CNS & Nervous systems

Question 1

What is the function of Nervous System

Answer 1

Sensory Function
Integrative Function
Motor Function

Question 2

what does the sensory function do ?

Answer 2

detects internal ( Blood acidity) & External stimuli ( rain landing on arm)

Question 3

What does the integrative function do ?

Answer 3

process sensory information &

Makes decisions for appropriate responses

Question 4

what does the motor function do ?

Answer 4

activates effectors through cranial and spinal nerves & Stimulates effectors –> cause muscle to contract and glands to secrete

Question 5

What is in the CNS

Answer 5

Brain & Spinal Cord

Question 6

What is in PNS

Answer 6

Nerves, Cranial Nerves, Spinal nerves, ganglia, sensory receptors,

Question 7

what do Cranial Nerves do ?

Answer 7

Emerge from brain

Question 8

what do spinal nerves do?

Answer 8

emerge from spinal cord

Question 9

what are ganglia?

Answer 9

small clusters of nervous tissue, consisting of neuron cell bodies that are located outside of brain

Question 10

what are sensory receptors ?

Answer 10

Nervous system structures that monitor changes in the external and internal environment

Question 11

what are neurons ?

Answer 11

form complex networks within brain and spinal cord.

Function : Controlling muscle activity, regulating glandular secretions, thinking, remembering, sensing

Question 12

What are Neuroglia?

Answer 12

Support, Nourish , protect neurons, and maintain homeostasis in interstitial fluid.

Question 13

Cell body of Neuron?

Answer 13

Nucleus surrounded by cytoplasm and many typical cellular organelles ( Mitochondria , Golgi complex )

Question 14

what do Nissl Bodies do ?

Answer 14

Its where protein synthesis occurs.

• it is used to replace cellular components
• Regenerates damaged axons in pns

Question 15

What are dendrites ?

Answer 15

receiving or input portions of neuron

Question 16

What is the axon?

Answer 16

propagates impulses toward another neuron, muscle fiber, or gland cell

Question 17

What are schwann Cell?

Answer 17

Form Myelin sheath around axons in PNS

Question 18

What is the Meylin Sheath?

Answer 18

Multilayred lipid and protein layer that covers the axons.

Electrically insulates the axon and increase speed of impulse conduction.

Question 19

What is the neurolemma?

Answer 19

Layer of the schwann cell that encloses the myelin sheath

Question 20

What are the Node of Ranvier ?

Answer 20

gaps in myelin Sheath , between cells

Question 21

Types of Neuroglia in CNS?

Answer 21

1. Microglia
   - Phagocytize microbes and damaged nervous tissue
2. Ependymal Cells
   - produce and assist in the circulation of cerebrospinal fluid
3. Astrocytes
   - help maintain appropriate chemical environment for the generation of impulses
4. Oligoderocytes
   - form and maintain myelin sheath around CNS axons

Question 22

Types of Neuroglia in PNS?

Answer 22

1. Schwann Cells

Question 23

What is gray matter ?

Answer 23

Unmyelinated axons superficial in brain

* Deep in Spinal Cord*

Question 24

What is the White matter?

Answer 24

Presence of myelinated axons from oligodendrocytes

• Deep in brain*
• Superficial in spinal cord *

Question 25

what is agraded Potential ?

Answer 25

Origin: located in dendrites and cell body Types of Channel : Ligand-gated or mechanically gated ion channel Conduction : Short communication Size: Less than 1 mV to More than 50 mV Duration : Long Polarity : Hyper-polarizing OR Depolarization Refractory Period : Not present

Question 26

what are action potentials?

Answer 26

Origin : Arise at trigger points and propagate along axon Type of Channel: Voltage - gated channel for Na+ & K+ conduction : Communication over longer distances Size : all or none , about 100 mV Duration : shorter Polarity : Depolarizing phase ---> repolarizing phase --> Returns to resting membrane potential Refractory period : Present

Question 27

What is the function of cerebrospinal fluid ?

Answer 27

Protects the brain and spinal cord against chemical and physical injury. And Circulation

Question 28

What is the formation of the cerebrospinal fluid?

Answer 28

1. lateral ventricle 2. third ventricle 3. Fourth ventricle 4.

Question 29

What is the function of the brain stem ?

Answer 29

Relay center for processing and controlling involuntary reflexes for vision