Physiology Lecture Quiz #2 study guide

Which membrane potential opens a sufficient number of the voltage-gated Na+ channels to cause a significant change in the membrane potential (making it much less negative).

-60 mV

What is the resting membrane potential of the neuron used in the experiment?

-80 mV

A chemical synapse ALWAYS includes which of the following? 1. axon terminal 2. presynaptic cell 3. synaptic cleft 4. postsynaptic cell 5. dendrite

1, 2, 3, 4

Put the following events associated with thyroid hormone production and release in the correct sequential order. Metabolism is regulated. Iodine is concentrated by the thyroid gland. Thyroxine and triiodothyronine are produced. Iodine is combined with the amino acid tyrosine.

2, 4, 3, 1

The following are steps involved in transmission at the cholinergic synapse: 1. Chemically gated ion channels on the postsynaptic membrane are opened. 2. Calcium ions enter the axon terminal. 3. An action potential depolarizes the axon terminal at the presynaptic membrane. 4. Acetylcholine is released from storage vesicles by exocytosis. 5. Acetylcholine binds to receptors on the postsynaptic membrane. The correct sequence for these events is

3, 2, 4, 5, 1.

Arrange the following events in the proper sequence: 1. Efferent neuron graded potential reaches threshold and fires an action potential. 2. Afferent neuron graded potential reaches threshold and fires an action potential .3. Target organ responds. 4. CNS reaches decision about response. 5. Sensory receptor detects change in the environment.

5, 2, 4, 1, 3

Most neurons have at least two processes extending from the soma, or cell body. Which type of neuron only has one process extending from the cell body?

A pseudounipolar neuron

The pituitary hormone that controls the release of hormones from the adrenal cortex is

ACTH

Which of the following choices best describes the path of sensory information from the receptor into the spinal cord?

Afferent neuron to dorsal root ganglion to dorsal horn

Glial cells

All of the answers are correct.

When two or more graded potentials arrive at the trigger zone, which of the following could happen?

An excitatory and inhibitory signal can cancel each other out; two excitatory stimuli may be additive, and summation could occur; and two inhibitory stimuli may be additive, resulting in lower excitability.

Once a stimulus binds a receptor on the cell's membrane, what could happen next?

Any of these actions could happen next.

Which two properties determine how fast neurons conduct action potentials?

Axon diameter and the leak resistance of the membrane

Which of the following is a peptide hormone?

Calcitonin

Which of the following structure allows communication between the two hemispheres of the brain?

Corpus callosum

Which is the main inhibitory neurotransmitter in the brain?

GABA

Multiple sclerosis (MS) is a central nervous system disorder that results from demyelination of axons in the central nervous system. Which type of tissue would be least at risk for damage from MS?

Gray matter

How do endocrine hormones reach their target cells?

Hormones are transported through the blood stream to target cells.

Where do most action potentials originate?

Initial segment

During an action potential, activation of voltage-gated sodium and potassium channels occurs at different rates. What is the effect of this difference on ion flow across an axon membrane?

Initially, Na+ flows into the cell and then K+ flows out of the cell.

Which statement about the hypothalamus is FALSE?

It receives sensory fibers from the optic tract, ears, and spinal cord.

If an increase in extracellular potassium hyperpolarizes a neuron, which of the following would be correct?

It would change the membrane potential to a more negative value.

What would happen to the membrane potential if a resting cell suddenly became more permeable to Ca++?

It would depolarize.

The major determinant of the resting potential of all cells is

K+ gradient between the blood and interstitial fluid.

A stroke may have different effects on a patient depending upon where in the brain it occurs. Where would a stroke have occurred if a right-handed patient loses the ability to write (agraphia) because of lack of sensation?

Left parietal lobe

When voltage-gated Na+ channels of a resting neuron open,

Na+ enters the neuron and the neuron depolarizes.

The rising phase of the action potential is due to

Na+ flow into the cell only.

Which type of receptor would bind acetylcholine and be found in skeletal muscle?

Nicotinic cholinergic

If a hyperpolarizing graded potential and a depolarizing graded potential of similar magnitudes arrive at the trigger zone at the same time, what is most likely to occur?

Nothing. They will cancel each other out.

Which glial cells form myelin in the central nervous system?

Oligodendrocytes

What characterizes repolarization, the second phase of the action potential?

Once the membrane depolarizes to a peak value of +30 mV, it repolarizes to its negative resting value of -70 mV.

What effect did decreasing the extracellular sodium have on the resting membrane potential?

Only a small change occurred, because the resting neuron is not very permeable to sodium.

Which statement about peptide hormones is FALSE?

Peptide hormones in the bloodstream are always bound to carrier proteins.

What is the role of activated protein kinases?

Phosphorylate proteins.

Which anterior pituitary hormone is the only one that has a nonendocrine cell as its target?

Prolactin

Myelin is formed by

Schwann cells and oligodendrocytes.

In this experiment, which stimulus causes the membrane potential to reach the threshold value?

Stimulus 3

The sympathetic and parasympathetic nervous systems are divisions of which system?

The autonomic nervous system

What would the levels of TRH be in a person that has Graves' disease? Why?

The levels of TRH should be low because thyroid hormone is on a negative feedback loop.

What characterizes depolarization, the first phase of the action potential?

The membrane potential changes from a negative value to a positive value.

What event triggers the generation of an action potential?

The membrane potential must depolarize from the resting voltage of -70 mV to a threshold value of -55 mV.

What effect did increasing the extracellular potassium have on the resting membrane potential?

The resting membrane potential became less negative.

Why are Na+, K+, and Cl- the only ions considered in the GHK equation when calculating resting membrane potential (Vm)?

These are the ions to which cell membranes are permeable at rest.

The posterior pituitary gland secretes

Vasopressin (ADH).

What opens first in response to a threshold stimulus?

Voltage-gated Na+ channels

What is the first change to occur in response to a threshold stimulus?

Voltage-gated Na+ channels change shape, and their activation gates open.

The link between a first messenger and a second messenger in a cell that responds to peptide hormones is usually

a G protein.

A friend of yours is working in a pharmaceutical development lab where they are working on a drug to cure Graves' disease. He poses the following four ideas listed below. Which would be the best solution?

a drug that breaks down the antibodies produced

A weak, subthreshold stimulus will result in _______.

a small depolarization at the receiving end of the neuron

Match the type of signal to its description. A. graded potential B. action potential C. both originate(s) at the trigger zone

action potential

Match the type of signal to its description. A. graded potential B. action potential C. both require(s) a minimum stimulus to occur

action potential

What is the mechanism of action of lipid-soluble hormones?

activation of genes, which increases protein synthesis in the cell

After a lipid-soluble hormone is bound to its intracellular receptor, what does the hormone complex do?

acts as a transcription factor and binds to DNA, activating a gene

Information coming into the central nervous system is transmitted along ________ neurons.

afferent and sensory

Match each hormone with its primary source. A. prolactin B. insulin C. aldosterone D. melatonin E. calcitonin F. epinephrine adrenal cortex

aldosterone

The all-or-none principle states that

all stimuli great enough to bring the membrane to threshold will produce action potentials of identical magnitude.

Match each term with the appropriate description. A. peptide hormone B. steroid hormone C. amino acid-derived hormone D. anterior pituitary E. hypothalamus F. posterior pituitary derivatives of tyrosine

amino acid-derived hormone

A depolarizing synaptic potential is also known as _______.

an excitatory postsynaptic potential

Match each term with the appropriate description. A. peptide hormone B. steroid hormone C. amino acid-derived hormone D. anterior pituitary E. hypothalamus F. posterior pituitary true endocrine gland of epithelial origin

anterior pituitary

Match the term with its description. A. ependymal cells B. astrocytes C. satellite cells D. schwann cells E. oligodendrocytes F. microglia highly branched cells that transfer nutrients between blood vessels and neurons

astrocytes

An excitatory postsynaptic potential occurs _______.

at the receiving end of the interneuron

Match these brain areas with their locations. A. primary somatic sensory cortex B. visual cortex C. auditory cortex D. association areas temporal lobe

auditory cortex

Match the part of the neuron to its description. A. dendrites B. axon C. cell body location of voltage-gated ion channels

axon

Neurotransmitter is stored and released from

axon terminals and axon varicosities.

Which functions in the control of movement?

basal nuclei only

Steroid hormones are lipophilic. This allows steroid hormones to ____.

bind to intracellular receptors

The amplification of the signal from a water-soluble hormone is achieved through an increase in _______.

cAMP in the cytoplasm

When adenylyl cyclase is activated,

cAMP is formed.

Match each hormone with its primary source. A. prolactin B. insulin C. aldosterone D. melatonin E. calcitonin F. epinephrine thyroid

calcitonin

A damaged neuron has a better chance of survival and repair if the ________ is/are undamaged.

cell body

Match the part of the neuron to its description. A. dendrites B. axon C. cell body make(s) proteins necessary for repair of damaged neuron

cell body

Match the part of the neuron to its description. A. dendrites B. axon C. cell body supported by satellite cells

cell body

Which is NOT located in the medulla oblongata?

centers for eye movement control

Match the glial cell to the nervous system division in which it is found. A. central nervous system B. peripheral nervous system ependymal cells

central nervous system

Match these brain areas with their descriptions. A. cerebellum B. hypothalamus C. thalamus D. cerebrum receives sensory input from the inner ear's receptors for equilibrium and balance

cerebellum

What keeps intracellular receptors from binding to DNA before a hormone binds to the receptor?

chaperone proteins (chaperonins)

Which type of synapse is most common in the nervous system?

chemical

Cerebrospinal fluid is secreted by the

choroid plexus.

Language and verbal skills tend to be ________ side of the brain.

concentrated on the left

The structure that connects the two cerebral hemispheres is the

corpus callosum.

Which of the following hormones has intracellular receptors?

cortisol

Match the part of the neuron to its description. A. dendrites B. axon C. cell body receive(s) most of the incoming synapses

dendrites

The multiple thin, branched structures on some neurons whose main function is to receive incoming signals are the

dendrites

An excitatory postsynaptic potential (EPSP)

depolarizes a neuron, increasing the likelihood of an action potential.

Match these terms with their descriptions. A. gray matter B. white matter C. ascending tracts D. descending tracts E. propriospinal tracts carry primarily efferent signals from the brain

descending tracts

Cell bodies of sensory neurons are located in

dorsal root ganglia.

The absolute refractory period of an action potential

ensures one-way travel down an axon, allows a neuron to ignore a second signal sent that closely follows the first, and prevents summation of action potentials.

Match the term with its description. A. ependymal cells B. astrocytes C. satellite cells D. schwann cells E. oligodendrocytes F. microglia cells that are a source of neural stem cells

ependymal cells

Match each hormone with its primary source. A. prolactin B. insulin C. aldosterone D. melatonin E. calcitonin F. epinephrine adrenal medulla

epinephrine

Anterograde and retrograde axonal transport are forms of ________ transport.

fast

Typically, when steroid hormones bind to their receptors,

gene transcription may increase or decrease.

Match these terms with their descriptions. A. gray matter B. white matter C. ascending tracts D. descending tracts E. propriospinal tracts unmyelinated, consists of cell bodies, dendrites, and axon terminals

gray matter

An axon that is more negative than the resting membrane potential is said to be _______.

hyperpolarized

Match each term with the appropriate description. A. peptide hormone B. steroid hormone C. amino acid-derived hormone D. anterior pituitary E. hypothalamus F. posterior pituitary site of vasopressin synthesis

hypothalamus

Match these brain areas with their descriptions. A. cerebellum B. hypothalamus C. thalamus D. cerebrum playing key roles in homeostasis, an area that contains centers for hunger and thirst, as well as controlling the autonomic nervous systems

hypothalamus

Which brain area is considered to be a key integrating center for homeostasis?

hypothalamus

Which two organs of the body release hormones that lead to the release of thyroid hormone?

hypothalamus and anterior pituitary

Interneurons are found

in the CNS.

If TRH levels increase, what will directly happen to the levels of TSH and thyroid hormone?

increase; increase

Match each hormone with its primary source. A. prolactin B. insulin C. aldosterone D. melatonin E. calcitonin F. epinephrine pancreas

insulin

The inactivation gate

is coupled to the movement of the activation gate, but is much slower.

The channels that provide for the movement of potassium in the resting neuron are _______.

leakage

Some types of antihistamines make one sleepy, others do not. This difference is partly because of a difference in

lipid solubility.

Match each hormone with its primary source. A. prolactin B. insulin C. aldosterone D. melatonin E. calcitonin F. epinephrine pineal

melatonin

Which of these functions is NOT related to the reticular formation?

menstrual cycle

A suprathreshold stimulus results in _______.

more action potentials

Spatial summation refers to

multiple graded potentials arriving at one location.

Increasing the voltage resulted in which of the following?

no change to the action potential

A single action potential is described as _______.

not graded

Match the term with its description. A. ependymal cells B. astrocytes C. satellite cells D. schwann cells E. oligodendrocytes F. microglia cells in the CNS that form myelin

oligodendrocytes

The inhibitory neurotransmitters of the CNS act by opening ________ channels.

only Cl-

The point during an action potential when the inside of the cell has become more positive than the outside is known as the

overshoot

Match each term with the appropriate description. A. peptide hormone B. steroid hormone C. amino acid-derived hormone D. anterior pituitary E. hypothalamus F. posterior pituitary lipophobic molecule that interacts with receptors on cell surface

peptide hormone

The majority of hormones in the body are

peptide hormones.

Match the glial cell to the nervous system division in which it is found. A. central nervous system B. peripheral nervous system Schwann cells

peripheral nervous system

The afferent and efferent neurons together form the

peripheral nervous system.

Cyclic AMP is degraded by __________.

phosphodiesterase

Water-soluble hormones affect target cells by binding to __________.

plasma membrane receptors

Match these functions with the correct brain area. A. medulla oblongata B. pons C. midbrain D. reticular formation relay station for transfer of information between the cerebrum and cerebellum; coordinates breathing control with other areas

pons

Match each term with the appropriate description. A. peptide hormone B. steroid hormone C. amino acid-derived hormone D. anterior pituitary E. hypothalamus F. posterior pituitary storage and release site for oxytocin

posterior pituitary

Which ion(s) is/are higher in concentration inside the cell compared to outside?

potassium

When sodium channels open during an action potential, the opening is caused by

presence of positive charge.

Match each hormone with its primary source. A. prolactin B. insulin C. aldosterone D. melatonin E. calcitonin F. epinephrine anterior pituitary

prolactin

The pituitary hormone that stimulates milk production by the mammary glands is

prolactin

The sodium-potassium exchange pump

requires ATP to function.

Match these functions with the correct brain area. A. medulla oblongata B. pons C. midbrain D. reticular formation network to coordinate arousal and sleep, but also involved in blood pressure regulation and pain modulation

reticular formation

Match the term with its description. A. ependymal cells B. astrocytes C. satellite cells D. schwann cells E. oligodendrocytes F. microglia cells that form supportive capsules around cell bodies

satellite cells

Match the term with its description. A. ependymal cells B. astrocytes C. satellite cells D. schwann cells E. oligodendrocytes F. microglia cells that myelinate only one axon each; multiple cells per axon

schwann cells

When a catecholamine or peptide hormone binds to receptors on the surface of a cell,

second messengers are activated.

To increase the amount of neurotransmitter released onto a postsynaptic cell, the presynaptic cell would have to

send action potentials with higher frequency.

The stimulus for graded potentials includes _______.

sensory stimuli and neurotransmitter

Calcium is important in the synapse because it

signals the exocytosis of the neurotransmitter.

Steroid hormones are synthesized in the ________ of the cell.

smooth endoplasmic reticulum

Establishing the resting membrane potential requires energy through the use of the _______.

sodium-potassium pump

The pituitary hormone that stimulates cell growth and metabolism in many tissues is

somatotropin.

Match each term with the appropriate description. A. peptide hormone B. steroid hormone C. amino acid-derived hormone D. anterior pituitary E. hypothalamus F. posterior pituitary cannot be stored in secretory vesicles

steroid hormone

For the structures listed below, choose one of the following: A. structure is composed of gray matter B. structure is composed of white matter limbic system

structure is composed of gray matter

For the structures listed below, choose one of the following: A. structure is composed of gray matter B. structure is composed of white matter ventral horn

structure is composed of gray matter

Autonomic motor neurons are subdivided into the

sympathetic and parasympathetic braches.

When a second EPSP arrives at a single synapse before the effects of the first have disappeared, what occurs?

temporal summation

Increasing the strength of the stimulus applied to the sensory receptor increased _______.

the frequency of action potentials in the sensory neuron, the amount of neurotransmitter released at the axon terminal of the sensory neuron and the frequency of action potentials in the interneuron

The Nernst equation can be used to predict

the membrane potential resulting from permeability to a single ion.

Which stimulus was at or above threshold?

the moderate and strong stimuli

What does the Goldman-Hodgkin-Katz equation take into account that the Nernst equation does NOT?

the permeabilities of the ions

The minimum voltage that is required to generate an action potential is called the _______.

threshold voltage

Which hormone's receptor is always bound to DNA, even when the receptor is empty?

thyroid hormone

Which hormone is NOT an amino acid derivative?

thyroid-stimulating hormone

Most amine hormones are derived from ____.

tyrosine

The resting membrane potential results from

uneven distribution of ions across the cell membrane and differences in membrane permeability to ions.

Match these terms with their descriptions. A. dorsal horns B. columns C. ventral root D. dorsal root ganglia E. nuclei motor fibers leave the spinal cord's gray matter via this

ventral root

Match these terms with their descriptions. A. gray matter B. white matter C. ascending tracts D. descending tracts E. propriospinal tracts myelinated axons with very few cell bodies

white matter