2.1 The Cells of the Nervous System Flashcards Preview

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Flashcards in 2.1 The Cells of the Nervous System Deck (30)
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0
Q

Neurons

A

Receive information and transmit it to other cells

1
Q

Nervous system consists of which kind of cells?

A

Two: neurons and glia

2
Q

Estimated numbers of neurons in humans

A

100 billion

4
Q

Membrane (or plasma menbrane)

A

The surface of a cell. It’s structure separates the inside of the cell from the outside enviroment.

5
Q

Nucleus

A

The structure that contains the chromosomes (DNA; hereditary controll)

6
Q

Mitochondrion (mitochondria)

A

The structure that preformes metabolic activities, providing the energy that the cell requires for all other activities

7
Q

Ribosomes

A

The sites at which the cell synthesize new protein molecules that provide building materials for the cell

8
Q

Endoplasmic reticulum

A

A network of thin tubes that transport newly synthesized proteins and other substances to other locations

9
Q

Motor neuron

A

Has its cell body (soma) in the spinal cord. It recives excitation (arousal, sensation) from other neurons throught its dendrites and conduts impulses along its axon to a muscle.

10
Q

Sensory neuron

A

Neuron that is highly sensetive to a particular type of stimulation, such as light, sound or touch

11
Q

Dendritic spines

A

The short outgrowths that receive incoming information. That information apparently plays a key role in learning and memory

12
Q

Soma ( or cell body)

A

Contains the nucleus, ribosomes, and mitochondria. Most metabolic work of the neuron occurs here

13
Q

Axon

A

Is the neuron’s information sender, conveying an impulse toward other neurons or an organ or muscle

14
Q

Myelin sheath

A

An insulating material that covers vertebrate axons

15
Q

Nodes of Ranvier

A

Also known as myelin sheath gaps, are the gaps formed between the myelin sheaths and can generate electrical activity

16
Q

Presynaptic terminal (or end bulb or bouton/button)

A

Axons many branches each of which swells at its tip. This is the point from which the axon releases chemicals from one neuron and the next

17
Q

Afferent axon (afferent starts with “a” as in admit)

A

Brings information into a structure

Every sensory neuron is this to the rest of the nervous system

18
Q

Efferent axon (efferent starts with “e” as in exit)

A

Carries information away from a structure

Every motor neuron is this from the nervous system

19
Q

Interneuron or intrinsic neuron

A

A nerve cell found within the CNS that acts as a link between sensory neurons and motor neurons

20
Q

Glia

A

Type of cell in the nervous system that, in contrast to neurons, does not conduct impulses over long distances.
The brain has several types with different functions

E.g. Astrocytes, microglia and radial glia

21
Q

Astrocytes

A

Is star-shaped glia and wrap around the presynaptic terminals (button) of a group of functionally related axons. It

  • sends messages
  • remove waste material created when neurons die
  • controll the amount of blood flow to each brain area
  • dilate the bloodvessels to bring more nutrients into the area of heightend activity in some brain areas
22
Q

Microglia

A

Cells that remove waste materials such as viruses, fungi, and other microorganisms.

They function like part of the immune system

23
Q

Oligodendrocytes (OL-i-go-DEN-dro-cytes)

A

In the brain and spinal cord
Specialized type of glia that build the myelin sheaths that surround and insulate certain vertebrate axons (same as the Schwann cells)

24
Q

Schwann cells

A

In the periphery of the body
Specialized type of glia that build the myelin sheaths that surround and insulate certain vertebrate axons (like the oligodendrocyte)

25
Q

Radial glia

A

Guide the migration of neurons and their axons and dendrites during embryonic development. When embryological development finishes most radial glia differentiate into neurons

26
Q

Blood-brain barrier

A

The vertebrate brain does not replace damaged neurons (unlike skin cells and blood cells), so to minimize the risk of irreparable brain damage, the body builds a wall along the sides of the brain’s blood vessels. This wall keeps out most viruses, bacteria, and harmful chemicals

27
Q

Active transport

A

The brain uses a protein-mediated process that expends energy to pump chemicals from the blood into the brain. These chemicals include things like

  • glucose (the brain’s mail fuel)
  • amino acids (the building blocks of proteins)
  • purines
  • choline
  • few vitamins
  • iron
  • certain hormones
28
Q

Glucose

A

A sugar

Vertebrate neurons depend almost entirely on this

29
Q

Thiamine

A

Vitamin B1 that the body needs to use glucose

30
Q

Dendrites

A

Branching fibers that get narrower near their ends. It receives information from other neurons