Flight or Flee Aldana Syeda Erycha Thomas Lexi

1. Lexi, Aldana, Syeda, Erycha & Thomas

2. Structures and Function of the Brain
stem
• Brain stem structure/definition- is part of the
brain containing the midbrain, pons, and
medulla oblongata.
• -Function of the brain stem – performs
sensory, motor, and reflex functions

3. Brain Stem

4. Structure and function of the
Cerebellum
• function of the cerebellum –performs with 3 general
functions, all of which have to do with the control of
skeletal muscles:
• -1 acts with the cerebral cortex to produce skilled
movements by coordinating the activities of groups of
muscles
• -2 helps control posture it functions below level of
consciousness to make movements smooth instead of
jerky, steady instead of trembling , and efficient and
coordinated instead of ineffective, awkward, and
uncoordinated .
• -3 controls skeletal muscles to maintain balance.

5. Cerebellum

6. Identifying and Describing Cranial
Nerves
• -structure/definition: any of the twelve pairs of
nerves that attach to the undersurface of the
brain and conduct impulses between the brain
and structures in the head, neck, and thorax
• olfactory nerve- helps you smell
• optic nerve- helps you see
• oculomotor nerve- helps with eye movements
• trochlear nerve- responsible for eye movements
• trigeminal nerve- responsible for chewing
movements, head and face movements.

7. Cranial Nerves continued…
• Abducens nerve- responsible for abduction of eye or movements
• Facial nerve- responsible for facial expressions, secretion, of saliva
and tears , taste
• Vestibulocochlear nerve- responsible for hearing and equilibrium.
• Glossopharyngeal- responsible for the sensations of the tongue,
swallowing movements, secretion of saliva, aid in reflex control of
blood pressure and respiration.
• Vagus- responsible for sensations and movements of organs
supplied e.g. slows heart, increases peristalsis and contracts
muscles for voice production.
• Accessory nerve- responsible for shoulder movements, turning
movements of head, movements of viscera, voice production.
• Hypoglossal nerve- responsible for your tongue movements.

8. Cranial
Nerves

10. • Made of strong white fibrous tissue
• Outer layer of the meninges
• Inner periosteum of the cranial bones
• Protects inner layers including brain
• Delicate cob-web like
• Between Dura matter and Pia matter
• Adheres to outer surface of meninges
• Transparent
• Adheres to outer surface of the brain and spinal cord
• Contains blood vessels

11. Cervical Plexus
Cervical Plexus
(C1 through C4)
(C1 through C4)
Brachial Plexus
(C5 through T1)
Lumbar Plexus
Sacral Plexus
L4 and L5 through
S1 and S4

12. • Innervate the muscles and skin of the neck, upper
shoulders, and part of the head
• Exiting the plexus, phrenic nerve, which innervates
the diaphragm
• Deep within shoulder
• Passes from ventral rami of spinal nerves C5 through T1
• Beneath clavicle
• Toward upper arm
• Innervates the lower part of the shoulder and entire arm

13. • Made from intermingling fibers from the first four
lumbar nerves
• Lumbar region of back
• Divides into many branches supplying the thighs
and legs
• Formed fibers from the fourth and fifth lumbar
nerves and the first four sacral nerves
• Lies in pelvic cavity on the anterior surface of the
piriformis muscle
• Forms the sciatic nerve
• Through buttocks and back of thigh
• Supplies all leg skin

15. • Within spinal cavity
• From foramen magnum to the lower border of the first
lumbar vertebra
• Averages about 18 inches
• Conducts information to and from brain
• Reflex center for all spinal reflexes

16. Structure of Spinal Nerves

17. Function of the Diencephalon
Thalmus: Plays two parts in -Plays a part in Plays an indirect but
the mechanism responsible the arousal/ essential role inn
for sensations alerting maintaining water
A. Impulses from mechanism balance
appropriate receptors, on -Plays a part in -Helps control function
reaching the thalmus, the mechanism of every cell in the body
produce conscious that produces -Maintains the waking
recognition of the crude, complex reflex state
less critical sensations for movements -Regulates appetite
pain, temperature and -Maintains normal body
touch temperatue
B. Neurons whose Hypothalmus:
dendrites and cell bodies Helps control and
lie in certain nuclei of the integrate the
thalamus relay all kinds responses made
of sensory impulses, by visceral affects
-Responsible for emotions by all over the body
associating sensory impulses -The link between
with feelings of pleasant and the cerebral
unpleasant cortex and the
lower centers

18. Structure of the Diencephalon

19. Function of CSF
• CSF (Cerebrospinal fluid)
• Provides a supportive, protective cushion
• A reservoir of circulating fluid that gets
monitored by the brain for changes in the
internal environment.

20. Somatic Sensory Pathways in CNS
• A relay of neurons that send impulses to the
sensory area’s
• Primary Sensory Neurons: Conduct from
Periphery to central nervous system
• Secondary Sensory Neurons: Conduct from
cord and brainstem up to thalamus
• Tertiary Sensory Neurons: Conduct from the
thalamus to the post central gyrus of the
parietal lobe

21. Central Sulcus
Frontal Lobe Parietal Lobe
Lateral
Fissure Occipital
Lobe
Temporal
Lobe

22. Cerebral Cortex
• Cerebrum – largest and uppermost division of
the brain and has 2 divisions
• The cortex has six layers that each has millions
of axon terminals
• Each area of the cerebrum represents a gyrus
• The cerebrum contains the frontal lobe,
parietal lobe, occipital lobe, and the temporal
lobe

23. Cerebrum
Midbrain
Pons
Medulla
Spinal Cord

24. Somatic Motor Pathways
• Pyramidal tracts are those who fibers come
together in the medulla to form pyramids
• Extrapyramidal tracts consist of all motor
tracts from the brain to the spinal cord
• Sets of coordinated muscle commands the
control muscle activity is called a motor
program

25. Medial Pectoral
Suprascapular
Axillary
Radial
Lateral
Pectoral
Musculocutaneous
Ulnar
Median Medial Root
Medial Brachial
pectoral

26. Dermatomes and Myotomes
• Each skin area supplied by sensory fibers is
called dermatome
• A myotome is a skeletal muscle or group that
receives motor axons from a given spinal
nerve
• There is a overlap among myotomes thus
some skeletal muscle organs may be
innervated by motor axons