1. The Human Brain

2. Divided into two hemispheres and quartered into lobes
Cerebrum -The largest division of the brain.
Divided into two hemispheres and quartered into lobes
Cerebrum
Cerebellum

3. Cerebral Cortex - The outermost layer of gray matter making up cerebrum.

4. Cerebral Features: Gyri – Elevated ridges “winding” around the brain.
Sulci – Small grooves dividing the gyri
Central Sulcus – Divides the Frontal Lobe from the Parietal Lobe
Fissures – Deep grooves; divide large regions of the brain
Longitudinal Fissure – Divides the two Cerebral Hemispheres
Transverse Fissure – Separates the Cerebrum from the Cerebellum
Sylvian Fissure – Divides the Temporal Lobe from the Frontal and Parietal Lobes

5. Lobes of the Brain (4) Frontal Parietal Occipital Temporal

6. Investigation (Phineas Gage)
Frontal Lobe
It plays an integral role in the following functions:
- Memory Formation
- Emotions
- Decision Making/Reasoning
- Personality
(Investigation: Phineas Gage)
Investigation (Phineas Gage)
Modified from:

7. Frontal Lobe Primary Motor Cortex – Controls movements of the body.
Broca’s Area – Controls facial neurons, speech, and language comprehension. Located on Left Frontal Lobe.
Olfactory Bulb - Responsible for sensation of Smell

8. Investigation (Phineas Gage)
Primary Motor Cortex
Broca’s Area
Olfactory Bulb
Regions
Modified from:

9. Lobotomies * Desired Effects: * Possible Side Effects:
- Diminished Rage
Decreased Aggression
Improved mood
* Possible Side Effects:
- Epilepsy
- Poor Emotional Responses
Uncontrolled, repetitive actions, gestures, or words
Death

10. Parietal Lobe
The Parietal Lobe of the brain is located deep to the Parietal Bone of the skull.
It plays a major role in the following functions/actions:
Cognition
Information Processing
Pain and Touch Sensation
Spatial Orientation
Speech
Visual Perception (Proprioception)
Modified from:

11. Parietal Lobe
Somatosensory Cortex – Processes sensory information about touch, location of limbs, pain and temperature.
Gustatory Cortex – Primary site involved with the interpretation of the sensation of Taste.
Sensory
Homunculus

12. Primary Somatosensory Cortex
Primary Gustatory Cortex
Modified from:
Regions

13. Located at the very back of the brain.
Occipital Lobe
Located at the very back of the brain.
Primary function: processing of visual information. (seeing colors, as well as perceiving and recognizing objects)
Modified from:

14. Occipital Lobe
Primary Visual Cortex (PVC) – Receives electrical signals from receptors in the eyes and transforms these signals into meaningless basic visual sensations. (lights, lines, shadows, colors, textures)
Visual Association Area – located next to PVC. Transforms basic sensations into visual perceptions such as a person, object, or animal.

15. Neglect Syndrome
The failure of a patient to see objects or parts of the body on the side
Opposite the brain damage.

16. Visual Association Area
Primary Visual Cortex
Visual Association Area
Regions
Modified from:

17. Temporal Lobe
The Temporal Lobes are located on the sides of the brain, below the Parietal Lobe
They play an integral role in the following functions:
Hearing
Speaking coherently
Ability to understand verbal and written material.
Memory (hippocampus)
Modified from:

18. Arcuate Fasciculus - White matter tract that connects Broca’s Area and Wernicke’s Area. Allows for coordinated, comprehensible speech. Damage may result in:
Conduction Aphasia - Where auditory comprehension and speech articulation are preserved, but speech repetition is affected.
Arcuate Fasciculus

19. Temporal Lobe – Cortical Regions
Primary Auditory Cortex – Responsible for hearing
Primary Olfactory Cortex – Interprets the sense of smell once it reaches the cortex via the olfactory bulbs. (Not visible on the superficial cortex)
Wernicke’s Area – Language comprehension. Located on the Left Temporal Lobe.
Wernicke’s Aphasia – Language comprehension is inhibited. Words and sentences are not clearly understood, and sentence formation may be inhibited or nonsensical.

20. Temporal Lobe Hippocampus: Formation of new episodic memories
and the retrieval of old memories.
Damage to Hippocampus does not affect ability to learn
new skills only to form memories. (procedural vs. autobiographic)

21. Primary Auditory Cortex
Wernike’s Area
Primary Olfactory Cortex (Deep)
Conducted from Olfactory Bulb
Regions
Modified from:

22. Lobes and Structures of the Brain
A. Central Sulcus
B. Frontal LOBE
C. Sylvian/Lateral Fissure
A. (groove) G.
D. Temporal Lobe B. F.
E. Transverse Fissure
F. Occipital Lobe
C. (groove)
G. Parietal Lobe E. D.
(groove)

23. Further Investigation
Phineas Gage: Phineas Gage was a railroad worker in the 19th century living in Cavendish, Vermont. One of his jobs was to set off explosive charges in large rock in order to break them into smaller pieces. On one of these instances, the detonation occurred prior to his expectations, resulting in a 42 inch long, 1.2 inch wide, metal rod to be blown right up through his skull and out the top. The rod entered his skull below his left cheek bone and exited after passing through the anterior frontal lobe of his brain.
Frontal

24. Remarkably, Gage never lost consciousness, or quickly regained it (there is still some debate), suffered little to no pain, and was awake and alert when he reached a doctor approximately 45 minutes later. He had a normal pulse and normal vision, and following a short period of rest, returned to work several days later. However, he was not unaffected by this accident.
Frontal

25. Q: Recalling what you have just learned regarding the frontal lobe, what possible problems or abnormalities may Gage have presented subsequent to this type of injury (remember the precise location of the rod through his brain)?
A: Gage’s personality, reasoning, and capacity to understand and follow social norms had been diminished or destroyed. He illustrated little to no interest in hobbies or other involvements that at one time he cared for greatly. ‘After the accident, Gage became a nasty, vulgar, irresponsible vagrant. His former employer, who regarded him as "the most efficient and capable foreman in their employ previous to his injury," refused to rehire him because he was so different.’
Q: It is suggested that Gage’s injury inspired the development of what at one time was a widely used medical procedure. What might this procedure be, and how does it relate to Gage’s injury?
A: The frontal lobotomy. This has been used with the intention to diminish aggression and rage in mental patients, but generally results in drastic personality changes, and an inability to relate socially. This procedure is largely frowned upon today, with the development of neurological drugs as treatments.
Frontal

26. Approximately 1 trillion cells. (1,000,000,000,000)
What’s in your brain?
Approximately 1 trillion cells. (1,000,000,000,000)

27. Glial Cells Most numerous brain cell (900 billion) Three Functions:
Scaffolding to guide the growth of new neurons / support mature neurons
Insulation: to prevent interference from other electrical signals.
Release chemicals that influence a neuron’s growth and function.

28. The Neuron The “Fax Machine” of the Human Body
Has two specialized extensions, one for receiving
and the other is for transmitting electrical
signals.

29. DENDRITES Receive information from other neurons, organs and muscles.
Bring information TO the cell body

30. AXONS
Axons – Send information AWAY from the cell body to neighboring neurons, organs, or muscles.
Axon terminals - the hair-like ends of the axon that store neurotransmitters

31. The Neuron
                                                      

32. Parts of a Neuron
Myelin sheath - the fatty substance that surrounds and protects nerve fibers
Node of Ranvier - one of the many gaps in the myelin sheath
Schwann's cells - cells that produce myelin