Neurones - Cells and Tissues of the nervous system Part 1 Flashcards
What are the 2 parts of the CNS?
brain and spinal cord
What is the role of the PNS?
takes information to the CNS and takes commands from the CNS to the periphery
What nerves are involved in the PNS?
the 12 pairs of crania nerves and the 33 pairs of spinal nerves
What are the 2 sub-divisions of the PNS?
sensory (afferent) division
motor (efferent) division
How can the motor (efferent) system be divided?
somatic motor and autonomic
How can the autonomic NS be sub-divided?
sympathetic and parasympathetic
What 2 types of cells make up the NS?
Neurones
glial cells
Name the gold and purple cells?
gold = neuron
purple = glial cells
What is a neurone, and what are the cells like?
structural and functional unit
excitable cells
impulses carries as AP
What is a glial cell?
non-excitable supporting cell
What is larger a neurone or a glial cell?
neurone much larger
multiple dendrites and one axon
What happens at the end of an axon?
synaptic terminals
Which of these choices describes a typical neurone?
- in only one direction from the cell body to synaptic terminal
Why are the neurone different which carry motor and sensory information?
as the AP can only be transmitted uni-directionally
Describe the nucleus of a neurone?
loose chromatin
prominent nucleolus
What are the cell organeeles of a neurone?
mitochondria, rER, diffuse golgi app
what are rER called and why?
Nissl bodies
they appear as a dark stain
Does the neuronal cell body have a high or low metabolic rate?
High, uses up a lot of glucose
What is the cytoplasm called in the cell body?
perikaryon
What is the cytoplasm called in the axon?
axoplasm
Are neurones short or long lived?
long living
Are neurones amitotic or mitotic?
amitotic
if you lose a neurone, they are lost forever
What are the 3 types of neurones?
multipolar
bipolar
pseudounipolar
What neurones are multipolar neurones?
interneurons
motor neurones (NS to periphery)
What is the advantage of a pseudounipolar neuron?
AP can go straight through bypassing the cell body
What type of neurone are sensory neurones?
pseudounipolar
What neurones are bipolar?
CNI
CNII
Where does the cell body of a multipolar neurone lie?
in the CNS
motor neurones
What does the cell body of pseudounipolar neurones form?
form the dorsal root ganglia of spina cords
form ganglia of cranial nerves
What is the term for increased induction due to the myelin sheath?
saltatory conduction
Why does the myelin sheath speed up conduction?
the AP skips from one node to another instead of going all the way through the axon
What are 2 forms of neurones? (myelin sheath)
myelinated neurones
non-myelinated neurones
What cells form the myelin sheath in the PNS?
Schwann
What cells form the myelin sheath in the CNS?
Oligodendrocytes
Why is the myelin sheath important?
multiple sclerosis
patchy loss/scarring of myelin sheath (demylenation) causes nerve conduction across axon abnormal
