microscopic anatomy of the heart and blood vessels anatomy Flashcards
cardiac muscles are striated with troponin T or F
T (troponin bc of the alternating thick and thin filaments)
myofibrils are
bundle of protein filaments that contain the contractile elements of the cardiomyocyte
Sarcomere
smallest contractile unit in the myofibril
intercalated discs and gap junctions allow rapid flow of repolarization or depolarization signal?
depolarization signal
cardiac muscles have rhythm and contract spontaneously T or F
T
Light bands/I bands
thin filament - contain ACTIN
Dark bands/A bands
thick filaments (run entire length) contain myosin
tunica externa/adventitia contains what
collagen and elastic fibers
tunica externa/adventitia roles
protects the vessel, prevent over expansion, anchors to surrounding tissue
tunica media is a smooth muscle that contains
large arteries that have an external elastic lamina
tunica intima 3 layers
- endothelium - simple squamous epithelium
- subendothelium - loose connective tissue, maiy larger vessels
- basement membrane/internal elastic lamina
capillaries also contain 3 vessel wall layers T or F
F, only tunica intima layer
capillaries function
Connect arterial & venous systems, exchange nutrient, oxygen & waste
3 types of capillaries
continuous, fenestrated, and sinusoidal
continuous cap.
no pores or fenestrae ex. in muscle, connective tissue, & nervous tissue
Fenestrated cap.
pores with a pore diaphragm ex. pancreas, endocrine glands, intestines
Sinusoidal cap.
irregular channels or blood pools ex. liver, spleen, endocrine glands, pancreas & intestines
arteries carry
oxygenated blood
smallest type of artery and vein
arterioles (have narrow lumen and thick muscular wall involved in regulating vascular pressure)
venules can form venous plexi
elastic arteries =
conducting arteries like aorta
muscular arteries =
distributing arteries like tibial artery
large veins have what kind of muscle and vessel wall
longitudinal smooth muscle + tunica externa
cardiac muscle layers
from inner to outer layer
- Endocardium
- Myocardium
- Epicardium
- Pericardial cavity
- Parietal layer of serous pericardium
- Fibrous pericardium