Functions and Structure of the Circulatory System

Flashcards covering the key concepts and terms related to the functions and structures of the circulatory system.

Pulmonary vessels

Transport blood from the right ventricle through the lungs to the left atrium.

Systemic vessels

Transport blood from the left ventricle through all parts of the body to the right atrium.

Major Functions of the Circulatory System

Carries blood to body tissues, exchanges nutrients and waste, transports hormones and immune components.

Tunica intima

The innermost layer of blood vessels, consisting of endothelium and related structures.

Tunica media

Middle layer of blood vessels, made of smooth muscle cells and varying amounts of elastic and collagen fibers.

Vasoconstriction

Contraction of smooth muscle resulting in decreased blood flow.

Vasodilation

Relaxation of smooth muscle resulting in increased blood flow.

Elastic arteries

Largest diameter arteries with more elastic tissue than muscle; examples include the aorta.

Muscular arteries

Arteries that regulate blood supply by constricting or dilating, characterized by a thick muscular layer.

Capillaries

Smallest blood vessels where exchanges between blood and interstitial spaces occur.

Hepatic portal system

Veins that carry nutrient-rich blood from the intestines to the liver, where it can be processed.

Arteriosclerosis

Degenerative changes in arteries that make them less elastic.

Atherosclerosis

Deposition of plaque on arterial walls, affecting medium and larger arteries.

Tunica Externa

The outermost layer of blood vessels, consisting of connective tissue that provides structural support and flexibility.

Arteries

carry blood away from heart and get smaller as they get further from the heart

Arterioles

small branches of arteries that lead to capillaries , regulating blood flow and pressure.

Continuous capillaries

are a type of capillary where the endothelial cells provide a continuous lining, allowing for the efficient exchange of gases and nutrients while minimizing leakage.

Fenestrated capillaries

are a type of capillary with small openings in the endothelial lining, allowing for greater permeability to proteins and larger solutes, typically found in areas like the kidneys and intestine.

Sinusoidal capillaries

are a type of capillary with larger openings and a discontinuous endothelial lining, facilitating the transfer of large molecules and cells, commonly located in the liver, spleen, and bone marrow.

Capillary Network

blood flows from arterioles to metarterioles to the thoroughfare channel to arterial capillaries to venule capillaries to venule

Arteriovenous anastomoses

are connections between arterioles and venules that allow blood to bypass the capillary system, helping to regulate blood flow and pressure.

Glomus

is a specialized structure in the circulatory system consisting of a compact network of blood vessels involved in thermoregulation and the regulation of blood flow, often found at the ends of digits and in areas exposed to environmental temperature changes.

Pathologic arteriovenous anastomoses

are abnormal connections between arterioles and venules that can disrupt normal blood flow, potentially leading to various clinical complications and affecting blood pressure regulation.

Veins

are blood vessels that carry deoxygenated blood back to the heart, with the exception of the pulmonary veins, which transport oxygenated blood from the lungs to the heart. They have thinner walls compared to arteries and often contain valves to prevent backflow.

Venules

are small blood vessels that collect deoxygenated blood from capillaries and transport it to veins, playing a key role in the circulatory system by facilitating blood flow and exchange.

Small Veins

are the blood vessels that receive deoxygenated blood from venules and transport it to larger veins, continuing the pathway back to the heart.

Portal Veins

are blood vessels that carry blood from one organ to another, primarily serving the liver. Go through primary and secondary capillart network

Valves

are structures within veins and the heart that prevent the backflow of blood, ensuring unidirectional flow and maintaining proper circulation. found in veins greater than 2mm, more in the lower extremities

Vasa Vasorum

are small blood vessels that supply the walls of arteries and veins, providing nutrients and oxygen to the tissue.

Three parts of aorta

include the ascending aorta, aortic arch, and descending aorta.

Ascending aorta

right and left coronart arteries branch from here

Aortic arch

Brachiocephalic artery, left common carotid and left subclavian artery

Descending aorta

supplies blood to the thorax and abdomen through its branches.

Epinephrine/Norepinephrine

Hormones released by the adrenal glands that increases cardiac output and vasoconstriction

Antidiuretic hormone

A hormone produced by the hypothalamus and secreted by the posterior pituitary gland, which regulates water retention in the kidneys. It plays a key role in maintaining blood pressure

Angiotensin II

A peptide hormone that increases blood pressure by causing blood vessels to constrict, aldosterone production, ADH secretion, thirst and cardiac output secretion

EPO

A hormone that stimulates red blood cell production in the bone marrow, increases vasoconstriction, raising bp

Aldosterone

A steroid hormone produced by the adrenal cortex that increases salt and water reabsorption that goes into kidneys that increases blood volume, raising bp

Atrial Natiuretic peptide and brain natiuretic peptide

Hormones released by the heart that promote vasodilation leading to a decrease in blood pressure and blood volume. has to make you pee