Nervous System Info Pt. 2

Meninges

Membranes that protect the brain and spinal cord; lie between bone and soft tissue

Dura Mater

Tough, dense connective tissue that is the outermost meninge

Arachnoid Mater

Middle meninge, web-like; space contains CSF

Pia Mater

Inner most meninge; attached to surface of brain and spinal cord; contains blood vessels and nerves; nourishes CNS

Interventricular Foramina

Connects the third to the lateral ventricles

Cerebral Aqueduct

Connects the third and fourth ventricles

Choroid Plexuses

Secrete CSF, special capillaries of pia mater covered by ependymal cells

Arachnoid Granulations

Absorbs CSF after it exchanges substances

140 ml

Average volume of CSF

Forebrain

Prosencephalon

Midbrain

Mesencephalon

Hindbrain

Rhombencephalon

Forebrain

Divides into the telencephalon and diencephalon

Hindbrain

Divides into metencephalon and myelencephalon

Mesencephalon

Persists throughout development (use the fancy name)

Forebrain

Becomes the cerebrum, basal nuclei, and diencephalon

Midbrain

Mesencephalon remains as …

Hindbrain

Becomes cerebellum, pons, and medulla oblongata

Telencephalon

Anterior portion of forebrain; gives rise to the lateral ventricles, cerebrum, and basal nuclei

Diencephalon

Posterior portion of the forebrain; gives rise to the third ventricle, thalamus, hypothalamus, posterior pituitary gland, and pineal gland

Mesencephalon

Gives rise to the cerebral aqueduct and midbrain (fancy name)

Metencephalon

Anterior portion of hindbrain; gives rise to the fourth ventricle, cerebellum, and pons

Myelencephalon

Posterior portion of the hindbrain; gives rise to the fourth ventricle and medulla oblongata

Falx Cerebri

Separates cerebral hemispheres

Corpus Callosum

Connects cerebral hemispheres

Gyri

Ridges in the brain

Sulci

Shallow grooves on the surface of the brain

Fissures

Deep grooves in the surface of the brain

Longitudinal Fissure

Separates the cerebral hemispheres (fissure)

Transverse Fissure

Separates the cerebrum from the cerebellum

Cerebral Cortex

Contains abt 75% of all neuron cell bodies in NS; thin layer of gray matter on outside of cerebrum

White Matter

Contains bundles of myelinated axons that connect cell bodies to other portions of the NS

Cutaneous Sensory Area

In parietal lobe; interprets sensations on skin

Wernicke’s Area or sensory speech area

Found in temporal/parietal lobe; usually left hemisphere; understanding and formulating language

Visual Area

Found in occipital lobe, interprets vision

Auditory area

Found in temporal lobe, interprets hearing

Sensory area for taste

Found near the base of the central sulcus, includes part of insula

Sensory area for smell

Arises from centers deep within the temporal lobes

Association Areas

Regions that are not primarily motor or sensory, connect the cerebral cortex; analyze and interpret sensory information; provide memory, reasoning, verbalization, judgement, and emotions

Frontal Lobe Association Areas

Concentration, planning, complex problem solving; emotional behavior, judging consequences

Parietal Lobe Association Areas

Understanding speech, choosing words to express thoughts and feelings

Temporal lobe association areas

Interpret complex sensory experiences, stores memories of visual scenes, music, and complex patterns

Occipital lobe association areas

Analyze and combine visual images with other sensory experiences

Insula

Translates sensory info into proper emotional responses

Primary motor areas or motor cortex

Found in frontal lobes, controls voluntary muscles, most nerve fibers cross over in brainstem

Broca’s area

Anterior to primary motor cortex, usually in left hemisphere, controls muscles needed for speech

Frontal Eye field

Above Broca’s area, controls voluntary movements of eyes and eyelids

Short-term memory

Neurons connected in a circuit that is constantly stimulated; when impulse flow ceases, so does memory

Long-term memory

Changes structure or function of neurons, makes new synaptic connections by increasing branching of processes

Long-term potentiation

Increase in neurotransmitter release and effectiveness of synaptic transmission upon repeated stimulation

Basal nuclei

Masses of gray matter deep within cerebral hemispheres; produce dopamine and control voluntary movement

Nucleus, putamen, globus pallidus

3 parts of basal nuclei

Thalamus

Gateway for sensory impulses ascending to cortex; receives all sensory impulses (except smell); channels impulses to appropriate part of cortex

Hypothalamus

Maintains homeostasis by regulating visceral activities

Limbic system

Consists of several structures in various brain parts; controls emotional responses, feelings, survival oriented behavior; reacts to potentially life-threatening upsets

Midbrain

Contains bundles of fibers that join lower parts of brainstem and spinal cord with higher part of brain

Cerebral peduncles

main motor pathways that connect cerebrum to lower nervous system

Corpora quadrigemina

Centers for visual and auditory reflexes

Red nucleus

Role in postural reflexes

Pons

Relays impulses between medulla oblongata and cerebrum and from cerebrum to cerebellum; regulates rhythm of breathing

Medulla Oblongata

Conducts ascending and descending impulses between brain and spinal cord; contains cardiac, vasomotor, respiratory, and nonvital control centers

Reticular Formation

filters incoming sensory info, passing some to cortex and discarding the rest; arouses cortex into wakefulness; decreased activity cause sleep

Slow wave

Person is tired, decreasing activity of reticular formation, restfulness and dreamlessness, reduced BP and RR, 3 stages

REM

HR and RR irregular, dreams

Cerebellum

Contains dentate nucleus; integrate sensory info abt the body position, coordinates muscle activity and posture

Falx cerebelli

Separates cerebellum

Vermis

Connects cerebellum halves

Alpha

Type of wave; awake, resting eyes closed

Beta

Type of wave; active mental activity, under tension

Theta

Type of wave; mostly in children, in some adults in sleep or stress

Delta

Type of wave mostly in sleep

Alpha

Beta

Theta

Delta

Cervical Enlargement

Supplies nerves to upper limb; part of spinal cord

Lumbar Enlargement

Supplies nerves to lower limbs; part of spinal cord

Conus Medullaris

Tapering region of spinal cord below lumbar enlargement

Filum Terminale

Cord of connective tissue that anchors spinal cord to coccyx

Cauda Equina

Group of lumbar and sacral nerves extending downward from conus medullaris in vertebral canal

Anterior Median fissure and posterior median sulcus

2 grooves that extend whole length of spinal cord

Funiculi

White matter in spinal cord is arranged into …

Horns

Gray matter in the spinal cord is arranged into …

Monosynaptic reflex

Contains 2 neurons: sensory and motor

One synapse in spinal cord

Polysynaptic

Contains sensory neuron, interneuron, and motor neuron

Reciprocal innervation

Withdrawal reflex; flexors contract, extensors are inhibited

Ascending tract

Conducts sensory impulses to brain

Descending tracts

Conduct motor impulses from the brain to motor neurons and effectors

Fasciculus gracilis and cuneatus

2 tracts; ascending; conduct sensory impulses associated with the sense of touch, pressure, and body movement from skin, muscles, tendons, and joints to the brain; located in the posterior funiculi

Spinothalamic tract

Located in lateral and anterior funiculi; ascending; conducts sensory impulses associated with the senses of pain, temperature, touch, and pressure from various body regions to the brain

Spinocerebellar tracts

Located in lateral funiculi; ascending; conducts sensory impulses required for coordination of muscle movements form muscles of lower limbs and trunk to cerebellum

Corticospinal tracts

Descending tract; located in lateral and anterior funiculi; conducts motor impulses associated with voluntary movements from brain to skeletal muscles

Reticulospinal tracts

Descending tract; located in lateral and anterior funiculi; conducts motor impulses associated with the maintenance of muscle tone and activity of sweat glands from brain

Rubrospinal tracts

Descending tract; located in lateral and anterior funiculi; conducts motor impulses associated with muscular coordination from the brain

Somatic NS

Cranial and spinal nerves that connect CNS to skin and skeletal muscles

Autonomic NS

Cranial and spinal nerves that connect CNS to viscera

Endoneurium

Loose connective tissue surrounding individual axons

Perineurium

Loose connective tissue surrounding fascicles

Epineurium

Dense connective tissue that surrounds a group of fascicles

Nerve

Bundle of axons in the PNS