Anatomy & Physiology II - Vasculature

Flashcards covering key concepts of vasculature in anatomy and physiology.

Arteries

Blood vessels that carry blood away from the heart.

Veins

Blood vessels that carry blood toward the heart.

Capillaries

Small blood vessels where exchange of gases, nutrients, and waste occurs.

Tunica media

Middle layer of blood vessels, consisting primarily of smooth muscle and elastic fibers.

Tunica externa

Outer layer of blood vessels, made of collagen fibers and providing structural support.

Lumen

The interior space of a blood vessel.

Arterioles

Smallest arteries that regulate blood flow into capillary beds.

Endothelial cells

Cells lining the blood vessels that control blood flow and regulate exchange.

Vasodilation

The widening of blood vessels resulting from the relaxation of the smooth muscle.

Vasoconstriction

The narrowing of blood vessels resulting from contraction of the smooth muscle.

Capacitance vessels

Veins that can hold large volumes of blood; also known as storage vessels.

Aortic pressure

The pressure exerted by blood in the aorta during systole.

Diastolic pressure

The pressure in the aorta during the relaxation phase of the heart cycle.

Systolic pressure

The maximum pressure in the arteries during ventricular contraction.

Mean arterial pressure (MAP)

Average blood pressure in a person's arteries during one cardiac cycle.

Blood viscosity

The thickness and stickiness of blood, influencing resistance to flow.

Peripheral resistance

Resistance to blood flow within the circulatory system, mainly influenced by blood vessel diameter.

Systemic circulation

The part of the circulatory system that carries blood to and from the body.

Pulmonary circulation

The part of the circulatory system that carries blood to and from the lungs.

Elastic arteries

Large arteries that conduct blood away from the heart and have high elastin content.

Muscular arteries

Medium-sized arteries that distribute blood to specific body organs.

Capillary beds

Networks of capillaries where exchange of materials occurs.

Lymphatic vessels

Structures that carry lymph, a fluid that contains infection-fighting white blood cells.

Fenestrated capillaries

Capillaries with pores that enhance permeability, commonly found in kidneys.

Continuous capillaries

Least permeable type of capillaries, with tightly sealed endothelial cells.

Sinusoid capillaries

Highly permeable capillaries with large openings, found in liver and spleen.

Precapillary sphincters

Smooth muscle that regulates blood flow into capillaries.

Hydrostatic pressure

The pressure exerted by a fluid due to gravity.

Osmotic pressure

Pressure required to prevent water from flowing through a semipermeable membrane.

Net filtration pressure (NFP)

The difference between hydrostatic and osmotic pressures, dictating fluid movement.

Reactive hyperemia

Increased blood flow to an area due to prior inadequate blood supply.

Autoregulation

Intrinsic mechanisms that ensure blood flow to an organ meets its metabolic needs.

Angiogenesis

The formation of new blood vessels from existing ones.

Myogenic controls

Regulation of blood flow based on the response of vascular smooth muscle to changes in pressure.

Baroreceptors

Sensory receptors that detect changes in blood pressure.

Rennin-Angiotensin-Aldosterone system

Hormonal system that regulates blood pressure and fluid balance.

Aldosterone

Hormone that promotes sodium reabsorption in kidneys, influencing blood pressure.

Thoroughfare channel

Direct connection between arterioles and venules in capillary networks.

Vasa vasorum

Small blood vessels that supply the walls of large blood vessels.

Muscular pump

Mechanism that aids venous return via contraction of skeletal muscles.

Respiratory pump

Mechanism that aids venous return through pressure changes during breathing.

Systemic veins and venules

Blood vessels that return deoxygenated blood back to the heart.

Coronary arteries

The arteries that supply blood to the heart muscle itself.

Veins vs. Arteries

Veins have thinner walls and larger lumens than arteries; they contain valves.

Blood flow

The volume of blood that flows through a vessel, organ, or entire circulation in a given period.

Vascular resistance

The resistance that blood vessels offer to blood flow.

Total blood volume

The total amount of blood circulating within the cardiovascular system.

Interstitial fluid

Fluid found in the spaces between cells, derived from blood plasma.

Endothelial dysfunction

Loss of normal function of the endothelium, which can lead to vascular diseases.

Pressure gradient

Difference in pressure that drives blood flow.

Cardiac output (CO)

The volume of blood pumped by the heart per minute.

Sphygmomanometer

Instrument used to measure blood pressure.

Pulse pressure

The difference between systolic and diastolic pressure.

Vascular shunt

Direct connection that allows blood to bypass capillary beds.

Atherosclerosis

A condition in which fatty deposits build up in the artery walls.

Hypertension

Sustained high blood pressure, often above 140/90 mm Hg.

Circulatory shock

A condition in which blood vessels inadequately fill and cannot circulate blood normally.

Hypovolemic shock

Shock resulting from significant blood loss.

Cardiogenic shock

Shock caused by a failure of the heart to pump blood adequately.

Neural regulation

Control of blood vessel diameter by the nervous system.

Hormonal regulation

Control of blood vessel function through hormones.

Epinephrine

Hormone released by the adrenal glands that increases heart rate and blood pressure.

Norepinephrine

Hormone and neurotransmitter that increases blood pressure and heart rate.

Atrial natriuretic peptide (ANP)

Hormone that reduces blood pressure by causing vasodilation and increased sodium excretion.

Fluid reabsorption

Process by which fluid moves back into capillaries from interstitial fluid.

Respiratory gases exchange

The transfer of oxygen and carbon dioxide across capillary membranes.

Blood-brain barrier

A selective permeability barrier that protects the brain from harmful substances.

Nutrient absorption

Process where nutrients move from digestive tract to the bloodstream via capillaries.

Thermoregulation

The process by which the body maintains its internal temperature.

Extrinsic controls

Regulatory mechanisms that respond to conditions outside localized tissues.

Local vasodilators

Substances that induce relaxation of smooth muscle in blood vessels.

Mechanical stress

Physical pressure or force applied to blood vessels, influencing their function.

Vascular tone

The degree of constriction experienced by a blood vessel relative to its full dilation.

Aortic dissection

A serious condition in which the inner layer of the aorta tears.

Vein valves

Structures in veins that prevent the backflow of blood.

Lymphatic system

Network of vessels that drains excess interstitial fluid and returns it to the blood.

Proteins in blood plasma

Substances such as albumin that influence osmotic pressure and fluid balance.

Medulla oblongata

Part of the brainstem that regulates cardiovascular function.