Anatomy & Physiology 11: Blood Vessels and Regulation

Comprehensive vocabulary flashcards covering blood vessel anatomy, capillary exchange, and blood pressure regulation mechanisms as outlined in the Exam 2 Study Guide.

Tunica intima

The inner layer of a blood vessel wall.

Tunica media

The middle layer of a blood vessel wall, containing smooth muscle.

Tunica externa

The outer layer of a blood vessel wall.

Internal elastic membrane

A layer of elastic fibers located between the tunica intima and the tunica media.

External elastic membrane

A layer of elastic fibers located between the tunica media and the tunica externa.

Vasa vasorum

Small vessels that supply nutrients and oxygen to the cells of the tunica media and tunica externa.

Aneurysm

A bulge in the wall of an artery caused by a weak spot; if it bursts, it results in massive internal bleeding.

Fenestrated capillary

A type of capillary that has pores in its endothelial lining to allow specific substances to enter or leave the blood.

Sinusoid capillary

A capillary type that allows for the exchange of large substances such as plasma proteins and blood cells.

Vasomotion

The rhythmic changes in vessel diameter (contraction and relaxation) that control blood flow at the capillary level.

Precapillary sphincters

Muscular rings that guard the entrance to each capillary and can dilate or constrict to regulate local blood flow.

Capitance vessels

Another name for veins, referring to their ability to expand and hold a large distribution of blood volume.

Atherosclerosis

The buildup of fatty plaques in the walls of arteries, which increases total peripheral resistance (TPR).

Systolic pressure

The peak arterial blood pressure recorded during ventricular contraction.

Diastolic pressure

The minimum arterial blood pressure recorded during ventricular relaxation.

Mean Arterial Pressure (MAP)

The average pressure in the arteries, calculated using the formula $\text{MAP} = \text{Diastolic BP} + \frac{1}{3}(\text{Systolic BP} - \text{Diastolic BP})$.

Hypotension

An abnormally low blood pressure.

Hypertension

An abnormally high blood pressure.

Filtration

The movement of fluids and solutes from the blood to the interstitial fluid, primarily driven by hydrostatic pressure.

Reabsorption

The movement of fluids and solutes from the interstitial fluid back into the blood, primarily driven by osmotic pressure.

Edema

The swelling of tissues that occurs when capillaries filter more fluid than they reabsorb.

Autoregulation

A level of cardiovascular regulation where local factors cause immediate, localized adjustments in blood flow.

Baroreceptors

Receptors that monitor arterial blood pressure and send signals to the vasomotor center.

Chemoreceptors

Receptors that monitor the blood for hypoxia (low $O_2$), hypercapnia (high $CO_2$), and changes in pH.

Vasomotor center

An area in the brain with sympathetic neurons that adjust vessel diameter to maintain homeostatic blood pressure.

Angiotensin II

A hormone produced in response to renin that causes vasoconstriction and the release of ADH and Aldosterone to increase blood pressure.

ANP and BNP

Hormones released from the heart in response to high blood volume/pressure that promote sodium excretion and water loss to lower blood pressure.