Lecture 19 - Vascular System Flashcards
What is the innervation of arteries?
Vasomotor
Sympathetic innervation that controls the smooth muscle, and thus the diameter of the lumen
What is the structure of an artery?
Intima: endothelium
Media: smooth muscle
Adventitia: fibrous material
What is the major division of the circulatory system?
Pulmonary
Systemic
Describe blood flow around the heart
- Venous return via IVC and SVC into right atrium
- Right ventricle
- Pulmonary artery
- Lungs
- Pulmonary vein
- Left atrium
- Left ventricle
- Aorta
- Body
What are the different types of vessels?
Arteries Arterioles Capillaries Venules Veins Lymphatics Lymph vessels
Describe the flow of lymph around the body
- Interstitial fluid drains into lymph capillaries
- Afferent lymph vessels
- Lymph node
- Efferent lymph vessel
- Lymph duct
- Draining back into circulation
Why is there a pressure difference in the pulmonary and systemic circulation? What is this difference?
Pulmonary: low pressure, because the blood doesn’t have to travel far
Systemic: high pressure, because the blood must travel all around the body
Is any part of the body avascular?
Yes:
Epidermis
Articular cartilage
How may an artery and vein be distinguished when dissecting?
Arteries always have a lumen, due to the thick smooth muscle wall
Veins collapse, and there is no visible lumen
When does an artery normal branch?
At a joint, such as the elbow
What are the different branches that an artery can form?
Muscular branch Nutrient branch Articular Cutaneous Arteriae nervorum Vasa vasorum
Where does an artery usually run?
Down the midline, in the flexor compartment
Arteries conduct high pressure blood. What confers this function?
The elastic fibres in the artery wall allow it to expand, and then bounce back to push the blood on
How does the body control blood flow to different regions in different conditions?
The smooth muscle in the wall confers this property
When activated, the artery restricts in areas where excess blood is not needed.
The artery dilates where more blood is needed
What is one of the main functions of arterioles?
‘Resistance vessels’
Control the flow and pressure into the capillaries
What is the main function of capillaries?
‘Exchange vessels’
They have a very thin wall that allow them to carry out this function
What is an anastomosis?
This is when two arteries meet without a communicating capillary
They provide collateral circulation
What is collateral circulation?
Alternative routes of circulation
We’re are anastomoses usually found?
In skeletal muscle
Joints, where circulation may be impaired due to bending of joint
What is an anatomical end artery?
Where are they usually found?
These are arteries that do not connect with another artery
They are normally found in region that hang or stick out
Finger Toes Brain Heart Appendix