A&P - Chapter 29 (Part 1) Flashcards
Angiogenesis
Formation of blood vessels
What are 3 types of blood vessels?
- Arteries
- Veins
- Capillaries
What do arteries do?
Carries blood AWAY from the heart ventricles
What is the largest artery of the body?
Aorta
- closest to the heart
What kind of circulation happens in capillaries?
Microcirculation
What do capillaries do?
It is the site of gas and nutrient exchange between blood and tissue fluid around cells
- capillary beds/network
Where is the highest concentration and metabolic rate?
Capillaries
What do veins do?
Bring blood TOWARDS the heart atria
What are the largest veins?
Superior vena cava and inferior vena cava
- closest one to the heart
What are 4 types of materials that make up the wall of a blood vessel?
- Endothelial tissue/endothelium
- lining - Collagen fibres
- Elastic fibres
- Smooth muscle tissues
What does the endothelial tissue do?
Provides the lumen of blood vessels with a smooth surface
What does endothelial tissue influence? (2)
- Blood flow
2. Intravascular blood clotting
What tissue allows for exchange of gases, nutrients and other substances?
A special type of simple squamous epithelium
What do intercellular clefts between the cells and fenestrations do?
They dictate movement of substances in and out of the blood vessel
What do collagen fibres do?
They provide blood vessels with strength and some flexibility
- not as much as elastic fibres
What is the function of the collagen fibres?
To keep the lumen of blood vessels open
- strengthen blood vessels walls
What do elastic fibres do?
They arrange concentrically in large elastic arteries allowing for distention and recoiling
What do elastic fibres maintain?
Passive tension of blood vessels of normal blood pressure
Passive tension
Stretched beyond its resting strength
Where are smooth muscle tissue found?
In the walls of all blood vessels
- except capillaries
Where is the highest concentration of smooth muscle tissue? (2)
- Elastic arteries
2. Muscular arteries
Active tension
Contraction
What are the 3 blood vessels layers?
- Tunica intima
- Tunica media
- Tunica externa
What layer is the tunica intima?
The inner layer
- single layer of squamous epithelial cells
What layer is the tunica media?
The middle layer
What kind of tissue is the tunica media layer?
Smooth muscles of elastic tissue
What vessel has thicker walls?
Arteries
Why do arteries have a thicker wall?
To withstand systole
- contractions
What is the tunica media important for?
Blood pressure regulation
- smooth muscles (ANS)
Where is the tunica externa/adventitia located?
It is the outermost layer of the blood vessel
What is the tunica externa made up of?
Collagen fibres
What does tunica adventitia do?
It reinforces the wall of the vessel to withstand pressure
Which vessel has the thickest tunica externa?
Veins
What does tunica intima contain in veins?
One way valves to prevent back flow of blood
What is not found in arteries?
One way valves
