Nervous System Test

What two parts is the nervous system divided into

The central nervous system (CNS) and the peripheral nervous system (PNS)

What does the central nervous system contain?

The brain and the spinal cord

What does the peripheral nervous system contain?

All the other nerves of the body

What is a nerve cell also known as

A neuron

What is a neuron made up of?

Dendrite, cell body, and axon

What are dendrites?

A dendrite conducts the impulse to the cell body

What is the cell body

The cell body has a nucleus and relays impulse to axon

What is the axon?

The axon conducts impulse away from the cell body

What are the different types of neurons

A motor neuron, a sensory neuron, and an interneuron

What is a motor neuron

A motor neuron has short dendrites and a long axon. The motor neuron takes a message from central nervous system to an effector [ muscle or gland]

What is a sensory neuron

A sensory neuron has a short axon and long dendrite. A sensory neuron takes message from receptor to central nervous system

What is an interneuron

A interneuron is made up of a short dendrite and short axons. An interneuron is found completely within the central nervous system. It also relays information from sensory to motor neuron.

What do the three neurons do together?

They function together to relay information to and from the brain or spinal cord

In what order does the axon, dendrite, and cell body always travel in

It travels in the order of of dendrite, cell body, and then axon

Why do nerve impulses travel quickly?

Nerve impulses can travel really quickly because of myelin.

How does myelin make nerve impulses travel really quickly

Myelin acts like an insulator, it is a lipid substance made by Schwaan cells.

How does the nerve impulse travel

The nerve impulse will travel by saltatory conduction where it jumps from node of Ranvier to node of Ranvier

How is a nerve impulse propagated along a neuron - What is the first step

In resting potential, sodium-potassium pump is working to move sodium ions to the outside of the cell and potassium ions to the inside of the cell.

How is the process of the first step of propagating a nerve impulse along a neuron possible

Active transport is used as a protein pump and energy to support the first step of propagating a nerve impulse along a neuron

What is the second step of how a nerve impulse can be propagated along a neuron

Threshold- if the signal recieved by the neuron is strong enough and the voltage reaches a threshold, it will trigger an action potential

What is the third step so a nerve impulse is propagated along a neuron

Depolarization- Sodium gates open and sodium moves into the cell by facilitated diffusion. This causes the inside of the cell to be positively charged and the outside to be negatively charged.

What is the fourth step to ensure a nerve impulse is propagated along a neuron

Repolarization- sodium gates close and potassium gates open so that potassium moves out across the membrane by facilitated diffusion. This results in the inside of the neuron being more negative in comparison to the outside

What is the fifth step that makes sure a nerve impulse is propagated along a neuron

Hyperpolarization- potassium gates close, but there is more potassium ions on the outside then potassium ions in the inside. The membrane potential drops below resting potential

What happens after the 5th step of how a nerve impulse is propagated along a neuron

Resting potential must be re-established before another action potential can occur [ refractory period] This occurs with the sodium potassium pump actively transporting sodium ions out and potassium ions in

What is the last step of how a nerve impulse is propagated along a neuron

A nerve impulse is electrical because depolarization and repolarization are due to the movement of positively charged ions across the membrane.

How do nerve impulses travel from one neuron to another neuron

There is a gap or space between 2 neurons that is called a synapse [ synaptic cleft]

What happens to the nerve impulse since there is a gap or synapse between the axon of one nerve cell and the dendrite of another nerve cell

The nerve impulse must be transmitted via neurotransmitters

What is the 1st step of the process of synaptic transmission

The action potential reaches the end of the axon [ pre-synaptic membrane] and this causes the release of calcium which causes the synaptic vesicles to fuse with the pre-synaptic membrane and release the neurotransmitter by exocytosis

What is the second step of the process of synaptic transmission

The neurotransmitter diffuses from the pre-synaptic membrane to the post-synaptic membrane

What is the third step of the process of a synaptic transmission

The neurotransmitter binds to a specific receptor on a protein channel in the post-synaptic membrane

What are the two types of neurotransmiters?

Excitatory and inhibitory

What are two common neurotransmitters

Noradrenalin [ norepinephrine [NE] and Acetylcholine [ACh]

Where are the two common neurotransmitters found

Found in the central nervous system and the peripheral nervous system

Depending on the type of receptor found at the postsynaptic membrane, these two neurotransmitters may be either…

Excitatory or inhibitory

Where are receptors found

Only found on the post-synapatic membrane so the nerve impulse travels in one direction from the axon to the dendrite.

What happens if the neurotransmitter is excitatory?

Then the action potential will continue along the next nerve cell [ nerve impulse continue]

What happens if the neurotransmitter is inhibitory?

Then the action potential will not continue along the next nerve cell [ nerve impulses stop]

What are neurotransmitters immediately destroyed by

Enzymes

What happens to Norepinephrine when enzymes destroy them

It gets broken down

What else is broken down

Acetylcholine

What happens after Norepinephrine and acetylcholine are broken down?

The products are returned back to the pre-synaptic and used to make more neurotransmitters

What does the products that are being returned back prevent

This prevents the neurotransmitters from continually stimulating the nerve cell

What happens after the products are returned back to the pre-synaptic and more neurotransmitters are made

The axon is now ready to recieve and transmit another action potential

What is action potential

An action potential is a rapid electrical signal that travels along a neuron or muscle cell, allowing communication and triggering responses like nerve impulses or muscle contractions.

What is a reflex

A reflex is a automatic response to a stimulus and does not involve conscious though

What happens to the message that is generated during a reflex

The message goes through the spinal cord to a motor neuron

When is the brain notified of the message that happens when a human reflexes

The brain is only notified after the reflex is complete

Why is the brain only notified after the reflex is complete

This saves time in not thinking about an action

What are some examples of reflexes

The knee-jerk, moving your hand when something is hot, and blinking

What happens during a reflex

A receptor that is sensitive to heat, pressure, pain, PH, and texture passes the information to the sensory neuron

Where does the sensory neuron pass information during a reflex to

The sensory neuron passes the information to an interneuron in the spinal cord that relays to an effector [ muscle/gland cell] so a response/action takes place

What does the central nervous system functions in

organizng sensory inputs into meaningful actions

How does the brain, that is part of the central nervous system organize sensory inputs into meaningful ways

Processes sensory data, regulates your thoughts and emotions, generates memories, and decides on voluntary motor outcomes

How does the spinal cord, that is part of the central nervous system organize sensory inputs into meaningful actions

primary pathway that carries messages between the brain and the peripheral body, while also managing reflex loops

What does the peripheral nervous system function in

Connects the centralized system to external and internal environment through two specialized pathways

What are the two specialized pathways that the peripheral nervous system connects the centralized system to the external and internal environments

Afferent [sensory] - collects a sensory stimuli and Efferent [motor]- which takes commands away from the central nervous system and delivers them to target tissues. This division is split into two distinct sub-systems

What are the names of the two distinct sub systems that is the division of commands taking away and being delivered to target tissues

Autonomic and somatic

Division of the peripheral nervous system: What is the autonomic nervous system

The autonomic nervous system controls involuntary actions, have nerves that control smooth muscle, and have nerves that control organs

Division of the peripheral nervous system: somatic nervous system

The somatic nervous system controls voluntary actions, have nerves that control skeletal muscles, and have nerves that control skin

What is the autonomic nervous system divided into

Parasympathetic nervous system and the sympathetic nervous system

What is the condition of the parasympathetic nervous system to operate

During normal resting conditions, known as the “ house-keeper” and sometimes referred to “rest and digest”

What happens to the pupils when the parasympathetic nervous system is operating

The pupils contract and become smaller

How is the digestive system when the parasympathetic nervous system when operating

Digestion is promoted and functioning properly “ rest and digest”

How is the heart rate impacted when the parasympathetic nervous system when operating

The heart rate decreases

What is the breathing rate when the parasympathetic nervous system when operating

Breathing rate decreases

What are the conditions for when the sympathetic nervous system will operate

During moments of stress, commonly known as the “ fight or flight” mode related to anxiety

What happens to the pupils when the sympathetic nervous system is operating

The pupils relax, allowing more light to enter

What is digestion like when the sympathetic nervous system is operating

It is inhibited, causing digestive issues such as bloating, cramps, or rumbling.

What happens to the heart rate when the sympathetic nervous system is operating

The heart rate increases

What happens to breathing when the sympathetic nervous system is operating

Breathing rates increase

What is adrenalin released by

By the adrenal glands

What does adrenalin initiate

Adrenalin initiates the “fight or flight” response causing different things to occur in the body

What happens when the “fight or flight” mode is turned on

Heart rate and blood pressure increase, breathing rates increase, liver converts glycogen into glucose for an immediate burst of energy, pupils widen, hearing and vision get sharper, and digestion and immune response slow down for the body to focus on potential threats

What is the medulla obongata

Controls heart rate, breathing rate, blood pressure, and controls reflexes such as sneezing, vomiting, hiccups, and coughing.

What is the cerebrum function

The cerebrum’s function is memory, conscious though, and processing sensory information.

What are the 4 lobes called in the cerebrum

Occipital, temporal, parietal, and frontal

What is the occipital lobe responsible for

sight

what is the temporal lobe responsible for

hearing and smell

What is the parietal lobe responsible for

touch, pressure, and pain

What is the frontal lobe responsible for

conscious thought

What is the function of the thalamus

relays station for directing sensory information to the correct part of the cerebrum

What is the function of the cerebellum

Coordination of movement and balance

What is the function of the hypothalamus

Center for homeostasis such as hunger, sleep, thirst, body temperature, water balance, and blood pressure

What is the function of the corpus callosum

Holds two hemispheres of the cerebrum together, conducts impulses from one side of the brain to the other side

What is the pathway of an impulse in a reflex arc?

From the sensory neuron to the interneuron, then to the motor neuron

What type of cell is found only in the central nervous system

Interneuron

Which part of the nervous system functions to lower blood pressure and heartrate after a frightening experience

The parasympathetic nervous system

Rapid conduction of a nerve impulse in vertebrates is due to

Myelin sheath

Automatic response to specific external stimuli require

Simplified pathways called reflex arcs

If potassium ions could not diffuse out of the axon, which of the following would result

Repolarization would not occur

If a person’s ability to integrate information from both hemispheres of the brain is impaired, the portion of the brain that is most likely to be affected is the

Corpus collosum

What activity accompanies high activity of the cerebellum

Performing a gymnastics routine

The post synaptic membrane is at the end of a

dendrite

Neurotransmitters move into the gap between two neurons by the process of

Diffusion- released by exocytosis

What happens to the neurotransmitters once they have crossed the gap

They bind to a specific receptor [ lock and key]

In what situation does the sympathetic nervous system respond

“Fight or flight” - when frightened or excited which leads to the release of adrenalin

What division is the sympathetic nervous system part of

Autonomic