Flashcards in Histology Deck (28):
Name the elastic arteries that branch from the aorta
Left common carotid
How does the abdominal aorta terminate?
Bifurcates into the left and right common iliac arteries in the pelvis
How does the aorta maintain blood pressure during diastole?
The elastic walls of the aorta recoil to maintain the pressure on the blood. (Elastic recoil)
What are the 3 major types of arteries?
What are the 3 layers in the walls of arteries and veins?
Describe the intima of a large artery
Endothelial cells with long axes parallel to the long axis of the artery. Narrow subendothelium of connective tissue with discontinuous internal elastic lamina.
Describe the media of a large artery
40-70 fenestrated elastic membranes. Smooth muscle cells and collagen between these lamellae. Thin external elastic lamina may be present.
Describe the adventitia of a large artery
Thin layer of fibroelastic connective tissue containing vasa vasorum, lymphatic vessels and nerve fibres.
Describe the intima of muscular arteries
Endothelium, subendothelial layer and thick internal elastic lamina.
Describe the media of muscular arteries
40 layers of smooth muscle cells. Prominent external elastic lamina.
Describe the adventitia of muscular arteries
Thin layer of fibroelastic connective tissue containing vasa vasorum (not prominent), lymphatic vessels and nerve fibres.
Give an example of an absolute end artery
The central artery to the retina
What is bridging?
The compression of a segment of coronary artery during systole, resulting in a narrowing that reverses during diastole.
Arteries with a diameter
What are metarterioles?
The arteries that supply blood to capillary beds. They have pre capillary sphincters and the smooth muscle layer is not continuous.
Where does blood flow fastest?
Where the total cross sectional area is least
What are the 3 types of capillaries?
What is the most common capillary type and where is it found?
Located in: nervous tissue, muscle, connective tissue, exocrine glands and lungs.
Where are fenestrated capillaries found?
Gut, endocrine glands and renal glomerulus.
Where are sinusoids found?
Liver, spleen and bone marrow
What cells are pericytes capable of dividing into?
Muscle cells or fibroblasts
Describe the histology of small and medium sized veins
Have a well developed adventitia, the intima is thin and the media is thin.
Describe the histology of large veins
Well developed adventitia
Do NOT have a prominent media
What are venae comitantes?
Deep, paired veins that accompany one of the smaller arteries. The 3 vessels are wrapped in one sheath so the pulsing of the artery promotes venous return.
How is the muscle distributed in large veins?
Longitudinal smooth muscle in adventitia
Circular smooth muscle in the media
What occurs anatomically at the sternal angle? (T4-T5)
Mediastinum separated into superior and inferior compartments
Bifurcation of trachea
Bifurcation of pulmonary trunk
Which part of the mediastinum is the heart enclose in?
The inferior, middle part.