Unit 4 Practice Test ( Nervous System )

A stimulus either causes an action potential or it doesn't. This is called

an all-or-none response

The oculomotor nerve

adjusts pupil size to the level of lighting.

What structures are formed from neural crest cells?

all of the choices form from neural crest cells...sensory, autonomic, enteric neurons; pigmented body cells, adrenal medulla, facial bones

The spinal cord begins at the

foramen magnum

The spinal cord

links the peripheral nervous system to the brain

An action potential

occurs when the local potential reaches threshold level

Visceral and emotional reactions to odors is a function of the:

secondary olfactory area in the frontal lobe

Where is cerebrospinal fluid found around the spinal cord?

subarachnoid space

Which of the special senses contains receptor neurons that are the only nerve cells in direct contact with the outside environment?

smell

During depolarization of the plasma membrane,

sodium ions move rapidly into the cell.

Cranial nerve function includes

somatic motor

The Roman numerals assigned to each cranial nerve reflect

the sequence from anterior to posterior in which they emerge from the brain

There are ____ pairs of cranial nerves and ____ pairs of spinal nerves.

12; 31

The accessory nerve

All of these choices are correct...has fibers that join the vagus nerve, has both a cranial and spinal component, provides innervation to the trapezius and sternocleidomastoid muscles, is cranial nerve XI

What ion(s) cause(s) depolarization in olfactory neurons?

Both Na+ and Ca2+

The round window

acts as a mechanical release for waves within the cochlea.

The pineal body

appears to play a role in controlling the onset of puberty

Reflex arcs

are capable of receiving a stimulus and yielding a response

The abducens nerves

are involved in eye movement

A change in the resting membrane potential has the following characteristics (non-propagated, graded, can summate). This type of change can

be a consequence of an increase in the permeability of Na+

Voltage-gated sodium channels are sensitive to changes in the extracellular concentration of

calcium ions

Taste buds

can only perceive taste if molecules are in solution

Neurotransmitters

cause the production of action potentials in the postsynaptic membrane

Cerebrospinal fluid is produced by the _____ and is reabsorbed by the _____.

choroid plexus, arachnoid granulation

The lacrimal glands

constantly produce a fluid called tears

The optic disc

contains no photoreceptor cells

The peripheral nervous system includes the

cranial nerves

The enteric nervous system consists of plexuses within the walls of the

digestive tract

The sensory root of a spinal nerve is also referred to as

dorsal root

From which germ layer does the nervous system form?

ectoderm

What space, found between the vertebral wall and the dura mater, is the area for injecting anesthesia for childbirth?

epidural space

The autonomic nervous system

has two sets of neurons in a series

Rods, a type of photoreceptor cell, respond to light (stimulus) by

hyperpolarizing

The photoreceptor cells are located

in the photoreceptive layer of the retina.

Local hyperpolarization in a snyapse is called a(an)

inhibitory postsynaptic potential

The corpus callosum

is a band of commissural fibers that connects the right cerebral hemisphere to the left cerebral hemisphere.

Why does inhaling deeply and slowly through the nose help to identify an odor?

more air containing the odor is brought into contact with the olfactory epithelium

The central nervous system develops from a flat mass of tissue called the neural

neural plate

The ventral root of a spinal nerve contains

only motor fibers

Blood vessels enter the eye and nerve processes exit the eye at the

optic disc

Digestion of food is regulated by the

parasympathetic division of the ANS

Synaptic vesicles contain neurotransmitters and are present in the

presynaptic terminals

The attenuation reflex

prevents damage to delicate ear structures

During a spinal tap, cerebrospinal fluid is obtained from which of the following locations?

subarachnoid space

The interthalamic adhesion connects the two portions of the

thalamus

The sciatic nerve is composed of the

tibial nerve and common fibular nerve

There are _____ enlargements of the spinal cord where nerves supplying the extremities enter and leave.

two

Which of the following is NOT a primary odor class?

umami

Intercostal nerves are formed from the

ventral rami of thoracic spinal nerves

The motor root of a spinal nerve is also referred to as the

ventral root