Unit 9: Nervous Tissue - theory

Anatomy and Physiology I Theory Class

electrical

in a(n) _______ synapse, there is a direct connection between the two cells so that ions can pass directly from one cell to the next.

leak

ions that move across the membrane randomly often use a ______ channel.

ligand

a grouping of channels that are opened or closed in response to the binding of a chemical messenger known as ______ channels.

chemical

in a(n) ______ synapse, a neurotransmitter is released from one cell, and it affects the other cell.

mechanically-gated

a ________ channel is one where touch can cause the channel to be opened.

voltage-gated

a change in charge will cause the _______ channels to open.

peripheral nervous system (PNS)

this location-based division of the nervous system includes all the neural tissue found outside the CNS.

automatic nervous system (ANS)

a component of the efferent division of the nervous system, this group of cells provides automatic regulation of smooth muscle, cardiac muscle, and glandular secretions at a subconscious level.

afferent division

this functional division of the PNS includes cells bringing sensory information to the CNS from receptors in peripheral tissues and organs.

central nervous system (CNS)

this location-based division of the nervous system contains the brain and spinal cord.

efferent division

this functional division of the PNS includes neural tissues carrying somatic and motor commands out of the CNS to muscles and glands.

true

the somatic functional division of the nervous system controls skeletal muscle contractions.

motor, sensory, or association

neurons are classified on the basis of their function as ________.

cranial

which of the following cavities contains a component of the central nervous system?

autonomic

which functional division of the nervous system would be responsible for the physiological changes seen during exercise (e.g., increased heart rate and sweating)?

dendrites

highly branched processes, providing locations for other neurons to communicate with the cell body

nissl bodies

formed by ribosomes and rough endoplasmic reticulum. they synthesize proteins and neurotransmitters.

axon terminal

bulb-shaped axon endings that form a synapse, or site of connection with the next cell.

myelin

cause the action potentials to jump from node to node, thus increasing the speed that information is transmitted.

astrocytes

what type of neuroglia cells helps to form the blood-brain barrier?

microglia

the smallest and rarest of the neuroglia in the CNS are ________, which are phagocytic cells derived from white blood cells that migrated to the CNS.

chemically gated channels

which type of active channels in the plasma membrane open or close when they bind certain chemicals, such as neurotransmitters?

false

leak channels are always open.

mechanically gated channel

what type of gated channel opens or closes in response to distortion of the membrane?

action potential

change in voltage of a cell membrane in response to a stimulus that results in transmission of an electrical signal; unique to neurons and muscle fibers

depolarization

movement of a cell’s membrane potential to a more positive value (moving closer to zero).

repolarization

movement of a cell’s membrane potential to a more negative value.

hyper polarization

movement of a cell’s membrane potential to a more negative value past -70mV.

depolarizes

an action potential will NOT result unless the membrane ______ sufficiently to threshold level.

true

the all-or-none principle applies to excitable membranes, such as neuron membranes. this principle states that either a stimulus is great enough to depolarize a membrane to threshold and thus trigger an action potential, or the stimulus is not able to depolarize to threshold and thus an action potential does not occur.

cholinergic

a chemical synapse at which the neurotransmitter is acetylcholine is called a(n) ______ synapse.

serotonin

an important neurotransmitter in controlling your emotions and feelings of happiness is _______.

excitatory neurotransmitters

an action potential can be triggered if all is released

inhibitory neurotransmitters

no action potential can occur if all is released

adrenaline

produced in stressful situations. increases heart rate and blood flow. leads to physical boost and heightened awareness. also known as epinephrine.

GABA

calms firing nerves in the CNS. high levels improve focus, low levels cause anxiety. also contributes to motor control and vision.

noradrenaline

affects attention and responding actions in the brain. contracts blood vessels, increasing blood flow. also known as norepinephrine.

acetylcholine

involved in thought, learning, and memory. activates muscle action in the body. also associated with attention and awakening.

dopamine

feelings of pleasure and euphoria, movement, and motivation. people repeat behaviors that lead to dopamine release. associated with addiction.

glutamate

most common neurotransmitter. involved in learning and memory. regulates development and creation of nerve contacts.

serotonin

contributes to well-being and happiness. helps sleep cycle and digestive system regulation. affected by exercise and light exposure.

glutamate

glutamatergic system

serotonin

serotonergic system

dopamine

dopaminergic system

GABA

GABAergic system