Topic 4 - Circulation and The Heart Flashcards
Whats tendenous fibrous
prevent atroventricular valves turning inside out
Why would the atrioventricular valves turn inside out?
due to the pressure when the heart contacts
what are coronary arteries
theyre wrapped around the heart to supply blood to cardiac muscle of the heart
What is cardiac muscle and where is it thicker and why?
- thicker muscle of the heart. Makes up the thick middle layer of the heart.
thicker LHS bc of higher blood pressure is needed to pump blood further to alll the tissues of the body
3 types of muscle in the heart
- myocardium (cardiac muscle)
- skeletal
- smooth muscle
another name for cardiac muscle?
- myocardium
what are the semi lunar valves
- aortic valve
- pulmonary valve
what are the atrioventricular valves
- tricuspid
- bicuspid
4 types ofcirculatory systems:
- open and closed systems
- single or double
whats a closed system
blood confined to blood vessels only
circulation and the heart
what’s a single system?
in the body
- blood is only pumped once around the whole system
circulation and the heart
what’s a double system?
in the body
where blood is pumped twice
humans have this
4 advantages to a double circulatory system?
pressure, conc. , organisms
- conc. gradient maintained, as deocygenated blood and oxygenated blood dont mix.
- blood pressure to body tissue is higher
- blood pressure to lungs is lower, avoids damaging the capillaries in lungs and increases time for gas exchange
- organisms can develop larger bodies
myogenic meaning
- originating in muscle tissue (rather than nerve impulses).
the hearts ability to initiate its own contraction is referred to as …..?
myogenic
depolarisation of the heart meaning
to trigger its contraction
where does depolarisation oif the heart begin?
Sinoatrial Node
Depolarisation spreads through atria causing ….?
- atrial systole
non conductive tissue of the heart is called?
annulus fibrous
what does the annulus fibrous stimulate
- another region of conducting tissue called Atrioventricular Node
what conduction fibres does the AVN pass the depolarisation onto?
Bundle of His
what does the Bundle of His split into?
and what does this cause?
- two branches called Purkinje fibres
- causes ventricular systole
explain how depolarisation of the heart is carried out
including systole and diastole
- SAN
- Atrial systole
- Annulus fibrous
- AVN
- atrial diastole
- into Bundle of His
- Apex
- Bundle of His splits into two branches - Purkinje Fibres
- causing ventricular systole
What are the 3 stages of cardiac cycle
- atrial systole
- ventricular systole
- cardiac diastole
whats atrial systole
- atrial contract
- forces atrioventricular valves to open amd blood flows into ventricles
whats ventricular systole
- ventricles contract
- causing atrioventricular valves to open, allowing blood to leave LV through aorta and RV through Pulmonary Artery
whats cardiac diastole
- atria and ventricles relax, pressure inside heart chambers decrease.
- This causes semi-lunar valves to relax in aorta and P.A to close, preventing backflow
what is the blood made up of?
- Plasma
- Erythrocytes (RBC)
- Leukocytes (WBC)
- Platelets
3 functions of the blood:
- transport
- formation of lymph
- tissue fluid
- defense against pathogens
plasma
what it does?
- transports digested food products (e.g glucose, amino acids), nutrient molecules, hormones, excretory products (e.g CO2, urea)
- Transfers heat around the body
another name for RBC
Erythrocytes
Erythrocytes (RBC)
what they do and their adaptation?
- transports O2 and some CO2
- adapt via their bioconcave shape and lack of nucleus + contains heamoglobin
no nucleas means more surface area for O2
biconcaveshape = easy moving
another name WBC
Leukocytes
2 types of leukocytes
- Granulocytes
- Agranulocytes
leukocytes
what are the cells that come under granulocytes and function
- eutrophils (phagocytosis)
- Basophils (histamines - inflamation/allergic response)
- Eosinophils (response to parasites, allergic reactions, inflamation, immunity)
what are the cells that come under Agraulocytes and function
- Monocytes ( call on other white blood cells to help treat injury and prevent infection.)
- lymphocytes (involved in specific immune response)
Platelets
what they are and do?
- Fragments of megakaryocytes (large cell that has a lobulated nucleus, is counf especially in bone marrow, is the source of blood platelets)
- involved in blood clotting
what are Megakaryocytes
large cell that has a lobulated nucleus, is counf especially in bone marrow, is the source of blood platelets
