Chapter 11-15 Anatomy and Physiology

Arrange the following in order from the diencephalon down 1) spinal cord 2)midbrain 3)medulla 4)pons

2,4,3,1

how many spinal?

31

How many peripheral are there

43

Which of the following statements accurately describe events that occur as a result of a local potential reaching threshold?

A positive feedback cycle develops in which depolarization causes activation gates of Na+ ion channels to open

The motor neurons responsible for making a fist are

multipolar

what does the peripheral nervous system consist of?

nerves and sensory organs

Gaps or interruptions in the myelin sheath are called

nodes of Ranvier

an action potential

occurs when the local potential reaches threshold level

Multiple sclerosis is a neurological disorder in which myelin sheaths in the CNS are destroyed. What neuroglial cells is being damaged in multiple sclerosis?

oligodendrocytes

Digestion of food is regulated by the

parasympathetic division of the ANS

The part of the brain that connects the medulla to the midbrain is the

pons

The primary somatic sensory or general sensory area is located in

prefrontal gyrus

Synaptic vesicles contain neurotransmitters and are present in the

presynaptic terminals

Depolarization of the nerve cell membrane occurs when there is a rapid influx (inflow) of

sodium ions

The junction of neuron with another cell is a/an

synapse

Most sensory input that ascends through the spinal cord and brainstem projects to the

thalamus

What does the CNS consist of

the brain , and spinal cord

The cerebral gyri increase

the surface area of the cortex

The cerebral aqueduct connects

the third ventricle to the fourth ventricle

The plasma membrane of a neuron is more permeable to potassium ions because

there are more leak ion channels for K+ than Na+

In some cells, an after potential occurs because

there is prolonged, elevated permeability to potassium during re-polarization.

The motor (efferent) division of the peripheral nervous system

transmits impulses from the CNS to skeletal muscle

Dentists anethetize a portion of the ____ nerve to stop pain impulses from the teeth.

trigeminal

Damage to the brainstem is usually fatal

true

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

two

What cranial nerve is exclusively sensory

vestibulocochlear (VIII)

White matter is composed of

Collection of unmyelinated axons

What is the large C-shaped mass of white matter that consists of nerve fibers that connect the two cerebral hemispheres?

Corpus callosum

Axons

Have distal portion that branches from the presynaptic terminals.

Mr. Miller has been hospitalized for the flu. The flu virus increases membrane permeability to potassium. You would expect his cells to

Hyperpolarize

An IPSP is inhibitory because it

Hyperpolarizes the postsynaptic membrane

The spinal cord

Links the peripheral nervous system to the brain

what is false regarding neuroglia ?

Neuroglia produce action potentials for skeletal muscles

What is found in the lateral gray horns of the spinal cord?

The cell bodies of autonomic motor neurons

What is found in the dorsal root ganglion?

The cell bodies of psuedo-unipolar sensory neurons.

The speed of an action potential depends upon

The diameter of the axon, thickness of myelin sheath, and whether or not an axon is myelinated or not

Association fibers connect

areas of the cerebral cortex within the same hemisphere

Dermatomal maps are important clinically because they

can be used to help locate nerve damage

The cerebral medulla

consists of many nerve tracts of white matter beneath the cerebral cortex

What is NOT a function of the cerebellum?

controlling heart rate

The sensory (afferent) division of the peripheral nervous system

conveys action potentials to the CNS

The gray matter on the outer surface of the cerebrum is called the

cortex

the fact that the right side of the brain controls the left side of the body is explained by the

decussation of the pyramids in the medulla

Receptor molecules

determine whether a neurotransmitter will be excitatory or inhibitory

Gap junctions are functional ___ synapses.

electrical

Local hyper-polarization in a synapse is called an

inhibitory postsynaptic potential

A change in resting membrane potential confined to a small area is called a(n)

local potential

What are the functions of the nervous system?

1. detect stimuli 2. conduct impulses 3. integrate and evaluate impulses (stimuli) 4. respond

how many cranial are there?

12

Place parts of reflex in order beginning with sensory receptor: 1) motor neuron 2) interneuron 3) effector 4)sensory neuron 5) sensory receptor

5,4,2,1,3

Which of the following activities would stimulate the reticular formation

A clock radio in the morning

Microglia

Are phagocytic cells in the CNS

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

Calcium ions

Each voltage-gated Na+ ion channel has two voltage sensitive gates: an activation gate and an inactivation gate. Which of the following would occur during depolarization?

Both activation and inactivation gates are open

Which of the following situations occurs in electrically excitable cells?

Depolarization causes voltage-gated sodium ion channels to open

Sensory neurons carrying action potentials from pain receptors synapse within the spianl cord with interneurons. These interneurons synapse with motor neurons leading back to an effector and ascending neurons that carry action potentials toward the brain. This is an example of a(n) ____ pathway.

Divergent

The thickest of the meninges is the

Dura mater

When repolarization of a neuron is complete, the

Original polarity of the neuron is restored

Which two portions of the brain are involved in controlling respiration?

Pons, medulla oblongata

Schwann cells differ from ologodendrocytes in which of the following ways.

Schwann cells form a myelin sheath around a portion of only one axon, while oligodendrocytes can surround portions of several axons

cerebrospinal fluid fills the

Subarachnoid space

Gray matter has little myelination, whereas white matter is abundant in myelination

TRUE

If the charge difference across the plasma membrane is decreased,

The membrane potential is more negative.

Suppose both excitatory and inhibitory neurons synapse with a single postsynaptic neuron. What determines if an action potential is initiated in the postsynaptic neuron?

The number of EPSPs in relation to the number of IPSPs

what is true?

The resting membrane potential is proportional to the tendency for K+ to diffuse out of the cell.

what do cavities of the neural tube become in the adult brain?

Ventricles

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

an all-or-none response

When a neurotransmitter binds to its receptor and increases the permeability of the postsynaptic membrane to sodium ions,

an excitatory postsynaptic potential (EPSP) will result.

The middle, thin, spider-like meninx is the

arachnoid mater

The abducens nerves

are involved in eye movement

Protein synthesis in neurons occurs in

cell bodies or soma

What are the two nervous systems?

central and peripheral nervous systems.

The lateral fissure separates ____ from the rest of the cerebrum

cerebellum

Which of the following brain areas serves as the major control center of the autonomic nervous system and endocrine system?

hypothalamus

During the absolute refractory period, the cell

is insensitive to further stimulation

reflexes function in

keeping body from falling. Maintaining blood pressure. Maintaining blood CO2 levels. Removing the body from painful stimuli.

Which portion of the brainstem is continuous with the spinal cord?

medulla oblongata