Anatomy: Nervous System

Question 1

What is the CENTRAL Nervous System?

Answer 1

Located in brain and nerves
Integrates information and generates responses; involved in conscious thought and reflexes.

Question 2

What is the PERIPHERAL Nervous System?

Answer 2

Located outside CNS (Spinal Nerves & Cranial Nerves)
Transmits Sensory info back to the CNS
Controls involuntary functions (via the autonomic nervous system) and voluntary movements (via the somatic nervous system).
MOTOR OUTPUT

Question 3

What is the Sensory (Afferent) Division of the PNS, what does it consist of and what are their functions?

Answer 3

Consists of Somatic Sensory Division and Visceral Sensory Division.
Somatic: Carries general sensory signals from muscles, bones, joints, and skin to the CNS.
Visceral: Carries signals from ORGANS to the CNS.

Question 4

What is the Motor (Efferent) Division of the PNS, and what does it consist of and what are their functions?

Answer 4

Consists of Somatic Motor Division, and Autonomic Nervous System.
Somatic: Carries Signals from the CNS to the skeletal muscles to perform an action. (voluntary)
Autonomic: Carries signals to smooth muscles, cardiac muscles, and glands. (involuntary)

Question 5

What are Neurons?

Answer 5

Fundamental building unit of the Nervous System; Conducts electrical pulses.

Question 6

What are the Dendrites of the Neuron?

Answer 6

The receptive region that receives the signals from other cells.

Question 7

What is the Axon of the Neuron?

Answer 7

Conducting region, sends electrical signal.

Question 8

What is the Axon Terminal of the Neuron?

Answer 8

Secretory region, sends or SECRETES chemical signal to the cell.

Question 9

Can Neurons undergo Mitosis after being damaged?

Answer 9

NO, instead, astrocytes go to fill in for that tissue.

Question 10

What are Astrocytes? (Neuroglial Cells) (CNS)

Answer 10

Glial Cells that provide structural support to neurons in the brain and spinal cord.
Creates Blood-Brain Barrier.

Question 11

What are Oligodendrocytes? (Neuroglial Cells) (CNS)

Answer 11

Glial Cells are produce Myelin, a fatty substance that insulates neuronal axons, facilitating faster electrical signal transmission.
They create Myelin Sheets around the neuron, increasing the speed of nerve impulse conduction.

Question 12

What are Microglial Cells? (Neuroglial Cells) (CNS)

Answer 12

Immune Cells, digest pathogens through Phagocytosis.

Question 13

What are Ependymal Cells? (Neuroglial Cells) (CNS)

Answer 13

Cells that line the spaces in the brain (ventricles) and the central canal of the spinal cord.
Produce cerebrospinal fluid (CSF), which cushions and protects the brain and spinal cord.

Question 14

What are Schwann Cells? (Neuroglial Cells) (PNS)

Answer 14

Cells that wrap around the axons of peripheral neurons to form myelin sheaths

Question 15

What are Satellite Cells? (Neuroglial Cells) (PNS)

Answer 15

Similar to Astrocytes, but simply surround and support Neuron Cell Bodies.

Question 16

What are Leak Channels?

Answer 16

Channels that are always opened and don’t need a stimulus to open.

Question 17

What are Voltage-Gated Channels?

Answer 17

Receives an action potential which leads to the release of something that is due to the opening of this channel.

Question 17

What are Ligand-Gated Channels?

Answer 17

Chemical messenger binds to channel, and When Ligands bind, channel opens

Question 18

What are Mechanically-Gated Channels?

Answer 18

Ion channels that respond/open to physical forces acting on the cell membrane.

Question 19

What is an EPSP?

Answer 19

Excitatory Postsynaptic Potential
A temporary depolarization of the postsynaptic membrane potential due to the influx of positively charged ions (usually sodium, Na⁺).
Increases in the likelihood of an action potential.

Question 19

What will happen if Myelin was lost on an Axon? Give an example.

Answer 19

Higher energy demands, and various neurological symptoms, significantly affecting the function of the nervous system.

Example: Multiple sclerosis (MS) – patients may experience a range of symptoms, including weakness, sensory disturbances, coordination problems, and cognitive issues.

Question 20

What is an IPSP?

Answer 20

Inhibitory Postsynaptic Potential
A temporary hyperpolarization of the postsynaptic membrane potential, making it less likely to fire an action potential.

Question 21

What is Spatial Summation?

Answer 21

Involves simultaneous stimulation from multiple neurons, leading to combined effects on the postsynaptic neuron.

Question 22

What is Temporal Summation?

Answer 22

Involves repeated stimulation of the same neuron over a short period, leading to cumulative effects.