Cardiovascular Physiology (Anatomy I) Flashcards
(15 cards)
Structure and function of the heart each ventricle please
Right ventricle - deoxygenated low pressure blood pumped to lungs not very far
Left ventricle- High pressure oxygenated blood to all organs of the body, arteries have thick muscular walls for constriction etc
Different valves of the heart
Atrioventricular valves: Bicuspid and tricuspid
Semi lunar valves: aortic and pulmonary
What is chordae tendineae
Atrioventricular valves are attached to specialised tendons called chordae tendinae which are regulated by papillary muscles
So when ventricles contract so does papillary contract to keep the valve in place and not turn inside out
What is bulk of the heart made up of?
Made up of cardiac muscle cells termed myocardium
Inner surface of myocardium has thin endocardium
What is a cardiac myocyte?
Contain majority of the contractile elements for the heart
Eg actin and myosin filaments
NB: myocyte basically means muscle cell
What is the Cardiac conduction system
SA node and AV node contain nodal cells which initiate contractile response for working myocytes
Spontaneously depolarise and activity can be modified by autonomic nerve impulses (ANS)
The sequence of excitation is similar to skeletal muscles, what is the sequence?
Involves increase in cytosolic calcium
Contraction of atria and ventricles precisely coordinated to prevent closure of AV valves during filling wave of excitation.
Explain the cardiac action potential
1.Rapid depolarisation of sarcolemma Na goes into cell
2.Plateu as Ca2+ enters
3.depolarisation as K+ flows out
Parts to an ECG and how to read it
P wave: as SA node fires and atrial depolarisation
QRS complex: AV node fires ventricular depolarisation and atrial repolarisation
T wave: ventricular repolarisation
What is systole and diastole in the cardiac cycle?
Systole: ventricular contraction (QRS complex)
Diastole: ventricular relaxation, atrial contraction
What is stroke volume (SV) and cardiac output (CO)
SV=EDV-ESV volume of blood pumped per contraction/heartbeat
Cardiac output is total volume blood pumped by ventricle per minute CO=SV x HR
Blood pressure is force exerted by blood circulating in arteries against walls how is it measured?
Systolic pressure over diastolic pressure
120 over 80 is normal pressure of people
Name the type of blood vessels and main differences
Arteries
Capillaries (don’t have three tissue layers)
Arterioles
Venules
Veins (have valves to stop back flow and less smooth muscle)
Composition of blood
Plasma-watery liquid containing many dissolved substances
Red blood cells (erythrocytes)
WBCs (leukocytes)
Platelets
Plasma is mostly water some proteins,organic, and non organic compounds
RBC and WBC facts
RBCs make up 45% of blood in men and 42% in women
WBCs defend against pathogens
types of WBC:
1.Neutrophils and monocytes that carry out phagocytosis
2.Lymphocytes that produce antibodies and anti microbial chemicals
3.eosinophils defend against parasites in allergic response
4.basophils- secrete histamine and herapin
