Unit 1: Vascular Anatomy Flashcards
In the circulatory system, what are the 3 layers of the tunica?
- Tunica Intima
- Tunica Media
- Tunica Adventitia
In the circulatory system, which layer of the tunica is the thickest in the arteries?
Tunica Media
In the circulatory system, which layer of the tunica is the thickest in the veins?
Tunica Adventitia
Why do arteries have the highest amount of smooth muscle and elastin?
Responds to blood leaving the heart rapidly under high pressure
What is Systolic Blood Presure (SBP)?
- Pressure within arteries during ventricular contraction
- Reflects work of the heart
- Reflects strain agains the arteries
What is Diastolic Blood Pressure (DBP)?
- Pressure within the arteries during ventricular relaxation
- Reflects peripheral resistance or ability of blood to flow from arteries to capillaries
What is definition of Mean Arterial Pressure (MAP)?
The average pressure at which blood flows and reflects the ability of the blood to perfuse tissue.
**NOT the average of SBP & DBP**
What is the equation for Mean Arterial Pressure (MAP)?
MAP = DBP + (1/3 x PP), where PP = SBP - DBP
What is the normal range for MAP?
- Normal: 70 - 110 mmHg
- < 60 mmHg: inadequate tissue perfussion → careful moving patient out of bed
What are branches of arteries called?
Arterioles
What stimulates the arterioles?
SNS stimulation
The arterioles are considered the _________ vessels.
resistance
What are arterioles mainly composed of?
- Media and smooth muscle
- responds to constricting in response to SNS stimulation
What is the role of the capillaries?
- Exchange fluids, nutrients and waste products
- Moves molecules via diffusion through cell or via pores between cells
What effect does histamine have on capillaries?
- Causes tightening of the cells which makes the pores wider and allows escape of proteins that would not normally be able to leave
- Keeps large items in, small diffuse out
