BioMed Neuro Test

What are the overall functions of the nervous system?

Its the master control center, controls all thought, action and emotion, uses electrical impulses to interpret and respond to whats happening

List components of the nervous system

Brain, spinal cord, sensory organs, nerves

3 primary functions of nervous system

1) sensory imput, 2) intergration 3) motor output

Give example of the nervous system functions

Sensory imput - you see a red light, Integration - system integrates this means stop, Motor output - muscles of leg move and press brake

What is the structural organization of the nervous system

CNS - brain and spinial cord, PNS - nerves outside CNS

What are the primary functions of the CNS

Integration center, takes in all subconscious info

Describe the primary function of the PNS

links all parts of the body by carrying impulses from CNS to glands/muscles

What are 2 subdivisions of PNS

Sensory or Afferent - nerves that carry info to CNS

Motor or Efferent - nerves that carry info from CNS

What are 2 subdivisions of the motor division

Somatic - allows conscious/voluntary control of all skeletal muscle, Autonomic - regulates events that are automatic or involuntary

Name 2 cell types found in nervous system

Neuroglia and Neurons

List examples of central nervous system neuroglia

Ependymal cells, Oligodendrocytes

List examples of PNS neuroglia

Satellite, schwann cells

fibers that receive signals from other neurons and transmit them to the cell body.

Dendrites

the metabolic center of the neuron, containing the nucleus

Cell body

neurons fibers that conduct impulses away from the cell body

Axon

Branches at the end of an axon that contain vesicles of neurotransmitters

Axon terminal

covering composed of Schwann cells that insulates nerve fibers and increases rate of transmisson

Myelin sheath

cells that are wrapped around axon ; produce myellin

Schwann cells

gaps along the axon that are not covered by myelin sheath; impulses jump from node to node

Nodes of raniver

When is the neurotransmitter released from the axon terminals?

When a nerve impulse reaches an axon terminal, it stimulates the release of neurotransmitters

What is a synapse

The space between 2 neurons where neurotransmitters are released and received, allowing communication between them.

What are the 2 types of nerve fiber bundles

White matter – myelinated axons in tracts
Gray matter –unmyelinated cell bodies

List 3 types of neurons based on function

Sensory Neurons - carry impulses from
receptors such as the skin to the CNS

Interneurons- connect sensory and motor
neurons in the CNS
Motor Neurons - carry impulses from the
CNS to a muscle or gland

What are proprioceptors?

They’re sensosary receptors in the muscles and tendonsthat provide information about body position and movement.

What are 4 different neurons structures on number of processes extending from cell body

1. Unipolar
2. Bipolar
3. Multipolar (most
common)
4. Pseudounipolar

What are 2 major functional properties of neurons

Irritability – ability to respond to a stimulus
and convert it into a nerve impulse
• Conductivity – ability to transmit the impulse
to other neurons, muscles, or glands

What is resting potential?

It the electrical charge difference across the neuron's membrane when it is not actively sending an impulse

What excites a neuron

Light
• Sound Waves
• Pressure
• Chemicals
• Neurotransmitters

What happens during depolarization?

A stimulus temporarily changes the permeability of the neuron membrane, allowing sodium ions to enter, making the inside of the neuron more positive.

What triggers an action potential?

If the stimulus is strong
enough and the influx
of sodium ions is great
enough the
depolarization
activates a nerve
impulse or action
potential

What is meant by “All or nothing response”

The impulse is either entirely conducted over the axon or it doesn’t happen at all, they is no partial response.

What is repolarization

The cell pushes out extra positive charges and gets back to its resting state, ready to send another signal.

Neuron at rest is __________

polarized

Stimulus changes _________ __________

membrane permablity

Depolarization and generation of

action potential

Action potential propogates along ______ ________ of neuron

entire length

__________ membrane returns to resting state

repolarization

______________ ___________ restores ion balance

Sodium - potassium pump

What happens when an action potential reaches axon terminal?

Tiny bubbles (vesicles) carry chemicals (neurotransmitters) to the edge of the neuron.

- They pop open and release the chemicals into the gap (synapse).

- The chemicals attach to special spots (receptors) on the next neuron to pass the message!

Define neurotransmitter and list some examples

Chemicals released at the
end of an axon terminal
that diffuse across the
synapse and transfer the
nerve impulse to another
nerve, muscle, or gland
• Ex: serotonin (top),
norepinephrine (bottom), and
acetylcholine

Explain how nerve impulses are electrochemical

Action potential
along the axon
is electrical
• Transmission of
the impulse
across the
synapse is
chemical

What are reflexes?

are rapid, predictable, involuntary
responses to stimuli

Contrasting 2 types basic types of reflexes

Somatic - skeletal muscles

Automonic - heart, glands

5 elements of a reflex arc

1.Receptor – responds to stimulus
2. Sensory (afferent) Neuron
3. Integration center – spinal cord
4. Motor (efferent) Neuron
5. Effector – muscle or gland stimulated

4 major brain regions

1.Cerebrum
2. Diencephalon
3. Brain stem
4. Cerebellum

Describe appearance of cerebrum

Its the largest and most superior parts of the brain, is composed of 2 hemispheres, surface shows eleved ridges of tissue called gyri and shallow grooves called sulci

What is the structure and function of the cerebral cortex

It is the outermost layer of cerebrum, composed of gray matter, and responsesable for 5 senses

What are the lobes of the cerebral cortext

Frontal, pateirel, temporal, occipital

What is the function of the frontal lobe

Motor function
• Problem solving
• Memory
• Language
• Judgment
• Socially acceptable
behavior

What is the function of the parietal lobe

Processes sensory information such as touch, temperature, and taste

What is the function of the temporal lobe

Auditory perception, olfactory area is deep inside

What is the function of the occipital lobe?

Visual processing and perception.

Describe the corpus callosum

Large fiber tract that connects the two cerebral
hemispheres
Allows communication between the two sides of the
cerebral cortex

Where is the diencephalon located?

Superior to the brainstem

What is the diencephalon major structures?

Thalamus, hypothalamus, epithalamus

What are the functions of thalamus and epithalamus?

Thalamus: relay station for sensory impulses traveling
to the sensory cortex
Epithalamus: contains the pineal gland and choroid
plexus which forms the cerebrospinal fluid

What are the functions of the hypothalmus?

Important in maintaining
homeostasis; maintains
body temperature, water
balance, and metabolism
• Part of the limbic system
which controls emotions
and drives such as hunger &
thirst
• Controls the pituitary gland

List 3 parts of brain stem and primary function of each

Midbrain – reflex center
for vision and hearing,
eye movements
• Pons – coordinates
information between
brain areas, involved in
breathing
• Medulla Oblongata –
blood pressure,
breathing, heart rate

What is the structure and function of cerebellum

Precise timing for
skeletal muscle activity
• Balance and equilibrium
• Makes body
movements smooth &
coordinated

What are 3 protective structures in the CNS

Bones, Meninges and CSF

What are 3 the meninges?

Dura mater - tough, outer layer, Arachonid mater - web like layer spans subarachnoid space, Pia Mater - innermost mebrane that clings tightly to the surface of the brain and spinal cord

What is cerbrospinal fluid?

A clear fluid that surrounds and protects the brain and spinal cord, providing cushioning and nutrient delivery.

What is the blood brain barrier?

A selective permeability barrier that protects the brain from harmful substances in the bloodstream while allowing essential nutrients to pass through.

List some facts about the spinal cord

Contects brain to nerves, enclosed within vertebrae, major reflex center

What are spinal roots and how are they related to the spinal cord?

They’re nerve branches that connect the spinal cord to the rest of the body.

What are 3 connective tissue wrappings found on a nerve?

Endoneurium: surrounds each neuron
• Perineurium: surrounds a group of neurons or fascicle
• Epineurium: surrounds a nerve

Describe spinial nerves

Spinal nerves are mixed nerves that carry motor, sensory, and autonomic signals between the spinal cord and the body. They arise from the spinal cord and emerge through the intervertebral foramina.

Describe cranial nerves

Cranial nerves are pairs of nerves that emerge directly from the brain, primarily responsible for motor and sensory functions of the head and neck. There are 12 pairs, each with specific roles, including vision, smell, and facial movement.

What is the autonomic nervous system function?

It is a subdivison of PNS that controls body activites, maintains homostatsis, includes neurons that control: cardiac muscle, smooth, glands

What are the primary functions of the 2 divisions of the autonomic nervous system?

Sympathetic - mobilizes body during extreme situations, Parasympathetic - allows us to relax and conserve energy

What are the causes and effects of traumatic brain injuries

Occurs when an external
force injures the brain, Common causes are
falls, auto accidents, and
violence, Can result in physical, cognitive, social, or
emotional symptoms

What is a concussion

A mild form of traumatic
brain injury, Caused by a jolt, bump, or
blow to the head that
causes the brain to move
rapidly inside the skull

What is meningitis causes and symptoms

It is acute inflammation of the mengines, caused by virial or bacterial infeaction, most common symptoms are severe headache and neck stiffness

What is multiple sclerosis?

A chronic disease that affects the central nervous system, characterized by the destruction of the myelin sheath surrounding nerve fibers, leading to a range of neurological symptoms such as fatigue, difficulty walking, and vision problems.

What is alzhemiers disease?

Mental illness caused by progressive brain cell death,

What is Parkinsons disease

A motor system disorder that leads to trembling of the
hands, arms, legs, jaw or face and impaired balance
and coordination
• Results from a loss of brain cells in an area of the
midbrain called the substantia nigra

What is paralysis?

A loss of ability to
move or feel anything
in all or part of the
body
• Results from illness,
poison, or injury
• Most often results
from stroke or spinal
cord injury

What is a stroke and what are the 2 kinds?

A stroke is the death of brain
cells that occurs when an
area of the brain is deprived
of oxygen due to poor blood
flow
• Ischemic: blood flow is
blocked by a clot
• Hemorrhagic: blood vessel
leaks or ruptures