Human Circulatory System: Components, Blood Vessels, and Pathologies

What is the function of the circulatory system?

Transport blood, oxygen, nutrients to the body and export waste products out of the body.

What are the main three components of the circulatory system?

Heart, blood vessels, blood.

What are the 3 types of blood vessels?

Arteries, veins, capillaries.

What do arteries carry?

Blood away from the heart.

What type of blood do arteries carry?

Oxygenated blood.

What do veins carry?

Blood to the heart.

What type of blood do veins carry?

Deoxygenated blood.

True or False: Veins have a higher internal pressure compared to arteries.

False.

What are the 3 layers that comprise an artery?

Tunica Adventitia/Externa, Tunica Media, Tunica Intima.

What is the composition of the Tunica Adventitia/Externa?

Collagen.

What is the function of the Tunica Adventitia/Externa?

Protective outer layer.

What is the composition of the Tunica Media?

Thick elastic tissue, muscle.

What is the function of the Tunica Media?

Maintain high pressure to pump blood long distances.

What is the composition of the Tunica Intima?

Endothelial cells.

What is the function of the Tunica Intima?

Protective inner layer, secretion and absorption.

List the classification of arteries from largest to smallest.

Elastic arteries, muscular arteries, arterioles.

Why are elastic arteries found closest to the heart?

They have a thick tunica media to withstand high pressure and project blood far distances.

Name an example of an elastic artery.

Aorta.

Why do muscular arteries need more muscle?

They are further from the heart and need muscle to propel blood to peripheral tissues.

What feature is unique to arterioles?

Sphincters that regulate blood pressure and flow.

What is the composition of arterioles?

Narrow lumens with the tunica media as the thickest layer.

What is the width of a capillary?

One red blood cell.

What layers comprise a capillary vessel?

One layer of endothelial simple squamous cells surrounded by a basement membrane.

Which type of capillary is the most permeable?

Sinusoid capillary.

Which type of capillary is the least permeable?

Continuous capillary.

What does it mean for capillaries to be 'selectively leaky'?

Leakiness is based on hydrostatic pressure within the capillary.

What is the difference between filtration and reabsorption in capillary beds?

Filtration is fluids exiting arterial capillaries; reabsorption is fluids entering venous capillaries.

Why is a vein's wall thinner than an artery's?

Blood pressure has declined significantly by the time it reaches veins.

What are the three mechanisms used to get blood back to the heart against gravity?

Valves, normal body movement, skeletal muscle pump.

True or False: Veins get thinner in diameter the closer they get to the heart.

False; they get thicker.

What is a venule?

A vessel that links veins and capillaries together.

What tissue is not present in venules?

Muscle.

What is aortic dissection?

A tear in the wall of the aorta causing abnormal blood flow.

List the causes of aortic dissection.

Hypertension, atherosclerosis, aortic aneurysm, connective tissue disorders, trauma, some medications, family history.

How is aortic dissection treated?

Via surgery and aggressive control of risk factors.

What is a capillary rupture?

Breakage of a capillary causing RBCs to flow out.

True or False: Capillary ruptures can resolve themselves independently.

True.

What is an edema?

Swelling caused by abnormal accumulation of fluid in a tissue/organ.

What is the difference between pulmonary edema and tissue edema?

Pulmonary edema is fluid accumulation in the alveoli; tissue edema is fluid accumulation in tissues.

List the causes of tissue edema.

Injury, infection, heart/liver/kidney failure, medications, pregnancy.

List the causes of pulmonary edema.

Congestive heart failure, heart attack, cardiomyopathy, hypertension, inhalation of toxic chemicals, injury, near-drowning.

How is an edema treated?

RICE (rest, ice, compression, elevation), garments, medication, proper physical activity.

What are varicose veins?

Damage to a valve in a vein causing abnormal blood flow and pooling.

List the causes of varicose veins.

Weak valves, increased blood pressure, family history.

How are varicose veins treated?

Surgical removal or techniques to close off impacted veins.