CVS Physiolgy Flashcards
Name three functions of the CVS
Rapid transport of nutrients Hormonal control Immune support Thermo regulation Removal of waste products of metabolism
Name the two circuits of the circulatory system
Systemic and pulmonary
Which artery leaves the left ventricle
Aorta
Which vein empties into the right side of the heart
Superior and inferior vena cava
What is aortic pressure
120/80mmHg
What %of cardiac output do the following recurve Lungs Kidneys Liver and GI tracts Brain
100%
20%
24%
13%
Name the two phases of blood and the % each one makes up
45% cellular
55% plasma
How long do red cells white cells and platelets last
120 days
6hours
7-10 days
Where are plasma proteins synthesised?
The liver
What is an erythrocytes
Red blood cell
What is the function of the plasma proteins?
Exert osmotic pressure for absorption of iteestinal fluid.
Participate in the clotting cascade
What is a leukocyte
White blood cell
What is irons role one haemaglobin
Oxygen binding site
Where are erythrocytes produced
Bone marrow
What is the role of the hormone erythropoietin and where is is produced
Produced I’m kidneys
Stimulates erythrocytes differentiation and production by bone marrow, in response to low oxygen supply
Define platelets
Cell fragments essential for blood clotting
What is the decrease in ability for the blood to carry oxygen
Anaemia
Name three causes of anaemia
Dietary deficiency in iron, B12 and folic acid
Bone marrow failure due to drugs or cancer
Blood loss from the body
What is the prevention of blood loss
Hemostatis
where are the baroreceptors located
carotid sinus
aortic arch
Which nerve innervates each naroreceptors
Vagus = aortic arch Glossopharngeal = carotd sinus
where is the aortic valve ausculated
2nd intercostal space right of midlne
where is the pulmonary valve ausculated
2nd interc ostal space left of msiline
Tricuspid valve
4th intercostal space left of miline
Mitral valve (apex)
5 th intercostal space - mid clavicular line
What creates the 1st heart sound
AV vales closing at start of ventricular systole
What creates the 2nd heart sound
semilunar valves closing at end of ventricualr systole (s2)
where do the coronary arteries originate from?
left and right aortic sinuses
What does the LCS biffercate into
LAD and Circumflex
What does the right coronary arteries supply>
RA RV SAN (60%) AVN Posteriro Septum (70%)
Left coronary aryerey supplies?
LAD anterior and inferior aspects of LV
anterior septum (window artery)
LA - posterior aspect of LV
what is the difference bewteen veins and arteries?
Veins: Larger Lumen Thinner media Less smooth muscles and elastin Have valves
Arteries
Smaller luemn
Thicker wall
More elastic and smooth muscle layer
what are the three mjor stages of embryological developemnt?
Formation of primitice heart tube
Looping
Septation
When do you hear the first heart beat?
day 22
What develosp from the first 2 aortic arches
minor head vessels
What develops from the 3rd aortic arch -
common carotid and proximal interal carotid
What develops from the 4th arotic arch
R - right sub clavian
L - aortic arch
What develops from the 5th aortic arch
not present in humans
6th aorti arch develops into?
R = right pulmonary arterey
L = left pulmonary arterey
Ductus areteiousus
Dorsal aorta becomes the
Descending aorta
Role of AVN
delay atrio ventricular depoalrisation
explanation:
The atrioventricular node is the only part of the heart that allows transmission of action potential from atria to ventricles. It causes a delay to allow the atria to completely empty of blood before the ventricles contract. This delay occurs due to the ‘pre-potential’ of the AVN pacemakers cells. There is no specific system to co-ordinate artial contraction, the action potential spreads via gap junctions. Normally rhythm is initiated by the sino-atrial node. Contraction is a physical process, unlike depolarisation which is an electrical process. Atrio-ventricular tachycardias may even involve the AVN - it does not prevent them. - See more at: http://one2onemedicine.com/learning-material/pre-clinical-medical-science/?category=cardiocascular#sthash.UvjddoG6.dpuf
What is systollic pressure
Pressure at ventricualr contraction
Whats diastollic pressure
Pressure at ventricualr relaxation - ventricualr filling
Normal BP?
120/80mmHg
High BP (hypertensions)
140/80 mmHg
How do you calcualte CO
SV x HR
Stroke volume x Heart Rate
Starlings Law define
The Frank–Starling law of the heart (also known as Starling’s law or the Frank–Starling mechanism or Maestrini heart’s law) states that the stroke volume of the heart increases in response to an increase in the volume of blood filling the heart (the end diastolic volume) when all other factors remain constant.
What do barorecptors do in regards to low blood pressure being sensed
send AP to cv centre in medulla
send signals to poterior pituatary to control ADH
Nmae the three hisological layers of the heart
endocardium
myocardium
epicardium
Name three key features of cardiac muscles
central nucleis
intercalated discs
branching
What are the three main layers in the arterey called>
Tunica Adventitia
Tunica Media
Tunica Intima
What denotes heart dominace?
whetehre the RCA or LCA supplies the posterior interventricualr septum
what are the major branches of the ascending aorta
Coronary arteries
Brachiocephalic
Left CCA
Left sub clavian arterey
Summarise Starlings Law
increased pre load (EDV) is proportional to increases in stroke volume resulting greater contractility of cardiac myocytes
