MNSR12 Flashcards
The function of a nervous system is:
- To coordinate the activity of the muscles
- To monitor the organs
- To construct and stop input from the senses (sight,
hearing, touch, smell, taste) - To initiate actions
Cells that receive sensations are called
receptors
Cells that make the appropriate response are called
effectors
what is the nervous system divided into
-Central Nervous System (CNS)
*Brain
*Spinal cord
-Peripheral Nervous System (PN.
* All other nerves and neurons
that do not lie within the CNS
Tissues of the body develop from three primary germ layers:
Ectoderm, Endoderm, and Mesoderm
Central Nervous System (CNS)
-Develops from a specialized
region of _______ called the
_______. developement of neural system called ______.
ectoderm,
neural plate
neurulation
Some ______ cells form a hollow
tube in the midline which by day 22-24
forms a solid cylinder of cells (notochord)
mesodermal
the notochord drives
neurulation
what is neurulation
induction of overlying ectoderm to form the neural tube
Malformations of the neural tube are
known as
Neural Tube Disorders (NTDs)
3 Most common tube defects
—Anencephaly (head)
—Encephalocele (Head)
—Spina bifida (spine)
what prevents NTDs
Folic Acid Supplements
what is folic acid supplements
- Supplementation prevents neural
tube defects. - Also known as Natural B vitamin
(vitamin B9). - First isolated from spinach leaves.
- Needed to synthesize DNA bases.
- ~70% reduction in NTDs with
400mg/daily (100% RDA)
periconceptional use. - Also used to alleviate side-effects
of some immunosuppressant
drugs.
what time period is folic acid supplements used
1 month before conception to 12
weeks post-conception.
what does PNS split into
autonomic and somatic
what does autonomic nervous system split into
sympathetic, parasympathetic and enteric
what does somatic nervous system consist of
- Includes all neurons connected with
the muscles, sense organs and skin
which information does somatic nervous system deal with
sensory from sense receptors to spinal chord
where does somatic nervous system control the body movements from
from spinal chord to muscles
neuron Consists of four parts:
- Dendrites
- Soma (cell body)
- Axon
- Synaptic terminal
where is the nucleus located in neuron
soma
what is cytoplasm called in neuron
perikarvon
what does nissl bodies consist of
- Formed of large aggregations
of rough ER - Site of protein synthesis
what are microfilaments and microtubule called in neuron
neurofilaments and neurotubules
where are neurotubules found
Found in the axons and
dendrites
dendrite size
<1 mm
axon size
up to 1 meter
- Longest nerve is the
Sciatic
nerve (ischiatic nerve).
Damage to the Sciatic nerve
called.
sciatica
3 types of neurons+describe them
Pseudo-unipolar - sensory.
Bipolar - specialised. sensory
neurons found in the retina,
inner ear and olfactory
mucosa.
Multipolar - the most
common.
Pseudounipolar structure and function
- Sensory neuron in the PNS
Connects sensory organ to the spinal cord - A single process extending from the soma
- One long dendrite (exception!)
- One short axon
-Connects to the spinal cord - The dendrite of a pseudo-unipolar neuron is structurally and
functionally an axon
-Myelinated
bipolar structure and function
Transmission of specialized senses (e.g. eye)
One dendrite
One axon
Part of the sensory pathway
Smell, sight, taste, hearing and vestibular functions
multipolar structure and function
- Many dendrites
- One single axon (usually long and
may branch) - Large amounts of information
received - Largely based in the CNS
- Motor neurons (efferent)
- Interneurons
what is a ganglia
a mass of
nerve cell bodies and dendritic structures outside of CNS walls
is brain a fusion of many ganglia?
yes
what is a plexus
interconnections between ganglia
to form a complex system of ganglia.
what does a ganglia contain
mainly of somata and
dendritic structures.
what does a galgia network provide
Provide relay points and
intermediary connections between
different neurological structures in
the body, such as the peripheral and
central nervous systems.