Functions, anatomy, Glia, Meninges

Question 1

nervous system functions

Answer 1

voluntary movement, perception, homeostasis, higher functions.

Question 2

cerebral anatomy

Answer 2

forebrain, brain stem, cerebellum, spinal cord

Question 3

Where does Voluntary movement occur in the brain and what are type of neurons does it recruit?

Answer 3

Motorneuros.
In spinal cord for body movements, in brain stem for head and above movement

Question 4

Neuros anatomy

Answer 4

Body/soma, dendrites/ arbor, axons, synaptic terminal, synapses

Question 5

What is produced in the body/some of the neuron?

Answer 5

Protein

Question 6

What are dendrites responsible for?

Answer 6

collecting information locally and sending it to axons

Question 7

Axon function

Answer 7

transport information throughout the body to the next cell

Question 8

What is a synaptic terminal, what’s it’s function and where is it located?

Answer 8

Part of a neuron located at the end of an axon. It contains vesicles filled with neurotransmitters, which are chemical messengers. When an action potential reaches the synaptic terminal, it triggers the release of these neurotransmitters into the synapse.

Question 9

What is the electric signal called (information) that reaches synaptic terminal and triggers the release of the neurotransmitters?

Answer 9

action potential/ spike.

Question 10

What is the small gap in between neurons called?

Answer 10

synaptic cleft.

Question 11

What is a synapse and what is it made of?

Answer 11

The entire junction where communication occurs between 2 neurons (or a neuron and another cell, like a muscle cell).

The presynaptic terminal,
The synaptic cleft,
The postsynaptic membrane.

Question 12

What is the postsynaptic membrane?

Answer 12

contains receptors on the receiving neuron or target cell that bind to the neurotransmitters.

Question 13

How are neuros different from one another?

Answer 13

1. Structure - different shapes, sizes
2. Function - sensory, motor, interneurons
3. Neurotransmitter type - dopaminergic, seratonergic, cholienergic
4. location - cortical, spinal, cerebral
5. firing patterns - tonic, phasic.
6. myelination
7. synaptic connections - diverging circutis, converging circuits.
8. plascticity

Question 14

Multipolar Neurons

Answer 14

Have many dendrites and one axon. Common in the brain and spinal cord, they are involved in motor control.

Question 15

Bipolar Neurons

Answer 15

Have one dendrite and one axon. Found in sensory organs like the eyes and ears, these are involved in transmitting sensory information.

Question 16

Unipolar (or Pseudounipolar) Neurons

Answer 16

Have one projection that splits into two branches. Common in sensory pathways, they transmit information from the body to the spinal cord.

Question 17

Sensory Neurons

Answer 17

Carry signals from sensory receptors (like skin or eyes) to the brain or spinal cord.

Question 18

Motor Neurons

Answer 18

: Transmit signals from the brain or spinal cord to muscles or glands, initiating movement or action.

Question 19

Interneurons

Answer 19

Found within the brain and spinal cord, these neurons connect other neurons and are involved in processing information, reflexes, and decision-making.

Question 20

Dopaminergic Neurons

Answer 20

Release dopamine and are involved in reward, motivation, and movement.

Question 21

Serotonergic Neurons

Answer 21

Release serotonin, playing a key role in mood regulation, sleep, and appetite.

Question 22

Cholinergic Neurons

Answer 22

Release acetylcholine, important for muscle activation and cognitive functions.

Question 23

Cortical Neurons

Answer 23

Found in the cerebral cortex, involved in higher-order functions like thinking, perception, and decision-making.

Question 24

Spinal Neurons

Answer 24

Located in the spinal cord, these are critical for transmitting signals between the brain and the rest of the body.

Question 25

Cerebellar Neurons

Answer 25

Located in the cerebellum, these neurons help coordinate movement and balance.

Question 26

Tonic Neurons

Answer 26

Fire steadily and maintain a consistent output of action potentials.

Question 27

Phasic Neurons

Answer 27

Fire action potentials in bursts, usually in response to specific stimuli.

Question 28

Myelin and its function

Answer 28

a fatty, insulating layer that surrounds the axons of many neurons in the nervous system.
Its main function is to increase the speed at which electrical impulses, or action potentials, travel along the axon. Myelin acts like insulation on a wire, preventing electrical signals from leaking out and allowing them to move more efficiently.

Question 29

Diverging Circuits

Answer 29

Some neurons send signals to many other neurons, spreading information.

Question 30

Converging Circuits

Answer 30

Others receive input from many neurons, integrating various signals.

Question 31

Glial cells (or glia) and role

Answer 31

non-neuronal cells in the nervous system that provide support, protection, and nourishment to neurons. While neurons are responsible for transmitting electrical signals, glial cells play essential roles in maintaining the health and functionality of the nervous system.

Question 32

Types of glia

Answer 32

astocytes (cns), olygodendrocytes (cns), Shawn cells (pns), microglia (cns)

Question 33

Astrocytes function

Answer 33

structural support, regulate the blood-brain barrier (which controls the passage of substances from the bloodstream into the brain), and maintain the chemical environment around neurons by absorbing excess neurotransmitters.

Question 34

Oligodendrocytes function

Answer 34

produce the myelin sheath in the CNS, wrapping around axons to speed up signal transmission.

Question 35

Schwann cells function

Answer 35

produce the myelin sheath in the peripheral nervous system (PNS), insulating and protecting axons to increase the speed of nerve signals.

Question 36

Microglia

Answer 36

act as the immune cells of the CNS. They protect against infections and clear away dead or damaged cells by engulfing them (a process called phagocytosis).

Question 37

describe Myelinated Axons

Answer 37

These axons are covered by a myelin sheath, a fatty layer produced by oligodendrocytes (in the CNS) or Schwann cells (in the PNS). The myelin is not continuous but is segmented, with small gaps known as nodes of Ranvier.

The presence of myelin significantly increases the speed of signal transmission. The electrical impulses “jump” from one node of Ranvier to the next in a process called saltatory conduction, allowing signals to travel much faster.

These have much faster conduction velocities, with some reaching speeds of up to 120 meters per second (m/s). This is critical for rapid reflexes and coordinated movement.

Because myelinated axons only need to propagate action potentials at the nodes of Ranvier, they use less energy. Fewer ions are moved across the membrane, reducing the workload on the sodium-potassium pumps that restore ion balance after each impulse.

These are generally found in parts of the nervous system where rapid, precise communication is essential, such as in motor neurons controlling muscles, or sensory neurons transmitting information to the brain.

Question 38

describe Unmyelinated Axons

Answer 38

These axons lack a myelin sheath, although they may still be associated with Schwann cells, they are not wrapped in layers of myelin. In these axons, the Schwann cells support the axon but do not provide the same insulating properties.

the nerve impulse travels continuously along the axon in a slower process called continuous conduction. The absence of myelin means the signal moves more gradually.

Signals move much slower, typically around 0.5 to 2 m/s. These are involved in slower processes, like transmitting pain or regulating internal organs.

require more energy because the entire length of the axon must propagate the action potential, leading to more ion movement and increased activity of sodium-potassium pumps.

are typically involved in slower processes, like regulating body functions (e.g., digestion, heartbeat) or transmitting chronic pain signals.

Are generally smaller in diameter, which also contributes to their slower conduction speed.

Question 39

Meninges and the layers

Answer 39

Protectice layer between the brain and spinal cord. Dura, arachnoid, pia

Question 40

PNS

Answer 40

includes all the nerves outside the brain and spinal cord, has a much greater capacity for regeneration.

Question 41

CNS

Answer 41

includes the brain and spinal cord, has a very poor capacity for regeneration.