Chapter 20 - The Circulatory System: Blood Vessels and Circulation

What are the three basic types of blood vessels?

- Capillaries

- Arteries

- Veins

Which category includes the smallest blood vessels?

Capillaries

The smallest of the resistance arteries are called _____________

Arterioles

Arrange the three classes of arteries in order from largest to smallest

- Conducting (elastic/large)

- Disturbing (muscular/medium)

- Resistance (small)

The movement of carbon dioxide from the tissue into the capillary blood occurs via ____________

diffusion

Which of the following are types of capillaries?

- Continuous Capillaries

- Fenestrated Capillaries

- Sinusoids Capillaries (discontinuous capillaries)

Which type of blood vessel carries blood away from the heart?

Arteries

The walls of arteries and veins are composed of three layers called tunics. Place the tunics in order, starting with the innermost layer, and ending with the outermost layer.

- Tunica interna (tunica intima)

- Tunica media

- Tunica extrema (tunica adventitia)

Match each type of capillary to its most likely location

1) Continuous Capillaries

2) Fenestrated Capillaries

3) Sinusoids (discontinuous capillaries)

1) Continuous Capillaries - Occur in most tissues, such as skeletal muscles

2) Fenestrated Capillaries - important in organs that engage in rapid absorption or filtration (i.e. the kidneys, endocrine glands, small intestine, and choroid plexuses of the brain)

3) Sinusoids - Areas where large proteins and cells need to enter or leave the bloodstream (e.g. liver spleen)

Why are capillaries sometimes called the exchange vessels of the cardiovascular system?

Most exchange b/n the blood and the tissue fluid occurs across capillary walls

The capillary wall consists of which of the following layers?

- Endothelium

- Basal lamina

Which of the three primary categories of blood vessels carries blood back to the heart?

- Veins

A capillary bed is an organized network of:

capillaries

Fluid exchange mainly occurs in which of the following?

capillaries

Postcapillary ____________ are the smallest of veins

venules

List the following vessels in order of those that have the highest blood pressure to those that have the lowest blood pressure

- Aorta

- Large arteries (systemic artery)

- Small arteries (systemic artery)

- Arterioles

- Capillaries

- Venules

- Small veins (systemic vein)

- Large veins (systemic vein)

- Venae cava

Which of these is a vein?

Veins have larger diameter and a thinner wall

Which of the following are functions of the endothelium?

- Repels red blood cells and platelets to retain flow

- Acts as selectively permeable barrier to materials entering or leaving the bloodstream

- Secretes chemicals that stimulate dilation or constriction

Match each hormone to its description:

A) Angiotensin II

B) Aldosterone

C) Natriuretic peptides

D) Antidiuretic hormone

A) Angiotensin II - A potent vasoconstrictor that raises the blood pressure. Its synthesis requires angiotensin-converting enzyme (ACE). Hypertension is often treated with drugs called ACE inhibitors which block the action of this enzyme, thus lowering angiotensin II levels and blood pressure.

B) Aldosterone - "salt-retaining hormone" primarily promotes Na⁺ retention by the kidneys. Since water follows sodium osmotically, Na⁺ retention promotes water retention, thereby supporting blood pressure.

C) Natriuretic peptides - hormones that are secreted by the heart that antagonize aldosterone. They increase Na⁺ excretion by the kidneys, thus reducing blood volume and pressure. They also have a generalized vasodilator effect that helps lower blood pressure.

D) Antidiuretic hormone - ADH primarily promotes water retention, but at pathologically high concentrations it is also a vasoconstrictor - hence its alternate name, "arginine vasopressin". Both of these effects raise blood pressure.

Which of the following are possible consequences of edema?

circulatory shock and tissue death

A __________ is an autonomic, negative feedback response to changes in blood pressure

baroreflex

Name the mechanism that describes the ability of a tissue to adjust its own blood supply through vasomotion or angiogenesis

autoregulation

The term microvasculature (or microcirculation) refers to which of the following?

Arterioles, Capillaries, and Venules

Large molecules, such as clotting proteins and albumin synthesized by the liver, enter the blood through which of the following?

Sinusoids (discontinuous) capillaries

The physical force exerted by a liquid against a surface such as a capillary wall is called ______________ pressure

Hydrostatic

Rank the types of veins from smallest to largest:

- Postcapillary venules

- Muscular venules

- Medium veins

- Venous sinuses

- Large veins

A weak, bulging point in the wall of a heart chamber or blood vessel that presents a threat of hemorrhage is known as a(n):

aneurysm

Arterial sense organs monitor blood chemistry and blood pressure in order to help regulate which of the following?

heartbeat, blood vessel diameters, and respiration

Match each type of shock to its possible cause:

a) Hypovolemic shock

b) Obstructed venous return shock

c) Neurogenic shock

d) Septic shock

A) Hypovolemic shock - produced by a loss of blood volume as a result of hemorrhage, trauma, bleeding ulcers, burns, or dehydration

B) Obstructed venous return shock - occurs when any objet, such as a growing tumor or aneurysm, compresses a vein and impedes blood flow

C) Neurogenic shock - a form of venous pooling shock that results from a sudden loss of vasomotor tone, allowing the vessels to dilate. This can result from causes as severe as brainstem trauma or as slight as an emotional shock

D) Septic shock - a form of venous pooling shock that occurs when bacterial toxins trigger vasodilation and increased capillary permeability

A process in which hydrostatic pressure forces a fluid through a selectively permeable membrane (especially a capillary wall) is known as:

filtration

Chemicals given off by the systemic capillary blood to the perivascular tissues often include which of the following?

- oxygen

- glucose and other nutrients

- antibodies

- hormones

In arteries and veins, the outermost layer of the vessel wall is called the tunica ____________

externa

Peripheral resistance is directly affected of which of the following?

blood viscosity, vessel length, and vessel radius

All of these will easily diffuse the plasma membrane:

- Carbon dioxide, oxygen, and steroid hormones easily diffuse across the plasma membrane (and lipid soluble hormones)

- Glucose, large proteins, charged molecules, and lipid insoluble molecules must pass through protein channels, pores, or intercellular clefts

The basal lamina is the non-cellular, proteinaceous material that surrounds the capillary _____________ cells and separates it from adjacent connective tissue

endothelial

Which term refers to the autonomic feedback response to changes in blood chemistry?

chemoreflex

Venous return (the flow of blood back to the heart) is achieved by which of the following mechanisms?

- The pressure gradient

- Gravity

- The skeletal muscle pump

- The thoracic (respiratory) pump

- Cardiac suction

In arteries and veins, the tunica ___________ is usually the thickest layer of the vessel wall

media

Diastolic pressure is the minimum arterial blood pressure occurring during which of the following?

ventricular relaxation

Identify the tissues that comprise the capillary endothelium:

- simple squamous epithelium

- loose connective

___________ venules receive blood from capillaries

postcapillary

True or false: Aldosterone leads to decreased blood pressure by inhibiting the reabsorption of sodium and thus water by the kidneys

False

Why is it important for conducting arteries to maintain elasticity?

- Their recoil helps maintain blood pressure between heartbeats

- Their expansion and recoil helps keep the blood flowing during diastole

- Their expansion reduces systolic stress on smaller arteries

True or false: Capillary exchange is a two way movement of fluids and substances

True

Vasoconstriction primarily results from contraction of smooth muscle in the tunica ___________

media

The nucleus in the medulla oblongata that transmits efferent signals to the blood vessels and regulates vasomotion is known as the _______________ center

vasomotor

Which of the following are functions of vasoreflexes?

- They modify perfusion to an organ or tissue

- They help regulate blood pressure

Which type of venule receives blood from the postcapillary venule?

Muscular venules

_______________ is a process in which endothelial cells pick up material on one side of the plasma membrane by pinocytosis or receptor-mediated endocytosis, transport the vesicles across the cell, and discharge the material on the other side by exocytosis

Transcytosis

Edema may be caused by which of the following?

- Increased capillary filtration

- Reduced capillary reabsorption

- Obstructed lymphatic drainage

Widening of vessels is known as:

vasodilation

(This is due to the relaxation of the muscle of its tunica media and the outward pressure of the blood exerted against the wall)

_______________ are the type of blood vessel that links arterioles to capillaries

metarterioles

Growth of lipid deposits in the arterial walls resulting in an increase in blood pressure can be described as which of the following?

atherosclerosis

- These deposits can become calcified "complicated plaques", giving the arteries a hard, bonelike consistency

A patient with a blood pressure reading of 110/80 has:

normal BP

The growth of new blood vessels is called:

angiogenesis

-Over a long time, hypoxic tissue can increase its own perfusion through agiogenesis

(also refers to embryonic development of blood vessels)

A thrombosis will induce _____________ in the tissues that the vessel supplies

ischemia - results from insufficient blood flow to a tissue, typically resulting in metabolite accumulation and sometimes tissue death

High blood pressure is known as ________________

hypertension

Which of the following are examples of conducting arteries?

Aorta, common carotid, subclavian arteries, pulmonary trunk, and common iliac arteries

Regarding vessel diameter, widespread _______________ raises he blood pressure, while widespread ________________ lowers it

- vasoconstriction

- vasodilation

Low blood pressure is known as:

hypotension

All forms of circulatory shock fall into to categories:

1) cardiogenic shock - caused by inadequate pumping by the heart, usually as a result of myocardial infarction

2) low venous return (LVR) shock - in which cardiac output is low because too little blood is returning to the heart

Hemodynamics are based mainly on:

pressure and resistance

During exercise, blood flow to muscles is rapidly increased by which of the following methods?

Vasodilation

An anatomical convergence where two blood vessels merge and combine their bloodstreams is known as a(n):

anastomosis

Which of the following are regarded as the capacitance vessels because they expand easily to accommodate an increased volume of blood?

Veins - - because they are relatively thin-walled and flaccid, and expand easily to accommodate an increased volume of blood, therefore they have have greater "capacity" for blood containment than arteries do.

What is hypercapnia?

An excess of carbon dioxide in the blood

Veins have ___________ that ensure the one way flow of blood

venous valves

In the coronary blood vessels, ______________ and ____________ bind to Beta-adrenergic receptors and cause vasodilation.

norepinephrine, epinephrine

__________ is defined as the force that the blood exerts against a vessel wall

Blood Pressure (BP)

An organ or cell specialized to detect chemicals is a(n) ____________________

chemoreceptor

Venous return refers to the flow of blood back to the:

heart

What are the sympathetic responses to a drop in perfusion to the brain?

1) Increased heart rate

2) Increased contractility force

3) Vasoconstriction of arteries except those supplying the brain

______________ arteries deliver blood to specific organs.

Distributing (muscular or medium) arteries

True or false: Lipid-soluble substances diffuse easily through the plasma membrane, while lipid-insoluble substances must use channel proteins?

True

Blood flow is fastest in which of these blood vessels?

Aorta

The accumulation of excess fluid in a tissue is called __________

edema

Identify which of the following blood vessels are distributing (muscular, or medium) arteries.

- brachial

- femoral

- renal

- splenic

- pulmonary

Name the forces that oppose hydrostatic pressure along with the capillary and interstitial pressures:

Colloid Osmotic Pressure (COP)

A process in which hydrostatic pressure forces a fluid through a selectively permeable membrane (especially a capillary wall) is known as ______________

filtration

Changes in the diameter of a blood vessel are collectively known as which of the following?

Vasoreflexes

Which of the following are vasoactive chemicals?

- histamine

- bradykinin

- prostaglandins

Blood pressure is determined by which of the three variables?

1) Cardiac output

2) Blood volume

3) Resistance to flow

______________ contribute to vessel growth and repair by retaining the ability to differentiate into endothelial and smooth muscle cells

Pericytes

The difference between the colloid osmotic pressure of the blood and that of the tissue fluid, and usually favoring fluid absorption by the blood capillaries is known as _____________ pressure

oncotic

Hypotension may be caused by which of the following factors?

- blood loss

- dehydration

- anemia