BIO 108: Heart Cardiovascular System

What is the hollow center where blood flows?

Lumen

Which tunica:

__ - (endothelium) inner most layer, contacts blood

Tunica Interna

Which tunica:

__ - thickest layer, smooth muscle fibers & elastic fibers

Tunica Media

Which tunica:

__ - outer coat, elastic & collagen fibers

Tunica Externa

Which blood vessel class:

__ - carry blood away from heart.

Arteries

Which blood vessel class:

__ - are smallest branches of arteries.

Arterioles

Which blood vessel class:

__ - are smallest blood vessels, location of exchange between blood and interstitial fluid, chemicals and gases diffuse across walls.

Capillaries

Which blood vessel class:

__ - collect blood from capillaries.

Venules

Which blood vessel class:

__ - return blood to heart.

Veins

Which arteries:

• Decrease diameter of lumen by contracting smooth muscle.

• Blood pressure ↑

Vasoconstriction

Which arteries:

• Increase diameter of lumen by relaxing smooth muscle.

• Blood pressure ↓

Vasodilation

Which arteries:

• (Conducting) largest diameter.

• Walls can stretch to preserve pressure.

Elastic arteries

Which arteries:

• Elastic energy acts as a pressure storage.

Pressure Reservoir

Which arteries:

• (Distributing) medium-sized.

• Contain more smooth muscle → greater vasoconstriction & vasodilation to adjust blood flow.

Muscular Arteries

What is opposition to blood flow due to friction between blood & inner wall?

Resistance

__ - found near almost every cell in the body, known as exchange vessels.

Microcirculation

Blood flow increases in local capillaries when metabolic activity __.

increases.

__ are 10 to 100 capillaries in a network.

Capillary Bed

__ are vessels that emerges from arteriole.

Metarteriole

__ is the distal end of metarteriole.

Thoroughfare Channel

__ control blood flow through true capillary.

Precapillary Sphincter

Which type of capillaries:

__ - almost totally intact.

Continuous

Which type of capillaries:

__ - gaps between endothelial cells.

Intercellular Clefts

Which type of capillaries:

__ - contains small pores in endothelial cells.

Fenestrated

Which type of capillaries:

__ - is fairly porous.

Sinusoid

What are these characteristics of:

• Collect blood from the capillaries

• Wall are still porous but not as much as the capillaries

• Can also help mildly with exchange

Venules

What has three layers as an artery - just not as thick?

Veins

What is not designed to withstand high pressure, and lumen is larger than an artery?

Veins

What flap like cusps, prevent back flow of blood?

Valves

Capillary Exchange:

About __ of blood is constantly moving materials in and out of blood & interstitial fluid.

7%

Basic mechanisms of capillary exchange:

__ - O2, CO2, amino acids, hormones move by simple diffusion.

Diffusion

Basic mechanisms of capillary exchange:

__ - large water soluble molecules (insulin, antibodies) are activity moved by the endothelial cells.

Transcytosis

Basic mechanisms of capillary exchange:

__ - large amount of material moves together from high pressure to low pressure.

Bulk Flow

Which Bulk Flow type:

• From capillaries → interstitial fluid

Filtration

Which Bulk Flow type:

• From interstitial fluid → capillaries

Reabsorption

Out = __, __ capillary pressure, 24L/day

filtration, high

In = __, __ capillary pressure, 21L/day

reabsorption, decreased

Systolic blood pressure is the __ pressure in arteries during __.

highest, systole.

Diastolic blood pressure is the __ pressure obtained in arteries during __.

lowest, diastole.

Size of the lumen - the smaller the __ the greater the __.

lumen, resistance.

Blood viscosity - the greater the __ (thickness) the greater the __.

viscosity, resistance.

Total blood vessel length - the longer the __ the greater the __.

blood vessel, resistance.

What is the volume of blood flowing back to the heart, uses the valves veins to prevent back flow?

Venous Return

__ - using muscles of arms and legs to “milk” blood back to the heart.

Skeletal muscle pump

__ - during inhalation the diaphragm compresses abdominal veins, breathing out compresses thoracic veins.

Respiratory pump

Which neural mechanism:

__ - carotid bodies and aortic bodies monitor blood, respond to changes in chemical composition, particularly pH and dissolved gases.

Chemoreceptors

Which neural mechanism:

__ - stretch receptors in arterial walls respond to changes in blood pressure.

Baroreceptors

Which of the baroreceptors:

__ sinuses - maintain blood flow to brain.

Carotid

Which of the baroreceptors:

__ sinuses - monitor start of systemic circuit.

Aortic

Which neural mechanism:

__ - monitor joint movement.

Proprioceptors

Which endocrine mechanism:

__ - increase rate and contraction.

E and NE

Antidiuretic hormone (ADH) - reduces __ at kidneys, __ volume & contraction.

water loss, increase

Which endocrine mechanism:

__ - thirst, increase volume & peripheral vasoconstriction.

Renin-Angiotensin-Aldosterone

Which endocrine mechanism:

__ - stimulates red blood cell production, increases volume.

Erythropoietin (EPO)

Natriuretic peptides (ANP, BNP) - excessive __ stretching → __ blood volume.

diastolic, lower