Blood Vessel Structure and Function

False (B)

Large lumen and tunica externa

<p>elastic fibers</p> Signup and view all the answers

<p>Veins = Wide lumen and valves Arteries = Thick walls and narrow lumen Capillaries = Thin walls for exchange Valves = Prevent backflow of blood</p> Signup and view all the answers

<p>To carry blood away from the heart (A)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>tunica externa</p> Signup and view all the answers

<p>capillaries</p> Signup and view all the answers

<p>Arteries = Carry blood away from the heart Veins = Carry blood back to the heart Capillaries = Facilitate gas exchange Arterioles = Regulate blood flow to capillaries</p> Signup and view all the answers

<p>It contains smooth muscles and elastic fibers. (A)</p> Signup and view all the answers

<p>False (B)</p> Signup and view all the answers

<p>diffusion</p> Signup and view all the answers

<p>tunica intima</p> Signup and view all the answers

<p>Fenestrations (C)</p> Signup and view all the answers

<p>True (A)</p> Signup and view all the answers

<p>vasoconstriction</p> Signup and view all the answers

<p>lower</p> Signup and view all the answers

<p>Capillaries = One cell thick, site of exchange Arteries = Thick wall, carry blood under high pressure Veins = Thinner walls, carry blood back to the heart Arterioles = Smaller arteries, regulate blood flow</p> Signup and view all the answers

Veins have a large lumen (central opening) which allows for the passage of blood under low pressure back to the heart. This is in contrast to arteries which have smaller lumens due to higher blood pressure.

Veins have a thin tunica media, a layer of smooth muscle and elastic fibers, compared to arteries due to lower blood pressure in veins.

Veins have valves to prevent backflow of blood, especially against gravity. This ensures blood flows in one direction towards the heart.

The tunica externa provides structural support and strength to veins.

The most notable difference between arteries and veins is their structure. Arteries have a thicker wall and a narrow lumen, while veins have a thin wall and a wide lumen.

Blood vessels that carry blood away from the heart under high pressure.

Smaller arteries that connect arteries to capillaries.

Tiny blood vessels, one cell thick, responsible for exchange of substances between blood and tissues.

Small veins connecting capillaries to larger veins.

Blood vessels that carry blood back to the heart under low pressure.

Outermost layer of blood vessels, made of collagen, providing strength and support.

Middle layer of blood vessels, containing smooth muscle and elastic fibers, responsible for maintaining blood pressure and regulating blood flow.

Innermost layer of blood vessels, made of squamous epithelial cells, reducing friction between blood flow and vessel walls.

The central hollow space of a blood vessel through which blood flows.

The narrowing of blood vessels due to contraction of smooth muscle.

The widening of blood vessels due to relaxation of smooth muscle.

Small pores in the walls of capillaries that allow for the passage of substances in and out of the blood.

The process of substances moving across a membrane from an area of high concentration to an area of low concentration.

Tissue fluid that surrounds cells, carrying nutrients and removing waste products.

A network of capillaries that connect arterial to venous circulation, providing extensive surface area for exchange.