chap 9 nervous system

crashing out rn

axon hillock

where axon originates

gyrus

ridges

sulci

shallow grooves

fissure

deep grooves

corticospinal (pyramidal)

originates in the cortex of the brain and conducts impulses that control skeletal muscle movements (passes through medulla oblongata)

ganglion

masses of cell bodies

tracts

bundles of myelinated axons

Which three regions of the brain process sensory information?

diencephalon, cerebellum, and cerebrum

extrapyramidal tract

control movements associated with balance, posture and muscle tone

a - diencephalon; b - brainstem; c - cerebrum; d - cerebellum

The left and right cerebral hemispheres are connected by a broad, flat bundle of axons called the

corpus callosum

falx cerebri

part of the dura mater, separates the left and right cerebral hemispheres.

What does the longitudinal fissure separate?

right and left cerebral hemispheres

transverse fissure

separates the cerebrum from the cerebellum

cerebral cortex

The thin layer of gray matter that forms the outermost layer of the cerebrum

1 - frontal, 2 - parietal, 3 - temporal, 4 - occipital

cutaneous senses

anterior parietal lobe

visual senses

posterior occipital lobe

auditory senses

posterior temporal lobe

taste

base of central sulcus & insula

smell senses

deep in temporal lobe

white matter

myelinated axons

gray matter

unmyelinated axons

The cerebral cortex is divided into what THREE functional areas?

sensory, association, & motor

What makes up the bulk of the cerebrum and provides connections between different parts of the brain?

white matter

basal nuclei (or ganglia)

Masses of gray matter deep within each cerebral hemisphere that facilitate voluntary movement.

basal nuclei

caudate nucleus, putamen, globus pallidus

A withdrawal reflex involves contraction of ____ muscles and reciprocal inhibition of _____ muscles

flexor, extensor

Where is the epidural space located?

Between vertebrae and dura mater

dorsal root ganglia

masses of cell bodies for sensory neurons

dorsal root

Carries sensory (afferent) impulses from the body to the spinal cord.

dorsal root

Carries motor (efferent) impulses from the spinal cord to the body.

central canal

surrounded by gray commissure and contains CSF

gray commissure

connects left and right gray matter

Broca’s area

frontal lobe, usually on the left side; controls muscles that function in speaking

what inhibitory neurotransmitter does basal ganglia secrete?

Produce the inhibitory neurotransmitter, dopamine.

function of basal nuclei

Relay motor impulses from the cerebrum, and help control motor activities by interacting with the motor cortex, thalamus, and cerebellum.

left hemisphere dominance

 language-related activities of speech, writing, and reading, as well as complex intellectual functions.

nondominant hemisphere

specializes in nonverbal functions, such as body orientation in space, and controls emotions and intuitive thinking.

Wierncke’s area

understanding of written & spoken language. located in temporal lobe

What is the name of the neurons that leave the spinal cord and synapse with skeletal muscle fibers?

lower motor neurons

Where are the cell bodies of lower motor neurons (LMNs) located?

In the ventral horn of the spinal cord or the cranial nerve nuclei in the brainstem

What is the function of lower motor neurons (LMNs)?

LMNs transmit impulses from the CNS to skeletal muscles, directly stimulating muscle contraction. They serve as the final common pathway in the motor system.

Where are the cell bodies of upper motor neurons (UMNs) located?

In the motor cortex or the brainstem.

What is the function of upper motor neurons (UMNs)?

UMNs send motor signals from the brain to the spinal cord or cranial nerve nuclei, coordinating voluntary movement by regulating lower motor neurons.

The motor area responsible for voluntary movements of the eyes and eyelids is located in the

frontal lobe

True or false: Because of their location, the pyramidal cells of the motor cortex are also called upper motor neurons.

true

The area of the brain responsible for the voluntary movements of the eyes and eyelids is called the:

eye field

basal nuclei function

facilitate voluntary movement

Parkinson and Huntington disease are disorders associate with altered activity from what area of the brain?

basal nuclei

cerebral aqueduct

Which ventricle is located on the midline of the brain beneath the corpus callosum and surrounded by the diencephalon?

third

What structure connects each lateral ventricle to the third ventricle?

interventricular foramen

The cavities in the brain that store cerebrospinal fluid are the ______.

ventricles

Which ventricle is in the brainstem anterior to the cerebellum?

fourth

Which ventricle is continuous with the central canal of the spinal cord and have openings leading to the subarachnoid space?

fourth

Which of the following are functions of CSF?

protection, buoyancy, stable ionic concentration

Flow of CSF proceeds through the ventricles and channels in this order:

• 2 Lateral ventricles.

• Interventricular foramina.

• Third ventricle.

• Cerebral aqueduct.

• Fourth ventricle, which is continuous with the central canal of the spinal cord and the subarachnoid space of the meninges.

1 - pituitary gland; 2 - thalamus; 3 - pineal gland

limbic system

connected structures in the brain that produce emotion

optic chiasma

(op'tik ki-az'mah) X-shaped structure on the underside of the brain formed by optic nerve fibers (axons) that partially cross over to the visual cortex on the opposite side.

posterior pituitary gland

(pos-tēr'e-or pĭ-tu'ĭ-tār"e) Rear (posterior) lobe of the pituitary gland. It secretes oxytocin and antidiuretic hormone.

mammillary bodies

two rounded structures behind infundibulum

infundibulum

conical process behind optic chiasma where pituitary gland attaches

pineal gland

cone-shaped structure attached to the upper part of the diencephalon

Midbrain

• Located between the diencephalon and pons.

• Contains bundles of myelinated nerve fibers that convey impulses to and from higher centers of the brain. 

• Contains masses of gray matter that serve as centers for auditory and visual reflexes.

• Contains main motor pathways between cerebrum and lower portions of the nervous system.

pons

• Lies between the midbrain and medulla oblongata. 

• Transmits impulses to & from medulla oblongata and cerebrum.

• Also conducts impulses from cerebrum to cerebellum.

• Contains centers that help regulate the rate and depth of breathing.

reticular formation

Complex network of nerve fibers in the brainstem that arouses the cerebrum to a wakeful state.

What part of the brain acts as a gateway for sensory impulses and channels them to appropriate regions of the cortex for interpretation?

thalamus

The ______ of the brain maintains homeostasis by regulating visceral activities and controlling the endocrine system.

hypothalamus

The ______ is not a distinct structure; it includes parts of the cerebral cortex, diencephalon, and the basal nuclei.

limbic system

The optic nerves cross over at this structure called the _______ ________.

optic chiasm

two functions of thalamus

• Relays sensory information to the cerebral cortex

• Control of emotional experience and expressions

The brain area that regulates visceral activities, maintains homeostasis and links the nervous and endocrine systems is called the

hypothalamus

Which of the following parts of the brain compose a complex called the limbic system?

• thalamus

• temporal lobe of cerebrum

• frontal lobe of cerebrum

What is the infundibulum?

A process that connects the pituitary gland to the hypothalamus

In what part of the brain are the nuclei responsible for visual and auditory reflexes located?

midbrain

functions of pons

• Relay impulses between medulla and cerebrum

• Nuclei that control rhythm of breathing

• Relay impulses to the cerebellum

The medulla oblongata contains nerve fibers that connect what structures?

spinal cord & brain

Which of the following centers or reflexes have their nuclei located within the midbrain?

• visual reflex center

• auditory reflex center

medulla oblongata houses what reflexes?

coughing, sneezing, swallowing, vomiting.

Where is the reticular formation located?

through the brainstem

A structure called the vermis connects the two hemispheres of the

cerebellum

cerebellar penducles

nerve tracts via which the cerebellum communicates with other parts of the CNS

A complex network of gray matter found within all levels of the brainstem is called the:

reticular formation

The ______ nerve originates at the medulla oblongata and extends into the neck, chest and the abdomen.

vagus

List the effectors for the autonomic motor fibers of the vagus nerve.

Smooth muscle of viscera of thorax and abdomen

The accessory nerve (CN XI) has two branches. Indicate the name of the two branches.

• Spinal branch

• Cranial branch

List the effectors for the somatic motor fibers of the vagus nerve.

Muscles for speech and swallowing (in tongue, pharynx, larynx)

Indicate the cranial nerve that has both cranial and spinal branches.

Accessory Nerve (XI)

The spinal nerve are ______ nerves.

mixed

Spinal nerve C5 emerges ______ vertebra C5 and spinal nerve L5 emerges _____ vertebra L5.

above, below

The spinal cord has ____ pairs of cervical nerves, ____ pairs of thoracic nerves and ____ pairs of sacral nerves.

8, 12, 5

What areas of the body do spinal nerves innervate?

upper limbs, trunk, lower limbs

The thoracic, lumbar, and sacral spinal nerves are associated with (named for) the vertebra that are ______ the nerve's point of emergence from the vertebral column.

superior to

what is the cauda equina?

Lumbar and sacral nerves that extend inferior to the spinal cord but within the vertebral column