Blood vessels L8 Flashcards
What are all blood vessels lined with?
endothelium
-Lines ALL BV blood vessels
_Thin Flattened layer of cells
-provides a slippery and Smooth surface for the inside of all BV blood vessels
What is endothelium?
endothelium Lies ALL BV blood vessels
Is a Thin Flattened layer of cells
provides a slippery and Smooth inner surface for all blood vessels
What is the function of elastic fibres?
allows the vessels to Stretch
Which fibres in blood vessels allow them to stretch?
Elastin fibres
What is the function of smooth muscle fibres?
Wrapped around blood vessels
allows the BV to change diameter (via vasoconstriction and vasodilation)
Which fibres in blood vessels allow them to change diameter?
Smooth muscle fibres
- they Wrap around BV
- Allows them to change diameter(via vasoconstriction and vasodilation)
How do blood vessels change diameter?
via vasoconstriction and Vasodilation of the Smooth muscle which is wrapped around the BV blood vessels
What is the function f collagen fibres?
tough, inelastic strand
Prevent the vessel wall from stretching to a point of rupture
Which fibres present in blood vessels are there for the most structural support?
Collagen fibres
- are Tough and Inelastic strands
They prevent the vessel wall from stretching to a point of rupturing
Which fibres are touch and inelastic, and prevent the blood vessel wall from stretching to a point of rupture?
collagen fibres
Are collagen fibres elastic or inelastic?
Inelastic
- they are tough, inelastic strands of CT
- Prevent the blood vessels wall from stretching to a point of rupture
How many classes of blood vessels are there in the Cardiovascular system?
7
Heart –> 1. elastic arteries –> 2. muscular arteries –> 3. arterioles –> 4. capillaries –> 5. venules –> 6. veins –> 7. coronary arteries
What are the 7x classes of blood vessels there are in the cardiovascular system, in order, beginning from the heart?
Heart
- elastic arteries –>
- muscular arteries –>
- arterioles –>
- capillaries –>
- venules –>
- veins –>
- coronary arteries
What is the relationship between the orientation of exit of the aorta and pulmonary trunk?
Aorta twists around the pulmonary trunk during exit
What are features of arteries in general?
- Plenty of elastin fibres
- therefore high compliance
- Wall can therefore be easily stretched or expand
- Or walls can be thicker as there is more pressure
- Gradual change in vessel thickness as it leaves heart
Heart –> finger thick Elastic arteries –> pencil to pin thickness of muscular arteries (range due to smooth muscle’s ability to change diameter (r4 effect on flow) and can distribute out to rest of body (reason for control of flow as blood doesn’t flow entire body at once, needs to be directed to where is needed)) –> hair thing arteriole
In general, what type of fibres is found in reasonable abundance in all arteries?
Elastin fibres -allows for: high compliance ability to stretch and expand walls to become thicker due to higher pressure
What are the main features of Elastic arteries?
- Pulse and Pressure Absorbers
- They take they brunt of the pressure of the pump
- also called Conducting arteries
- less than 1cm in size - size of a finger
- Is the first vessels which leave the heart (approx. first 15cm)
- Largest arteries
- effects the rate of Ejection (from the ventricle) and run off (leaving elastic arteries into arterial tree)
- contains Thin sheets of up to 50 sheets of Fenestrated Elastic fibres. found in the Middle tunic
- high proportion of elastin fibres, designed to be stretchy. Thin comparatively. Results in a Big, Eleatic, rubbery, soft artery - During systole: Heart is trying to Reduce volume. In turn generates pressure. Expands the store fore the bolus of blood which is leaving the ventricle. Ek –> Eep. More blood enters the elastic artery than can exit into the arterial tree (therefore the elastic arteries expands to accommodate) (rate of ejection>rate or run off into arterial tree)
- During Diastole: the bolus of blood that is being stored in the elastic artery Is pushed out into the Arterial tree via Elastic recoil. (Eep –> Ek), results in an absorption of pressure and a Smooth instead of pulsatile flow of blood leaving the ventricle
- allows the blood to be ALWAYS flowing down the arterial tree- as cells need a constant, not pulsatile, supply of blood, therefore this elastic recoil allows the supply to be constant (pressure absorber)
What is the overall name for elastic arteries?
Pulse and Pressure absorbers
-they take the brunt of pressure from the ventricle ejecting and absorbing it through energy conversion (Ek –> Eep –> Ek)
Conducting arteries
What are the Pulse and Pressure absorbers of the cardiovascular system?
Elastic arteries
What is another name for elastic arteries?
Conducting arteries
What is another name for conducting arteries?
Elastic arteries
What is the size of a finger?
Elastic arteries
What is the relative size of an elastic artery?
size of a Finger
Less than 1cm
Which arteries are they largest?
Elastic arteries
Less than 1cm width, FINGER size
-muscular arteries are pencil –> pin
-arterioles are hair
What two rates are there being controlled by elastic arteries?
rate of:
Ejection (pushed out of ventricle)
Run off (out of elastic arteries)
What is the structure of Elastin arteries?
up to 50 sheets of fenestrated elastin
Located in middle functional tunic
Thin comparatively
-designed to be stretchy
How many sheets of fenestrated elastin are there in elastic arteries’ middle tunics?
up to 50 sheets of Fenestrated elastin
Thin comparatively
Fenestrated elastin found in Middle tunic (functional layer)
-designed to be stretchy
What do elastic arteries look like?
First part leaving the heart
Rubbery, thin, Big/width, Elastic , soft arteries
How does the run off of stored blood in the elastic artery get pushed out into the arterial tree?
Via elastic recoil
When does elastic recoil come into use?
when the stored blood (with stored Eep) is pushed out into the arterial tree