Brain and Nervous System Divisions

components of nervous system

• brain

• spinal cord

• sensory organs

• nerves

functions

• sensory

  • takes in information

• integration

  • makes sense of info

• motor

  • responds

3 main components of the brain

• brain stem

  • basic life functions like breathing/heart rate

• cerebellum

  • balance and coordination “muscle memory”

• cerebrum

  • conscious thought, voluntary movement, reasoning, emotion

  • Parts of it: frontal, parietal, temporal, and occipital lobes

Division of Nervous system

• Central Nervous System (CNS)

  • brain

  • spinal cord

• Peripheral nervous system (PNS)

  • cranial nerves

  • spinal nerves

PNS

• contain a sensory division and motor division

sensory division

• contains sensory receptors that convert info from stimulus into a nerve impulse and transmit it back to the CNS to make sense of it

• monitors environmental changes such as light and sound

• detects changes in homeostasis

Types of sensory receptors

• photoreceptors - detect light (eyes)

• chemoreceptors - detect chemicals change (skin, muscle)

• thermoreceptors - detect temperature change (skin)

• mechanoreceptors - (movement) they detect pressure change (skin, muscle)

• nociceptors - detect pain (everywhere)

Motor division

• uses peripheral neurons to carry impulses from the CNS to an effector which will cause a response

  • ex: muscle contraction, gland secretion

somatic nervous system

• controls skeletal muscle and voluntary movement

autonomic nervous system

• controls effectors that are involuntary

  • ex: heart, smooth muscle, certain glands

Autonomic Nervous system parts

• parasympathetic nervous system

• sympathetic nervous system

parasympathetic nervous system

• “rest and digest” - normal state

  • salivation

  • sexual arousal

  • lacrimation (crying)

  • urination

  • digestion

  • defecation (poop)

sympathetic nervous system

• “fight or flight” - triggered under stress or intense emotion

  • accelerated breathing and heart rate (increases blood flow)

  • inhibition or slowing of digestion

  • pupils dilate

  • tunnel vision

  • increased muscle tension for extra strength and speed

Amygdala

• processes threats/fear

• regulates emotion

frontal lobe

• voluntary movement, speech production, decision making, personality expression

hippocampus

• creates long-term memories

• connects memories with emotions

corpus callosum

• transfers info between the brains hemispheres

thalamus

• manages sensory perception, motor functions, alertness, sleep and memory

hypothalamus

• maintains homeostasis by regulating temperature, hunger, thirst, sleep, and mood

occipital lobe

• interpretes retinal signals into images, color, motion, and depth