Transcript The Central Nervous System

Section 8 Vocabulary
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Basilic: royal
Cephalic: head
Serratus: saw
Protract: to draw forth
Retract: draw back
Condyle: knuckle
Collateral: side by side
Quadratus: squared
Hamate: hooked
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Lunate: moon-shaped
Synovial: with egg
Bursa: purse
Prostate: to stand
before
Ectopic: out of place
Fimbrial: fringe
Gracilis: slender
Malleolus: hammer
Meniscus: crescent
The Central Nervous System
Chapter 12
I. Protection of the CNS
A. Bone- skull & vertebrae
B. Meninges- connective tissue
1. Dura mater-outer layer, thick, DWF
2. Arachnoid- middle, delicate
3. Pia mater- innermost, thin, attached to
brain, vascular
I. Protection of the CNS
• C. Cerebrospinal Fluid (CSF)- clear,
watery fluid that fills all cavities
within and around nervous system;
choroid plexus (capillaries) separate
CSF from blood by ependymal cells.
I. Protection of the CNS
C. CSF Functions
1. Cushions brain and spinal cord
from mechanical injury
2. dissolves and transports
substances filtered from blood
3. Medium for exchange of
nutrients and waste products
between blood and brain
I. Protection of the CNS
D. Blood- prevents sudden or
extreme fluctuations in CSF;
provides fluid for CSF
II. Spinal Cord
• Extends from foramen
magnum to L1
• Fills the vertebral foramina
along with meninges, CSF,
adipose, and blood vessels
• Conducts impulses to and
from brain
• Serves as integrator or reflex
center (ex. Papillary, patellar)
Spinal Cord Protection
By the vertebral column, meninges, cerebrospinal
fluid, and vertebral ligaments.
II. Spinal Cord
A. Ascending tracts- sensory
impulses up the SC to the brain;
named for where it terminates
in the brain
1. lateral spinothalamic tract
2. anterior
“
“
3. fasciculu gracilis and cuneatus
4. spinocerebellar tracts
II. Spinal Cord
B. Descending tracts- from the
brain down the SC; motor
impulses; names for where it
originates in the brain
1. lateral corticospinal tracts
2. anterior “
“
3. lateral reticulospinal tracts
4. medial
“
“
5. rubrospinal tracts
III. Brain
Consists of 100 billion neurons &
900 billion glia; ~ 3 lbs; cell
division of neurons only occurs
in prenatal development???
III. Brain
A. Brain Stem
1. Medulla Oblongata- lower part of brain
stem; attaches to spinal cord; contains
reticular formation of gray and white
matter
A. vital centers- regulate heartbeat,
respiration, bp, diameter of blood
vessels
B. Reflex centers- coughing, sneezing,
swallowing, vomiting
III. Brain
A. Brain Stem
2. Pons- middle part
of brain stem;
connects
cerebellum to brain
stem; relay
between upper
and lower CNS;
affects rate of
respiration
III. Brain
A. Brain Stem
3. Midbrain
(mesencephalon)above pons; upper
part of brain stem;
also contains
reticular formation
A. cerebral peduncles- nerve tracts to and from the
cerebral hemispheres
B. red nucleus- relay station; coordinates impulses
between cerebellum and cerebrum; muscle control
C. corpora quadrigemina- pupil constriction reflex;
relay station for auditory impulses
III. Brain
B. Cerebellum- “little
brain”; 2nd largest part
of brain; below
cerebrum; gray
matter outside and
white matter (arbor
vitae) inside
FUNCTIONS:
1. Coordinate skel muscle
movt; maintain equil/
balance
2. receive info about touch,
vision, sound
3. maintain posture with sk.
muscles
III. Brain
C. Diencephalon
1. Thalamus- middle below cerebrum;
gray matter; relay station to carry
impulses to cerebrum
2. FUNCTIONSA. pain, temp, touch senses
B. emotions of un/pleasantness
C. Mechanism for arousal
D. plays a part in mechanisms that produce
complex reflex movements
III. Brain
C. Diencephalon
2. Hypothalamus- beneath the
thalamus; holds pituitary gland and
mamillary bodies; links nervous and
endocrine systems.
III. Brain
C. Diencephalon
2. Hypothalamus- FUNCTIONSA. autonomic center- olfactory neurons for
smell (in mam bodies)
B. relay station between cerebrum and
lower brain centers
C. produce hormones to maintain water
balance (ADH), thirst center
D. produce “releasing hormones”- growth
hormone, oxytocin, GnRH
E. maintains wake state
C. Diencephalon
2. Hypothalamus- FUNCTIONSF. Regulates appetite and satiety center
G. Regulates body temperature- blood
vessels/ sweat glands
H. Pleasure center- eating, drinking, sex
III. Brain
C. Diencephalon
3. Pineal body- pine cone shape,
endocrine gland, aka epiphysis,
secretes hormone melatonin for
biological clock, daylight vs. sleep
III. Brain
• C. Diencephalon
– 4. Optic chiasma- right and left
optic nerves cross here
III. Brain
• D. Cerebrum
Largest part of the brain; 2
wrinkled hemispheres; axons of
neurons may interconnect with
same hemisphere, other
hemisphere, or other parts of
CNS
D. Cerebrum
1. Structures
A. Corpus callosum- tissue joins 2 hemispheres;
white, curved; surrounds ventricles
B. Cerebral nuclei- gray matter; aka basal ganglia;
regulates voluntary motor functions such as
walking
D. Cerebrum
1. Structures
C. Cerebral Cortex- surface; outer 2-4 mm is gray
matter with white matter below
1. white shallow grooves or fissures- sulci (singular- sulcus)
2. wrinkled peaks or convolutions – gyri (singular- gyrus)
D. Lateral Ventricle- cavity in each hemisphere;
fluid filled; generally enlarges with age
D. Cerebrum
2. Main Lobes or Regions
A. Frontal- personality, voluntary motor control
B. Parietal- processing sensation
C. Occipital- visual cortex
D. Temporal- auditory cortex, emotions, memories
E. Insula / Island of Reil- link between emotion and
cognition
III. Brain
D. Cerebrum
3. Functions of Cerebral Cortex
A. Sensory- touch, pressure,
temperature, body position
(proprioception), vision, hearing,
taste, smell; sensory speech
(Wernicke’s area)
B. Motor- voluntary movements
D. Cerebrum
3. Functions of Cerebral Cortex
C. Integrative- all functions between
sensation and motor/ effection
1. consciousness- impulses from ret
formation; awareness; REM; meditation
2. language- speak, write, hear, see words;
motor speech (Broca’s area)
3. emotions-limbic system- anger, fear,
sexual feelings, pleasure, sorrow
4. memory- short-term and long-term; use
hippocampus
IV. Right vs Left Hemisphere
Right
creative
musical
artistic
spatial perception
Left
speech
language
hand movt
calculation
Cerebrum
II. Spinal Cord
Extends from foramen magnum
to L1; fills the vertebral
foramina along with meninges,
CSF, adipose, and blood
vessels; conducts impulses to
and from brain; serves as
integrator or reflex center (ex.
Papillary, patellar)
II. Spinal Cord
A. Ascending tracts- sensory
impulses up the SC to the
brain; named for where it
terminates in the brain
1. lateral spinothalamic tract
2. anterior
“
“
3. fasciculu gracilis and cuneatus
4. spinocerebellar tracts
II. Spinal Cord
B. Descending tracts- from the
brain down the SC; motor
impulses; names for where it
originates in the brain
1. lateral corticospinal tracts
2. anterior “
“
3. lateral reticulospinal tracts
4. medial
“
“
5. rubrospinal tracts
V. Electroencephalogram (EEG)
Map out brain waves or impulse
activity; measured by
frequency (Hz) and amplitude
(V)
A. Alpha- relaxed
B. Beta- busy
C. Theta- drowsy
D. Delta- deep sleep
V. Electroencephalogram (EEG)
V. Electroencephalogram (EEG)