Cardiovascular - Blood Vessels Flashcards
What are the three types of blood vessels?
- Arteries
- Capillaries
- Veins
Which type of blood vessels carries blood away from the heart?
Arteries
Which type of vessel carries blood towards the heart?
Veins
Which type of vessel carries blood towards the lungs?
Arteries
Which type of vessel carries blood away from the lungs?
Veins
Which vessel is the site of substance exchange between the blood and body tissues?
Capillaries
What are tunica, and what are their three classifications?
- Tunica are the layers of arteries or veins
- Three layers:
- Intima
- Media
- Externa
Which Tunica layer is made up of smooth muscle tissue and elastic fibres?
Tunica Media
Why do arteires have a thicker Tunica Media?
- To withstand higher blood pressure
- By having more smooth muscle and elastic fibres, the arteries are able to dilate and contract more
Do capillaries have tunica layers?
No, they are only one cell thick to allow for easier substance exchange
What is a lumen?
The inside space of a blood vessel, where blood flows through
What are arterioles?
Smaller blood vessels which branch off from arteries
What is a venule?
Smaller blood vessels that branch off Veins
What is the Arterial System?
- Elastic Arteries
- Smooth Arteries
- Arterioles
- Terminal Arteriole
- Capillaries
What is the Venous System?
- Large Veins
- Small Veins
- Venules
- Post Papillary Venule
VENOUS RETURN IS IN OPPOSITE ORDER
Label the lines from this Capillary Bed
What is the Vascular shunt composed of?
- Metarteriole (Arteriole)
- Thoroughfare Channel (Venule)
Why is the whole capillary bed (network) not always used?
When resting, not as much blood is needed to be transported, so only vascular shunt can be used and true capillaries unused
What do the precapillary sphincters determine?
- If sphincter open, blood travels through true capillaries
- If closed, blood only travels through vascular shunt
How is blood pressure measured?
MM Hg
Milimetre’s of Mercury
What is the average blood pressure when leaving the heart?
120 mm Hg
What is the blood pressure when returning to the heart? (through Vena Cava)
0 mm Hg
What is the average Capillary Blood Pressure?
17-36 mm Hg
Why is low capillary blood pressure desirable?
Capillaries are only one cell thick, high pressure could cause vessels to burst
What is the average blood pressure in the venous system?
15 mm Hg
Which valves form in the folds of the Tunica Intima?
Hinge-Link Flaps
What is the ‘Muscular Pump’?
Skeletal Muscle contracts to force blood in the veins upwards towards the heart
What is Venoconstriction?
Veins contract under sympathetic control, pushing blood towards the heart
Where are the pressure point locations of the:
- Common carotid artery
- Brachial artery
- Radial artery
- Common carotid artery - Neck
- Brachial artery - Elbow joint
- Radial artery - Wrist
How is blood pressure (BP) defined?
Force per unit area exerted on the wall of a blood vessel by its contained blood (mm Hg)
What are the main sources of blood resistance?
- Viscosity - (thickness)
- Total blood vessel length
- Blood vessel diameter
What are vessels naturally partially constricted?
To allow for:
- Vasoconstriction
- Vasodilation
