LECTURE 5: heart anatomy part 2 Flashcards
atrioventricular valves function is to…
prevent blood returning to aria during ventricular contraction
AV valve on right side
tricuspid valve
AV valve on left side
bicuspid valve
AV valves are …. during diastole?
open
AV valves are …. during systole?
closed
semilunar valves function is to…
Prevent blood returning to ventricles during filling (diastole).
SL valves on right side
Pulmonary (semilunar) valve, 3 cusps.
SL valves on left side…
Aortic (semilunar) valve, 3 cusps
describe the opening and closing of SL valves in relation to blood flow
Pushed open as blood flows out of heart. Close as blood starts to back flow
SL valves are …. during diastole?
shut
SL valves are …. during systole?
open
papillary muscles
finger like projections of ventricular wall, tip of papillary muscle has chords attached to end of muscle that are attached to free end of AV valve leaflets
4 major arteries in heart
- right coronary artery
- left coronary artery
- anterior interventricular artery
- circumflex artery
3 major veins in heart
- coronary sinus
- great cardiac vein
- small cardiac vein
RHS is drained by…
small cardiac vein
LHS is drained by…
great cardiac vein
myocardium function
beating of heart
myocardium features
Features of both smooth and skeletal muscle as well as cardiac muscle specific specialisations
cardiac muscle cell structure
- Striated
- Short, branched cells
- One or occasionally 2 nuclei/cell
- Central (oval shaped), nucleus
- Cytoplasmic organelles packed at the poles of nucleus
how are cardiac muscle cells interconnected?
Interconnected with neighbouring cells via intercalated disks (ICD’s)
intercalated disks
- Boundary between 2 cells
- Intercalated discs = region between cardio myocytes
3 junction types
- adhesion belt
- desmosomes
- gap junctions
adhesion belts as a junction
linking actin to actin -vertical portion (transfers force)
desmosomes as a junction
linking cytokeratin with cytokeratin
buttons cells together keeping them fused
gap junctions as a junction
electrochemical communication- horizontal portion
purkinje cells are
Bloated’ non-contractile cardiac muscle involved with electrical conduction
autonomic nerves alter the rate of…
conduction impulse generation
the conduction system is responsible for
the co-ordination of heart contraction and of atrioventricular valve action
features of purkinje cells
- (some) Peripheral myofibrils.
- Central nucleus
- Mitochondria
- Glycogen
- Lots of gap junctions
- Some desmosomes & few adhesion belts
- 1% of cardiac cells
cardiac muscle vs. skeletal muscle
Nuclei, branched striations, cell shape, mitochondria, intercalated disks
