Mastering A&P practice questions exam 3

How many pairs of spinal nerves emerge from the spinal cord?

31 pairs

Trace the pathway of sperm through the duct system during ejaculation.

Epididymis, ductus deferens, ejaculatory duct, urethra

The metabolic center of the neuron is indicated by ________.

Label D

Identify the pathway of vibrations as they travel from one ossicle to the next.

Malleus, incus, stapes

Karen, who is in her mid-forties, has been slurring words and has partial loss of vision in her left eye. She is also having coordination problems. Her doctor thinks she has an autoimmune disease that is destroying the myelin sheaths surrounding nerve fibers. If the doctor's diagnosis is correct, the disease Karen has is __________.

Multiple Sclerosis

What statement best describes the resting state of a neuron? A) Neurons are depolarizing and generating an action potential. B) Neurons are propagating the action potential. C) Neurons are restoring the ionic conditions utilizing the sodium-potassium pump. D) Neurons are polarized with more sodium ions outside the cell and more potassium ions inside the cell. E) Neurons are repolarizing as potassium ions diffuse out of the cell.

Neurons are polarized with more sodium ions outside the cell and more potassium ions inside the cell.

What cells form the myelin sheaths around nerve fibers in the PNS?

Schwann cells

What is the first event of an action potential?

Sodium gates open and the membrane depolarizes.

Why does the action potential only move away from the cell body?

The areas that have had the action potential are refractory to a new action potential.

Saltatory conduction is a faster type of nerve impulse transmission that occurs along myelinated axons. Why is nerve impulse transmission faster in myelinated neurons?

The nerve impulse can jump from one node of Ranvier to the next, speeding the rate of nerve impulse transmission.

Which statement describes a function of the spinal cord? A) The spinal cord initiates reflexes. B) The spinal cord sends sensory information to the brain and carries motor signals from the brain to motor neurons. C) The spinal cord carries sensory information toward the central nervous system (CNS). D) The spinal cord carries motor signals to skeletal muscles.

The spinal cord sends sensory information to the brain and carries motor signals from the brain to motor neurons.

What endocrine gland is located in the neck?

Thyroid

The velocity of the action potential is fastest in which of the following axons?

a small myelinated axon

Hypersecretion of growth hormone could lead to which of the following conditions?

acromegaly

Which substance can cross the placental barrier and may cause a life-threatening birth defect?

alcohol

Neurons either conduct action potentials along the length of their axons, or they remain at rest. This statement best describes ________.

all or nothing response

synaptic response to action potential step 1

an action potential arrives at the synaptic terminal

What hormone stimulates the kidneys to reabsorb water as urine is being formed?

antidiuretic hormone (ADH)

synaptic response to action potential step 2

calcium channels open and calcium ions enter the synaptic terminal.

What brain dysfunction results when blood supply to a region (or regions) of the brain is blocked and vital brain tissue dies, as by a blood clot or a ruptured blood vessel?

cerebrovascular event

The membrane that covers the outer surface of the eye and lines the eyelids is the ________.

conjunctiva

The large fiber tract that allows communication between the two cerebral hemispheres is called the ________.

corpus callosum

Which of the following does NOT belong to the Central Nervous System?

cranial nerves

What part of a neuron receives signals and sends a message to the cell body?

dendrite

Membranous extensions that receive signals and send it to the cell body of a neuron are called:

dendrites

Lidocaine is used as a local anesthetic to block the sensation of pain. It operates by preventing sodium channels from opening in affected neurons. The specific event lidocaine prevents is ________.

depolarization

What divides the outer ear from the middle ear?

ear drum

Which portion of the retina contains a concentration of cones?

fovea centralis

What specific receptor cells respond to chemicals dissolved in saliva?

gustatory cells

If the hair cells in the spiral organ of Corti are damaged, what sense is impaired?

hearing

The blockage of cerebrospinal fluid (CSF) outflow in the brain can cause accumulation of fluid, resulting in cranial enlargement in infants. This condition is called __________.

hydrocephalus

Control of temperature, endocrine activity, metabolism, and thirst are functions associated with the ________.

hypothalamus

Which gland is located above the lateral end of each eye and releases tears?

lacrimal

Stimulation of sour receptors occurs in response to ________.

lemons

The biconvex structure that focuses light on the retina is the ________.

lens

The brain and spinal cord are protected and cushioned by three connective tissue membranes that are collectively called ________.

meninges

Mr. Warren has spinal cord damage that prevents nerve impulses from being carried from the CNS to muscles or glands. What specific type of neuron has been damaged?

motor neuron

The difference between grey and white matter is that white matter has:

myelin sheathing

Where are the olfactory receptors located?

nasal cavity

synaptic response to action potential step 4

neurotransmitter molecules diffuse across the synaptic cleft.

The female reproductive organs, known as ________, produce both eggs (ova) and hormones such as estrogen and progesterone.

ovaries

The small, peg-like projections of the tongue's surface are called ________.

papillae

What division of the autonomic nervous system is often called the "rest-and-digest" division?

parasympathetic

The delicate innermost membrane, or meningeal layer, that clings to the surface of the brain and spinal cord is known as the ________ mater.

pia

Immediately after an action potential is propagated, which one of the following ions rapidly diffuses out of the cell into the tissue fluid?

potassium ions

Sensory receptors located in muscles and tendons are termed ________.

proprioreceptors

What is the function of the sperm cell's acrosome?

release enzymes to help penetrate the follicle cells surrounding the oocyte

Which layer of the eye contains photoreceptors known as rods and cones?

retina

What type of photoreceptor cell allows us to see gray tones in dim light, and provides our peripheral vision?

rods

The largest nerve in the body, the sciatic nerve, belongs to the ________ nerve plexus.

sacral

Which function of the nervous system uses receptors to monitor changes inside and outside the body?

sensory function

A neuron at rest would have a greater concentration of ______________ outside the cell.

sodium

Anesthetics block nerve impulses by interfering with membrane permeability to ions, thus preventing an action potential from being generated. Which ion is being blocked?

sodium

What ion depolarizes the membrane when it diffuses into the axon of a neuron?

sodium

Hair cells that function as hearing receptors are located within the ________.

spiral organ of Corti

What causes sodium to suddenly move into a neuron (cell) though sodium channels causing the cell to become more positive on the inside and negative on the outside?

stimulus

The five taste sensations are ________.

sweet, sour, bitter, salty, umami

Preparing the body for the "fight-or-flight" response during threatening situations is the role of the

sympathetic nervous system

The gap between two communicating neurons is termed ________.

synaptic cleft

The hormone produced by male testes, which is necessary for sperm production is ________.

testosterone

synaptic response to action potential step 5

the neurotransmitter molecules bind to receptors in the plasma membrane of the receiving neuron, causing ion channels there to open.

Where are olfactory receptors located?

the superior region of the nasal cavity

What part of the central nervous system (CNS) gives rise to sympathetic nerves?

thoracic and lumbar regions of the spinal cord

In what part of the female reproductive tract does fertilization typically occur?

uterine (Fallopian) tube

synaptic response to action potential step 3

vesicles containing neurotransmitter fuse with the plasma membrane of the sending neuron

Static equilibrium receptors are located in the ________.

vestibule

Which one of the following is the correct sequence of nerves that exit the spinal cord, from superior to inferior?

Cervical spinal nerves, thoracic spinal nerves, lumbar spinal nerves, sacral spinal nerves

Which disease is a progressive, degenerative disease of the brain that ultimately results in dementia and is associated with a shortage of acetylcholine?

Alzheimer's Disease

How is an action potential propagated along an axon?

An influx of sodium ions from the current action potential depolarizes the adjacent area.