Anatomy and Physiology chapter 9

What does the term Neuro mean

nerve/ nervous system

What does the term Enceph mean

brain (inside the head)

What does the term Myelo mean

pertaining to bone marrow/ white matter

What does the term Polio mean

grey matter

What 2 body systems does the body use to communicate?

Endocrine System and Nervous System

In terms of speed, the endocrine is _____________ compared to the nervous system

Slower

What is the purpose of the endocrine system

Use hormones, the blood stream carries signals (over time system)

What is the purpose of the nervous system

Uses neurotransmitters, neurons and synapses carry signals (quicker system, acts for a moment)

What are the 2 main nervous systems

Central Nervous System (CNS)
Peripheral Nervous System (PNS)

What are the 2 supporting cells in the Nervous System

Neurons and Neuroglia

Neurons have what 2 distinct parts to them

Dendrites and Axons

Are Dendrites of a neurons responsible for afferent or efferent

Afferent

Are axons of a neuron responsible for afferent or efferent

Efferent

How are afferent cells described

Sensory or feeling, saying ouch

How are efferent cells described

Effector or moving, moving hand from a fire

The word neuron can also be known as

Soma/ perikaryon

Nerve fibers are also known as what

Dendrites and Axons

True/False: Neuroglia are involved with transmission

False

What do neuroglia do

Provide support functions to the neurons

How does the Soma of a neuron look

Appears grey (grey matter)

How does the Axon of a neuron look?

Whitish yellow, covered in myelin (white matter)

The myelin sheath is made up of ___________ cells

Glial

What are the glial cells called within the CNS

Oligodendrites

What are the glial cells called within PNS

Schwann Cells

What is the purpose of the myelin sheath

Act as an insulator and speed up transmission

What is the Nodes of Ranvier

Spaces in between glial cells on the axon

What parts of the body make up the CNS

brain and spinal cord

What parts of the body make up the PNS

Cranial Nerves (originate directly from the brain )
Spinal Nerves (emerge from the spinal cord)

What direction does afferent fibers impulses go?

TOWARDS CNS

What direction does efferent fibers impulses go?

towards the Periphery (appendages)

True/False: most nerves in the PNS are both afferent and efferent

True

Somatic Nervous system makes up the voluntary nervous system, which type of muscle is specific to this

Skeletal

The autonomic nervous system makes up the unconscious/involuntary system, which type of muscles are specific to this

Cardiac and Smooth muscles

What are the 3 states a neuron can be in

Resting State
Depolarization
Repolarization

What is a neuron doing in the resting state

A neuron is not being stimulated

What is happening to a neuron during depolarization

Nerve is firing

What is happening to a neuron during repolarization

Actively returning to resting state

True/False: moving ions creates an electrical charge

True

When is the resting membrane potential established

When a neuron is not being stimulated

What is the resting membrane potential maintained by?

Sodium-Potassium pump

The resting membrane potential creates a voltage gradient across the neuron cell membrane: what does this mean

A neuron is ready to fire at any time

Sodium is unable to enter the cell, making sodium _______________

extracellular

Potassium is more negative than sodium and is free and able to leave a cell at any time this means it is ________________

intracellular

Are their other ions and molecules within the cytoplasm that contributes to the negative charge

Yes

Positive ions are located ___________ of a cell while negative ions are located _______________________

outside, inside

What are the steps to depolarization

1. Neuron is stimulated by afferent stimuli
2. Sodium channel opens
3. Overall charge across cell membrane switches
4. Action potential is established

What are the steps to repolarization

1. Sodium channels quickly close
2. Potassium channels open
3. Overall change across cell membrane switches
4. Resting membrane potential is re-established

What is the refractory period

A new impulse cannot travel down an axon until the neuron completely returns to its resting state (repolarization)

What is the all or nothing principle

Not every stimulus causes depolarization, it needs to meet a certain threshold. It is either on or nothing is happening

A stimulus that is strong enough to cause depolarization is called________________

Threshold stimulus

True/False: anything weaker than the threshold will not result in depolarization

True

True/False: anything stronger will result in a different nerve stimulus

False, anything stronger will result in the SAME nerve stimulus

How is a nerve impulse created

sodium rushing in and causing neighboring sodium channels to open that results in a wave of depolarization moving across the cell membrane

What is saltatory conduction

Nodes od Ranvier provides a shortcut for sodium channels to open, quicker way for axons to transmit nerve impulses

How do neurons communicate with each other

The Synapse

True/False: neurons touch each other

False, neurons do not physical touch each other

Where is the synaptic cleft located

the space between neurons

What are the Pre-synaptic neurons

the nerve that transmits the signals

What are neurotransmitters

The chemical that released by the per-synaptic neurons

What does post-synaptic neurons do

Receive the neurotransmitters

What is a telodendron

End of the axon that contains synaptic knobs in the pre-synaptic neurons

What happens when depolarization reaches synaptic knob

The neurotransmitters are released into the synaptic cleft

True/False: specific receptors bind to specific neurotransmitters

True

What to excitatory neurotransmitters do

Instigates threshold stimulus

What do inhibitory neurotransmitters do

Alter membrane potential to create a higher threshold necessary for stimulus to occur

What causes hyperpolarization?

Inhibitory neurotransmitters creating the higher threshold for stimuli

Can a neurotransmitter excite a particular neuron and calm another down?

Yes, a neurotransmitter can excite one neuron and inhibit another

What are some examples of post-synaptic neurotransmitters

Acetylcholine
Catecholamines

How does the recycling of a neurotransmitter molecules occur

The neurotransmitters needs to be removed from receptors by enzymes (acetylcholinesterase) to form smaller non-functional parts which are re-absorbed by the synaptic knob

What is the cerebrum of the brain

whole brain, contains the lobes and longitudinal fissure

What is the cerebellum

Smaller and caudal to the cerebrum, coordinated movement, balance and posture

What part of the brain is affected in Cerebellar Hypoplasia in cats from Feline Parvovirus (Feline Distemper)

Cerebellum

What makes up the diencephalon in the brain

Thalamus
Hypothalamus
Pituitary Gland

What does the thalamus do

Sensory information relay center, tries to decide who to send what to

What does the hypothalmus do

interface between nervous and endocrine (president)

What does the pituitary gland do

Endocrine master gland, controlled by the hypothalmus

What is the brainstem

Connection between brain and spinal cord
Controls life support functions
Contains respiratory center, cranial nerves, blood pressure, vomiting center

What are meninges?

connective tissue layers that surround the brain, bunch of layers, space, layers, space,...... bone

Where is cerebrospinal fluid located

Surrounds the brain and spinal cord within meninges
Also found in some ventricles of the brain holding liquid
Flow easily to maintain safe pressure

What is the blood-brain barrier

Barrier that separates capillaries from the nervous tissue
Capillaries are covered by glial cells and lack fenestrations
Prevents molecules from passing straight from blood into the brain

How many cranial nerves are there?

xII (12)

What are cranial nerves

Originate in the brain and directly enter the peripheral nervous system bypassing the spinal cord

What is the acronym for the cranial nerves

OOOTTAFVGVAF (oh oh oh to touch a fair virgin's glossy vagina after hours)
Olefactory
Optic
Oculomotor
Trochlear
Trigeminal
Intermediate
Abducent
Vestibulo-Choclear
Glosso-Pharyngeal
Vagus
Hypoglossal
Accessory

Where does the spinal cord run from

Brain stem through vertebrae

What is the purpose of the spinal cord

conduct sensory information and motor instructions

Where is the grey matter located in the spinal cord

Central, this is opposite to the brain as the outside of the brain (cerebellum) is the grey matter

Dorsal root nerves do what

Afferent (IN), sensory function

Ventral root nerves do what

Efferent (OUT), motor function

True/False: the spinal cord is a two way street

False, it is a one way highway

What is the purpose of the autonomic nervous system

Controls body functions at a subconscious level

What nervous system is located on the thoracolumbar spine and has a chain of ganglia just outside the spinal cord

Sympathetic Nervous System

What nervous system is rest and restore and is located in the cranium and the sacrum that contains ganglia located further away from the spinal cord

Parasympathetic Nervous System

What are preganglionic neurons

Neuron cell bodies located in the CNS

What are postganglionic neurons

Axons that extend to the PNS and meet a ganglion that carries an impulse to the target organ

True/False: in voluntary nervous systems, the neuron body communicates directly with the target organ

True

True/False: axons of preganglionic neurons are longer in the Sympathetic Nervous System

False, axons are shorter in the Sympathetic and Longer in the Parasympathetic

Where is the sympathetic ganglion chain located in relation to the spinal cord

Right next to the spinal cord

Nerve bodies are located within clusters of the brain and are called ___________

nuclei

True/False: the sympathetic nervous system is mostly in charge of stimulating the GI tract

False, the parasympathetic nervous system is in charge of stimulating the GI tract

True/False: one of the goals for the sympathetic nervous systems is to get the blood pressure up

True, because the sympathetic nervous system is the oh shit system