Exam 1 Week 2: ppt 1 Cells Basics

Question 1

• Four types of cells in nervous system

Answer 1

1. – Neuron: the individual neuron is the genetic, anatomic, functional, and trophic unit 2. – Neuroglial cells: play a variety of roles in support, injury, and disease of the nervous system 3. – Neuroblasts – ability to reproduce & differentiate into new neurons 4. – Non-neuron & non-glial cells – capillary endothelial cells

Question 2

how many connections between neurons are there in the brain?

Answer 2

• It is estimated that there are 10-100 trillion connections between neurons

Question 3

does the complexity of neural activity in the brain come from a large number of neurons or a large number of connections between neurons?

Answer 3

Large number of connections between neurons

Question 4

Do neurons have the capacity to divide?

Answer 4

there is a lack of mitotic activity in mature neurons (they can’t divide), but there are neuroblasts ( Capable of division & neurogenesis ) in some areas of the brain (the subgranular zone of dentate gyrus of the hippocamus where new granule cells are generated; and the Subventricular zone (SVZ) of the lateral ventricles where new neurons are generated to become interneurons in the olfactory bulb )

Question 5

neuroblasts

Answer 5

* Capable of division (reproduction of themselves) & neurogenesis – formation of new neurons * are Found in * Subgranular zone (SGZ) of dentate gyrus of the hippocampus where new dentate granule cells are generated * Subventricular zone (SVZ) of the lateral ventricles where new neurons are generated to become interneurons in the olfactory bulb

Question 6

Two place neuroblasts are found

Answer 6

1. Subgranular zone (SGZ) of dentate gyrus of the hippocampus where new dentate granule cells are generated 2. Subventricular zone (SVZ) of the lateral ventricles where new neurons are generated to become interneurons in the olfactory bulb

Question 7

Why do we have Neurogenesis in the Dentate gyrus?

Answer 7

the thought is that new memory formation and consolidation of memory in this area can utilize the formation of new neurons, although new neurons are not required for that to occur

Question 8

why do we have neurogenesis in the olfactory bulb?

Answer 8

the thought is that there is an enhancement of olfactory memories or enhanced olfactory discrimination as a result of the neurogenesis

Question 9

what does recent evidence in animals suggest about astrocytes?

Answer 9

– Recent evidence in animals suggest astrocytes can be reprogrammed into neuroblasts which can develop into functioning neurons in brain and spinal cord

Question 10

Does repair from damage involve formation of new neurons?

Answer 10

Repair from Damage does not involve formation of new neurons but rather the formation of new connections between neurons

Question 11

What two things results in the complexity of connections between neurons?

Answer 11

1. the precise connectivity patterns and 2. the Ability to change is in connections or in connecting neurons

Question 12

What are the unique functions of neurons (as opposed to glial cells) (2)

Answer 12

1. – Communication between neurons 2. – Integration of neural information

Question 13

What are 3 roles that nerve cells share with glia?

Answer 13

1. – Overall excitability of nervous system 2. – Local regulation of transmitter availability 3. – Regulation of strength of communication and connection

Question 14

Three structural classifications of neurons

Answer 14

1. Multipolar neurons 2. Bipolar neuro 3. Unipolar neurons

Question 15

Unipolar/Pseudo-unipolar neuron: What is it and where is it found?

Answer 15

One of three structural classifications of neurons 1. – Single process extending from the soma 2. – Found in sensory spinal nerves, some cranial nerves & cerebellum

Question 16

Bipolar neuron: What is it and where is it found?

Answer 16

One of three structural classifications of neurons 1. – Two processes extending from the soma 2. – Found in the retina and in cranial nerves I and VIII 3. – Cortical spindle neurons

Question 17

Multipolar neuron: What is it and where is it found?

Answer 17

One of three structural classifications of neurons – Three or more processes extending from the soma – Multiple dendrites & single axon – Numerous throughout the nervous system

Question 18

Three main functional classification of neurons

Answer 18

1. Sensory (afferent; ascending) 2. Motor (efferent; descending) 3. Interneurons (internucial) neurons that connect other neurons * Long projection - commissural * Short projection - local circuit

Question 19

Two types of Interneurons

Answer 19

1. Long projection - Commissural 2. Short projection - Local circuit

Question 20

Can neurons be classified as excitable or inhibitory?

Answer 20

Yes. There is two classifications: 1. – Excitatory – increases the activity of neurons that it activates 2. – Inhibitory – decreases the activity of neurons that it activates