anatomy test 3

Neurology flashcards

define neurology

the study of normal functions and disorders of nervous system

whats the nervous system responsible for

all behaviors, memores, and movements

list 3 asic functions of nervous system

sense change

interpret change

react to change

what does the nervous system us to sense and react to stimuli

sensory receptors

effectors

how does reacting with effectors present

muscular contraction

glandular secretion

what are major structures of the nervous system

brain

cranial nerves

spinal cord

spinal nerves

ganglia

enteric plexus

sensory receptors

how many cranial nerves come from the base of the brain through the ___ of the skull

12;foramina

whats a nerve

a nerve is a bundle of hundreds or thousands of axons, each of

which courses along a defined path and serves a specific region of

the body.

the spinal cord connect to the ___ through the ____ of the skull and is encircled by the bones of the vertebral column

brain, foramen magnum

how many pairs of spinal nerves emerge from the spinal cord

31

true or false each spinal nerve serves a specific region of body

describe ganglia

groups of cell bodies of neurons located outside the brain and spinal cord

what does enteric plexuses do

helps regulates the digestive system

sensory receptors are part of neurons that ___

Sensory receptors are either parts of neurons or specialized cells that

monitor changes in the internal or external environment.

what’s another name for sensory neurons

afferent

what do association or interneurons do?

Serve the integrative function

– Analyze the sensory information, store some aspects, and make decisions

regarding appropriate behaviors

whats a name for motor neurons and what do they do

efferent

Serve the motor function

– Respond to stimuli by initiating action.

what does the central nervous system consist of

brain and spinal cord

What does the peripheral nervous system consist of

cranial and spinal nerves that contain both sensory and motor fibers

What does the peripheral nervous system do

connects CNS to muscles, glands and all sensory receptors

What are the sub divisions of the pns and are they voluntary or involuntary

somatic (voluntary)

Autonomic (involuntary)

Enteric

What does the somatic nervous system consist of and what parts of the body does it connect to the cns

Afferent (sensory) neurons from cutaneous and special sensory

receptors to the CNS

– Efferent (motor) neurons to skeletal muscle tissue

What parts of the body does the autonomic nervous system connect to the the cns

sensory neurons from visceral organs to CNS

– motor neurons to smooth and cardiac muscle and glands

What are 2 subdivisions of the autonomic ns and what do they do

sympathetic division; e.g., speeds up heart rate

• parasympathetic division; e.g., slows down heart rate

true or false there are neurons in the enteric nervous system that extend the length of te gi tract

true

true of false the neurons of the enteric plexus depend on the ANS and CNS to operate

No, they operate independently

what do the afferent and efferent neurons of the ens do

Sensory neurons of the ENS monitor chemical changes within the

GI tract and stretching of its walls

• Enteric motor neurons govern contraction of GI tract organs, and

activity of the GI tract endocrine cells.

what are chemoreceptors for

respond to chemicals

mechanoreceptors are for…

responding to mechanical stimuli

what are the two types of cells in the nervous system and describe them

Neurons: functional cells of the nervous system. Transmit information from one part of the

body to another.

2. Neuroglia: support cells.

which are smaller neurons or neuroglia and which is more abundant

neuroglia

What can happen because neuroglia divides so much

Gliomas: tumors that

result from rapid mitosis

of neuroglia

what is the reason when you have nerve damage theres little regeneration

neurons are post mitiotic and dont divide

whats the functional unit of the nervous system

neuron

do neurons have capacity to produce action potentials

yes

What are the parts of a neuron

Cell body

– single nucleus with prominent

nucleolus

– Nissl bodies (chromatophilic

substance): rough ER and free

ribosomes for protein synthesis

– neurofilaments give cell shape

and support

– microtubules move material

inside cell

• Cell processes: dendrites and axons

Dendrites conduct impulses ___ the cell body

toward

true or are axons or dendrites specialized for contact with other neurons

dendrites

which cell process is unmyelinated

dendrites

do axons conduct impulses towards or away from the body

away

true or false in axonal transport the cell body is location for most protein synthesis if so give an example

neurotransmitters and repair proteins

what are the axonal transport systems

slow and fast

true or false in slow axonal transport movement in one direction only- away from cell body

• 1-5 mm per day

true

What does fast axonal transport do and describe it

Fast

• moves organelles and materials along surface of microtubules

• 200-400 mm per day

• transports in either direction

• substances to be used/recycled in cell body

what are examples of fast axonal transport and disease and how does it work

Fast axonal transport: route by which toxins or

pathogens reach neuron cell bodies

– tetanus (Clostridium tetani bacteria): disrupts motor neurons

causing painful muscle spasms

– When bacteria enter the body through a laceration or puncture

injury, the wound is more serious if it is in the head or neck

because of shorter transit time

What are the structural classifications for neurons and describe them

Based on number of processes found on cell body

• Multipolar: several dendrites and one axon

– most common type: interneurons and motor neurons

• Bipolar neurons: one main dendrite and one axon

– found in retina, inner ear and olfactory epithelium

• Unipolar neurons: one process only (develops from a bipolar)

– are always sensory neurons

Define nerves

a bundle of hundreds or thousands of axons, each of

which courses along a defined path and serves a specific region of

the body

are dendrites myelinated or unmyelinated

unmyelinated, because they are specialized for contact with other nuerons

Blank ____ neurons carry impulses from sensory receptors to the central nervous system

Afferent

the autonomic nervous system controls ___ & ____ muscles and glands

smooth and cardiac

the myelin sheath in the cns is produced by _____

oligodendrocytes

the myelin sheath in the pns is produced by

Schwann cells

Purpose of myelin sheath

The myelin sheath is a fatty, insulating layer wrapped around nerve cell axons that functions primarily to speed up electrical impulse conduction and provide metabolic support. It enables rapid, efficient signaling (saltatory conduction) through gaps called nodes of Ranvier, crucial for healthy motor and sensory function.

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are the functional unit of the nervous system

nuerons

the ___ is the part of a neuron that conducts impulses away from the cell body

Axon

The ___ is matter in the CNS consist primarily of myelinated axons (processes)

white

Describe the difference between the sympathetic and parasympathetic divisions of the nervous system

sympathetic speed up the heart rate and para sympathetic slows down the heart rate

the ____ matter in thr cns consist primarily of myelinated axons (processes

White

explain how fast and slow axonal transport differs

Fast transports in both directions and allows for the movement of organelles and materials along surface of microtubules (200-400mm)

Slow only allows for movement away from body in 1-5 mm per day

What is the functional significance of nodes of ranvier

Allows for high-speed/efficient signal transmission through "saltatory conduction," where action potentials "jump" from node to node.

what is the role of Na+/K+ Atp pump in maintaining resting membrane

The Na+/K+ATPase pump maintains the resting membrane potential (typically around \(-70mv) by actively transporting three sodium ions (Na+) out of the cell and two potassium ions (K+) in, using ATP.

what are the structural classifications of neurons and their make up and explain where theyre found

Multipolar- several dendrites and 1 axon, primarily found in cns, and most common type is interneurons and motor neurons.

Bipolar: one dendrite and one axon, found in retina, inner ear and olfactory epithelium

Unipolar: only one process and develops from Bipolar, always sensory neurons

3 types of ion channels and examples

Leakage channels: gates open and close constantly

allowing specific ions to diffuse through

– specific types we’ll consider: Na, K, and Ca

Gated channels open and close in response to a stimulus

– specific types we’ll consider: Na+, K+, and Ca2+ (voltage, ligand, mechanical)

Active Transport Channels

– Na+/K+ ATPase pump keep resting cell membrane

function of leakage channels, gated channels, and active transport channels

leakage: remain randomly open to allow ions (K+) and (Na+) to pass through continuously. They are crucial for maintaining the neuron's resting membrane potential, creating a negative charge inside the cell (roughly -70 mV).

gated: Control ion flow in response to specific triggers to allow for electrical signaling like action potentials.

Active Transport : Actively move ions (e.g., Na+, K+, Ca2+) against their concentration gradient, which is crucial for maintaining the resting potential that passive channels rely on.

What are the 3 types of gated ion channels and whats their functions

3 types of gated ion channels:

Voltage-gated channels respond to a direct change in the membrane

potential. Fig. 12.11 a

• Types we’ll consider: Na+, K+, and Ca+2

Ligand-gated channels respond to a specific chemical stimulus. Fig. 12.11

b

• Type we’ll consider: Na+ channels responding to the neurotransmitter

acetylcholine

Mechanically gated ion channels respond to mechanical vibration or

pressure.

major structures of nervous system and their function

The nervous system is organized into the central nervous system (CNS—brain and spinal cord) for processing information and the peripheral nervous system (PNS—nerves and ganglia) for transmitting signals throughout the body. Key functions include sensory input (detecting changes), integration (processing), and motor response (acting on information).

3 basic function of nervous system

sense stimuli, interpret information, and respond

what is the role of myelination in the nervous system

protect and insulate axons

accelerate speed of signal transmission

draw a nerve cell

what are divisions of the nervous system

CNS & PNS

what are the sub divisions of the nervous system

Somatic, autonomic (parasympathetic and sympathetic), enteric

Where do sensory neurons transport information from and to

from the skin, muscles, joints, sensory organs, and viscera organs to the cns

what doe motor neurons do

send motor nerve impulses to muscles and glands

wat do interneurons do

connect sensory to motor neurons

Example of voltage gated channel

Na+, K+, Ca2+

Example of Ligand gated channel

Na+ channels responding to the neurotransmitter acetylcholine

What is a disease related to axonal transport

tetanus

How does tetanus work

disrupts motor neurons causing painful muscle spasms

What does the myelin sheath consist of and what does the neurilemma

Myelin sheath: multiple layers of Schwann cell plasma membrane

wrapped around an axon

• Neurilemma is cytoplasm and nucleus of the Schwann cell

myelinated axons are considered

white matter

when are myelin sheaths completely developed

after 1 year

What are some diseases where you see yelin degeneration

multiple sclerosis

diabetes mellitus

true or false when axons are severed they can regenerate

true

where do unmyelinated axons rest

invaginations of Schwann cells or

oligodendrocytes

true or false unmyelinated cells can be considered white matter

no gray matter

Oligodendrocytes myelinate the axons in what part of the nervous system

cns

You only see neurilemma in what part of the nervous system and why

in the pns bc it comes from schwann cells

Why is there little regrowth after injury in the cns

lack of a distinct tube and neurilemma

What do these all have in common, nerve cell bodies, dendrites, axon terminals,

bundles of unmyelinated axons and neuroglia

gray matter

How does gray matter look in the spinal cord

forms an H- shaped inner core surrounded by white matter

how does gray matter present in the brain

thin outer shell of gray matter covers the surface and

is also found in clusters called nuclei inside the CNS

In terms of the brain what is the nucleus

a mass of nerve cell bodies and dendrites inside the cns

What are the two types of electrical signals neurons use to communicate and describe each one

action potentials that can travel long distances

– graded potentials that are local membrane

changes only

true or false depolarization causes the cell to be less negative and the outside to be come more positive

true

true or false with action potential Voltage does not diminish as the action potential is propagated away from the site of stimulus

true

what is hyperpolarization

Voltage does not diminish as the action potential is propagated

away from the site of stimulus

true or false Graded potentials occur most often

in the axons and cell body of a

neuron.

False graded potentials occur most often in the dendrites and cell body of a neuron.

How do graded potentials arise

Source of stimuli

– mechanical stimulation of membranes with mechanical gated ion channels (pressure)

– chemical stimulation of membranes with ligand gated ion channels (neurotransmitter)

• Graded/postsynaptic/receptor or generator potential

– ions flow through ion channels and change membrane potential locally

– amount of change varies with strength of stimuli

• Flow of current (ions) is local changeonly

• If the graded potential is great enough, then voltage-gated ion channels open and an action