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