Bio 132 - Nervous System and Action Potentials: Learning Objectives

cerebrum

the largest part of the brain, responsible for a wide range of functions including thought, language, memory, and motor control

frontal lobe

planning, problem-solving, movement, emotional regulation, and personality

occipital lobe

processes visual information and perception of color and motion

temporal lobe

processes auditory information, visual memory, emotion, and language comprehension

parietal lobe

processes sensory information, spatial awareness, and the five senses

primary somatosensory cortex

processing sensory information from the body, including touch, pain, temperature, and proprioception

primary motor cortex

responsible for initiating voluntary movements, located in the posterior portion of the frontal lobe

cerebellum

coordinates and regulates muscular activity

midbrain

motor movement, eye movement, and processes visual and auditory information

pons

respiratory control, balance and taste, and influences sleep cycles and facial movement and sensations

medulla oblongata

connects the pons and spinal cord and controls essential processes like breathing, heart rate, blood pressure, and reflexes like swallowing and coughing

corpus collosum

language, memory, and sensory information processing

reflex arc

neural pathway that controls reflexes, which are rapid, automatic, and involuntary responses to stimuli

autonomic reflex

control blood pressure, breathing, ensure tissue oxygenation

somatic reflex

responsible for involuntary, automatic responses controlled by the somatic nervous system

parts of a nueron

the cell body (soma), dendrites, and the axon

membrane resting potential

uneven distribution of ions between the inside and the outside of the cell

leaking channels

ion channel that are always open, allowing ions to flow across the cell membrane continuously without the need for external stimuli

sodium-potassium pumps

moves three sodium ions out of the cell and two potassium ions into the cell, both against their concentration gradients, using energy from ATP

action potential

rapid change in electrical potential across a cell membrane, specifically the nerve cells (neurons), that allows for the transmission of electrical signals

voltage gated ion channels

enable the passage of selected inorganic ions across cell membranes that open and close in response to changes in transmembrane voltage, and signal neurons

how is an action potential propagated along an axon

depolarization and repolarization, facilitated by voltage-gated sodium channels and potassium channels

changes in membrane charges as an action potential progresses

membrane is polarized, with a negative charge on the inside relative to the outside, then depolarization, the membrane potential becomes less negative (or even positive) due to an influx of positive ions followed by a repolarization phase where the membrane potential returns to its resting state as positive ions flow out

saltatory conduction

nerve impulses move down a myelinated axon with excitation occurring only at nodes of Ranvier

Schwann cells

glial cells that form the myelin sheath on axons outside the brain

Oligodendritic cells

type of glial cell in the brain that form the myelin sheath, while dendritic cells are a type of immune cell

Describe the structures of a chemical synapse and explain how they transmit an action potential from one cell to another

an action potential triggers the presynaptic neuron to release neurotransmitters

excitatory postsynaptic potentials

a change in membrane potential of a postsynaptic cell that makes it more likely to fire an action potential

inhibitory postsynaptic potentials

decreases the likelihood of a neuron firing, effectively inhibiting the generation of an action potential

postsynaptic membrane potential

the change in electrical charge across the membrane of a neuron's postsynaptic terminal

spatial summation of postsynaptic potentials

multiple presynaptic neurons release neurotransmitters simultaneously, leading to a combined excitatory postsynaptic potential that may or may not reach the threshold for triggering an action potential

temporal summation of postsynaptic potentials

multiple postsynaptic potentials summate to produce a larger overall response