CENTRAL NERVOUS SYSTEM ANATOMY *blue is for honors

I: Protection: Skull, Meninges and CSF: see p82 color book:

_______________________: specialized capillary network projecting from the pia mater into the ventricles of the brain forming cerebral spinal fluid (70% of CSF) 99% water, (glucose, aa, salt, less density and protein than plasma)

            ~ 150 mL CSF in ventricles and subarachnoid space

·         Dura mater, __________ , pia mater

·         CSF Circulation: lateral > interventricular foramen > 3rd > cerebral aqueduct > 4th

·         Superior sagital sinus and arachnoid villi

·          

II. BRAINSTEM: medulla, pons and midbrain

Medulla oblongata w/ pyramidal tracts, houses cranial nerves:  vestibulocochlear,, hypoglossal, glossopharyngeal, vagus, accessory  and *penumotaxic center, * CV & Vasomotor center VITAL CENTERS

top of the spine, two bulges of white matter = pyramids (pyramid tracts)

·         Anterior/ventral surface: major voluntary motor pathways from cerebrum and decussation

·         Posterior/dorsal surface: 2 pairs of ascending tracts

1.       fasciculi gracilis

2.      fasciculi cuneatus : touch , body pressure and position

·         All ascending sensory and descending motor tracts

·         VITAL CENTERS (CV and Vasomotor center)

o        ____________________ (rate/force of heart) diameter = vasodilation

o        ____________________: adjust basic rhythm of breathing

o        Reflex: vomit, cough, sneeze, swallow

o        Reticular formation: gray matter from spine to thalamus

o        Keeps cerebrum ____________________

o        Reflex centers: cardiac, vomit, sneeze, vasomotor, cough, respiratory, swallow

o        12 pairs of cranial nerves

 

Pons w/ Reticular formation is a relay pathway between the motor cortex and the cerebellum also functions as a  *pneumotaxic center *houses cranial nerves: trigeminal, abducens, and facial.

·         Respiration center

·         Reflex w cranial nerves 5-8, eye, chewing, facial expression, taste, equilibrium

·         RF and cranial nerve origin

 

Midbrain w/ cerebral peduncles

·         __________________________: Righting reflexes

o        Superior colliculi: visual reflex center

o        Inferior colliculi: auditory reflex center

·         Cranial nerve origin: cranial nerves oculomotor and trochlear

·         Cerebral peduncles: crus cerebri: descending tracts

·         Substantia nigra: pigmented neurons in motor fxn and produces the precursor for the neurotransmitter ________________

·         RF: ascending paths

·         __________________ (pink)important for acting as a relay between motor cortex and muscles of the limbs  for limb flexion;  cranial nerves 3 and 4 with the eye

·         Roof Midbrain: muscle tone and posture

CEREBELLUM

·         Arbor vitae: ___________________________________________

·         Some cognitive function in predicting motor movements

·         Fine coordination: 3 main function

o        Smooth not jerky, steady not trembling

o        Muscle tone and posture

o        Flocculonodular lobe= equilibrium and posture

·         Hemispheres separated by falx cerebelli

·         Cereballar cortex – gray

·         But mainly white matter underneath : arbor vitae

·         30 million purkinje cells in cerebellar cortex

·         integrate infor motor activity to keep informed about body position

·         axons carry infor to nuclei for relay to brainstem

 

DIENCEPHALON

Thalamus: all sensory except smell to the cerebrum

·         expresses _________ with hypothalamus

·         cognition: awareness and acquisition of knowledge

 

Hypothalamus  w/ VITAL CENTERS: maintain and regulate ____________________

·         sleep and wake patterns

·         controls _____________ system; links with the nervous system

·         secretes variety of hormones that regulate pituitary

·         secretes oxytocin and antidiuretic hormone

·         osmotic balance (thirst)

·         thermoregulation

·         appetite

·         sexual behavior and emotional aspect of sensory 

Pituitary gland: _________________________ secretes: posterior lobe: secretes oxytocin and antidiuretic hormone; anterior lobe: ACTH affects adrenal cortex; TSH affect thyroid and thyroxin; FSH,LH affects ovary and testes; Prolactin affects mammary glands; GH for bone growth;

 

Mammillary bodies:

·         activate ________________________ such as swallowing and licking the lips and may be involved in relaying olfactory messages

 Epithalamus

·         pineal gland: produces melatonin for __________________________

 

choroid plexsus: specialized capillary network projecting from the pia mater into the ventricles of the brain forming cerebral spinal fluid

 

Reticular Formation: groups of neurons clustered in the spinal cord through the medulla, pons and midbrain.  Have axons that reach into the diencephalon (specifically the hypothalamus, thalamus and cerebellum )  Form the RAS*

 

 RAS *(reticular activating system): nuclei axons connect hypothalamus, thalamus, cerebellum and spinal cord to send sensory information to keep the cortex alert and conscious ALSO acts as a _________________ for _______________________ to the cortex…filters out 99% of sensory input as unimportant.  Has to be inhibited in order to sleep

 

CEREBRUM12 billion nerves and 50 billion glial cells

Cortex

 Fissures longitudinal fissure (flax cerebri)

 Gyri

 Sulci

 Hemispheres

lobes: frontal, parietal, occipital, temporal, central and limbic

neocortex: new mostly only in mammals

Ventricles/CSF

Cerebral white matter:

1.       association (within hemispheres)

2.      commissure –connects neoccortex of hemispheres (corpus callosum)

3.      projection

 

Basal Nuclei: deep within white matter surrounding 3rd ventricle they influence: _________________

________________________________________________ via premotor cortex

·         subconscious movement

·         humans: planning, programming movement, information feedback with cortex,

·         help decisions about sensory input

 

Limbic: _______, autonomic, subconscious motor and sensory drives, sexual behavior, biological rhythms

Motivation=pleasure or punishment

Limbic is the connection between emotional and cognitive mechanisms

 

Amygdala nucleus: part of the limbic system located deep within each hemisphere/ important part of emotional feelings linked to cognitive input (pleasure and fear emotions)________ conditioning sends input to hypothalamus to signal the ____________________ NS to act

Reticular Activating System: nuclei axons connect hypothalamus, thalamus, cerebellum and spinal cord to keep the cortex _______ and ____________. Also acts as a filter for sensory input to the cortex … filters out 99% of sensory input as unimportant

o        RAS: arousal system

o        Complex polysynaptic path in brainstem and thalamus RF

o        Receives messages from neurons on spine and other parts and communicates with cerebral cortex with complex circuits

o        Ultimately responsible for consciousness

o        Extent of RAS activity determines state of alertness (focus)

o        Slow stimulation get sleepy and bored

o        Toss and turn at night due to RAS

o        Effects the way we react to stimuli

o        If damaged= deep permanent coma

o        When RAS is stimulated the whole NS is stimulated for 30 sec

 

Function:

  1. __________________: interprets signals so we “know: what we are seeing, hearing, tasting, smelling …
  2. __________________: responsible for all voluntary movement  (somatic) / some involuntary (autonomic)
  3. __________________: all intellectual activities of cerebral cortex: learning, reasoning, memory storage, recall, language abilities, even consciousness

 

VB. Lobes:

___________: primary motor area allows conscious movement of skeletal muscles, higher intellectual reasoning, complex memory

 

___________: somatic sensory area : impulses from sensory receptors are localized and interpreted; path are X’d, able to interpret characteristics of objects feel with hand and to comprehend spoken and written language

 

___________: visual cortex, receives visual info via thalamus (primary visual area)integrates info to formulate response (visual association area)

 

___________: emotion, personality, memory behavior, auditory and olfactory area, complex memory (both neo and old cortex)

 

___________: (linked with temporal) ring of cortex around cerebral ventricles, connections between emotional and cognitive mechanism, emotional, autonomic, subconscious motor and sensory drives, sexual behavior, biological rhythms

 

Specialization areas:  *see pg 435   

primary motor in precentral gyrus,: motor cortex: control voluntary skeletal movment

 

primary sensory in postcentral gyrus *see Homunculi pg 436),: somatosensory area:: receives infro from skin, joint via thalamus

 

 

Cerebral dominance: (     ) language abilities, mathematics, intellectual functions with language

                                    (      ) spatiotemporal matter, recognize face, appreciates and recognizes music

VC. DISORDERS:  

Alzheimers disease

 

Parkinson’s disease

 

Stroke

Aphasia

Concussion

Contussion

Cerebral contusion

 

VI: Spinal Cord

Anatomy

 

 

 

 

 

 

 

VII: Disorders and Clinical Applications

Lumbar puncture

Spinal tap vs epidural

Spina Bifida

Anencaphaply

Paralysis

Spinal Shock

ALS

Poliomyelitis

 

VIII: Neurotransmitters and the effects of drugs on NS

Catecholamines                          Nitric oxide

Indolamines                             Carbon monoxide

Dopamine                                cocaine

Norepinephrine

Serotonin

GABA

Endorphins

Enkaphalins