exam 3 sg 2

Artery role

A blood vessel that carries blood away from the heart (usually oxygenated, except in the pulmonary circuit).

artery function

Thick, muscular walls to handle high pressure.

Arteriole role

A small branch of an artery leading to capillaries.

Arteriole function

Regulate blood flow and pressure by constricting/dilating.

Conducting Arteries (Elastic Arteries)

Largest arteries (e.g., aorta); stretch and recoil with heartbeat.

Distributing Arteries (Muscular Arteries):

Deliver blood to specific organs (e.g., renal artery to kidney).

Resistance Arteries (Arterioles):

Control blood flow into capillaries; major role in blood pressure regulation

 Vein role

A blood vessel that returns blood to the heart (usually deoxygenated).

vein function

Thinner walls and larger lumen than arteries; often have valves to prevent backflow.

 Venule

Small veins that collect blood from capillaries and join to form larger veins.

 Sinus (Venous Sinus)

A large, thin-walled vein with no smooth muscle; collects blood in areas like the brain (e.g., dural venous sinuses) or heart (coronary sinus).

Capillaries

Tiny vessels (one-cell thick) where gas, nutrient, and waste exchange occurs between blood and tissues.
🧬 Connect arterioles to venules.

Continuous

least permeable (muscle, brain)

Fenestrated

more permeable (kidneys, intestines)

Sinusoidal

most permeable (liver, bone marrow)

 Portal Systems

A vascular system where blood flows through two capillary beds before returning to the heart.

 Anastomoses

Direct connections between two vessels (artery-artery, vein-vein, or artery-vein).

Tunica Interna (Intima)

innermost layer; smooth surface for blood flow

Tunica Media

Middle layer; Regulates diameter of the vessel

Tunica Externa

Outermost layer; Anchors and protects the vessel.

Arties components

carry blood away from heart

thicker

high blood pleasure

more elastic

no valves

vein components

carry blood toward the heart

low pressure

thinner

less elastic

has valves

Deoxygenated Blood Path:

• Right ventricle →

• Pulmonary semilunar valve →

• Pulmonary trunk →

• Right & left pulmonary arteries →

• Lungs (gas exchange: CO₂ out, O₂ in)

Oxygenated Blood Path:

• Lungs →

• Pulmonary veins (2 from each lung) →

• Left atrium

Which vessels and structures are involved in the pulmonary circuit?

• Right ventricle

• Pulmonary trunk and arteries

• Pulmonary capillaries (in lungs)

• Pulmonary veins

• Left atrium

Aortic Arch:

• Brachiocephalic → R subclavian, R common carotid; L common carotid; L subclavian

Descending Aorta Branches:

Celiac trunk, SMA, IMA, renal, gonadal, iliacs, femoral, etc.

Coronary Circulation:

Right/Left coronary arteries & branches

SVC:

Head, arms, upper body

IVC:

Lower body, renal, hepatic, gonadal, iliac

Portal System:

GI organs → liver → IVC

Lymphatic System function

Return fluid to blood, filter pathogens, immunity

Lymphatic System pathway

Lymph capillaries → vessels → nodes → ducts → subclavian veins

Lymphatic System organs

Red bone marrow, thymus, lymph nodes, tonsils, spleen

Lymphatic System ducts

thoracic

right lympathic

Thoracic Duct:

Left body, lower body

Right Lymphatic Duct:

Right upper body