Chapter 20 BV guide

veins

Tunica interna

The innermost layer of blood vessels that lines the vessel and is exposed to blood.

Tunica media

The middle layer of blood vessels made of smooth muscle, responsible for vasomotion.

Tunica externa

The outer layer of blood vessels, composed of loose connective tissue that anchors the vessel.

Conducting arteries

Largest arteries that expand during systole and recoil during diastole to lessen fluctuations in blood pressure.

Distributing arteries

Medium-sized arteries that distribute blood to specific organs.

Resistance arteries

Small arteries known as arterioles that control the amount of blood sent to various organs.

Precapillary sphincters

Muscle cells that regulate blood flow into capillaries by opening or closing entrances.

Continuous capillaries

Capillaries that have tight junctions between endothelial cells, allowing passage of small solutes.

Fenestrated capillaries

Capillaries with filtration pores, allowing rapid absorption or filtration in organs like kidneys and small intestines.

Sinusoids

Irregular capillary spaces that allow passage of larger molecules such as proteins and blood cells.

Blood pressure

The force exerted by circulating blood on the walls of blood vessels.

Systolic pressure

The blood pressure during ventricular systole.

Diastolic pressure

The blood pressure during ventricular diastole.

Pulse pressure

The difference between systolic and diastolic pressure.

Mean Arterial Pressure (MAP)

A measure estimating the average pressure in a person's arteries during one cardiac cycle.

Peripheral resistance

The resistance to blood flow in the blood vessels, affected by viscosity, vessel length, and radius.

Vasomotion

The process of changing blood vessel diameter through vasoconstriction and vasodilation.

Baroreflex

A neural control mechanism responding to changes in blood pressure through baroreceptors.

Chemoreflex

A neural control mechanism responding to changes in blood chemistry, such as O2 and CO2 levels.

Edema

Fluid accumulation in body tissues due to factors like increased hydrostatic pressure or decreased osmotic pressure.

Hypertension

Chronic resting blood pressure greater than 140/90 mmHg.

Aneurysm

A bulge in a blood vessel wall caused by weakening of the vessel.

Varicose veins

Swollen, twisted veins often seen in the legs due to faulty valves.

Coronary Arteries

Arteries that supply blood to the heart muscle.

Pulmonary artery

The artery carrying deoxygenated blood from the heart to the lungs for oxygenation.

Portal system

A system where blood flows through two consecutive capillary networks before returning to the heart.

Formula for Pulse Pressure

Pulse Pressure = Systolic Pressure - Diastolic Pressure.

Formula for Mean Arterial Pressure (MAP)

MAP = Diastolic Pressure + 1/3(Pulse Pressure).

Systolic Pressure in a Healthy Adult

Normal range is generally between 90 and 120 mmHg.

Diastolic Pressure in a Healthy Adult

Normal range is generally between 60 and 80 mmHg.

Blood Pressure Classification

Normal: <120/80 mmHg, Elevated: 120-129/<80 mmHg, Hypertension Stage 1: 130-139/80-89 mmHg, Hypertension Stage 2: ≥140/90 mmHg.