Week 6 Flashcards
what are the two types of nervous systems and what parts of the body are they in?
central nervous system - brain and spinal cord
perpheral nervous system - rest of the body
what are the 3 stages of stimulus in the nervous system?
integration - food smelt
coordination - decide if thats what you, want, are you hungry, prep to eat
response - eat the food or walk away.
what are the two cells in the nervous systems?
neurons and glias
what are the 2 features of neurons?
- cells specialsed for transmission of info
- come in 4 morphological types
what are the 3 features of glia nerve cells?
- they support neurons
- come in 5 basic types (4 in CNS, 1 in PNS)
- each type has a specific function
what are the 4 strutural components of neurons?
Dendrites (receive input, send info to cell body)
Cell body (contains nucleus and organelles, sums input/collects)
Axon (carries electrical impulses, may or may not myelinated)
Axon terminals (end of axon, neurotransmitter release)
What are the organisational terms lf the CNS?
group of cell bodies - nucleus bundle of axons - tract In cerebral cortex and spinal cord: Groups of cell bodies - grey matter Bundles of axons - white matter
what are the organisation terms in the PNS?
groups of cell bodies: ganlion/ganglia
bundles of axons: nerves
function components of neurons:
input, summation, conduction and output
what is the input zone fo the neuron?
dendrites and cell body. recieves chemical signals from other neurons.
what is the summation zone of the neuron?
axon hillox. decides whether or not to transmit signal further.
what is the conduction zone of the neuron?
axon. carries electrical signals between brain areas/to and from spinal cord/to and from prepheral sensory receptors.
what is the output zone of the neuron?
axon terminal. contact with input zone of other neuron s or effectors. release of neurotransmitters (chem signals)
what is the rule for type of chemical amongst cells?
within the cell - electrical
between cells - chemical
what are the 4 morpological types?
- mulitpolar
- bipolar
- unipolar
- anaxonic
explain the multipolar type of neuron:
multiple processes that emanate from the cell body
explain the bipolar type of neuron:
2 processes that emanate from the cell body (input zone + conduction/output zones)
explain the unipolar type of neuron:
one process emanates from the cell body. it branches out so one end becomes the dendrite/input zone, the opther end is the axon/output.
explain the anaxonic type of neuron:
axonless, all processes look the same so it is hard to tell where the input and out are.
what are the 4 types of CNS Glia cells?
- astrocytes
- microglia
- ependymal
- oligodendrocytes
astrocytes (3)
- supplies nutrients to neurons
- ensheaths blood capilaries
- transmits info
microglia (3)
- immune cells of CNS
- makes sure everything is tidy and in order
- engulfs microrganisms and debris
ependymal (2)
- they line fluid filled spaces of brain and sponal cord
- have hair like cilia to circulate cerebral spinal fluid.
oligodendrocytes (3)
- has many processes
- supports nerve fibres
- ensheaths nerve fibres in myelin
what is the PNS glia type and what does it do?
schwann cells:
- supports peripheral nerve fibres
- ensheaths them in myelin
- similar to oligodendrocytes in CNS
Myelin sheath (4)
- lipid (fat) wrapped around axon many times
- comes from oligdendrocytes in CNS, schwann cells in PNS
- increases velocity (speed) of the conduction of the electrical impulse down the axon.
- myelin sheath increases velocity, and so does then ranvier nodes (gaps in between myelin).
presynaptic neuron (2)
: contains synaptic vesicles (little packets of neurotransmitters)
: releases neurotransmitters (chem signal)
postsynaptic neuron (1)
: contains receptors for neurotransmitters
what does afferent mean?
afferent ascending: info into brain from around us
efferent/descending: response out of the brain to body
flow of info in the nervous systems:
update
name the features of somantic information:
thiings we have control over and are aware of.
- voluntary muscle control (skeletal muscle) [somatic EFFERENT eg.run]
- sensory info we are aware of [AFFERENT eg. seeing]
name the features of autonomic information:
things we are not aware of and dont control.
- involuntary muscle control [autonomic EFFERENT eg. heart beat]
- sensory info we cant control [automic AFFERENT eg. blood pressure]
what does efferent and afferent mean?
motor and sensory
what is the structure of tge somatic efferent division?
2 neurons between brain and effector (skeletal muscle)
- uppor motor neuron (command) CB in CNS brain, axon in CNS spine
- lowere motor neuron (action) CB in CNS spinal cord, axon in spinal nerve PNS. contracts effectors, ends in NMJ and uses ACh.
what is the structure of autonomic efferent divisions?
split into sympathetic and parasympathetic.
3 neurons between brain and effector.
1. CNS to CNS
2. CNS to PNS (axon myelinated)
3. PNS to PNS + effector (axon unmyelinated)
explain the location and structure of each of the neurons in the parasympathetic autonomic efferent division.
N2: CB in CNS (brain or sacral in spinal cord) LONG axon in PNS ending at autonomic ganglion. Axon is myelinated. [ACh] PREganglionic neuron.
N3: CB in PNS (autonomic ganglion) SHORT axon close to effector. Axon is not myelinated [ACh] POSTganglionic neuron.
what are the effectors?
somatic: skeletal muscle
autonomic: smooth muscle, cardial muscle, glands, adipose (fat) tissue.
explain the location and structure of each of the neurons in the sympathetic autonomic efferent division.
N2: CB in thorcolumbar level of spinal cord (thoracic or lumbar) SHORT axon ends at sympathetic ganglion chain in PNS. Axon is myelinated. [ACh] PREganglionic neuron.
N3: CB in PNS sympathetic ganglion chain. LONG axon ends in PNS at effector. Axon is not myelinated. [NE] POSTganglionic neuron.
why is N3’s axon umyelinated
becasue the axons are so small in order to have finer control of the effector that being myelinated makes so difference in speed.
what are the 2 neurotransmitters used?
ACh - acetylcholine
Ne - norepinephrine
ganglion/ganglionic =
in the PNS
What are the functions of the autonomic sympathetic system?
Fight or flight, prepares body for acute stress responses. Includes: - increased heart rate - sweat - pupils enlarged - less salivation - less gastric mobility - constricting blood vessels, more blood flow to muscles
What are the functions of the autonomic sympathetic system?
Rest and Digest. includes: - descreased heart rate - more gastric mobility - pupils smaller - more salivation
