Exam 2 BIOS 252 Chamberlain University

Rostral

towards the forehead

Caudal

toward the tail or spinal cord

reticular formation

a nerve network in the brainstem that plays an important role in controlling arousal

reticular activating system

Located in the upper brain stem; responsible for maintenance of consciousness, specifically one's level of arousal.

Cerebellum function

the "little brain" at the rear of the brainstem; functions include processing sensory input and coordinating movement output and balance BALANCE

Hypothalamus function

A neural structure lying below the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward.

4 regions of hypothalamus

mammillary, tuberal, supraoptic, preoptic

frontal lobe

The lobe at the front of the brain associated with movement, speech, and impulsive behavior. (primary motor lobe)

parietal lobe

receives sensory input for touch and body position (primary sensory area)

occipital lobe

visual cortex

insula

regions of cortex located at the junction of the frontal and temporal lobes

Thalamus

the brain's sensory control center, located on top of the brainstem; it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla (RELAY STATION BY OCCIPITAL LOBE)

brain

gray matter on the outside, white matter on the inside

spinal cord

gray matter on the inside, white matter on the outside

Dreams

a sequence of images, emotions, and thoughts passing through a sleeping person's mind (REM SLEEP)

Wernicke's area

controls language reception - a brain area involved in language comprehension and expression; usually in the left temporal lobe. Transmits speech to Broca's Area

Broca's area

Controls language expression - an area of the frontal lobe, usually in the left hemisphere, that directs the muscle movements involved in speech.

12 pair of cranial nerves

Attach directly to the brain and can be motor, sensory, or both

sensory cranial nerves

1, 2, 8 (I,II,VII)

motor cranial nerves

3, 4, 6, 11, 12 (III,IV,VI,XI,XII)

oculomotor, trochlear, abducens, accessory, hypoglossal

mixed cranial nerves

5, 7, 9, 10 (VVII,IX,X)

5 branches of facial nerves

temporal, zygomatic, buccal, mandibular, cervical

cranial nerve goes to innervate abdomen and thorax

visceral nerve

Divisions of the ANS

sympathetic and parasympathetic

sympathetic nervous system

the division of the autonomic nervous system that arouses the body, mobilizing its energy in stressful situations, fight or flight

parasympathetic nervous system

rest and digest; the division of the autonomic nervous system that calms the body, conserving its energy

adrenal cortex

the outer portion of the adrenal glands

adrenal medulla

secretes epinephrine and norepinephrine

Acetylcholine (ACh)

enables muscle action, learning, and memory

secreted by all preganglionic neurons in both divisions and by postganglionic parasympathetic nervous system.

Norepinephrine

secreted by all sympathetic postganglionic neurons

Alpha

Excitatory

Beta

inhibitory

Central control of autonomic functions

ANS regulated by levels of CNS

cerebral cortex

fear and anxiety

Hypothalamus

A neural structure lying below the thalamus; it directs several maintenance activities (eating, drinking, body temperature), helps govern the endocrine system via the pituitary gland, and is linked to emotion and reward.

spinal cord functions

defecation and micturation

cervical enlargement of spinal cord

Responsible for supplying nerves to the upper limb

lumbarenlargement

nerves to pelvic region and lower limbs

medullary cone

cord tapers to a point inferior to lumbar enlargement

cauda equina

collection of spinal nerves below the end of the spinal cord (L2 to S5)

Meninges

three protective membranes that surround the brain and spinal cord

Meninges layers (from superficial to deep)

dura mater, arachnoid mater, pia mater

cerebrospinal fluid

Fluid in the space between the meninges that acts as a shock absorber that protects the central nervous system. (in the subarachnoid space b/w arachnoid and pia layers)

gray matter

Brain and spinal cord tissue that appears gray with the naked eye; consists mainly of neuronal cell bodies (nuclei) and lacks myelinated axons.

gray matter function

site of information processing, synaptic integration

white matter function

abundantly myelinated axons that course up and down the cord providing communication between different levels of the CNS

funiculi

white matter columns on each side of the cord; 3 on each side

ascending tracts

carry sensory information up the spinal cord

descending tracts

carry motor commands down the spinal cord

Endoneurium

connective tissue external to neurilemma

perineurium

layers of squamous cells that wrap fascicles

Epineurium

connective tissue surrounding the entire nerve

Ganglion

A cluster of nerve cell bodies, often of similar function, located in the PNS.

spinal nerves

31 pairs of nerves arising from the spinal cord

cervical nerves

C1-C8 (8 pairs)

thoracic nerves

T1-T12 (12 pairs)

lumbar nerves

L1-L5 (5 pairs)

sacral nerves

S1-S5 (5 pairs)

coccygeal nerve

Co1 (1 pair)

dermatome

Area of skin supplied by a single spinal nerve

dermatome map

a diagram of the cutaneous regions innervated by each spinal nerve

Reflexes

quick, involuntary, stereotyped reactions of glands or muscle to stimulation

somatic receptors

in skin, muscles, or tendons

afferent nerve fibers

carry information from receptors to posterior horn of spinal cord or the brainstem

integrating center

A point of synaptic contact between neurons in gray matter of spinal cord or brainstem

Determines whether efferent neurons issue signal to muscles

efferent nerve fibers

carry motor impulses to skeletal muscle

Effectors

muscles or glands that carry out the response

stretch reflex

the contraction of a muscle in response to stretch of that muscle

patellar reflex

a reflex extension of the leg resulting from a sharp tap on the patellar tendon; one synapse between the afferent and efferent neurons

flexor reflex

the quick contraction of flexor muscles resulting in the withdrawal of a limb from an injurious stimulus

polysynaptic reflex

signals travel over many synapses on their way to the muscle

presynaptic neurotransmitter

acetylcholine

postsynaptic neurotransmitter

GABA

longitudinal fissure

separates cerebral hemispheres

Gyri

ridges of the brain

corpus callosum

a broad band of nerve fibers joining the two hemispheres of the brain.

Cerebrum (cerebral hemispheres)

83% of brain volume, important features and landmarks: gyri and sulci, longitudinal cerebral fissure, corpus callosum

Cerebellum (little brain)

second largest part of the brain; 50% of the neurons and 10% of brain volume

Brain stem

includes diencephalon, midbrain, pons, medulla oblongata

White matter (nickname)

bundles of myelinated axons; called tracts in the "CNS", "nerves" in the PNS.

central sulcus

separates frontal and parietal lobes

Parietal Lobe

A region of the cerebral cortex whose functions include processing information about touch.

Blood Capillaries

the smallest blood vessels in the body; protected by blood brain barrier

Brain protected by

blood; CSF barrier; forms tight junctions between the ependymal cells

medulla oblongata

Part of the brainstem that controls vital life-sustaining functions such as heartbeat, breathing, blood pressure, and digestion.

medial lemniscus

sensory tract to thalamus

corticospinal tracts

descending motor tracts to skeletal muscles

inferior olivary nucleus

relay center for signals to cerebellum