Lecture 17: Blood Vessels, Cardiac Muscle, Heart Development Flashcards
what does the septum transversum become
the central tendon of the diaphragm
what layers make up blood vessels
tunica intima (endothelium)
tunica media (muscle layer)
tunica externa (epithelial and CT)
type of epithelium that lines the lumen of all vessels
endothelium
- simple squamous epithelium w/ basal lamina
what 2 layers compose the tunica media
layer of smooth muscle
- for vasoconstriction
layer of external elastic lamina (EEL)
- fenestrated elastic layer separates media from adventitia
what is adventitia
CT w/ roughened edges for stabilization
what is the tunica externa made up of
fibroelastic tissue
- fibroblasts: type I collagen + elastic fibers
Vasa Vasorum: blood vessels of the vessels
- nourish the adventitia and media of larger vessles
- coronary blood vessels on the heart
nervi vascularis: nerves of the vessels
what are postcapillary venules
where WBCs come out from and go into tissues
– important for immune system and education of lymphocytes
tunica intima aka
Endocardium
tunica media aka
Myocardium
tunica externa aka
Epicardium
**where you find coronary blood vessels (vaso vasorum)
what layer of the tunicae contains vaso vasorum
epicardium
characteristics of the cardiac fibers found in the myocardium (tunica media)
- single, centrally located nucleus
- can branch, arranged in layers (laminae)
- lots of mitochondria and myoglobin
- intercalated discs w/ gap junctions
- large t-tubules, spare SR (b/c Ca comes mainly from extracellular)
what is the purpose of the joining b/w cardiac cells
- stick together
- communicate via gap junctions
what makes up the intercalated discs of cardiac muscle fibers
intercalated discs are where intercellular junctions occur
– Transverse portion
- fascia adherens
- desmosomes
– Longitudinal portion
- gap junctions
- less mechanical stress
during development, where does the heart receive oxygen from
the mother via umbilical cord
