1. The Brain

2. Cerebral Hemispheres (cerebrum)
Ridges - gyri
Grooves - sulci (shallow)
fissure (deep)
Longitudinal fissure
-separates in two halves

3. 4 Lobes of Cerebrum 2. Occipital - posterior *visual area
1. Parietal - somatic sense area
*crossed pathways
*pain, temperature, touch, taste (gustatory)
2. Occipital - posterior
*visual area

4. 3. Temporal - lateral areas
*hearing (auditory), smell (olfactory), and memory
4. Frontal - primary motor area
*Broca’s area (motor speech)
*Language comprehension

5. Cerebral cortex
Outermost layer of brain
Consists of gray matter
Precentral gyrus - motor
Postcentral gyrus - sensory
**Corpus Callosum- fiber tract connecting hemispheres ; white matter

6. Diencephalon Thalamus - sends sensory information to the proper region
Hypothalamus - body temperature, water balance, metabolism, limbic system (emotional-visceral : thirst, hunger, sex, pain, pleasure), regulates pituitary gland
Epithalamus - has pineal body & choroid plexus of third ventricle (makes CSF)

7. Cerebellum Located inferior and posterior to the cerebrum Controls
Timing of muscles
Balance &
Equilibrium
Ataxia - damage to cerebellum causing loss of balance & coordination

8. Brain Stem Midbrain - vision & hearing reflex
Pons - fiber tracts & breathing
Medulla Oblongata - heart rate,
blood pressure, breathing,
swallowing, vomiting
*Reticular Formation - length of brain stem
motor control of visceral organs
*RAS (Reticular Activating System) - consciousness
damage causes coma

9. Brain Protection Meninges - 3 tissue layers
Dura mater - outermost, tough, double-layered *attaches to skull
Arachnoid mater - middle layer, contains threadlike extensions
Pia mater - innermost, delicate *attaches to brain
Subarachnoid space is filled with CSF
Meningitis - - inflammation of meninges
Encephalitis - - inflammation of brain tissue

10. Cerebrospinal Fluid (CSF)
Watery cushion in & around brain and spinal cord
Formed in choroid plexuses
* Lumbar (spinal) tap
* Hydrocephalus - “water on the brain”
CSF builds up in brain ventricles
drained by a shunt

11. Blood-Brain barrier
Least permeable capillaries in body
Keeps out unwanted substances
Can’t keep out fats, respiratory gases, or fat-soluable molecules (alcohol, nicotine, anesthetics)