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A&P II - Ch. 4 - Vasculature
Valencia College - Derrickson
94
Anatomy
Undergraduate 2
02/05/2019

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Cards

Term

- A collective term that refers to all of the blood vessels of the body.

Definition

vasculature

Term

Name the blood vessels that comprise the vasculature transport blood from the heart to the cells of the body and then back to the heart.

Definition

heart → arteries → arterioles → capillaries → venules → veins → back to the heart

Term

Arteries.

- outer layer

- connective tissue that is composed of collagen fibers and elastic fibers

Definition

tunica externa

Term

Arteries.

- middle layer

- consists of:

1. smooth muscle

2. external elastic lamina

-- connective tissue that is composed of elastic fibers

Definition

tunica media

Term

Arteries.

- inner layer

- consists of: endothelium, basement layer, and internal elastic lamina

Definition

tunica interna

Term

- single layer of epithelial cells

- surrounds the lumen, which is the hollow space where the blood is located

- This term always refers to the epithelial cells that line the lumen of a blood vessel or a lymphatic vessel.

Definition

endothelium

Term

A thin layer of connective tissue that is composed of collagen fibers

Definition

basement membrane

Term

Connective tissue that is composed of elastic fibers

Definition

internal elastic lamina

Term

Arteries carry oxygenated blood from the heart to ________. 

Definition

arterioles

Term

The structure of an arteriole is intermediate between that of an artery and a capillary; what three layers does an arteriole contain?

Definition

an inner layer of endothelium

- a middle layer of basement membrane

- an outer layer of smooth muscle

Term

Arterioles carry oxygenated blood from the ______ to the ______.

Definition

arteries

capillaries

Term

Most cells in the body are located near at least one capillary; this is due to the fact that capillaries are the most numerous type of blood vessel. How many exist is the body?

Definition

about 10 billion of them exist in the body

Term

Which tissues in the body lack capillaries? How do they receive nutrients?

Definition

epithelia, cartilage, and the cornea and lens of the eye are all avascular

- Epithelia and cartilage receive nutrients via diffusion from nearby connective tissues.

- The cornea and lens receive nutrients via diffusion from the aqueous humor.

Term

Capillaries connect ______ to ______; in order to accomplish this goal, capillaries interact with one another to form _________.

Definition

arterioles

venules

capillary beds

Term

A capillary bed consists of what 2 major types of vessels?

Definition

- capillaries

metarteriole

Term

A ________ is a blood vessel that branches off of an arteriole, courses through the capillaries, and then empties into a venule. 

Definition

metarteriole

Term

The distal end of the metarteriole is called a __________.

Definition

thoroughfare channel

Term

The metarteriole functions as a __________ that bypasses the capillaries when the body cells near the capillaries are not in need of any nutrients.

Definition

vascular shunt

Term

Around the junction of the metarteriole and the capillaries are rings of smooth muscle called ___________ that function to regulate blood flow into the capillaries.

Definition

precapillary sphincters

Term

1. When the precapillary sphincters are _____ (i.e. the smooth muscle is relaxed), blood flows into the capillaries and into the metarteriole.

-- This is the case when nearby body cells are in need of nutrients (i.e. O2, glucose, etc).  2. When the precapillary sphincters are _____ (i.e. the smooth muscle is contracted), blood flows only into the metarteriole and bypasses the capillaries.

--This is the case when nearby body cells are satisfied with existing nutrient supplies and are no longer in need of any more blood.

 

 

Definition

1. open

2. closed

Term

A capillary is a microscopic blood vessel that consists of 2 layers. What are they?

Definition

endothelium (inner layer)

basement membrane (outer layer)

Term

- Single layer of epithelial cells

- This* of a typical capillary contains pores (holes) in the form of ________ and ________.

Definition

endothelium

intercellular clefts

fenestrations

Term

Pores that exist between the endothelial cells of a capillary.

Definition

intercellular clefts

Term

Pores that run through individual endothelial cells of a capillary.

Definition

fenestrations

Term

This* of a capillary is also porous, but these pores have no specific names.

Definition

basement membrane

Term

_________ are the only blood vessels that permit the exchange of gases, nutrients, and wastes between the blood and the cells of the body, transforming oxygenated blood into deoxygenated blood.

Definition

Capillaries

Term

True or False: Only relatively small molecules (such as gases, H2O, ions, glucose, amino acids, and hormones) are able to move across capillary walls.

Definition

True

Term

What substances typically diffuse across capillary walls directly through the lipid bilayer of endothelial cell plasma membranes?

Definition

lipid-soluble (hydrophobic)

O2, CO2, steroid hormones

Term

Most of these substances, which include ions and polar molecules such as glucose and amino acids, pass across capillary walls through the pores (intercellular clefts and fenestrations).

Definition

water-soluble (hydrophilic)

Term

______  can diffuse across capillary walls in all possible ways: by moving through the pores of the capillary wall or  by moving through endothelial cell plasma membranes.

Definition

Water

- Recall that although water is a hydrophilic molecule, it is small and has no charge.

Term

Which substances are mostly too large to diffuse through the pores of capillary walls and are therefore confined to the blood?

Definition

blood cells and plasma proteins (albumins, fibrinogen, etc.)

Term

____________ are able to move across the capillary wall via transcytosis (endocytosis followed by exocytosis), allowing protein hormones to leave the bloodstream and then bind to specific receptors on their target cells.

Definition

Protein hormones

Term

Note that any H2O that diffuses out of the blood into the interstitium (the spaces between and around body cells) is called __________.

Definition

interstitial fluid (ISF)

- Therefore, interstitial fluid is a type of extracellular fluid located between and around body cells, while blood is a type of extracellular fluid located within blood vessels.

- The H2O in the interstitial fluid can diffuse into body cells if needed.

If there is too much H2O in the interstitium, the excess interstitial fluid drains into a nearby lymphatic vessel (usually a lymphatic capillary) that transports the fluid back into the blood.

 

Term

The structure of a venule is intermediate between that of a capillary and a vein; hence, a venule contains an inner layer of ________, a middle layer of ________, and a thin, outer layer of ________. 

Definition

endothelium

basement membrane

smooth muscle

Term

Venules transport ____________ from the capillaries to the veins. 

Definition

deoxygenated blood

Term

A vein consists of what 3 layers?

Definition

1. tunica externa

2. tunica media

3. tunica interna

Term

Veins.

- outer layer

- connective tissue that is composed of collagen fibers and elastic fibers

 

Definition

tunica externa

- The tunica externa of a vein is thinner than the tunica externa of an artery because it contains less connective tissue.

Term

Veins.

- middle layer

- consists of smooth muscle

Definition

tunica media

- The tunica media of veins is thinner than the tunica media of arteries because it has less smooth muscle

Term

Veins.

- inner layer

- What does this layer consist of?

Definition

tunica interna

- consists of endothelium and basement membrane

Term

Many veins of the limbs contain valves; a __________ consists of folds of the tunica interna that function to prevent backflow of blood.

Definition

venous valve

Term

1. Contractions of __________ surrounding the veins help push blood up the veins; the valves prevent backflow of blood, making sure that the blood returns to the heart.

2. This ______________ is vital to this process of __________.   

Definition

1. skeletal muscles

2. skeletal muscle pump; venous return

Term

Veins transport __________ from venules to the heart.

Definition

deoxygenated blood

Term

Which has more connective tissue, arteries or veins?

Definition

Arteries

Term

Which has less smooth muscle, arteries or veins?

Definition

Veins

Term

Which contains valves, arteries or veins?

Definition

Veins (especially in the limbs)

Term

Describe the overall appearance of arteries and veins.

Definition

Arteries: round, thick wall

Veins: thin wall, often collapse

Term

1. When a blood vessel undergoes ________, the smooth muscle within its wall contracts. 2. Describe what happens with the blood vessel lumen.

Definition

1. vasoconstriction

2.  The blood vessel lumen becomes smaller, which causes a reduction in blood flow.

Term

What are the only blood vessels that do not vasoconstrict or vasodilate? Why?

Definition

- Capillaries; this is due to the fact that capillaries lack smooth muscle in their walls.

–The smooth muscle in the precapillary sphincters can constrict or dilate in order to regulate blood flow through the capillary.

Term

Give the % of blood in each cardiovascular component.

1. heart

2. systemic arteries and arterioles

3. systemic capillaries

4. systemic veins and venules

5. pulmonary blood vessels

Definition

1. 7%

2. 13%

3. 7%

4. 64%

5. 9%

Term

Most of the blood volume at any given time is found in the ____________; consequently, these* are called the _________ of the body. 

Definition

systemic veins and venules

blood reservoirs

Term

The ability of an object to stretch.

Definition

Compliance

- Examples:

-- rubber band: has a high compliance because it can be easily stretched

-- crowbar: has a low compliance because it is not easily stretched

Term

Veins have a _____ compliance because they contain thin walls that are easily stretched; consequently, veins are called the ___________.

Definition

high

capacitance elements

Term

Even though veins contain the majority of blood in the body, venous pressure is _______ (typically near ___mmHg in the large great veins like the inferior vena cava and superior vena cava).

Definition

very low

0

Term

1. Arteries have a ____ compliance compared to veins because arteries contain thick walls that are not as easy to stretch.

2. Consequently, arterial pressures are _________, varying between ___mmHg and ___mmHg.

Definition

low

typically high; 110; 70

- Hence, an increase in the blood volume of arteries causes an increase in arterial pressure because the arteries cannot stretch as much as the veins.

Term

The pressure that blood exerts on the walls of a blood vessel.

Definition

blood pressure

Term

Blood pressure is usually measured in the brachial artery using a device called the __________.

Definition

sphygmomanometer

Term

Blood pressure in any major artery of the body varies between the __________ and the __________.

Definition

systolic pressure

diastolic pressure

Term

- The maximum pressure exerted by blood on arterial walls

- Normally equals about 110 mmHg

Definition

systolic pressure (during ventricular systole)

Term

- The minimum pressure exerted by blood on arterial walls

- Normally equals about 70 mmHg

Definition

diastolic pressure (during ventricular diastole)

Term

Under normal circumstances, what should be a person's blood pressure?

Definition

110 mmHg / 70 mmHg

Term

What 4 things affect changes in blood pressure?

Definition

1. Stroke volume

2. Heart rate

3. Cardiac output

4. Blood vessel diameter (vasoconstriction, vasodilation)

Term

True or False: An increase in stroke volume and/or heart rate does not cause an increase in cardiac output.

Definition

False

- The increase in cardiac output means that more blood is ejected from the heart, which causes an increase in blood pressure due to the excess blood pushing on the walls of the blood vessels of the body.

Term

True or False: Vasoconstriction also causes an increase in blood pressure since blood pushes more on blood vessel walls due to the smaller volume of the blood vessels.

Definition

True

Term

True or False: A decrease in stroke volume and/or heart rate causes an increase in cardiac output.

Definition

False

- It decreases cardiac output, which means that less blood is ejected from the heart, which causes a decrease in blood pressure due to less blood pushing on blood vessel walls.

Term

_________ also causes a decrease in blood pressure since blood does not push as much on blood vessel walls due to the larger volume of the blood vessels.

Definition

Vasodilation

Term

Blood pressure is regulated via a _________________ that involves the cardiovascular center.

Definition

negative feedback system

Term

1. The cardiovascular center is located in the ________.

2. What is this part of the brain known as?

Definition

1. medulla

2. brain stem

Term

Part of the cardiovascular center gives rise to the _______________ that innervate the heart.

Definition

- parasympathetic (Vagus) nerves

Recall that stimulation of these nerves causes a decrease in heart rate.

Term

The cardiovascular center also makes connections with the cardiac accelerator nerves, which are __________  that innervate the heart.

Definition

sympathetic nerves

- Recall that stimulation of these nerves causes an increase in heart rate and an increase in ventricular contraction (stroke volume).

Term

The cardiovascular center has connections with the __________, which are sympathetic nerves that innervate the smooth muscle in the walls of the blood vessels of the body (except the capillaries).

Definition

vasomotor nerves

- Stimulation of these nerves causes vasoconstriction of most blood vessels in the circulation.

Term

What does the cardiovascular center receive information from?

Definition

baroreceptors

Term

1. What are sensory receptors that respond to changes in blood pressure?

2. Name the 2 major types.

Definition

1. baroreceptors

2. aortic arch baroreceptors and carotid sinus baroreceptors

Term

- Located in the wall of the aortic arch

- Connect with the cardiovascular center via the Vagus (X) nerves

Definition

aortic arch baroreceptors

Term

- Located in the walls of the carotid sinuses

- The carotid sinuses are dilated regions of the internal carotid arteries just above the area where these arteries branch off of the common carotid arteries

- Connect with the cardiovascular center via the glossopharyngeal (IX) nerves

Definition

carotid sinus baroreceptors

Term

baroreceptor reflex in response to a decrease in blood pressure.

1. A ______ causes a decrease in blood pressure.

2. The decrease in blood pressure causes the baroreceptors to stretch less than normal. Consequently, the baroreceptors send fewer ___________ to the cardiovascular center.

Definition

1. stimulus

2. action potentials

Term

baroreceptor reflex in response to a decrease in blood pressure.

3. The cardiovascular center responds by activating the _____________ that supply the heart, which causes an increase in stroke volume and heart rate, and therefore an increase in cardiac output. In addition, the cardiovascular center activates the __________ that supply most of the blood vessels of the body, which causes vasoconstriction.

4. The increase in cardiac output and the vasoconstriction cause an _______ in blood pressure back to normal.

Definition

3. cardiac accelerator nerves; vasomotor nerves

4. increase

Term

baroreceptor reflex in response to an increase in blood pressure.

1. A ______ causes an increase in blood pressure.

2. The increase in blood pressure causes the baroreceptors to stretch more than normal. Consequently, the baroreceptors send a large number of action potentials to the ____________.

Definition

1. stimulus

2. cardiovascular center

Term

baroreceptor reflex in response to an increase in blood pressure.

3. The cardiovascular center responds by activating the ___________ nerves that supply the heart, which causes the heart rate to decrease. A decrease in heart rate causes a decrease in cardiac output. In addition, the lack of ________ stimulation by the cardiovascular center results in vasodilation of blood vessels.

4. The decrease in cardiac output and the vasodilation result in a ________ in blood pressure back to normal.

Definition

3. parasympathetic (Vagus); sympathetic

4. decrease 

Term

Leaky venous veins can cause veins to become dilated and twisted in appearance, a condition called __________. The condition may occur in the veins of almost any body part, but is most common in the esophagus, anal canal, and superficial veins of the lower limbs.

Definition

varicose veins

Term

If filtration greatly exceeds reabsorption, the result is _______, an abnormal increase in interstitial fluid volume.

Definition

edema

Term

______, or fainting, is a sudden, temporary loss of consciousness that is not due to head trauma, follow by spontaneous recovery.

Definition

Syncope

Term

1. Physicians sometimes use _____________, which involves carefully massaging the neck over the carotid sinus, to slow heart rate in a person who has paroxysmal superventricular tachycardia.

2. Anything that stretches or puts pressure on the carotid sinus (hyperextension of the head, tight collars, etc.) may also slow heart rate and can cause _____________.

Definition

1. carotid sinus massage

2. carotid sinus syncope

Term

_______ is a failure of the cardiovascular system to deliver enough O2 and nutrients to meet cellular metabolic needs.

Definition

Shock

Term

Persistently high blood pressure

Definition

hypertension

Term

A thin, weakened section of the wall of an artery or a vein that bulges outward, forming a balloon-like sac.

Definition

aneurysm

Term

The removal of atherosclerotic plaque from the carotid artery to restore greater blood flow to the brain.

Definition

- carotid endarterectomy

Term

The presence of a blood clot in a deep vein of the lower limbs.

Definition

deep vein thrombosis

Term

Low blood pressure

Definition

hypotension

Term

Normal blood pressure

Definition

normotensive

Term

The closure or obstruction of the lumen of a structure such as a blood vessel.

Definition

occlusion

Term

An excessive lowering of systemic blood pressure when a person assumes an erect or semi-erect posture; it is usually a sign of a disease.

Definition

- orthostatic hypotension

Term

Inflammation of a vein, often in a leg

Definition

phlebitist

Term

An operation to remove a blood clot from a blood vessel.

Definition

thrombectomy

Term

1. When a blood vessel undergoes ________, the smooth muscle within its wall relaxes.

2. Describe what happens with the blood vessel lumen.

Definition

1. vasodilation

2. The blood vessel lumen becomes wider, which causes an increase in blood flow. 

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