Blood vessels Flashcards
What are the three distinct tissue layers in both arteries and veins?
The three distinct tissue layers are tunica interna, tunica media, and tunica externa.
These layers are present in both arteries and veins.
What is the innermost layer of arteries and veins called?
The innermost layer is called tunica interna, which is the endothelium.
The tunica interna is the innermost layer in both arteries and veins.
What is the middle layer of arteries and veins known as?
The middle layer is called tunica media, which contains circularly arranged smooth muscle and elastic fibers.
This layer provides structural support and elasticity.
What is the outer layer of arteries and veins composed of?
The outer layer is called tunica externa, which is mostly connective tissue and collagen fibers.
The tunica externa provides protection and support to the blood vessels.
What does ‘vasomotor’ refer to?
Actions of blood vessels to change their diameter
Vasomotor refers to actions of blood vessels to change their diameter.
What regulates vasomotor actions?
The medulla oblongata
These actions are regulated by the medulla oblongata.
What is vasodilation?
The lumen enlarges or widens. Smooth muscles in the walls of arteries or large veins relax, which leads to an increase in local blood flow (hyperemia) and a decrease in blood pressure.
Example sentence: Vasodilation occurs in response to increased demand for oxygen during exercise.
What is vasoconstriction?
The lumen becomes smaller or narrows. Smooth muscles in the walls of arteries or large veins contract, which leads to a decrease in local blood flow (ischemia) and an increase in blood pressure.
Example sentence: Vasoconstriction is a physiological response to cold temperatures to conserve heat.
What happens as the heart beats and ejects blood?
The arterial walls expand and recoil.
This arterial expansion is called a pulse.
Where can a pulse be felt?
A pulse can be felt in arteries near the surface of the body.
Example sentence: I could feel my pulse in my wrist.
Facial Pulse
On the mandible or jawbone in line with the corners of the mouth.
Example sentence: The facial pulse can be felt on the mandible near the corners of the mouth.
Brachial Pulse
Front of the elbow.
No additional information provided.
Femoral Pulse
Inner thigh between the pubic symphysis and anterior superior iliac spine.
No additional information provided.
Posterior Tibial Pulse
Between the medial ankle bone and the Achilles tendon.
No additional information provided.
Dorsalis Pedis Pulse
Top of the foot lateral to extensor hallucis longus.
No additional information provided.
What is the functional unit of the cardiovascular system?
Capillaries
This is where gas exchange occurs between blood and body cells
What is blood flow to capillary beds referred to as?
Microcirculation
Exchange of gases at the capillary level is called internal respiration
What is the exchange of gases at the capillary level called?
Internal respiration
Example sentence: During internal respiration, oxygen is taken up by the blood and carbon dioxide is released from the blood.
What is venous return?
The rate blood flows back to the heart.
Another mechanism that assists venous return is the skeletal muscle pump, the squeeze-and-release action against venous walls that occurs when skeletal muscles contract and relax
What is the skeletal muscle pump?
The squeeze-and-release action against venous walls that occurs when skeletal muscles contract and relax.
Another mechanism that assists venous return
What does the respiratory pump promote?
Venous return through pressure changes that occur during breathing.
The respiratory pump promotes venous return through pressure changes that occur during breathing.
What effect does inhalation have on pressure in the thoracic cavity and abdominal cavity?
Inhalation causes a pressure decrease in the thoracic cavity and an increase in the abdominal cavity, creating an upward ‘sucking’ effect, and pushing blood toward the heart.
Inhalation causes a pressure decrease in the thoracic cavity and an increase in the abdominal cavity, creating an upward ‘sucking’ effect, and pushing blood toward the heart.
What are changes in muscle tone inside venous walls called?
Venomotor tone
Changes in muscle tone inside venous walls are called venomotor tone.
What is the phenomenon called when there is a lack of venomotor tone leading to a sudden drop in blood pressure?
Postural (orthostatic) hypotension
Lack of venomotor tone contributes to a sudden drop in blood pressure and resultant dizziness when sitting or standing upright from a recumbent position, a phenomenon called postural (orthostatic) hypotension.
