - middle
epicardium - outermost
what makes up the myocardium
Cardiac muscle
what makes up the endocardium
epithelium and basement membrane and connective tissue
what makes up the epicardium
connective tissue and basement membrane and epithelium (visceral pericardium)
Describe the endocardium
lines heart chambers
simple squamous epithelium sitting on basement membrane
sits on connective tissue
forms valves
Describe the myocardium
thick middle layer of heart wall cardiac muscle (myocytes) branching fibres
striated muscle, lots of mitochondria, single central nucleus
intercalated discs
muscle bundles in different planes to close down chamber lumen
Describe the epicardium
outer layer of heart wall
simple squamous epithelium and basement membrane and connective tissue
epithelium is visceral layer of serous pericardium
contains main branches of coronary arteries
pathway of blood through the heart
in through the R atrium via superior or inferior vena cava
down to the R ventricle then out the L or R pulmonary artery
Back in through the L pulmonary veins into the L atrium and down to the L ventricle then out through aorta
heart valves
work passively
cusps - thin structures derived from endocardium
chordae tendinae and papillary muscles prevent valve failure
what does the term stenosis describe?
narrowing
what does the term incompetence describe?
widening
how does blood enter the coronary arteries
at diastole, the elastic recoil of aorta closes the aortic valve and blood enters the arteries
define diastole
phase of the heartbeat when the heart muscle relaxes and allows the chambers to fill with blood
how does the heart stay in place?
attachments:- central tendon of diaphragm, sternum, roots of great vessels
lined by serous pericardium
heart is free to move
what is the serous pericardium
epithelium
secretes pericardial fluid - lubricant
visceral layer - bound to the heart
parietal layer - bound to fibrous pericardium
visceral and parietal layers are continuous so give closed bag
allows freedom of movement during cardiac cycle
