Nervous System

What type of nerve fibers make up each of the following?

...

How long is the spinal cord?

17-18in

How many pairs of spinal nerves are present in the human body?

31 pairs

What is an effector? What are two types of effectors?

A cell that acts to certain stimuli. The two types are somatic, the body's striated muscles (back and arm) and autonomic, which are smooth muscles(Iris of the eye)

What causes cerebral palsy?

Abnormal development of the brain or damage to the development of the brain

Sensory nerves:

Afferent fibers

What is the myelin sheath?

An insulating layer forming around the nerves to allow electrical impulses to transmit quickly and efficiently.

46. What is the difference between ascending tracts and descending tracts of the spinal cord?

Ascending tracts carry sensory impulses and the descending tracts carry motor impulses

Why can't nerve fibers in the central nervous system regenerate?

Because the environment inhibits axon growth

What surrounds the spinal cord?

Bone, meninges, cerebrospinal fluid

Mixed nerves:

Both afferent and efferent fibers

What makes up the central nervous system?

Brain and spinal cord

What makes up the white matter in the central nervous system?

Bundles of axons coated with myelin sheaths to conduct, process and send nerve signals through the spinal cord.

What are the two main subdivisions of the nervous system?

CNS (Central Nervous system): make up the brain and spinal cord PNS (Peripheral nervous system): make up the nerves from the spinal cord to the rest of the body

What are the four parts of the human brain?

Cerebrum, diencephalon, brain stem, cerebellum

What is the function of the corpus callosum?

Communication pathway between the cerebral hemispheres

What is the makeup and function of the autonomic nervous system?

Consists of nerves that connects the CNS to the visceral organs, involuntary actions

What is the makeup and function of the somatic nervous system?

Consists of nerves that go to the skin and muscles, voluntary action

Hypoglossal

Contraction of muscles of the tongue

Accessory

Contraction of trapezius and sternocleidomastoid muscles

What are some examples of reflexes that take place in the body?

Coughing or sneezing

What bones surround and protect the brain?

Cranium

What are the three basic parts of a neuron?

Dendrites Axon Cell body/soma

What happens to sodium ions when a neuron receives a stimulus?

Diffuses into the cell

What three layers make up the meninges, starting with the outer layer?

Dura mater, arachnoid, and pia mater

Motor nerves:

Efferent fibers

What is the function of oligodendrocytes?

Enables fast saltatory impulse propagation

What is the function of the following structures making up the diencephalons?

Epithalamus: pineal gland extends from posterior margin

A myelin sheath is formed around axons within the CNS by Schwann cells.

False

An axon transmits impulses toward a neuron cell body.

False

Gray matter is made up of myelinated fibers.

False

Sensory nerves contain only efferent fibers

False

The CNS is made up of cranial nerves and spinal nerves.

False

The central sulcus divides the cerebrum into two hemispheres

False

The pons functions in body coordination, posture, and balance

False

The spinal cord extends from the base of the skull to the fourth lumbar vertebra.

False

What are ventricles?

Fluid-filled cavities in the brain

What is the starting point and ending point of the spinal cord?

From the foramen magnum to the level of the first lumbar vertebrae

What five lobes make up the cerebral hemisphere?

Frontal, parietal, occipital, temporal, insula

Cardiac center

Function: adjust heart rate and contraction strength

Vasomotor center

Function: regulates blood pressure

What are some examples of body functions controlled by the autonomic nervous system?

Heart rate, breathing rate, blood pressure, body temp

What is the function of the following structures making up the diencephalons?

Hypothalamus: regulates the ANS, behavior and emotion

what is a reflex?

Involuntary response to stimuli

What is the neurilemma, and what is its function?

It is the cytoplasmic sheath of some cells. It is the protective function for peripheral nerve fibres.

What is the function of the cerebellum?

Mediate subconscious contractions of skeletal muscles for coordination, posture, and balance

What functions are controlled by the cerebral cortex?

Memory, language, reasoning, intelligence, personality

What structures make up the brain stem?

Midbrain, pon, medulla

Act-

Motion

What makes up the peripheral nervous system?

Nerves that branch from the brain and spinal cord

What makes up the gray matter in the central nervous system?

Neuronal cell bodies and unmyelinated axons.

Where is the cerebral cortex located? What makes up the cerebral cortex?

Outermost portion of cerebrum and made up of gray matter

What is the function of cerebrospinal fluid?

Provides support and protection for CNS

What is the function of a dendrite?

Receives communication from other cells and neurons

Vagus

Sensory fibers from pharynx, larynx, esophagus, and visceral organs

Glossopharyngeal

Sensory fibers from tast receptors on posterior ⅓ of tongue motore fibers to muscles used in swallowing to salivary glands

What are the functions of the spinal cord?

Serves as a conduction pathway for impulses

Describe the appearance of a node of Ranvier

Short unmyelinated region between two segments of myelin in a myelinated nerve fiber.

How is memory affected as the nervous system ages?

Short-term memory is generally affected more than long term memory

Olfactory

Smell

What makes up the nervous system?

The CNS (Central Nervous system) and the PNS (Peripheral nervous system) which control nerve and brain communication and activity.

Describe how a nerve impulse is propagated along the length of a neuron through an action potential.

The threshold stimulus causes a localised action potential on the membrane. The rest of the membrane is in the resting condition. The action potential stimulates the next point. This continues point by point along the entire length of the neuron.

Myelin is a white fatty substance that surrounds nerve fibers

True

Nerves that carry both sensory and motor fibers are known as mixed nerves.

True

Neuroglia support and protect neurons.

True

Sneezing is an example of a reflex

True

Synapse is the name of the region of communication between two neurons.

True

The autonomic nervous system supplies motor impulses to visceral organs.

True

The body has 12 pairs of cranial nerves

True

The cerebral cortex consists of gray matter.

True

The function of a neuron is to transmit nerve impulses

True

The hypothalamus functions in the regulation of body temperature

True

The peripheral nervous system provides a communication network between the central nervous system (CNS) and the body

True

The sympathetic division of the autonomic nervous system prepares the body for fight or flight.

True

What is the function of the following subdivisions of the peripheral nervous system?

a. Afferent (sensory) division: This transmits information from the sensory experiences to the brain(PNS) b. Efferent (motor) division: This transmits impulses from the CNS to peripheral organs to cause an effect

Describe the following three general functions of the nervous system: sensory, integrative, and motor

a. Sensory functions: This provides information and feedback to the brain to recognize touch and protection from certain object b. Integrative functions: This is the conscious thought and feeling, understanding reason, and responsible for having certain behaviours and emotions, c. Motor functions: This is to control specific movements of muscles in order to perform certain tasks.

What function is performed by the following subdivisions of the efferent (motor) division?

a. Somatic nervous system: associated with body movement that is voluntary b. Autonomic nervous system: controls involuntary actions like beating of the heart and movement of blood.

Parasympathetic

brings the body' systems back to the normal state after an emergency

What is the function of an axon?

carries nerve impulses away from the cell body

cerebell/o

cerebellum

cerebr/o

cerebrum

abducens

eye movement

cephal/o

head

Vestibulocochlear

hearing and equilibrium

What is a synapse?

junction between two neurons

Trochlear

movement of eyes

Oculomotor

movement of eyes/ eyelids

neur/o

nerve

How is a nerve impulse transmitted across a synapse?

neurotransmitters are released into synaptic cleft to react with receptors on the postsynaptic cell

Sympathetic

prepares body for stress, stimulates responses for emergency, and inhibits visceral activities

-tion

process of

Respiratory center

regulates the rate rhythm, and depth of breathing

Trigeminal a. Ophthalmic b. Maxillary c.Mandibular

sensory fibers from cornea skin of nose, forehead, scalp sensory fibers from cheek, nose, upper lip teeth motor fibers to muscles to mastication

facial

sensory fibers from taste receptors on anterior ⅔ of tongue motor fibers to muscles of facial expression, lacrimal glands, and salivary glands

-lemma

sheath- covering

What is the function of neuroglia?

supports neurons physically and metabolically

What are the two subdivisions of the autonomic nervous system?

sympathetic parasympathetic

What is a resting membrane?

the cell membrane of a nonconducting, or resting, neuron

syn-

together, join

Optic

vision