Nervous Tissue

Question 1

What is the endocrine system responsible for?

Answer 1

Chemical message (hormones) that are secreted into the blood

Question 2

What is the nervous system responsible for?

Answer 2

Electrical and chemical signals, sending messages cell to cell

Question 3

What are the three main functions of the nervous system?

Answer 3

Collecting information
Process and evaluate
Initiate response

Question 4

What are the subdivisions of the nervous system?

Answer 4

Central Nervous System (CNS) brain and spinal cord

Peripheral Nervous System (PNS) cranial nerves, spinal nerves, and ganglia

Question 5

What is a nerve?

Answer 5

A bundle of nerve fibers wrapped in fibrous CT

Question 6

What is a ganglia?

Answer 6

A knot like swelling in a nerve when neuron cell bodies are concentrated

Question 7

What does the sensory division do for the PNS?

Answer 7

Carries signal from the receptors to the CNS

Question 8

What does the Motor division do for the PNS?

Answer 8

Carries the signal from the CNS to the glands and muscles

Question 9

True or false -

Visceral is referring to the internal organs

Answer 9

True

Question 10

________ is related to the skin, muscle, bone and joints

Answer 10

Somatic

Question 11

What does the visceral motor division do?

Answer 11

Signals to glands, cardiac and smooth muscle, visceral responses and reflexes

Question 12

________ which is apart of the ______ ____ ____ is used for calming.

Answer 12

Parasympathetic which is a part of the visceral motor division is used for calming.

Question 13

_____ ______ ______ sends signals to the skeletal muscle which allows for muscle contraction and somatic reflexes.

Answer 13

Somatic motor division

Question 14

What does the visceral sensory division do?

Answer 14

Carriers signals from the viscera to CNS

Question 15

True or false -

The somatic sensory division carries signals from the skin to the CNS

Answer 15

True - the somatic sensory division carries signals from the receptors to the CNS

Question 16

What are the universal properties of neurons?

Answer 16

Excitability (irritation)
Conductivity
Secretion

Question 17

What are other properties of neurons that make them different from other cells?

Answer 17

They have a high metabolic rate - high rate of O2 and glucose consumption
Extreme longevity –> last a lifetime
Nonmitotic (mostly) they do not divide after they mature

Question 18

What are interneurons?

Answer 18

Only found in the CNS and connect the motor and sensory pathways.
They receive signals from many neurons and carry out decision making

Question 19

______ is the body of the nerve cell and control center.

Answer 19

Neurosoma

Question 20

What is found in the neursoma?

Answer 20

Lots of mitochondria needed for energy
No centrioles (mature meurons) no mitosis

Question 21

What is the cytoplasm of the axon called?

Answer 21

Axoplasm

Question 22

What is the plasma membrane of the axon?

Answer 22

Axoteomma

Question 23

What branches off the neurosoma?

Answer 23

Dendrites

Question 24

What is the purpose of the dendrites?

Answer 24

To receives signals.
The more dendrites there are the more information that is getting into the cell.
This is the pathway for reception and processing

Question 25

What structure transmits nerve impulses away from the cell body and towards other cells?

Answer 25

Axon

Question 26

What are the structural classifications of neurons?

Answer 26

Multipolar Bipolar Unipolar Anaxonic

Question 27

What is the difference between a mutlipolar and bipolar neuron?

Answer 27

Multi has one axon with many dendrites, It is the most common in the CNS and makes up motor neurons Bipolar have one axon and one dendrite and are used for sensory. Found in the inner ear, retina and olfactory cells

Question 28

______ neuron has a single process leading away from the neurosoma that branches like a T and makes up sensory cells from skin and organs to the spinal cord

Answer 28

Unipolar

Question 29

______ neurons have many dendrites but no axon and are found in the retina, brain, and adrenal glands

Answer 29

Anaxonic

Question 30

What type of cell is capable of mitosis and outnumbers neurons by 10 to 1?

Answer 30

Neuroglia or Glial cells

Question 31

What are the functions of glial cells?

Answer 31

Protect neurons and help them function Bind neurons together and form framework tissue Guide migrating neurons to their destinations within embryo Insulation - prevents neurons from touching each other which makes the pathways more clear.

Question 32

What type of glial cells is found in the CNS?

Answer 32

Oligodendrocytes Ependymal cells Microglia Astrocytes

Question 33

What do oligordendrocytes do?

Answer 33

They are a large bulb shaped cell that forms myelin sheaths around nerves in the CNS.

Question 34

______ line internal cavities of the brain and secrete and circulate CSF.

Answer 34

Ependymal cells are found in the choroid plexus | Look like cuboidal epithelium but are not.

Question 35

________ are the least abundant of the glial cells and are phagocytes that look for debris and damage.

Answer 35

Microglia

Question 36

What glial cell type is the most abundant?

Answer 36

Astrocytes

Question 37

What are the seven functions of astrocytes?

Answer 37

Supportive framework Blood brain barrier Monitor neuron activity - regulate blood flow Secrete nerve growth factors Stabilizes chemical environment of CNS Adds or eliminates synapse Astrocytosis or sclerosis - neuron damage which forms scare tissue

Question 38

Where are astrocytes found?

Answer 38

Covers the brain surface and most non synaptic regions of neurons in the grey matter.

Question 39

What are the types of neuroglia found in the PNS?

Answer 39

Schwann cells | Satellite

Question 40

What is the difference between Schwann cells and Satellite cells?

Answer 40

Schwann wrap nerve fibers of the PNS to form myelin sheath. This provides insulation and increases speed of impulse Satellite cells surround the neurosoma in ganglia in the PNS, provide electrical insulation, and regulate the chemical environment.

Question 41

What does a myelin sheath do?

Answer 41

Insulates the nerve fiber. think of it as electrical tape.

Question 42

What produces myelin sheath?

Answer 42

Myilination which happens during fetal development and proceeds rapidly during infancy

Question 43

What is the difference between myelin sheaths in the PNS vs the CNS?

Answer 43

The PNS has Schwann cells that wrap around a single nerve fiber. There is no cytoplasm between the layers. The neurolemma is the thick layer on the outermost part of the sheath. This holds the nucleus and the cytoplasm. The CNS has oligrodendrocytes that wrap several nerve fibers. They are unable to move around a fiber like the PNS so the myulination spirals inward.

Question 44

What is the axon hillock?

Answer 44

It is at the base of the neorosoma and is the site where initiation begins.

Question 45

Why is the myelin shealth segmented?

Answer 45

It transfers the signal fast and also like a frog jumping. It is a way to make sure the signal is strong enough because id it is not it will not open the Na+ channel on the next shealth meaning the signal would stop.

Question 46

What are two factors that influence the speed of a signal?

Answer 46

Diameter of the fiber - the bigger it is the faster it is | Presents of myelin - speed signal conduction