1. Option A.2 The Human Brain

2. Development of the Brain
Occurs at the anterior portion of the neural tube
Process is called cephalization
Brain and spinal cord make up the central nervous system
Nerves that branch from CNS make up the Peripheral nervous system (PNS)
PNS divided into two parts
Autonomic NS (involuntary)
Somatic (voluntary)

3. Sympathetic VS. Parasympathetic NS
Controlled response
Sympathetic
(fight or flight)
Parasympathetic
(rest and digest)
Heart rate
Speeds up
Supplies more blood flow to body muscles to prepare for increased muscle contraction
Slows down
Returns heart rate to normal after stressful situation to allow body to rest and recover
Breathing
Increases O2 supply to meet increased demands of contracting muscles
Returns breathing to normal after a stressful situation
Iris
Dilates pupil (circular muscle)
More light available for optimal vision
Constricts pupil (radial muscle)
Constricts pupil back to normal based on availability of light
Digestion (blood flow to gut, saliva production, production of gastric juices
Decreases
Less energy is used for digestion so more is available to meet the increased need for muscle contraction
Increases
More energy used for digestion to replace the stored energy lost in order to be prepared for future needs

4. Human Brain Structures

5. Human Brain Structures & Functions
Medulla oblongata
Controls breathing and heart rate
Regulates digestion
Controls vomiting reflex
Cerebellum
Controls movement and balance
Hypothalamus
Coordinates actions of the endocrine & nervous system
Produces some of the hormones stored in the pituitary
Controls the release of pituitary hormones
Maintains homeostasis
Temperature regulation
Blood glucose levels
Blood solute concentration (osmoregulation)
Pituitary gland (anterior & posterior)
Stores & releases hormones when stimulated by Hypothalamus
Cerebral hemispheres
Control higher-level functions such as learning, emotions, problem solving and personality

6. Cerebral Cortex Largest structure in the brain
More highly developed in humans than other animals
Divided into two hemispheres
Contains extensive folding (to fit)
Higher order functioning
Learning
Memory
Speech
Emotions

7. Humunculus
Model of the body in which the size of each part corresponds to the proportion of somatosensory cortex and motor cortex

8. Cerebral Cortex

9. Cerebral Hemispheres Left Cerebral Hemisphere (right-hand controlled)
Right Cerebral Hemisphere
(left-hand controlled)
Involved in scientific and mathematical skill (reasoning and analytical)
Receives visual information from sensory receptors on the right side of the body
Controls muscle contractions on the right side of the body
Involved in creative and imagination (artistic and musical)
Receives visual information form sensory receptors on the left side of the body
Controls muscle contractions on the left side of the body

10. Specific Areas of Brain Functions
Brain region
Specific functions
Visual cortex
Interpret visual stimuli
Flips image input to upright visuals
Plays a role in producing images of memories & imagination
Broca’s area
Language
Language comprehension
Possible role in body gesture-word relationship
Wernicke’s area
Speech
Understanding the spoken language
Nucleus accumbens
Reward pathway
Dopamine release

11. Pupil Reflex Controlled by medulla oblongata
Circular muscle contract iris
Radial muscle constrict iris
Allows proper amount of light into the eye so as not to harm the eye

12. Pupil reflex and Brain Death
Bright light shone into each eye
If pupils do no constrict at once it is an indication of damage to the medulla oblongata

13. Energy and the Brain Brain metabolism requires large energy inputs
Has large numbers of neurons so it requires lots of oxygen
Adult human brains use 20% if basal metabolism, this number is even higher in infants and small children

14. Methods of research Animal experimentation Lesions
Surgical procedures
Drug use
Lesions
Physiological loss of functioning
Functional magnetic resonance imaging (fMRI)
Measure amount of blood flow to the brain
Can be compared to a normal brain
Autopsy
Can be compared in patient prior to death or normal patients