bio exam 3

A neuron has a resting potential of about _____ millivolts.

-70

sequence of events that occurs at a synapse

1. An action Potential arrives at the synaptic terminal 2 Calcium channels open, and calcium ions enter the synaptic terminal 3. vesicles containing neurotransmitters fuse with the plasma membrane of the sending neuron 4. Neurotransmitter molecules diffuse across synaptic cleft 5. The neurotransmitter molecules bind to receptors in the plasma membrane of the receiving neuron, causing ion channels there to open

Increased pressure in the ventricles would close what valve(s)?

AV valves only

Which of the following statements correctly characterizes an action potential?

Action potentials are initiated by depolarization of the membrane to threshold.

buildup of fatty deposits on the inner walls of arteries

Atherosclerosis

During which event of the cardiac cycle is systolic blood pressure measured?

Blood flows into the relaxed atria while the ventricles contract.

The functional barrier between blood and the brain is cerebrospinal fluid. T/F?

False

Which part of the brain functions as a relay station for information to the limbic system and the cerebral cortex?

Thalamus

Oligodendrocytes share which of the following in common with Schwann cells?

They are a type of neuroglial cell.

Blood pressure is highest in

arteries

Life-threatening aneurisms are most likely to occur in

arteries

When blood leaves the heart, it first enters

arteries

Which of the following influence(s) the speed of an action potential?

both the presence of a myelin sheath and the diameter of the axon

Exchange of nutrients and gases between blood and tissues is the primary function of

capillaries

A pacemaker is used to correct __________.

cardiac arrhythmias

Ventricular fibrillation is occurring in a patient who has just arrived in the emergency room. Which one of the following treatments may be applied immediately to correct this potentially fatal arrhythmia?

cardioversion

Conscious thought is associated with which one of the following?

cerebral cortex

accumulation of fluid in the tissues due to a weak heart becoming less efficient at pumping blood

congestive heart failure

The left and right cerebral hemispheres are interconnected by a nerve tract network called the ________.

corpus callosum

Blood pumped from the right ventricle is ________ and enters the ________.

deoxygenated; pulmonary trunk

blockage of a blood vessel, usually due to a floating blood clot

embolism

True or false. The circulatory system of humans is composed of two circulatory loops: the systemic circulation, in which blood flows between the heart and lungs, and the pulmonary circulation, in which blood flows between the heart and the rest of the body.

false

Multiple sclerosis (MS) is a demyelinating disease that causes disfunction of which type of cell?

oligodendrocytes

Blood flows from the right atrium of the heart into the

right ventricle.

Isovolumetric relaxation and ventricular filling (two phases of the cardiac cycle) take place during __________.

ventricular diastole

True or false. An individual who has suffered a stroke, which has caused damage in his cerebrum, and is now having problems with his hearing, has probably suffered damage to his occipital lobe.

False

Veins carry blood away from the heart. T/F?

False

Which of the following is NOT an important function of the myelin sheath around axons?

It prevents saltatory conduction in the neuron.

autoimmune disorder that results in damage to the myelin sheaths of CNS neurons; transmission of impulses is subsequently disrupted

MS

Which of the following is correct about the filling of the ventricles?

Most blood flows passively into the ventricles through open AV valves.

Describe the pressures in the atria and ventricles that would cause the opening of the AV valves.

Pressure in the atria would be greater than the pressure in the ventricles.

Which one of the following happens during repolarization of a neuron?

Sodium channels close, and potassium rushes out of the cell.

Which of the following events is the first to occur during an action potential?

Sodium channels open.

How does a cell generate the resting membrane potential?

Sodium is pumped out of the cell and potassium is pumped into the cell, creating a net negative charge inside of the cell.

What causes an action potential to be conducted along a neuron's axon?

The change in charge difference across the membrane spreads from open sodium channels, causing sodium channels farther along the axon to open.

Which of the following characteristics of the neuron cell membrane contributes to the maintenance of the resting membrane potential?

The sodium-potassium pump transports three sodium ions out of the cell for every two potassium ions it pumps into the cell.

Long-term memory occurs __________.

When neurons are permanently changed

All of the following mechanisms assist in returning venous blood to the heart, EXCEPT __________.

an increase in heart rate

sensation of tightness and pain in the chest associated with insufficient blood circulation to the heart

angina

As the blood travels through the circulatory system, the greatest drop in pressure occurs in the __________.

arterioles

Which of the choices represents the order of vessels through which blood passes after leaving the heart?

artery, arteriole, capillary, venule, vein

Control of smooth muscle and internal organs is the role of which division of the nervous system?

autonomic

An action potential moves along a(n) _____.

axon

There are several toxins that interfere with synaptic transmission. Botulism toxin, for example, interferes with the fusion of acetylcholine-containing vesicles with the membrane of the axon bulb. This would result in which one of the following?

blocking of neurotransmitter release by the presynaptic membrane

An __________ neurotransmitter causes __________ of the postsynaptic membrane.

both excitatory; depolarization and inhibitory; hyperpolarization are correct

Which one of the following parts of the brain regulates heart activity?

cardiovascular center

People who are intoxicated cannot coordinate their movements or walk a straight line because alcohol disrupts the normal function of which region of the brain?

cerebellum

Fluid in the lymphatic system, as well as interstitial fluid, is

derived from blood plasma.

What causes the aortic semilunar valve to close?

greater pressure in the aorta than in the left ventricle

death of a portion of the heart due to an inadequate oxygen supply

heart attack

Regulation of the production of breast milk, carbohydrate metabolism, and temperature control are some of the functions of the

hypothalamus

Put the phases of the cardiac cycle in the correct order, starting after ventricular filling.

isovolumetric contraction, ventricular ejection, isovolumetric relaxation

Which heart chamber receives blood from the pulmonary veins?

left atrium

Which chamber pumps oxygenated blood out the aorta to the systemic circuit?

left ventricle

Which of the following parts of the brain is associated with emotions and behavior?

limbic system

Control of respiratory rate, heart rate, and blood pressure is integrated through the

medulla oblongata.

inflammation of the connective tissue layers surrounding the organs of the central nervous system

meningitis

Which one of the following cells transmits impulses away from the central nervous system to the muscles and other organs?

motor neurons

The left ventricle has a more muscular wall than the other three chambers of the heart because the left ventricle

must pump blood into the aorta and throughout the entire body.

White matter of the spinal cord contains __________, whereas gray matter contains __________.

myelinated nerves; unmyelinated cell bodies

Blood pressure in veins is lower than that in arteries, and a series of ________ are necessary to prevent backflow of blood.

one-way valves

The transmission of a nerve impulse first triggers the _____.

opening of voltage-gated sodium channels and the diffusion of sodium ions into the neuron

The movement of blood through the pulmonary circuit transports __________.

oxygenated blood from the lungs to the heart

When speaking about the circulatory system, we know that ________.

oxygenated blood leaves the left ventricle and travels to all parts of the body; it then returns to the heart and enters the right atrium

These structures serve as gates that regulate blood flow from arterioles into capillaries.

precapillary sphincters

Which one of the following blood vessels transports oxygenated blood from the lungs to the heart?

pulmonary vein

Sodium-potassium pumps

restore the distribution of ions inside and outside a neuron's membrane following an action potential.

Which chamber receives blood from the superior and inferior vena cavae?

right atrium

Which heart chamber pumps unoxygenated blood out the pulmonary trunk?

right ventricle

A stimulus has opened the voltage-gated sodium channels in an area of a neuron's plasma membrane. As a result, _____ rushes into the neuron and diffuses to adjacent areas; this in turn results in the _____ in the adjacent areas.

sodium ... opening of voltage-gated sodium channels

Both voluntary and involuntary skeletal muscle movement are controlled through which one of the following divisions of the nervous system?

somatic division

brain damage caused by an inadequate supply of blood

stroke

A spinal reflex requires the participation of each of the following, EXCEPT __________.

the cerebral cortex

During an action potential

the inside of the neuron becomes positively charged relative to the outside.

At rest, which of these plays a role in establishing the charge differential across a neuron's plasma membrane?

the sodium-potassium pump moving sodium ions out of the neuron and potassium ions into the neuron

When a neuron is at its resting potential

there are more potassium ions inside the neuron than outside.

In which one of the following blood vessels is blood under the lowest pressure?

vein

The atrioventricular valves are closed when the

ventricles contract

What action of the heart produces the expansion and recoil of arterial walls that you can detect as your pulse?

ventricular systole and diastole