Ch 21: Circulatory System III

What are the efferent vessels?

Arteries

Which vessels carry blood away from the heart?

Arteries

What are the afferent vessels?

Veins

Which vessels carry blood toward the heart?

Veins

Which vessels are microscopic and connect small arteries to small veins?

Capillaries

In which vessels do gas exchange occur?

Capillaries

What is the term used to describe layers of arteries and veins?

Tunics

What is the inner layer of vessel wall that faces the lumen called?

Tunica interna

What lines the tunica interna?

Simple squamous epithelium

T/f: The tunica interna has a slick lining.

True

Which layer of the vessel wall has a selectively permeable membrane?

Tunica interna

What is the middle layer of the vessel wall called?

Tunica media

Which layer of the vessel wall is thick?

Tunica media

What does tunica media have within its wall (3)?

Smooth muscle, collagen, and elastin

Which layer of the vessel wall is responsible for vasoconstriction and vasodilation?

Tunica media

What is the outer layer of the vessel wall called?

Tunica externa

What is the tunica externa made of?

Loose connective tissue

Which layer of the vessel wall anchors the vessel to its surroundings?

Tunica externa

What is the term used to describe the network of small vessels that large vessels have?

Vaso vasorum

What are the resistance vessels?

Arteries

T/f: Arteries can withstand a high bp.

True

What are the biggest arteries called?

Conducting (elastic)

Which type of artery absorbs some pressure but also maintains it?

Conducting (elastic)

What is an example of a conducting artery?

Aorta

What type of artery is midsized?

Distributing

Which type of artery distributes blood to specific organs?

Distributing

What is an example of a distributing artery?

Femoral

What are the smallest arteries?

Resistance

How big are resistance arteries?

Less than 0.1 mm

What is the smallest example of a resistance artery?

Arterioles

Are resistance arteries named?

No

What is the term used to describe the short vessels linking arterioles and capillaries?

Metarterioles

Do elastic arteries have neurons?

Yes

What do elastic artery neurons sense?

Blood pressure and chemistry

What is the term used to describe baroreceptors in internal carotid artery wall?

Carotid sinuses

What nerve transmits signals to vasomotor and cardiac centers of the brainstem in carotid sinus?

Glossopharyngeal

What nerve transmits signals to respiratory centers of the brain in carotid bodies?

Glossopharyngeal

What is the term used to describe chemoreceptors near the branch point of the common carotid artery?

Carotid bodies

What is the term used to describe the chemoreceptors in the aortic arch?

Aortic bodies

What signal respiratory centers of the brain besides carotid bodies?

Aortic bodies

What are aortic bodies innervated by?

Vagus nerves

What division of the nervous system is the vagus nerve controlled by?

Parasympathetic

What are exchange vessels called?

Capillaries

What are exchanged between capillaries (3)?

Nutrients, wastes, and hormones

What makes up the capillary wall?

Endothelium and basal lamina

Name three routes through the capillary wall.

Intercellular clefts, filtration pores, and through endothelial cytoplasm

What are two ways through endothelial cytoplasm?

Transcytosis and diffusion

What is a means of getting through the endothelial cytoplasm for hydrophilic solutes?

Transcytosis

What is a means of getting through the endothelial cytoplasm for nonpolar solutes?

Diffusion

Fill in the blank: When a tissue is active, precapillary sphincters _____.

Relax and open

When precapillary sphincters relax, where does blood go?

Fills capillaries

Fill in the blank: When a tissue is inactive, precapillary sphincters _____.

Close

When precapillary sphincters close, where does blood flow?

From metarteriole to thoroughfare channel

When blood flows from metarterioles to thoroughfare channels what does it bypass?

Capillary bed

What are the holding tanks that contain most of the blood?

Veins

What are the capacitance vessels?

Veins

What are the smallest veins that are very porous and allow for exchange?

Postcapillary venules

What veins have smooth muscle in wall (tunica media)?

Muscular venules

What veins contain valves?

Medium

Why would some veins need valves?

Gravity

Which veins are individually named?

Medium veins

What veins have large lumens, very thin walls, and no smooth muscle?

Venous sinuses

Since venous sinuses have no smooth muscle what does that mean for vasomotion?

No vasomotion

Which veins have smooth muscle in all tunics?

Large

Where is most of the blood at rest?

Veins

What squeezes veins and forces blood through one-way valves toward heart?

Muscle

If you were in a cast how would that effect the skeletal muscle blood pump?

Get blood clots

What is the circulatory route from artery to capillary to vein called?

Simple path

What is a sequence of two capillary beds?

Portal system

Where are portal systems found?

Liver

Why does the liver have portal systems?

Extra filter

What is a vessel merger without intervening capillary bed?

Anastomosis

T/f: The pulmonary trunk is paired.

False

Where does the pulmonary trunk come from?

R ventricle

What type of blood do the pulmonary arteries carry?

Oxygen poor

T/f: Pulmonary arteries are paired.

True

Name the 5 vessels in the pulmonary circuit.

Pulmonary trunk, pulmonary arteries, lobar arteries, alveolar capillaries, and pulmonary veins

What type of blood do pulmonary veins carry?

Oxygen rich

T/f: Pulmonary veins are paired.

True

Name the three parts of the aorta.

Ascending aorta, aortic arch, and descending aorta

Name three structures that make up the aortic arch.

Brachiocephalic a, L common carotid a, and L subclavian a

What does the Brachiocephalic a branch off into?

L common carotid a and L subclavian a

What two structures make up the descending aorta?

Thoracis aorta and abdominal aorta

What structures separates the thoracic aorta and abdominal aorta?

Diaphragm

Name the arteries that make up the circle of Willis?

Anterior cerebral a, anterior communicating a, posterior cerebral a, and posterior communicating a

Name the dural venous sinuses.

Superior sagittal, inferior sagittal, and transverse

What are the arteries of the thorax?

Brachiocephalic trunk, L common carotid, and L subclavian

Name point A.

Common carotid a

Name point B.

External carotid a

Name point C.

Facial a

Name point D.

Internal carotid a

Name point E.

Vertebral a

Name point A.

Common carotid a

Name point B.

External carotid a

Name point C.

Facial a

Name point D.

Internal carotid a

Name point E.

Vertebral a

Name point A.

Vertebral a

Name point B.

Basilar a

Name point C.

Anterior cerebral a