Term | Definition |
Acetylcholine (ACh) | activates muscles, and is a major neurotransmitter in the autonomic nervous system, also has a role in attention and arousal |
acetylcholinesterase (AChE) | stop excitation of a nerve after transmission of an impulse. |
action potential | the change in electrical potential associated with the passage of an impulse along the membrane of a muscle cell or nerve cell. |
adrenal medulla | makes epinephrine (adrenaline) and norepinephrine (noradrenaline) |
adrenalin | a hormone secreted by the adrenal glands, especially in conditions of stress, increasing rates of blood circulation, breathing, and carbohydrate metabolism and preparing muscles for exertion. |
all or none response | the strength by which a nerve or muscle fiber responds to a stimulus is independent of the strength of the stimulus. |
autonomic nervous system | the part of the nervous system responsible for control of the bodily functions not consciously directed, such as breathing, the heartbeat, and digestive processes. |
axomembrane | is responsible for maintaining the axon's membrane potential. contains many ion channels to depolarize/hyperpolarize the axon. membrane of the axon |
axon | extends from the cell body. conducts impulses away from the cell body |
axoplasm | cytoplasm of axon. has a different composition of organelles and chemicals than cell body and dendrite cytoplasm |
calcium ion | Calcium ions are important mediators of a great variety of cellular activities, including the passing of information between neurons and down a neuron. |
cell body | the nucleus-containing central part of a neuron exclusive of its axons and dendrites that is the major structural element of the gray matter of the brain and spinal cord |
central nervous system | controls the brain & spinal cord. has interneurons |
cerebellum | the part of the brain at the back of the skull in vertebrates. Its function is to coordinate and regulate muscular activity. |
cerebrum | responsible for the integration of complex sensory and neural functions and the initiation and coordination of voluntary activity in the body |
contractile protein | mediate sliding of the contraction of a cell's cytoskeleton, and of cardiac and skeletal muscle. |
corpus callosum | a broad band of nerve fibers joining the two hemispheres of the brain. |
dendrite | a short branched extension of a nerve cell, along which impulses received from other cells at synapses are transmitted to the cell body. |
depolarization | axoplasm gains a positive charge compared to outside |
effector | an organ or cell that acts in response to a stimulus. |
excitatory neurotransmitter | the stimulate the brain to be depolarized |
hypothalamus | coordinates both the autonomic nervous system and the activity of the pituitary, controlling body temperature, thirst, hunger, and other homeostatic systems, involved in sleep cycle and emotional response |
impulse | the way nerves transmit info. |
inhibitory neurotransmitter | calm the brain and help create balance, cause a repolarization |
interneuron | conducts messages between sensory and motor neurons |
medulla oblongata | the continuation of the spinal cord within the skull, forming the lowest part of the brainstem and containing control centers for the heart and lungs. |
meninges | the three membranes (the dura mater, arachnoid, and pia mater) that line the skull and vertebral canal and enclose the brain and spinal cord. |
motor neuron | conducts nerve impulses from the cns to a muscle fiber or gland |
myelin sheath | insulates neuron. helps to speed iup impulse because of nodes of ranvier |
myelinated nerve fibre | a nerve fiber encased in a sheath of myelin |
neuroendocrine control centre | able to maintain homeostasis or internal balance in the body with the help of the autonomic nervous system. receives info from the blood |
neuron | a cell with an excitable membrane for the transmission of electrical signals |
neurotransmitters | bind with receptor sites on postsynaptic membrane during impulse travel across a synapse |
node of Ranvier | periodic gap in the insulating sheath (myelin) on the axon of certain neurons that serves to facilitate the rapid conduction of nerve impulses. |
norepinephrine | excitory |
parasympathetic division | inhibits or opposes the physiological effects of the sympathetic nervous system, as in tending to stimulate digestive secretions, slow the heart, constrict the pupils, and dilate blood vessels. |
peripheral nervous system | the part of the nervous system that consists of the nerves and ganglia outside of the brain and spinal cord. |
pituitary gland | the major endocrine gland. A pea-sized body attached to the base of the brain, the pituitary is important in controlling growth and development and the functioning of the other endocrine glands. |
polarity | Polarity in neurons is necessary for long range communication. Polarization is utilized in passing of electronic signals through neurons, which help to connect the Central and Peripheral Nervous Systems |
postsynaptic membrane | The part of the cell membrane of a neuron or muscle fiber with which an axon terminal forms a synapse. |
potassium gate | __ open, in response k + floods through to outside |
presynaptic membrane | The part of the cell membrane of an axon terminal that faces the cell membrane of the neuron or muscle fiber with which the axon terminal establishes a synapse. |
receptor | a sensory nerve ending that changes specific stimuli into nerve impulses |
reflex arc | involuntary response to stimuli |
refractory period | activity of Na/K pumps return ions to initial positions
gates are closed, unable to conduct impulse |
repolarization | restoring of initial polarity |
resting potential | when the neuron is not conducting an impulse
has high Na+ concentration outside, high K+ concentration inside. Negative inside |
saltatory transmission | impulse jumps from node to node |
Schwann cell | a cell that forms spiral layers around a myelinated nerve fiber between two nodes of Ranvier and forms the myelin sheath consisting of the inner spiral layers |
sensory neuron | conducts neve impulses from a sense organ to the CNS: receptor to spine |
sodium gate | __ in membrane open, Na+ rushes in |
sodium-potassium pump | maintain Na+ and K+ distribution/polarity |
somatic nervous system | the part of the peripheral nervous system associated with skeletal muscle voluntary control of body movements |
sympathetic division | inhibits or opposes the physiological effects of the parasympathetic nervous system, as in tending to reduce digestive secretions, speed up the heart, and contract blood vessels |
synapse | a junction between two nerve cells, consisting of a minute gap across which impulses pass by diffusion of a neurotransmitter. |
synaptic cleft | gap between neurons |
synaptic ending | often club-shaped endings by which axons make synaptic contacts with other nerve cells or with effector cells |
synaptic vesicle | a small secretory vesicle that contains a neurotransmitter, is found inside an axon near the presynaptic membrane, and releases its contents into the synaptic cleft after fusing with the membrane. |
thalamus | relaying sensory information and acting as a center for pain perception, sorts data |
threshold value | The maximum concentration of a chemical allowable for repeated exposure without producing adverse health effects. |