1. The Nervous System - Lab Exercise 5

2. Divisions of the Nervous System
Central nervous system (CNS) – brain & spinal cord
Peripheral nervous system (PNS) – cranial nerves & spinal nerves

3. The Central Nervous System
CNS well protected by bones (cranial & vertebrae), CT meninges, & cerebrospinal fluid (CSF)
Meninges – Connective tissues that surround and protect the brain and spinal cord (CNS)
3 layers:
Dura Mater
Arachnoid
Pia Mater

4. Meninges Dura Mater – tough, fibrous outer layer
2 layers thick around brain with creation of dural sinuses between layers;
1 layer around spinal cord with epidural space external

5. Meninges Arachnoid – “spidery” web-like middle layer
Pia Mater – delicate, thin inner layer; adhered to brain & cord; extension of pia mater (“filum terminale”) extends from tip of cord to coccyx to anchor cord in place
Subarachnoid space – between arachnoid & pia mater; contains cerebral spinal fluid (CSF)

6. Superior sagittal sinus
Dura mater (gray color)
Arachnoid (orange color)
Subarachnoid space (blue color)
Pia mater (red color)

7. The Brain Brain stem medulla oblongata (M.O.) pons midbrain
Diencephalon
thalamus
hypothalamus
mamillary bodies
epithalamus (pineal gland)
Cerebrum
Cerebellum
Cerebrum T P P H
midbrain M
Cerebellum
pons
m.o.

8. Cerebrum T P H
midbrain M
pons
Cerebellum
m.o
Spinal cord

9. The Brainstem medulla oblongata (M.O.) pons midbrain –
cerebral peduncle
cerebral aqueduct of midbrain
corpora quadrigemina
superior colliculi
inferior colliculi
pons
Cerebral peduncle
m.o.
Cerebral aqueduct of midbrain

10. Cerebral aqueduct of midbrain
Superior colliculus
Inferior colliculus
Cerebral peduncle

11. The Diencephalon thalamus intermediate mass hypothalamus
mamillary bodies
connects to pituitary gland via infundibulum
epithalamus (pineal gland) T
Intermediate mass of thalamus P H
infundibulum
Pituitary gland M

13. Cerebrum convolutions
gyrus
sulcus
4 lobes per hemisphere- frontal, parietal, temporal, occipital

14. The Cerebrum
corpus callosum
fornix
septum pellucidum

15. The Cerebellum gray matter “folia” white matter “arbor vitae”
separated from cerebrum by transverse fissure
Transverse fissure

17. Cerebrospinal Fluid (CSF)
clear, colorless fluid formed by filtration of blood plasma by choroid plexuses within ventricles of the brain.
functions in protection of CNS, support, nutrient supply, waste removal

19. CSF Circulation
Lateral ventricles (in cerebral hemispheres)  interventricular foramen  third ventricle (in diencephalon around thalamus)  cerebral aqueduct of midbrain  fourth ventricle (between pons/cerebellum)  subarachnoid space & central canal of SC
Lateral ventricle (behind septum pellucidum)
Third ventricle
Aqueduct of midbrain
Fourth ventricle

20. Reabsorption of CSF through arachnoid granulations (arachnoid villi) of dural sinuses (superior sagittal sinus)  into cerebral veins

21. Superior sagittal sinus
Arachnoid granulation (villus)

22. Cranial Nerves
12 pairs of nerves that connect to the brain; provide motor, sensory &/or autonomic (parasympathetic) function

23. I (olfactory bulb)
Olfactory tract
Optic chiasm
Optic tract II
III IV V
VII VI
VIII IX
XII X XI