Summary Blood vessels- anatomy and physiology

Blood vessels




I
Arteries Veins Capillaries




1.
Layers 3 3 1

Tunica
Fibrous Ct Fibrous Ct
Adventitia X
Tunica Smooth mt & Smooth mt & elastic fibres - less
Media elastic fibres than arteries X
Tunica Single layer endothelium,
squamous
Folds of endothelium, strengthened by Ct, semi lunar Single layer endothelium permeable to
Cusps (valves), continuous with endocardial lining of H20 & small molecules except plasma
epithelium, continuous with
Intima endocardial lining of heart
Heart Proteins

Carry blood away Carry blood to heart Direct contact with tissue
Function From heart Cells, directly serve cellular needs


Vasoconstriction


Vasodilation

, Il
Elastic Muscular Arteriole's

Smallest 10
Largest 1 cm Pencil lead - small finger -0,3 mm
Diameter - 2,5 cm

Alternative Resistance vessels
Conducting arteries Disturbing arteries
Name
Contains more elastin than Thickest, more smooth muscle Little more than single
others & less elastic but does have Layer of smooth muscle
Spirals around endothelial
Tm Elastin- holey sheets of elastic Elastic membrane on Tm
Lining
CT between layers of smooth
Muscle

Simple elastic tubes, Deliver blood to specific Arteriolar diameter varies
In response to neural, chemical
Inactive in
Organs, more active in & hormonal influence, diameter
vasoconstriction changes blood flow resistance

Pressure reservoirs- Vasoconstriction & less when constricted reduces flow
to those tissues when dilated-
Expand and recoil as Capable of stretching
Function increases blood flow

blood
Leaves heart, reduces
Pressure on arteries




Lead into capillary
Near heart, aorta & its Account for most
beds
major branches Named arteries in
Location Anatomy