Blood vessel questions Flashcards
Describe the difference btwn the epicardium and the endocardium
Epi- surface of heart– mesothelium and subepicardial layer of loose connective tissue
Endo- lines atria and ventricles— endothelium and sub endothelial layer of CT
What is the physiological significance of the number of elastic lamina in the aorta?
40-70 layers of fenestrated elastic lamellae
-withstand the constant pressure
How can you distinguish an elastic artery from a mixed artery?
Elastic media– thick in elastic
Tunica media and adventitia approx. the same thickness in mixed
What is the function of the fenestrae in the elastic lamina of the aorta?
allow the aorta to be more flexible
Describe what happens to the external elastic lamina as arterial vessels become smaller along the vascular tree
Gets smaller & smaller until it is no longer present in small vessels- arterioles
What is the medical importance of foam cells?
fat-laden macrophages seen in atherosclorosis
-indication of plaque buildup
Tunica intima
Internal elastic lamina
forms permeable/semipermeable barrier
Tunica media
smooth muscle
Variable amounts of elastic fibers and lamellae/reticular fibers/proteoglycans
Larger vessels have
- EEL
- Pericytes
controls diameter and blood pressure and movement
Tunica adventitia
outermost layer
fibroblasts and longitudinally oriented type I collagen and elastic fibers
Larger blood vessels- vasa vasorum
Provides support
attaches vessels to tissue
carries vessels and nerves
Internal elastic lamina
Borders the media
fenestrated layer of elastin
External elastic lamina
borders media of larger vessels on superficial portion
Vasa vasorum
provides nutrients to the vessel
Elastic artery
Aorta and main branches
intima- endothelial cells contain Weibel-Palade bodies
—store and release substances important for homeostasis and inflammation
Media- 40-70 layers fo fenestrated elastic lamellae
Adventitia- thin
Mixed, músculo-elastic arteries
Part of terminal abdominal aorta/ iliac arteries/ external carotids/axillary arteries
Has more internal elastic membrane
Transitional segment btwn large and medium arteries
Medium, muscular, distributing arteries
Most arteries are this type
innervated by ANS– regulates blood flow
Intima- thin– prominent IEL
Media- thick– EEL
Adventitia- may be as thick as media
–vasa vasorum and lymphatics are poorly developed