brain and cranial nerves

brainstem

Connects the spinal cord to the cerebrum; Location of cranial nerve nuclei

medulla oblongata

Pathway for ascending and descending nerve tracts; center for several important reflexes (e.g., heart rate, breathing, swallowing, vomiting)

pons

relays information between cerebrum and cerebellum; site of reflex centers

midbrain

serves as visual reflex center; part of auditory pathway

reticular formation

controls many brainstem activities, including motor control, pain perception, rhythmic contractions, and the sleep-wake cycle

cerebellum

controls muscle movement and tone; governs balance; regulates extent of intentional movement; involved in learning motor skills

diencephalon

connects the brainstem to the cerebrum; has many relay and homeostatic functions, as listed under each subdivision

thalamus

major sensory relay center, influences mood and movement

subthalamus

contains nerve tracts and nuclei

epithalamus

contains nuclei involved in motivation and reward behavior, and contains pineal gland

hypothalamus

major control center for maintaining homeostasis and regulating endocrine function

cerebrum

controls perception, thought, memory, emotion, and conscious motor activity; can override most other systems

cerebral cortex

contains sensory, motor, and association areas

hippocampus

involved with learning and memory

amygdala

involved with social behavior and emotions

basal nuclei

comtrols muscle activity and posture; largely inhibits unintentional movement when at rest

four major parts of the brain:

brainstem, cerebellum, diencephalom, and cerebrum

medulla oblongata function?

regulating heart rate, blood vessel diameter, respiration, swallowing, vomiting, hiccuping, coughing, and sneezing; also functions such as balance,coordination, and modulation of sound from the inner ear

pons function?

relay information from the cerebrum to the cerebellum; pontine respiratory center, works with the respiratory centers in the medulla oblongata to help control respiratory movements

midbrain function?

coordinated eye movement and pupil diameter; involved in the reflex movements of the head, eyes, and body toward these stimuli, such as loud noises, flashing lights, or startling pain

cerebellum function?

means “little brain”; controls balance, muscle tone, coordination (fine motor movements)

diencephalon

located between the brainstem and cerebrum; components: Thalamus, Hypothalamus, epithalamus

thalamus function?

The switchboard of the CNS; relays sensory information to the cortex from the rest of the body.

hypothalamus function?

Regulates hormonal functions, autonomic function, hunger, thirst and sleep.

pituitary gland

Sends out hormones to different organs in the body.

basal ganglia

Group of nuclei in the cerebrum; controls movement, including motor learning and planning

cerebrum

largest portion of the brain

cerebrum are divided into 2 hemisphere which is the?

left hemisphere and reignt hemisphere

cerebral cortex

controls thinking, communicating; initiates voluntary movements

gyri

folds on cerebral cortex to increase surface area

sulci

shallow indentations

fissures

deep indentations

left hemisphere

“dominant”; controls right side of the body; responsible for analysis, speech and math

right hemisphere

“non-dominant”; controls left side of the body responsible for Creativity, art, music

corpus callosum

connection between the 2 hemispheres

frontal lobe of the brain

Movement; Problem-solving; Concentrating; Thinking; Behavior, personality, mood

parietal lobe of brain

Sensation; Language; Perception; Body Awareness; Attention

temporal

Hearing; Language; Memory

occipital

Vision; Proprioception

gray matter

40% of the brain; serves to process information; contains most of the brain’s neuronal cell bodies

white matter

60% of the brain; made up of bundles, which connect various gray matter areas

dura mater

Outermost layer; form folds that separate right half of the brain from the left.

arachnoid mater

Middle layer; fragile layer that covers the entire brain.

pia mater

Innermost layer; contains blood vessels that runs into the brain’s surface

cerebrospinal fluid

forms a watery cushion to protect the brain and spinal cord; and provides nutrients.

olfactory

Sense of smell

optic

vision

oculomotor

Moves eye medially, upward, downward; upward and in together elevates upper eyelid; supplies extrinsic muscle of the eye

trochlear

Moves eye downward and medially together; supplies SO muscle.

trigeminal

Motor: muscle of mastication; sensory: sensation of touch, pain and temperature and anterior 2/3 of the tongue.

abducens

Moves eye laterally; supplies lateral rectus muscle.

facial

Motor: control facial muscle; taste of anterior 2/3 of the tongue.

vestibulocochlear

Cochlear: hearing; Vestibular: balance

glossopharyngeal

Motor: assist in swallowing (stylopharyngeus muscle); sensory and taste of posterior 2/3 of tongue.

vagus

Motor: supplies constrictor muscle of pharynx and intrinsic muscle of larynx; sensory: skin of external acoustic meatus and internal surface of laryngopharynx and larynx.

accessory

Cranial: controls swallowing movement; Spinal: movement of head and shoulder.

hypoglossal

Speech and swallowing.; controls tongue.

dyskinesia

General term for movement problems; often involves basal nuclei.

parkinson’s disease

Muscle rigidity, slow movement, resting tremors, and shuffling gait; linked to basal nuclei lesions.

huntington disease

Hereditary disorder causing involuntary movements and degeneration of basal nuclei.

cerebral palsy

Caused by brain damage during pregnancy or birth; includes muscle tone issues, tremors, and difficulty speaking or moving

cerebellar lesions

Jerky, ataxic (uncoordinated) movements and tremors when trying to control movements

alzheimer disease

Dementia with memory loss, confusion, and disorientation; caused by neuron loss in the brain

tay-sachs disease

Hereditary lipid-storage disorder; leads to paralysis, blindness, and death in infants

epilepsy

Seizures due to abnormal electrical activity in the brain, causing convulsions.

headaches

Pain caused by inflammation, muscle tension, or unknown factors.

dyslexia

Reading difficulties due to impaired ability to recognize letters and words.

stroke

Caused by blood supply loss to the brain; symptoms include paralysis and speech loss

somatic nervous system

Includes both sensory and motor neurons; Sensory neurons convey input from receptors for somatic senses and receptors for special sense

autonomic nervous system

Includes both sensory and motor neurons; Comes from autonomic (visceral) sensory neurons, mostly associated with interoceptors.

sympathetic division

Located in the lateral horns of the gray matter in the 12 thoracic segments and the first two/three lumbar segments of the spinal cord; Thoracolumbar division; Thoracolumbar outflow

parasympathetic division

Located in the nuclei of four cranial nerves in the brain stem (III, VII, IX, and X) and in the lateral gray matter of the second through fourth sacral segments of the spinal cord; Craniosacral division; Craniosacral outflow

autonomic tone

The balance between sympathetic and parasympathetic activity; regulated by the hypothalamus.

sympathetic response

“Fight or flight,” happens during physical and emotional stress. Favors body functions that support vigorous physical activity over the storage of energy.

parasympathetic response

“Rest and digest,” supports body functions that conserve and restore body energy during times of rest and recovery.

components of autonomic reflexes

Receptor, Sensory neuron, Integrating center, Motor neurons, Effector