Anatomy of CVS 2 Flashcards
3 tunics of blood vessels
Tunica intima
Tunica media
Tunica externa/adventitia
Structure of heart wall
Endocardium
Myocardiium
Epicardium
Do arteries or veins have smaller diameters
Arteries do, because of the thicker T. media
Arteries have a ___ T. media and ____ T adventia
Thick and thin
Veins have a ____ T. media and a ____ T. adventia
Thin and thick
Types of arteries
Elastic
Muscular
Arterioles
Where are elastic arteries found
Aorta, common carotid and pulmonary
What happens to the aorta during systole
it is stretched
What happens to the aorta during diatsole
The heart relaxes and the artery recoils and maintains the pressure on the blood
Why is the aorta able to recoil and stretch
Presence of extensive amounts of elastic fibres i T. media in the form of layers
What secretes the elastic fibres
smooth muscle cells
Where are muscular arteries found
Coronary arteries, radial and femoral
What is the function of muscular arteries
Controls distribution of blood to regions
Is there an elastic fibres between muscle cells in T. media
No
Where are elastic fibres found in muscular arteries
Concentrated in 2 well defined sheets called internal and external elastic laminae
Internal elastic laminae
Under epithelium
External elastic laminae
between T. media and T. adventitia
Do arterioles have any IEL
No
How many layers of smooth muscle is in the T. media of arterioles
1-2
Do arterioles have T.adventia
No
What is the innervation for arterioles
Sympathetic nerve innervation
What is the function of arterioles
To control blood pressure
Function of capillaries
Main exchange for nutrients and gases
Are capillary walls thin or thick
Thin
What tunics does the capillaries contain
Just T. intima
No T.adventitia or T. media
What are pericytes
Incomplete layer of cells surrounding basement membrane which have contractile properties
What is the function pf pericytes
They help control blood flow
What is the average diameter of capillaries
4.15 microm
Is the sum of diameters of all capillaries greater than the diameter of the aorta and what does this mean
Yes
Blood pressure is low
Types of capillaries
Continuous
Fenestrated
Discontinuous
Where are continuous capillaries found
Muscle, nerve and fat tissue
Features of continuous capillaries
Selective transport mechanism
Can control what is exchanged
Where fenestrated capillaries found
Small intestine
Endocrine glands
Kidneys
Features of fenestrated capillaries
SAllow larger molecules through and are more permeable
Where are discontinuous capillaries found
Liver, spleen and bone marrow
Features of discontinuous
Gaps between endothelial cells and basement membrane
Allow free passage of fluid and cells
What are sinusoids
A type of discontinuous capillaries found where large amount of exchange takes place
Where are sinusoids found
Liver and endocrine glands
What do the T.intima in the sinusoids contain
Phagocytic cells
What is the purpose of capillary beds and Arteriovenous shunts
Bypasses capillary beds in skin for thermoregulation
Capillary bed to vein
Small venule
Small-medium sized vein
T. intima
T. media
T.adventitia in vein
Thin
Thin
Thick
What does veins contain to prevent back flow
Valves
What are the valves made out of in the vein
folds of T.intima
Superficial vein
Thick walled
No surrounding support
Deep vein
Thin walled
surrounded by deep fascia and muscles
Function of lymphatic system
Drains tissue fluid lost from blood capillaries
Features of lymph capillaries
Blind ending
Lined by very thin endothelium
No fenestrations
How is the lumen maintained
Negative hydrostatic pressure
Blood supply to the blood vessels
Vasa Vasorum
Where are the lymphatics in the blood vessels located
T. adventitia
Nerve supply of blood vessels in skin
Sympathetic
Nerve supply of blood vessels in heart
Sympathetic and parasympathetic
