Thorax 09: Circulatory histology Flashcards
Is studying these flashcards for circulatory system histology enough?
Absolutely not; I need to study the histology itself for the practical exam
What are the important structures for this course to discriminate in the circulatory system histology?
Heart, elastic arteries, muscular arteries, arterioles, capillaries, venules, veins
Which circulatory system layer does atherosclerosis form?
Tunica intima
Where are Purkinje fibers usually located?
Subendocardium of the heart
What is on the outside layer of the epicardium?
Visceral serous pericardium
What are the two main components of myocardium?
Smooth muscle and capillaries
What are the main components of the epicardium?
Visceral serous pericardium, fat, capillaries
What vessel has the largest total cross section area?
Capillaries
What vessel has the smallest total cross section area?
Aorta
Which side of the cardiovascular system is high pressure? Low pressure?
Arterial side is high pressure; venous side is low pressure
Characteristics of elastic arteries
Elastic tissue dominant in tunica media but found in subendothelia as well
Characteristics of muscular arteries
Elastic fibers are concentrated in IEL between intima and media and EEL between media and adventitia; thin tunica media
Microcirculation
The part of the circulatory system where gas and nutrient exchange takes place
Characteristics of arterioles
Small lumen, no IEL, media contains only 3-4 rings of smooth muscle; adventitia is blended in with CT
Characteristics of capillaries
Lumen about the size of a single erythrocyte; nuclei buldge into lumen
Characteristics of Venules
No elastic fibers, media has 1-2 layers of smooth muscle
Characteristics of Veins
Large lumen, poorly developed IEL, 2-3 layers of smooth muscle
Characteristics of Muscular vein
Thin intima, 2-4 layers of smooth muscle, no IEL or EEL
Characteristics of Vena cavae
Distinct intima, thick adventitia
What type of arteries are coronary arteries?
Muscular arteries
Thoracic duct
A lymph duct that drains lymph from the left and all of the inferior sections of the body`
Characteristics of lymphatic capillaries
No erythrocytes, no basement membrane, anchoring filaments
Characteristics of Lymphatic vessels
No erythrocytes, one-way valves
Lymph nodes
Structues where afferent lymph vessels drain into and is the site of mingling between antigen-presenting cells and lymphocytes.
Why must the aorta remain elastic?
1) To dampen pulsatile flowout of the heart.
2) To allow perfusion of the coronary circulation
Vasa verosum
Vessels of large vessels that provide them with oxygen and nutrients (thick vessels cannot be nourished through passive diffusion)
What ways do lymphatic capillaries differ from blood capillaries?
1) Thin endothelium with scant basement membrane
2) anchoring filaments connect endothelium to surrounding tissue
3) No erythrocytes in lumen
Right lymphatic duct
A lymphatic duct that drains lymph from the upper right side of the body
What are the four main regions of the lymph nodes?
Cortex, paracortex, medulla, sinuses
What is the pathway of lymph through the lymph node?
Afferent lymphatics –> sinuses (subcapsular–> cortical –> trabecular –> medullary) –> efferent lymphatics
From central to peripheral, what are the 3 layers of lymphoid follicles
Germinal center, marginal zone, mantle zone
High endothelial venules
Specialized blood capillaries in the lymph nodes that permit the direct entry of lymphocytes into the lymph nodes
