3) The Central Nervous System (CNS)

• processes reflexes

• transmit nerve impulses to and from brain

spinal cord

• receives sensory input and initiates motor output

• controls life sustaining processes (respiration, circulation, digestion)

brainstem

• processes, integrates, and analyzes information

• involved with the highest level of cognition, voluntary initiation of movement, sensory perception, and language

cerebrum and cerebral cortex

_______ matter is unmyelinated nerve cell bodies

• cluster of cell bodies in CNS are nuclei

• axon terminals

gray

limbic system (gray matter):

• _____: emotion and memory

• ______: learning and memory

amygdala, hippocampus

_____ matter is myelinated axons

• axon bundles connecting CNS regions are tracts

  • contains very few cell bodies

white

the spinal cord’s central cavity is surrounded by ___ matter

gray

external to the spinal cords is ____ matter composed of myelinated fiber tracts

white

the spinal cord runs through ____ _____

vertebral column

____ lies between the bone and tissue to stabilize neural tissue and protect from bruising

• dura mater

• arachnoid membrane

  • subarachnoid space contains CSF secreted by choroid plexus

• pia mater

meninges

the entire CNS is bathed in clear, colorless fluid called _____

• contained within a system of ependymal cell lined, fluid filled cavity called VENTRICLES

CSF

CSF is made by ____ ____ (in lateral, 3rd, and 4th ventricles)

• made and drained into blood constantly

• total volume: about 150 mL

• is replaced every 8 hours

choroid plexuses

CSF contributes to brain homeostasis by providing

• _____: acts as a cushion and shock absorber

  • allows the brain to float in cranial cavity → reduce its weight by 97%

mechanical protection

CSF contributes to brain homeostasis by providing

• ______: provides optimal ionic composition for neuronal signaling and carries chemical signals like hormones that control sleep and appetite

chemical protection

CSF contributes to brain homeostasis by providing

• _____: allow for exchange of nutrients and wastes between blood and CNS

circulation

CSF Pathophysiology:

• _____ is the build up of CSF

  • overproduction of CSF

  • obstruction in ventricular system

  • problems with absorption

hydrocephalus

CSF Pathophysiology:

• Inflammation of CSF space

  • _______ (bacterial or viral) → vaccines

  • Infection or blood entry via hemorrhage/trauma

Meningitis

what significantly contributes to brain protection

cranium, subarachnoid space, CSF, dura mater

GABA receptors are ____ channels

ligand gated ion

Acetylcholinerase inhibition would

• _____ acetylcholine concentrations within synaptic cleft

increase

Acetylcholinerase inhibition would

• _____ post synaptic cholinergic receptors

stimulate

Opening voltage gated ____ channels initiates presynaptic NT vesicle formation in response to AP reaching the terminal boutons

Ca2+

L-arginine is amino precursor to _____

nitric oxide

tryptophan is amino precursor to _____

seratonin

Tyrosine is amino precursor to _____ (dopamines, Epine, NorE)

catecholamines

Histadine is amino precursor to _____

Histamine

Which NT is responsible for maintaining long term potentiation in the hippocampus?

Glutamate

Astrocytes, Ependymal cells, oligodendrocytes, schwann cells

neuroglial cells

which cell lines the ventricular choroid plexus and participates in formation of CSF?

ependymal cells

nicotinic acetylcholine receptors, NMDA receptors, GABA receptos

ligand gated ion channels

brain ridges

gyri

brain shallow grooves

sulci

deep sulcus in brain are called

fissures

deep _____ divides hemisphere into 5 lobes

sulci

______ lobe of brain: executive functions, thinking, planning, organizing, problem solving, emotions, behavior control, personality

frontal

_____ lobe of brain: movement

motor cortex

_____ lobe of brain: sensations

sensory cortex

_____ lobe of brain: perception, making sense of world, arithmetic, spelling

parietal

____lobe of brain: vision

occipital

____ lobe of the brain: memory, understanding, language

temporal

_____: Each hemisphere has abilities not shared with its partner

lateralization

one hemisphere is dominant for one process

• ex: left hemisphere dominant for language

cerebral dominance

____ hemisphere

• controls language, math, and logic

left

_____ hemisphere

• controls visual-spatial skill, emotion, artistic skills

right

in the cerebral cortex, 40% of brain mass is superficial gray matter

• Each hemisphere acts __________ (controls the opposite side of the body)

• Hemispheres are not equal in function

• gyri convolution increases surface area

• Conscious behavior involves the entire cortex

• conscious mind

contralaterally

three type of functional areas of cerebral cortex

• ____ controls voluntary movement

motor area

three type of functional areas of cerebral cortex

• _______ conscious awareness of sensation

sensory area

three type of functional areas of cerebral cortex

• _____ integrates diverse information

association area

Primary motor cortex

• _____ who’s axons make up corticospinal tracts

• allows conscious control of precise, skilled, voluntary movement

pyramidal cells

Major Sensory Areas

• _________ Receives information from the skin and skeletal muscles

  • Exhibits spatial discrimination → allows us to tell where in space we are

primary somatosensory cortex

Major Sensory Areas

• ________ Integrates sensory information

  • Forms comprehensive understanding of the stimulus

  • Determines size, texture, and relationship of parts

somatosensory association cortex

Major Sensory Areas

• Seen on the extreme posterior tip of the occipital lobe • Receives visual information from the retinas

primary visual cortex

Major Sensory Areas

• Surrounds the primary visual cortex • Interprets visual stimuli (e.g., color, form, and movement)

visual association area

Major Sensory Areas

• Located at the superior margin of the temporal lobe

• Receives information related to pitch, rhythm, and loudness

primary auditory cortex

Major Sensory Areas:

• Located posterior to the primary auditory cortex

• Stores memories of sounds and permits perception of sounds

• Wernicke’s area:

  • Responsible for the comprehension of language

auditory association area

Located in the anterior portion of the frontal lobe

• Involved with intellect, cognition, recall, and personality

• Necessary for judgment, reasoning, persistence, and conscience

• Closely linked to the limbic system (emotional part of the brain)

prefrontal cortex

areas of the body with the greatest density of receptors will have _____ areas on the somatesthetic cortex

larger

Damage to Broca’s Area results in inability to ______

• Present in only the left hemisphere

• A motor speech area that directs muscles of the tongue

• Is active as one prepares to speak

  • Speech preparation and production • i.e. word formation

speak

Damage to Wernicke’s Area results in inability to ________ and _____

• language comprehension

• Sounding out unfamiliar words

• Has a critical role in understanding both spoken and written words

• Damage to Wernicke’s area results in an inability to understand speech and an inability to read

understand speech, read

Located in the cortex of the insula

• Involved in conscious perception of visceral sensations:

  • Upset stomach

  • Full bladder

  • Feeling that you need to have a bowel movement

Visceral association area

Connect corresponding gray areas of the two hemispheres

• Allow the two brain hemispheres to function as one

Commissures

the largest and most important commissures is called the ___ ____

corpus callosum

_____ fibers:

• Connect different parts of the same hemisphere

association

_____ fibers:

• Enter the hemispheres from lower brain or cord centers

• They tie the cortex to the rest of the nervous system, and to the body’s receptors and effector organs

projection

Central core of the forebrain (deep grey matter), almost completely surrounded by the cerebral hemispheres

• Structures included:

  • Thalamus

  • Hypothalamus

  • Part of the pituitary gland

  • Pineal gland

diencephalon

• receives sensory input (except smell)

• impulses are sorted out, edited, and relayed as a group

thalamus

Maintains homeostasis and regulates the autonomic system.

• Contains centers for:

  • Hunger/satiety and thirst

  • Regulation of body temperature

  • Regulation of sleep and wakefulness

  • Sexual arousal and performance

  • Emotions of fear, anger, pain, and pleasure

  • Control of the endocrine system

  • Controls hormone secretion from the pituitary gland

hypothalamus

the _____ (temperature control) in hypothalamus: functions to regulate shiver, hyperventilation, vasodilation, and sweating

preoptic area

the ______ in the hypothalamus: produces antidiuretic hormone (ADH, vasopressin) to control urine volume/osmolarity by water reabsorption

supraoptic nucleus

the _____ in the hypothalamus: produces oxytocin – uterine contraction stimulation

paraventricular nucleus

• Rage and aggression:

• Fear

• Hunger/Satiety (addiction):

• Sex/sex drive (addiction):

• Reward (addiction) and Punishment:

limbic system

Short-term memory: recent events; transferred to longterm via ______ ______

• Sleep is needed for optimum memory consolidation

memory consolidation

Long-term memory (LTM): requires actual _______ changes; within the hippocampus

• termed long-term potentiation (LTP)

structural

» LTM classified into:

• ________- (implicit): memory of simple skills; conditioning (how to tie a shoe, how to ride a bike, etc.)

Nondeclarative

» LTM classified into:

• ________ (explicit): memory that can be verbalized; impaired in amnesia

  • Semantic: facts (names of the bones of the body)

  • Episodic: events (taking a practical exam on skeletal system)

Declarative

LTP Signal Transduction

1) ____ binds to AMPA receptor, allowing Na+ in

Glutamate

LTP Signal Transduction

2) cell _____, glutamate activates NMDA receptor channels (were inactive bc Mg2+ blocks the pore)

depolarize

LTP Signal Transduction

3) _____ allows Ca2+ and Na+ entrance

NMDA-R

LTP Signal Transduction

4) Ca2+ binds to calmodulin → activates ______ (Ca2+/calmodulin dependent protein kinase

CaMKII

LTP Signal Transduction

5) CaMKII causes more _________ to fuse to plasma membrane = strengthens synapse–becomes more sensitive to glutamate release (EPSP)

AMPA receptors

TP Signal Transduction

Activates protein kinase that activates a transcription factor called ______ (cyclic AMP response element binding protein): Activates genes to produce mRNA and proteins, including dendritic spines with AMPA receptors inserted

CREB

Emotions can both strengthen weaken memory formation:

• Emotional component to memory, the _____ is involved.

• Stress impairs memory consolidation in the hippocampus and working memory function of the prefrontal cortex.

• Post-traumatic stress disorder (PTSD) may result in hippocampus atrophy: Memories are stored but retrieval is hindered

amygdala

The amygdala and hippocampus have receptors for stress hormones, such as ________:

• can strengthen emotional memory formation via the amygdala but weaken hippocampus memory formation and memory retrieval

cortisol

what ion is involved in stimulating genetic transcription needed for learning and memory?

Ca2+

Suprachiasmatic nuclei (SCN): contain about 20,000 “clock cells” with activity that oscillates every _____ hours – main control of circadian rhythms

24

Entrained by information about day length via tracts from retinal ganglion cells by way of retinohypothalamic tracts

• Controls the secretion of _______ from the pineal gland which is the major regulator of circadian rhythms; secreted mainly at night

melatonin

NT involved in sleep:

• ______ - wakefulness

  • diphenhydramine (inverse H1-R agonist, crosses BBB, drowsiness)

histamine

NT involved in sleep:

• _______ (inhibitory) – sleep

Adenosine & GABA

NT involved in sleep:

• _________ – induces sleep categories

  • Two recognized categories:

    • 1) REM: rapid eye movement; state when dreams occur.

    • 2) Non-REM: also called resting sleep

Serotonin

REM sleep: Some brain regions are more active during REM sleep than during the waking state

• _______ system is very active during REM sleep.

• Breathing and heart rate may be very irregular.

• Benefits consolidation of non-declarative memories

Limbic

Non-REM Sleep: As you fall asleep, neurons _______ their firing rates, decreasing blood flow and energy metabolism

• Breathing and heart rate are very regular

• Non-REM sleep may allow repair of metabolic damage done to cells by free radicals and allows time for LTP needed to store memories

• Benefits consolidation of declarative memories

decrease

Only accounts for 2.5% of total brain mass

• Consists of 3 regions: ____, ______, _____

• Continuous with the spinal cord

midbrain, pons, medulla oblongata

______ Provides the pathway for tracts between higher and lower brain centers

• Associated with the 12 pairs of cranial nerves

brain stem

Olfactory - sensory → olfactory (smell) information from nose

CNI

Optic - sensory → visual information from eyes

CNII

Oculomotor - motor → eye movement, pupil constriction, lens shape

CNIII

Trochlear - motor → eye movement, somatic motor fibers to superior oblique muscle to direct eyeball

CNIV

Trigeminal - Mixed → sensory information from face, mouth; motor signal for chewing

CNV

Abducens - motor → eye movement; somatic motor fibers to lateral rectus muscle to direct eyeball

CNVI

Facial - mixed → sensory for taste, efferent signals for tear and salivary glands; facial expression

CNVII