Nervous Tissue

Question 1

What are the two constituents of the cells in nervous tissue?

Answer 1

Neurons & Neuroglia

Question 2

Where is the nervous tissue found?

Answer 2

Found in brain and spinal cord

Question 3

Why does injuring the network may be harmful?

Answer 3

no replacement for damaged cells for neurons - they do not divide

Question 4

What are the transmission times for neurons?

Answer 4

0.5-130m/s

Question 5

Name the three regions of a neuron

Answer 5

Receptive, conducting & secretory

Question 6

What is the cell body called?

Answer 6

Soma - includes the nucleus + mitochondria

Question 7

What is the receptive area of neurons?

Answer 7

Dendrites - receive information in the form of a chemical signal or an electrical signal

Question 8

What does the axon do in the neuron?

Answer 8

Propagates the electrical current/signal -

Question 9

What are the sensory neurons?

Answer 9

They transmit sensory receptors - signals to CNS

Question 10

What are motor neurons?

Answer 10

Transmit impulses from CNS to effector organs (muscles + glands)

Question 11

Name the 2 functional neurons

Answer 11

Sensory & Motor neurons

Question 12

What is the acronym for neurons

Answer 12

Sensory = Afferent; Motor = Efferent

Question 13

What does afferent mean?

Answer 13

Towards the CNS

Question 14

What does efferent mean?

Answer 14

Away from the CNS

Question 15

What pathway is the sensory neurons

Answer 15

To the CNS

Question 16

What pathway is the motor neurons?

Answer 16

Away from CNS

Question 17

What is the myelination of axons?

Answer 17

Electrical insulation of the axon

Question 18

What does the myeline do?

Answer 18

Allows faster conduction compared to non myelinated axons

Question 19

What is schwann cells?

Answer 19

Schwann cells serve as the myelinating cell of the PNS and support cells of peripheral neurons. A Schwann cell forms a myelin sheath by wrapping its plasma membrane concentrically around the inner axon

Question 20

What is oligodendrocytes?

Answer 20

Organise themselves in a different way -
the myelinating cells of the central nervous system (CNS). They are the end product of a cell lineage which has to undergo a complex and precisely timed program of proliferation, migration, differentiation, and myelination to finally produce the insulating sheath of axons.

Question 21

What is a synapse?

Answer 21

A place where information is transmitted from one neuron to another - can be electrical/chemical

Question 22

How do we activate neurons?

Answer 22

Excitable cells - responsive cells - generates electrical changes across cell membrane

Question 23

What is a concentration gradient?

Answer 23

Difference in conc of a molecule between one side of plasma membrane and the other - inside compared to outside - chemical driving force that drives for the net force

Question 24

What is an electrical gradient?

Answer 24

Difference in concentration of ions between the sides of the plasma membrane
- called resting membrane potential difference

Question 25

What is electrochemical gradient?

Answer 25

Combo of concentration + electrical gradient

Question 26

What do neurons possess?

Answer 26

A resting membrane potential

Question 27

What do we have to remember abt the structure of the neuron?

Answer 27

Thin layer of positive charge outside the membrane + negative charges inside the membrane

Question 28

What is resting membrane potential measured in?

Answer 28

Volts (V) or millivolts (mV)

Question 29

What are the changes in ion permeability?

Answer 29

They change the membrane potential for physiological responses

Question 30

When do the membrane potential diff increase

Answer 30

They increase when there is an influx of positive ions into the cell

Question 31

What is a neuroglia?

Answer 31

Any of the cells that hold nerve cells in place and help them work the way they should. The types of neuroglia include oligodendrocytes, astrocytes, microglia, and ependymal cells. Also called glial cell.