Midterms: Organization of the Nervous System

Question 1

Arborizations which form connections or synapses with other neuron

Answer 1

Dendrites

Question 2

What is the main job of an Axon?

Answer 2

conduct the impulse or the signal away from the cell body towards the other neuron /effector

Question 3

Connections b/w one neuron to another or an effector
Anatomically just gaps
Functionally: area wherein signal is modified

Answer 3

Synapses

Question 4

Types of Neurons

Answer 4

Unipolar
Bipolar (specialized or modified)
Pseudounipolar (specialized or modified)
Multipolar (common type)

Question 4

For ascending or afferent
Pain, pressure, touch will be notice in the skin
Then going to the ?

Answer 4

For ascending or afferent
Pain, pressure, touch will be notice in the skin
Then going to the midbrain, medulla pons cerebellum

Question 5

Emotions, sexual response, reaction to pain or pleasure, wakefulness
are all processed in the?

Answer 5

Subcortical level

Question 5

T or F
Efferent neurons are for Sensory

Answer 5

Efferent neurons are for Motor function
*Somatic Nervous System
- Motor pathways going to the skeletal system
- Used for conscious movement

Question 6

The lower brain or the sub cortical level is composed of?

Answer 6

(midbrain, pons, medulla, hypo, cerebellum, basal ganglia - they all modified the message)

Question 7

Function of the Cortical Level or the higher brain

Answer 7

Fuctions with other parts of the NS
Memory, thought
Converts signals to determinative and precise function
It is not the highest center in the nervous system

Question 8

What are the CNS SYNAPSES

Answer 8

Chemical synapses
Electrical synapses

Question 8

Axodendritic?
Axosomatic ?
Axoaxomic ?

Answer 8

Axodendritic (maraming connections); Axon + Initial Segment of another axon
.
Axosomatic (mas onti); Axon + Dendrite
.
Axoaxomic (mas lalong onti); Axon + Nerve Cell Body

Question 9

What are some alternative names for presynaptic terminals?

Answer 9

Terminal knobs, boutons, end-feet, or synaptic knobs.

Question 10

What is the primary function of presynaptic terminals?

Answer 10

Conduction of action potential and release of neurotransmitters.

Question 10

What triggers the release of neurotransmitters from presynaptic terminals?

Answer 10

Ca²⁺ influx via voltage-gated Ca²⁺ channels and activation of SNARE proteins.

Question 11

What are the two general classes of SNARE proteins involved in synaptic transmission?

Answer 11

V-SNARE and T-SNARE.

Question 12

Describe the location of presynaptic terminals in relation to the neuron.

Answer 12

Presynaptic terminals are found at the ends of nerve fibrils originating from many neurons and typically synapse onto dendrites and soma of the postsynaptic neuron.

Question 12

What components are involved in the activation of post-synaptic receptors?

Answer 12

Binding component and ionophore component.

Question 13

How do neurons in other parts of the spinal cord and brain differ from the anterior motor neuron?

Answer 13

They differ in cell body size, dendritic length, axon length, and the number of presynaptic terminals.

Question 14

What is the role of ion channels in neurotransmission?

Answer 14

Ion channels control the passage of ions, such as potassium and calcium, which are crucial for synaptic transmission.

Question 14

What physiological changes occur during excitation at the synapse?

Answer 14

Opening of Na and Ca channels, closure of Cl and K channels, and changes in cellular metabolism.

Question 14

What is the function of the ionophore component in post-synaptic receptors?

Answer 14

It passes through the postsynaptic membrane to allow ion passage into the postsynaptic neuron.

Question 15

What are ionotropic receptors and metabotropic receptors?

Answer 15

Ionotropic receptors directly gate ion channels, while metabotropic receptors act through second messenger systems.

Question 16

Describe the physiological changes associated with inhibition at the synapse.

Answer 16

Opening of Cl and K channels, activation of inhibitory enzymes, and alterations in receptor expression favoring inhibition.

Question 17

What is co-release of neurotransmitters?

Answer 17

Co-release refers to the simultaneous release of multiple neurotransmitters from a single presynaptic terminal.

Question 18

Differentiate between co-transmission and co-transmission with spatial segregation.

Answer 18

Co-transmission involves the release of multiple neurotransmitters from a single terminal, whereas co-transmission with spatial segregation involves distinct neurotransmitters being released from different regions of the same terminal.

Question 19

What does EPSP stand for, and what physiological changes does it involve?

Answer 19

EPSP stands for Excitatory Postsynaptic Potential. It involves the opening of Na or Ca channels, leading to depolarization or hypopolarization of the postsynaptic membrane.

Question 20

Define IFSP and describe its physiological effects.

Answer 20

IFSP stands for Inhibitory Postsynaptic Potential. It involves the opening of Cl or K channels, resulting in hyperpolarization of the postsynaptic membrane.

Question 20

What is orthograde transmission, and how does it contribute to nerve conduction?

Answer 20

Orthograde transmission refers to the transmission of nerve impulses in the direction of the axon terminal. It facilitates saltatory conduction, where nerve impulses jump from one node of Ranvier to another, speeding up conduction.

Question 21

What is presynaptic inhibition, and how does it occur?

Answer 21

Presynaptic inhibition involves the opening of Cl channels by GABA at presynaptic terminals, reducing neurotransmitter release.

Question 21

Explain temporal summation and spatial summation in synaptic transmission.

Answer 21

Temporal summation involves the cumulative effect of multiple stimuli arriving at the synapse in rapid succession, while spatial summation involves the combined effect of simultaneous stimuli from different synapses.

Question 22

Describe the characteristics of facilitated neurons.

Answer 22

Facilitated neurons have a hypopolarized membrane, exhibit electronic conduction to the soma, have few Na channels, and undergo summation of inhibitory or excitatory signals.

Question 22

What is the mechanism of action of strychnine on neuronal excitability?

Answer 22

Strychnine inhibits inhibitory neurons, increasing overall neuronal excitability by preventing the inhibition of excitatory signals.

Question 23

Explain the effects of acidosis on neuronal activity.

Answer 23

Acidosis depresses neuronal activity by lowering the pH level of the blood, potentially leading to a comatose state.

Question 23

What is the impact of hypoxia on neuronal function?

Answer 23

Hypoxia, or oxygen deprivation, can cause complete inexcitability of some neurons within seconds due to interrupted blood flow to the brain.

Question 23

How does alkalosis affect neuronal excitability?

Answer 23

Alkalosis increases neuronal excitability by raising the pH level of the blood, potentially leading to conditions like epileptic seizures.

Question 24

How do caffeine, theophylline, and theobromine affect neuronal excitability?

Answer 24

: They reduce the threshold for excitation of neurons, increasing their excitability.

Question 24

What effect do anesthetics have on neuronal threshold and membrane properties?

Answer 24

Anesthetics increase the threshold for excitation and alter the properties of neuronal membranes.

Question 25

Describe the steps involved in synaptic delay.

Answer 25

Synaptic delay includes the release of neurotransmitters, diffusion of neurotransmitters to the postsynaptic neuron, neurotransmitter-receptor interaction, changes in ion permeability, and the production of action potential.