Heart and Blood Vessels: Cellular Structure
This session will cover:
The three layers of the heart wall, epicardium, myocardium and
endocardium and the cellular organisation that distinguish epicardium
from endocardium, and cardiac muscle in the myocardium from other
types of muscle
How the structural features of these layers relate to function.
Purkinje fibres: their appearance in stained sections; location and
function
The normal tissue structure of a heart valve.
The three layers of blood vessel walls: tunica intima, media and
adventitia and how these layers differ between elastic arteries,
muscular arteries, veins, arterioles and venules, in relation to function.
Normal blood vessels of all these types, as seen by light microscopy of
sections.
Fenestrated and non-fenestrated capillaries, and sinusoids: structural
and functional differences and examples of where each is found
Key Points:
Blood vessels: Introduction, 3 layers
Arteries: elastic, muscular, arterioles
Capilaries: continuous, fenestrated
Veins and venules
Heart: epicardium, myocardium, endocardium, purkinje fibres, heart valves
Cardiovascular disease is the most common cause of death in Western countries
Here we can see an unhealthy
artery with an atheroma (A)
Blood Vessels
There are three layers of the blood vessel wall, these are from inside outwards:
, Tunica intima – Composed of endothelium and collagen
Tunica media – Composed of mainly smooth muscle (also have elastic fibres, giving a
degree of flexibility)
Tunica adventitia – Composed of mainly connective tissue (also have nerves,
fibroblasts etc.)
This histological image of a small artery shows the different layers
Tunica adventitia—
Is collagenous connective tissue that is loose to dense
-Its main function is to provide structural support and in some cases elasticity
-It also carried nerve supply and blood supply to the vessel
Tunica media—
It is mainly composed of smooth muscle
-Its main function is support, elasticity and contractility (giving tone)
-Allow physical regulation of blood flow
-Smoothing of blood flow (in elastic arteries only)
This session will cover:
The three layers of the heart wall, epicardium, myocardium and
endocardium and the cellular organisation that distinguish epicardium
from endocardium, and cardiac muscle in the myocardium from other
types of muscle
How the structural features of these layers relate to function.
Purkinje fibres: their appearance in stained sections; location and
function
The normal tissue structure of a heart valve.
The three layers of blood vessel walls: tunica intima, media and
adventitia and how these layers differ between elastic arteries,
muscular arteries, veins, arterioles and venules, in relation to function.
Normal blood vessels of all these types, as seen by light microscopy of
sections.
Fenestrated and non-fenestrated capillaries, and sinusoids: structural
and functional differences and examples of where each is found
Key Points:
Blood vessels: Introduction, 3 layers
Arteries: elastic, muscular, arterioles
Capilaries: continuous, fenestrated
Veins and venules
Heart: epicardium, myocardium, endocardium, purkinje fibres, heart valves
Cardiovascular disease is the most common cause of death in Western countries
Here we can see an unhealthy
artery with an atheroma (A)
Blood Vessels
There are three layers of the blood vessel wall, these are from inside outwards:
, Tunica intima – Composed of endothelium and collagen
Tunica media – Composed of mainly smooth muscle (also have elastic fibres, giving a
degree of flexibility)
Tunica adventitia – Composed of mainly connective tissue (also have nerves,
fibroblasts etc.)
This histological image of a small artery shows the different layers
Tunica adventitia—
Is collagenous connective tissue that is loose to dense
-Its main function is to provide structural support and in some cases elasticity
-It also carried nerve supply and blood supply to the vessel
Tunica media—
It is mainly composed of smooth muscle
-Its main function is support, elasticity and contractility (giving tone)
-Allow physical regulation of blood flow
-Smoothing of blood flow (in elastic arteries only)
