EVOLUTION AND DIVERSITY OF NERVOUS SYSTEMS

Development of nerve nets Cephalization and nerve cords

CEPHALIZATIONCEPHALIZATION

• Control the animals’ directional movements, and complex behavior• Some internal parasites have gone the reverse direction and lost it!•Mollusks: sessile ones e.g. clams no cephalization, squids and octopus though have more complex movement.

control the digestive tract, pancreas, and gallbladder

External &Internal Environment

THE BRAIN

Now close your eyes…….

• How many genes control the development of the CNS?

• What makes human brain so special?

•Is your mind separate from your body? Descartes asked in the 15th century.

CerebrumCerebrumCerebrum divided into 4 lobes:-Frontal lobe-Parietal lobe-Occipital lobe-Temporal lobe

- Lobes are named after the skull bones that lie over them

Folds:Hills: gyriValleys: sulci

White Matter: inside Myelinated axonsGrey: Outside (cerebral cortex)

FRONTAL LOBEFRONTAL LOBE

B. Premotor and C. Motor Areas

• Three parts:

a. Prefrontal cortex

PARIETAL LOBE

OCCIPITAL LOBEOCCIPITAL LOBE

• What happens when you see “stars”?

• What role does the occipital lobe have in the blind?

• Are visual prosthetics in our future?

TEMPORAL LOBETEMPORAL LOBE

3 functional categories: Can you identify these areas?-Primary sensory area – receiving signals from sensory nerves-Primary motor area – connects to motor neurons in brain stem and spinal cord-Association areas – remainder of cortex

- involved with complex processes: perception, thought

CROSS SECTION OF THE BRAINCROSS SECTION OF THE BRAIN

DIFFERENCES BETWEEN DIFFERENCES BETWEEN MALES AND FEMALESMALES AND FEMALES

• male brains 10% larger to accommodate larger muscle mass

• corpus callosum larger in females• females activate both hemispheres when dealing with

language and fine motor skills and matures 6 years earlier than boys

• males math area of the brain matures 4 years earlier than females

• Males have 6.5 times more grey “thinking” matter while females have 9.5 times white matter that connect different parts of the brain.

• frontal and temporal lobe is more organized in women and bigger.

http://www.youtube.com/watch?v=vKVwcwXc4DkAnimal planet

CerebellumCerebellum

BrainstemBrainstem

• Evolutionary older structures are regulate essential automatic and integrative functions

• 3 parts:

a. medulla oblongata

b. pons

c. midbrain (with reticular formation)

Medulla OblongataMedulla Oblongata

Pineal Pineal glandgland

• In humans, size of a grain of rice

• Produces melatonin

• Regulates sleep patterns

PonsPons

HypothalamusHypothalamus

• In humans, size of an almond

• Connects nervous system to endocrine system via pituitary gland

ThalamusThalamus• Receives and relays

sensory signals to cerebral cortex

• Motor control

• Regulate sleep and wakefulness

http://www.youtube.com/watch?v=u82nzTzL7ToADHD

AmygdalaAmygdala

Do you love me or are you IN Do you love me or are you IN love with me?love with me?

• The insula and striatum become activated with love.

• Sexual desire lights up the striatum area that's activated by things that are pleasurable, like sex and food.

• Love activates an area that's involved in the process of conditioning. This is the effect of having feelings paired with reward or pleasure.

HippocampusHippocampus

Test Yourself!Test Yourself!

What parts of the brain are stimulated when:• You visualize an image• Listen to the sounds of the room• Silently tap your finger• Count backwards• Remember a past event• Pinch yourself• Are shown a picture of a loved one