Human Phys Exam 2

3

how many neurons are necessary to form an integrative pathway

axon hillock

part of the neurons cell body that is connected to the axon

transmission

when the firing of a presynaptic neuron has some means to directly influence whether the postsynaptic cell fires an action potential

neurotransmitters

signal molecule that influences whether the postsynaptic cell fires an action potential

diffusion of neurotransmitters at synapses

what is the slowest part of the nervous system operating

diffusion

how do neurotransmitters travel from a pre-synaptic neuron to a post-synaptic neuron

glutamate

the most common excitatory neurotransmitter in your nervous system

GABA

major fast inhibitory neurotransmitter in the brain

acetylcholinesterase

enzyme that converts acetylcholine into acetate and choline

Coenzyme A

can weakly bond with acetate

antagonistic muscle

pairs of muscles that produce opposite mechanical actions across a joint

astrocyte

glial cell that converts glutamate into glutamine by adding a NH4+ group to it.

glutamine

turning into this allows glutamate to be reintroduced into a pre-synaptic neuron

indirect transmission

neurotransmitter binding does not directly open an ion channel, but instead triggers some form of second messenger system

neuropeptides

any of a variety of peptides released as signal molecules from neurons. They are often released from the same axon terminals as neurotransmitters

neuropeptides

protein-based chemical modulators made of short chains of amino acids

learning

when an organism’s response to a stimulus changes with experience

operant conditioning

modifying behaviors in response to feedback

classical conditioning

expand ability to recognize stimulus associated with good or bad experiences

neuromodulator

binds to receptors and triggers change that influences how a neuron responds to subsequent exposure to neurotransmitters

myofibril

long, thread-like rod packed inside a muscle cell (muscle fiber) that contracts

myofibril

tube made up of a series of sarcomeres

sarcoplasmic reticulum

space inside a muscle cell but outside the cytoplasm

more control

more motor neurons = more motor units = ???

neurulation

embryonic process in chordates where the flat dorsal ectoderm folds and internalizes to form the neural tube

sclerotome

Turns into bone and cartilage

myotome

Turns into skeletal muscle

dermatome

Turns into dermis/skin

somite

repeated chucks of anatomy in an early embryo in the mesoderm. Lined up in pairs along the dorsal nerve tube

myelin sheaths

spaced periodically along an axon can increase an action potential’s speed.

glial cells

non-neuronal support cells of the nervous system

gray matter

where the cell bodies and synapses are located

topographic organization

spatial arrangement of neurons and synapses in the CNS reflects the spatial distribution of incoming sensory neurons and skeletal muscles

golgi tendon organ

measures the tension/force on the junction between the tendon and the muscle

golgi tendon organs

keeps track of muscle contraction all throughout the body

muscle spindles

A sensory receptor inside the muscle belly that sits in parallel with muscle fibers.

muscle spindles

detects when a muscle is stretched

stretch reflex

muscle spindles detect a stretch and send a signal to activate more motor units to maintain stability/posture

golgi tendon reflex

sensory neuron detects to much force/tension and sends a signal to stop contraction to protect the muscle