A & P Nervous System Study Guide

Steps of synaptic transmission

-Nerve impulses arrive at axon terminal -Ca ions enter -Exocytosis of neurotransmitter -Diffusion through synaptic cleft -Binding to receptor of post-synaptic cell membrane

Sodium-potassium pump transorts

3 Na ions out of the cell & 2 K ions into the cell

The sodium-potassium pump actively transports _______ Na ions out of the cell for every ________ K ions transported into the cell. This reestablishes the ion distribution & helps maintain the resting membrane potential

3,2

How many spinal nerves are there?

31

There are______interconnected ventricles in the brain. The________is/are found in the cerebral hemispheres. These ventricles are connected to the single ventricle below it by 2_______________. The____________ is a narrow space in the midline of the brain, just below the corpus callosum. It is connected to the ventricle below it by a small canal located in the midline of the brain called___________. The_________ is found posterior to the brainstem & anterior to the___________. The ventricle is continuous w/the_____________ of the spinal cord & has openings into the__________ of the meninges

4, lateral ventricles, interventricular foramina, 3rd ventricle, cerebral aqueduct, 4th ventricle, cerebellum, central canal, subarachnoid space

When the membrane potential reaches the threshold, voltage-gated channels open, triggering a(n) __________________ at the location. This cycle continues, resulting in an action potentials traveling down the axon. This is also called _____________ conduction

Action potential, impulse

The cytoplasm contains many ________ such as phosphate, sulfate, & proteins. These contribute to the negative charge within the cell

Anions

9-Glossopharyngeal

Associated w/tongue/pharynx for swallowing

Star-shaped ______________ are found in the CNS. They serve several functions, from providing support to forming the _________________

Astrocytes,blood-brain barrier

What divisions of the N-system function independently & continuously, w/out conscious effort?

Autonomic

Divergence

Axons may branch at several points, diverging axons amplify an impulse

Convergence

Axons originating from different parts of the N-system leading to the same neuron; allows the N-system to collect, process & respond to info

Cell body has a single process that divides into 2 branches

Bipolar

Regulates visceral activities & involuntary responses; connects diencephalon to spinal cord

Brain stem

Where is the CSF located?

Brain/spinal cord

As the cells wrap around the axon, cytoplasm ends up in the outermost wrapping of the cell. This layer, containing organelles & the nucleus is called the _____ ______________

Cell membrane

The n-system is divided into the__________ N-system which includes the_________ & spinal cord, & the____________ n-system which includes cranial nerves, spinal nerves & ganglia. The peripheral n-system is further subdivided into an afferent(_____________) division & an efferent(_______________) division. The sensory division transmits impulses from the__________________. The motor division transmits impulses from the_________________. The motor division is divided further into a somatic motor division serving_____________ muscle & a(n) motor division serving_____________ muscle, cardiac muscle & glands

Central,brain, peripheral, sensory, motor, peripheral organs to CNS, CNS to peripheral organs, skeletal, autonomic, smooth**

Coordinates voluntary muscle movement

Cerebellum

Largest part of the brain;reasoning, memory & voluntary responses

Cerebrum

The CNS is composed of 2 organs, the superior_____________ & the inferior_____________.The brain consists of the____________ diencephalon, brainstem &________________, the most posterior-inferior portion. The brain is connected to the spinal cord via the____________. The_____________ provides 2 way communication between the CNS & the PNS

Cerebrum, cerebellum, brain stem, spinal cord

What structures secrete CSF?

Choroid plexuses(in pia mater)

Collection of myelinated axons which connect cerebral hemispheres

Corpus callosum

1 of the 4 major portions of the brain; surrounds 3rd ventricle

DIencephalon

Which of the following is an action of the sympathetic n-system?

Decrease heart rate

As these ions enter the cell, the membrane undergoes _______________ , with the membrane potential increasing to a peak of approximately +30mV

Depolarization

The rate of impulse conduction on an axon is dependent upon myelination & ______________ of the axon. Axons that are myelinated conduct impulses at a rate____________than unmyelinated axons. In____________ axons, an impulse is conducted over the entire surface of the axon membrane. In___________ axons, only the axon membrane exposed at the____________ undergo depolarization. Another factor affecting impulse conduction rate is the diameter of an axon. The__________ the diameter of an axon, the faster the impulse is conducted. Therefore, a large myelinated axon will conduct impulses___________ than a thin, unmyelinated axon

Diameter,faster,

What is the correct order of meninges from superficial to deep?

Dura mater, arachnoid mater, pia mater

Muscles & glands whose activities are controlled by nervous activity are called

Effectors

Cells called ________________ line the spaces of the CNS, called ______________ & form a membrane that covers the choroid process

Ependymal cells, ventricles

Neurotransmitters are considered to be_______________ when increase postsynaptic membrane permeability to NA ions will brane the postsynaptic membrane closer to threshold & may trigger impulses. Neurotransmitters that make reaching threshold less likely are considered_____________, because they decrease the chance that an impulse will occur

Excitatory, inhibitory

T/F The right cerebral hemisphere controls the muscles in the right hand responsible for righting

False

A deep groove on the surface on the brain

Fissure

What is CSF?

Fluid that supports/protects organs by absorbing forces that might otherwise jar/damage them

Intelligence

Frontal

Movement

Frontal

Personality

Frontal

What is a neuronal pool?

Groups of neurons that make synaptic connections w/each other & work together to perform a common function

Rige or convolution on the surface of the brain

Gyri

The membrane potential actually dips lower than -70 mV because the Potassium channels do not close quickly enough. This phase is called ______________

Hyperpolarization

In the diencephalon, links the endocrine to the neural systems

Hypothalamus

The _________________ is considered the autonomic control center of the body due to its regulation of hormonal secretion & heart rate. The majority of all afferent pathways pass through & synapse w/neurons of the___________. Comprised of parts of the cerebral cortex, diencephalon, & other deep nuclei, the___________ represents the area of emotional control. Composed of 3 parts, the __________ provides basic life support functions including roles in the cardio & respiratory systems

Hypothalamus, thalamus, limbic system, brain stem,

All-or-none response

If a neuron responds at all to a nerve impulse, it responds completely

Relay impulses between neurons in CNS

Interneurons

Neurons found within the CNS are classified as ____________ . Structurally, these are ______________ neurons

Interneurons, multipolar

5-Trigminal

Largest;eyes, tear glands, upper eyelids, upper gum/lip, innervate the muscle of mastication

8-Vestibulocochlear

Maintain equilibrium, hearing receptors

In the brainstem, controls vital visceral activities

Medulla oblongata

Membranes to cover & protect brain/spinal cord

Meninges

Cells called __________ act as phagocytic cells within the CNS, removing bacterial cells & cellular debris

Microglia

In the brainstem,has auditory/visual reflex centers

Midbrain

Parasympathetic N-system

Most active during ordinary, peaceful situations

Carry impulses from the CNS to the effectors

Motor

Output from the CNS is carried by neurons called ____________ . These are multipolar neurons that carry impulses out to structures in the periphery called _______________

Motor, effectors

6-Adbucens

Movement of eyes

4-Trochlear

Moves the eye

Cell body w/many processes, 1 axon & many dendrites

Multipolar

11-Acessory

Muscles of neck/back

12-Hypoglossal

Muscles that move tongue

Axons w/myelin sheaths are called _____________ & those that lack sheaths are called _____________

Myelinated, unmyelinated

An action potential results from the opening of____________. These channels open when the membrane potential reaches a level called ___________. This local current stimulates the _______________________ to reach its threshold

Na channels, threshold, adjacent membrane

In a resting neuron, the area just inside of the cell membrane is more _______ than the area outside of the cell membrane

Negative

In a resting neuron, the inside of the membrane has a more __________ charge than the outside of the membrane. This charge difference is called the resting membrane potential, which is the result of several factors

Negative

Large groups of cells within the CNS/PNS called _________ serve as supportive function for nervous tissue

Neuroglia

Gaps between neighboring segments of the myelin sheath are called _________ ____ ______________. At these points, the axon is not insulated

Nodes of Ranvier

The meylin sheath along an axon is not continuous. Between Schwann cells are gaps called

Nodes of Ranvier

Vision

Occipital

Myelin is formed in by 2 cell types:____________________ in the CNS & _______________ in the PNS

Oligodendrocytes, schwann cells

Na ions are found in a higher concentration __________ the cell, while Potassium is more abundant _________ the cell. As a result, Na ions want to diffuse from ___________________________ & K ions want to diffuse from __________________________

Outside, inside, outside to inside, inside to outside

Sensations

Parietal

In the brainstem, helps maintain breathing

Pons

Membrane permeability differs for Na & K. The membrane has more channels for _____________ than it has for _____________. Therefore, as the ions follow their diffusion gradient, more positive charges leave the cell than enter the cell

Potassium, sodium

The ___________ is sensitive to specific type of internal or external change, a stimulus. The______________ conducts an impulse about the stimulus towards the brain or spinal cord. Then, the________________ serves as a processing center for the info. The ______________ then conducts the impulse away from the brain or spinal cord. Finally, the _____________ responds to stimulation by the neuron, resulting in the behavioral action of the reflex

Receptor, sensory neuron,CNS, motor neuron, effector

As cations leave the cell, the membrane potential at that part of the membrane is restablishing resting membrane potential. This phase of action potential is called _______________

Repolarization

Sympathetic N-system

Responds to stressful, emergency situations

The_____________ is the alert systems of the body because of the tracts that provide communication between lower/higher brain regions. The largest portion of the brain is the______________, which controls voluntary muscle movement, sensory, integration & personality

Reticular formation, cerebrum

Spinal nerves emerge from the cord by 2 short branches, or___________, which lie within the vertebral column. The_________ root is the sensory branch of a spinal nerve by which it joins the spinal cord. The__________ root is the motor branch of a spinal nerve by which it connects w/the spinal cord

Roots, dorsal, ventral

Cells called__________cells wind & wrap around axons, forming the myelin sheath of myelinated axons in the PNS

Schwann

1-Olfactory

Sense of smell

Carry impulses from receptors to the CNS

Sensory

Info about our internal/external environment is detected by structures called______________________ which then convert the info into impulses. Nerve impulses then travel to the CNS along___________. Within the CNS, they are ________________, creating sensations, memories & emotional reactions. Decisions about responses(subconscious or conscious) are then made. This info is conveyed to _______________ via the ____________ division of the n-system

Sensory receptors, nerves, integrated, effectors, motor

Neurons that carry impulses from peripheral receptors to the CNS are classified ____________ neurons. They are typically ___________ neurons, though some are bipolar

Sensory, unipolar

10-Vagus

Speech, swallowing

A shallow groove on the surface of the brain

Sulcus

7-Facial

Tastes receptors, facial expression, tear/salivary glands

Hearing

Temporal

In the diencephalon, is a relay area for sensory impulses

Thalamus

An action potential will not occur unless the membrane potential at the _______________(the initial segment of the axon) reaches a level called _____________

Trigger point, threshold

Cell body w/a process arising from either end;1 dendrite & 1 axon

Unipolar

2-Optic

Vision

3-Oculmotor

Vision, focus lense, raise eyelid

As the peak of the action potential is reached, the Na channels close & the _____________________ open, allowing these ions to diffuse out of the cell

Voltage-gated Potassium channels

When threshold is reached, __________________________ of the initial segment open briefly, allowing ____________ to diffuse into the cell

Voltage-gated sodium channels, Na

Bundles of myelinated axons form N-system tissue called __________ matter; unmyelinated axons, dendrites, neuron cell bodies & synapses are found within n-system tissue called ________ matter

White, grey