nervous tissue & spinal cord

whats a ganglia

a cluster of nerve cell bodies in the peripheral nervous system

whats a nerve

cordlike organ that is composed of multiple nerve fibers surrounded by connective tissue

whats a nuclei

cell organelle containing DNA and surrounded by double membrane

whats a plexus

a network of blood vessels, lymphatic vessels, or nerves

function of a soma (cell body)

The core section of the neuron, the cell body, contains genetic information, maintains the neuron’s structure, and provides energy to drive activities.

function of neuronal nucleus

The control center houses the cell's genetic information and directs its activities. it’s responsible for transcription and protein synthesis.

function of axon hillock

The region of a neuron that controls the initiation of an electrical impulse based on the inputs from other neurons or the environment.

function of dendrite

Perform simple operations using electrical signals. They receive input from other neurons and carry those signals to the cell body.

function of axon

carry electrical impulses that are the means of communication within the brain and between the brain and the rest of the body

function of axolemma

relay signals between the neuron and its Schwann cells

function of axon terminal

transmit messages to other cells via use of neurotransmitters at synapses

function of schwann cell

aid in myelinating axons, directional guidance of neurons, and eliminate cellular debris, they cannot transmit synaptic messages, and can divide indefinitely throughout life.

function of neurilemma

responsible for the production of the myelin sheath around neuronal axons.

function of nodes (of ranvier)

allow for ions to diffuse in and out of the neuron, propagating the electrical signal down the axon.

function of sensory (afferent)

Nerve fibers are responsible for bringing sensory information from the outside world into the brain. Sensory information encompasses the special senses, such as vision, hearing, smell, and taste, as well as the senses of touch, pain, and temperature.

functions of motor (efferent)

Nerve fibers are responsible for carrying signals from the brain to the peripheral nervous system in order to initiate an action, such as removing your hand from a hot pan.

function of interneurons

play a crucial role in processing information and coordinating responses within the brain and spinal cord. By relaying signals, they help integrate sensory inputs with motor outputs, facilitating complex reflexes and behaviors.

Does the dorsal root contain sensory or motor neurons?

collection of primary sensory neurons.

Does the ventral root contain sensory or motor neurons?

motor neurons

what is the dorsal root ganglion?

a collection of nerve cell bodies located on the dorsal root of a spinal nerve.

What do the ascending tracts of the white columns convey?

These tracts carry sensory information

What do descending tracts of the white columns convey?

These tracts carry motor information

What level does the spinal cord originate?

foramen magnum

what level does the spinal cord terminate?

L1-L2

how many pairs of spinal nerves are there?

31 pairs

how many pairs of cervical spinal nerves are there?

8 pairs

How many pairs of thoracic spinal nerves are there?

12 pairs

how many pairs of lumbar spinal nerves are there?

5 pairs

How many pairs of sacral spinal nerves are there?

5 pairs..

how many pairs of coccygeal spinal nerves are there?

one pair

are spinal nerves sensory, motor, or mixed?

mixed nerves

What is the purpose of a reflex?

Provide a pre-wired quick response

What is an innate reflex?

automatic, unlearned basic functions, such as heart rate of salivation.

what is an acquired reflex?

learned response, such as riding a bike

what is an autonomic reflex?

An unconscious involuntary motor response triggered by sensory input to the internal organs, glands, and smooth muscle. (heart or smooth muscle)

what is a somatic reflex?

invouluntary movement of the skeletal muscle

what is a spinal reflex

Rapid, involuntary, and predictable responses to specific stimuli that are mediated by the spinal cord without requiring input from the brain.

what is a cranial reflex

An involuntary response triggered by a stimulus, where the signal travels through cranial nerves and is integrated in the brainstem. control actions like eyeblinking and pupil dilation.