Intro Flashcards
why do we have a CVS?
to transport O2 and other nutrients to tissues
label this heart and where do coronary heart arise and drain into ?
whats special about coronary arteries
- they don’t form many anatomoses ( join so b.v can be diverted)
- prone to atheroma (narrowing due to atheromatous plaque formation
label and why it important in surgery
allows clamping of the aorta to connect it to a hear-lung bypass machine
what are the groups f b vessels?
- veins
- arteries + arterioles
- capillaries
what are types of arteries
- large (conducting )
- medium (distributing )
conducting arteries what are they, examples ? their structure? whats special about them?
- aorta, brachiocephalic trunk (head, neck and upper limbs), carotid (head and neck), subclavian (upper limbs) iliac arteries (lower limbs)
- they contain more elastic and collagen fibres in theri walls allowing stretch and recoil in response to each pulse of blood
- they have their own oxygenated b supply= vaso vasorum (vessels of vessels)
distributing arteries
- contain smooth muscle cells and so they maintain blood flow through musclular contractions to the arterioles and capillaries
- radial and femoral arteries maintain blood flow to the upper limbs and lower limbs in respec
what must the CVS do as a whole
- maintain a 750ml.min-1 b flow to the brain at all times
- maintain constant b flow to the heart and kidney at all times
- deliver 5 and 25 l.min-1 of b to the body
what controls the mechanism of b flow
- resistance vessels - arterioles and pre capillary sphincters
what does the CVS doto cope with changes in cardiac output
- use the capacitance = store of b that can be used to cope with temporary imbalance between amount of b retruning to the heart and the amount required to pump out
- this store is the veins
what causes the valves to close
- small backflow at the start of systole
what are the nerves that can be seen in the DR in heart dsisection
-phrenic nerve ; made up of C345, supplies the pericardium and diaphram
what are the layers of the pericardium
- visceral = inner serous layer
- parietal = outer fibrous layer
where does the apex of the heart sit?
- 5th intercostal space midclavicular line on the left
what forms the left right inferior and superior boarders of the heart?
- I= apical part of left ventricle and reight ventricle
- S= left and right ventricles hit beneath the pul trunch and aorta
- L= left A +ventricle
- R= R a
transverse pericardial sinus
- finger posterior to the aorta and pulmonary trunk
where do coronary arteries arise from
- right Ca= right aortic sinus
- LeftCA= left aortic sinus
