Nervous system fundamentals (LECTURE)

Functional division of the nervous system

Autonomic and somatic nervous system

Autonomic Nervous System

Involuntary; Parasympathetic, Sympathetic, Enteric

Somatic Nervous System

Voluntary control and conscious perception; Motor and Sensory division

Leak Ion Channels

Allow specific ions to pass (Na/K)

Gated Ion Channels

Open due to stimulus (Mechanically, Voltage, Specific Ligand)

How is leak channels responsible for the permeability characteristics of a resting versus a stimulated plasma membrane

set the resting membrane potential

How is gated channels responsible for the permeability characteristics of a resting versus a stimulated plasma membrane

causes for depolarization, repolarization, and hyperpolarization

Action potential

Rapid all-or-none electrical signal across neurons and muscles

Why don't action potentials get smaller as it propagates

It recreates itself over and over in each segment of the membrane going down the axon. The signal is continually renewed rather than fading

Absolute refractory period

New AP cannot be generated

Relative refractory period

can fire again, but only if the stimulus is stronger

EPSP likelihood of generating an action potential

EPSPs increase the likelihood of an AP because they depolarize the membrane. Can add together through temporal or spatial summation to reach the threshold

IPSP likelihood of generating an action potential

IPSP's decrease likelihood of an action potential because they hyperpolarize the membrane, moving farther from threshold

Astrocytes

Hold everything together can secrete and absorb ions

Oligodendrocytes

myelin makers in the CNS

microglia

immune defense

ependymal

lines brain ventricles and help maken CSF

Schwann cells

makes myelin in PNS

Cerebrum

largest part of the brain responsible for conscious thought, sensory perception, and voluntary movement

Diencephalon

Brain region containing the thalamus and hypothalamus. Involved in sensory relay and homeostasis

Cerebellum

coordinates balance, posture, and fine motor control

Midbrain

portion of the brainstem involved in visual and auditory reflexes and motor control

Pons

brainstem structure that relays signals between cerebrum and cerebellum and helps regulate breathing

Medualla Oblongata

lowest part of brainstem that controls vital autonomic functions such as heart rate and respiration

Brainstem

structure connecting the brain and spinal cord, composed of the midbrain, pons, and medulla

Primary sensory cortices

first cortical areas to receive sensory input from the thalamus

sensory association areas

interpret and give meaning to sensory input

Examples of Primary sensory cortices

primary somatosensory cortex, primary visual cortex, primary auditory cortex

Examples of sensory association areas

somatosensory association cortex, visual association areas, auditory association areas

Primary motor cortex

voluntary movement

primary somatosensory cortex

touch, pressurem pain, temperature, propioception

Brocas Area

Speech production, motor planning for language

Wernickes Area

Language comprehension

Primary visual cortex

Basic visual cortex

Visual association cortex

interprets visual information

Primary Auditory Cortex

Basic sound processing

Auditory Association Cortex

Interpret sounds, speech, music

Prefrontal cortex

planning, judgement, personality, impulse control

Somatosensory association cortex

interprets sensory input

Pariental association cortex

spatial awareness

Insular cortex

taste, visceral sensation, emotional awareness

Contra-laterality

Each hemisphere controls opposite side of the body

Lateralization

certain functions are dominant in one hemisphere

Hypothalamus

Maintains homeostasis and regulates vital bodily functions