Download Nervous System - Seattle Central

Nervous System
Connections
CNS: Brain & Spinal cord
PNS: Ascending & descending nerves
• CNS
– Brain, spinal cord
– Processing center
– Nuclei
• PNS
– Spinal & cranial
nerves
– Information relay
system
– ganglia
Cranial nerves
•
•
•
•
•
•
•
•
•
•
•
•
I – Olfactory
II – Optic
III – Oculomotor
VI – Trochlear
V – Trigeminal
VI – Abducens
VII – Facial
VIII – Auditory
(Vestibulocochlear)
IX – Glossopharyngeal
X – Vagus
XI – Spinal Accesory
XII – Hypoglossal
S
S
M
M
SM
M
SM
S
SM
SM
M
M
Divisions of PNS
• Somatic
– Voluntary
• Autonomic
– Visceral
(involuntary)
• CNS
– Brain, spinal cord
– Processing center
– Nuclei
• PNS
– Spinal and cranial
nerves
– Information relay
system
– ganglia
Divisions of PNS
Conscious
control
Unconscious
control
Basic regulatory
& reflex
functions in
brainstem
Support and
Protection
•Meninges encase brain & SC
•Three layers:
•Dura mater
•Arachnoid
•Pia mater
•Between layers:
•Cerebrospinal fluid (CSF;
airbag for brain)
Ventricles
Meninges (spinal cord)
• Dura mater: outer layer
– Subdural space; Serous fluid
(lubricant)
• Arachnoid mater:
– Subarachnoid space (between
arachnoid and pia) filled with
CSF & blood vessels
• Pia Mater: inner layer
– Shrink wrapped to spinal cord
& brain
Spinal cord anatomy
• Gray matter: cell bodies & unmyelinated axons
• White matter: Myelinated axons
Major Features of Brain
Vertebrate Brain
• Hindbrain
– Medulla oblongata
– Pons
– Cerebellum
• Midbrain
• Diencephalon
– Thalamus
– Hypothalamus
• Telencephalon
– Cerebral cortex,
(white & gray
matter)
Vertebrate brain
• Mesencephalon: Visual
and Auditory reflex centers
(head-turning)
• Pons: Relay station for
sensory info.
• Medulla oblongata:
Regulate cardio, respiratory,
digestive activities
Medulla Oblongata
• Regulatory Nuclei:
– heart & respiratory rate,
blood pressure, coughing,
sneezing, vomiting,
swallowing, balance,
coordination, digestion,
sleep
• Pyramids:
– Descending motor nerves;
conscious control of skeletal
muscle
Pons
• Ascending & descending
nerve tracts
• Regulatory nuclei:
– Chewing & salivation;
respiration
– Initiates sleep
• Relay nuclei:
– Reticular Formation:
Share info between
cerebrum & cerebellum
Reticular Formation
• Filters out the
humdrum
• Relays the novel &
exciting
Midbrain
• Reflex nuclei
– Visual reflex; startle &
tracking
– Auditory reflex & nerve
tracts
• Regulatory nuclei
– Lens shape, pupil
diameter
– Initiates & terminates
body movements
– Initiates arousal
Diencephalon
• Thalamus
– Ascending sensory neurons
synapse here; project to
cerebrum
• Epithalamus
– Emotional & visceral
response to odors; pineal
body regulates long-term
cycles
• Hypothalamus
– Maintaining homeostasis via
hormone release
Cerebellum
• Gray and white matter
• Balance; maintains muscle
tone; coordinates fine
muscle movement
• Comparator: integrates
proposed movements with
current body position to
produce smooth, exact
movement
• Involved in learning new
balance-intensive activities
– Riding a bike, yoga, climbing
Movement & Body position
Cerebrum & its Regions
Complex info.
Processing
•Conscious thought
•Reasoning
•Memory creation & storage
Cerebral Space
Axons connect CNS - CNS and CNS -PNS
Association, commissural, projection
Axons connect CNS - CNS and CNS -PNS