Blood and lymphatic vessels Flashcards
The mammalian blood vessels consists of?
• Major arteries
• Arterioles
• Capillaries
• Veins
The arteries are divided into:
• Elastic arteries
• Muscular arteries
• Arterioles
• Capillary.
Elastic arteries include?
• Pulmonary trunk
• Aorta
major branches of the aorta and pulmonary trunk
• Brachiocephalic,
• Common carotid,
• Subclavian, and
• Common iliac arteries
Walls of the elastic arteries are primarily composed of:
Elastic connectivetissue fibres that provide resilience and flexibility during blood flow.
Mention the three coats of the walls of elastic arteries
• Tonica intima: the innermost layer that consist of endothelial lining and subendothelial connective tissue.
• Tonica media: the middle layer that consist of mainly elastic fibers
Tonica adventitia: the outer-most layer that contains mainly collagen and elastic fibers.
………… seperates tunica intima from tunica media
Internal elastic lamina
Vasa vasora are present in ……………
Tonica adventitia
………… separates tunica media from tunica adventitia
External elastic lamina
What are the features of the muscular artery
• Wall contains much smooth muscle
• It is relatively narrow and has non-collapsing lumen
• The tonica intima contains a single layer of endothelial cells and thin elastic connective tissue membrane
• The middle coat called tonica medial contains mainly smooth muscle fibers and little elastic fibers, collagen fibers.
• The outer layer called tonica adventia is made up of areola connective tissue
• The outer layer contains vasa vasorum.
…………… are the smallest branches of the arterial system?
Arterioles
The walls of arteriolar consist of ……………. layers of smooth muscle fibres
1-5
Arterioles have a diameter of …………….
100-500mm
The internal elastic lamina is absent in arteriole. True or false
True
…………….. are the smallest blood vessels.
Capillaries
The average diameter of capillaries is = ?
8 μm
Mention the three types of capillaries
• Continuous capillaries
• Fenestrated capillaries
• Sinusoids
What is the essence of the structural variations in capillaries?
Allows for different types of metabolic exchange between blood and the surrounding tissues.
What’s the distribution of continuous capillaries?
They are found in
• Muscle
• Connective tissue
• Nervous tissue
• Skin
• Respiratory organs
• Exocrine glands
Describe the continuous capillaries
Continuous capillaries are the most common. In these capillaries, the endothelial cells are joined and form an uninterrupted solid endothelial lining.
Fenestrated capillaries are characterized by ……………………
large openings in the cytoplasm of endothelial cells
What is the function of the large openings found in fenestrated capillaries?
They are designed for a rapid exchange of molecules between blood and tissues
What is the function of the large openings in the cytoplasm of endothelial cells of fenestrated capillaries?
They are designed for a rapid exchange of molecules between blood and tissues
Fenestrated capillaries are found in;
• Small intestine
• Kidney glomeruli
• Endocrine tissues and glands
Describe sinusoidal capillaries
Sinusoidal capillaries are blood vessels that exhibit irregular and tortuous (convoluted) paths.
Sinusoidal capillaries exhibit wide diameters with wide gaps between endothelial cells.
Where can sinusoidal capillaries be found?
• Liver
• Spleen
• And bone marrow.
What is the nature of basement membrane in sinusoidal capillaries?
Incomplete or absent
Describe the three layers of the venous wall
• tunica intima is the inner layer that consists of endothelium and sub-endothelial connective tissue
• Tunica media is the middle layer. It is thin and smooth muscle intermixes with connective tissue fibres.
•Tunica adventitia is the thickest laver with longitudinal smooth muscle fibers. It is the outer layer.
The lymphatic system consists of …………… and …………..
• Lymph capillaries
• Lymph vessels
The lymphatic system starts as ……………… in the connective tissue of different organs.
blind-ending tubules or lymphatic capillaries
What is the function of lymphatic vessels?
They collect the excess interstitial fluid lymph from the tissues and return it to the venous blood via the large lymph vessels; thoracic duct and right lymphatic duct
……………. Is the main vessel of the lymphatic system
Thoracic duct
Name the large lymph vessels
• Thoracic duct
• Right lymphatic duct
Why do lymph vessels contain more valves?
To prevent a backflow of collected lymph
Lymph vessels are found in all tissues except:
• The central nervous system
• Cartilage
• Bone
• Bone marrow
• Thymus
• Placenta
• Teeth.
