Nervous system and endocrine system Flashcards
What are Dendrites?
Branch like structures that receive an impulse from other neurons or a sensory receptor.
What are Nodes of ranivier?
Gaps between the myelin sheath which helps to speed up the transmission of the electrical impulses by allowing it to jump from node to node.
What are axon terminals?
At the end of an axon and they communicate the electrical impulses to the next neuron across a gap called a synapse.
What is the cell body(soma)?
The dendrites are connected to the cell body.
What is the axon?
Carries the electrical impulses from the cell body to the axon terminal.
What is the nucleus?
Contains all the genetic material for the neuron?
What are sensory neurons?
Receives impulses and carry them from the sense organs(eyes ,nose, ears, tongue , skin)to the spinal cord or the brain.
What are Relay neurons?
Connect sensory and motor neurons and interpret the impulse’s
They are only found in the brain and spinal cord.
What are motor neurons?
Carry impulses from the brain and spinal cord to the muscles or glands(effectors)
What is the function of the sensory neuron?
Transmits impulses from receptor cells to CNS.
What is the structure of sensory neurons?
Cell body
Long dendrites
Short axon
What is the role of dendrites in the sensory neurons?
Form synapses with the receptor.
What is the role of axon terminals in the sensory neurons?
Form synapses with relay neurons.
What is the function of relay neurons?
Connect sensory and motor neurons to form nerve circuits.
What is the structure of relay neurons?
Cell body
Short dendrites
Short axon
What are the role of dendrites in relay neuron?
Form synapses with sensory neurons?
What are the role of axon terminals in relay neurons?
Form synapses with motor neurons
What is the function of the motor neuron?
Transmits impulses from the CNS to effector.
What is the structure of motor neurons?
cell body
short dendrites
long axon
What is the role of dendrites in motor neurons?
Form synapses with the relay neurons
What is the role of axon terminals in motor relays?
Form synapses with effectors.
Where is the location of sensory neurons?
PNS
Where is the location of relay neurons?
CNS
Where is the location of motor neurons?
PNS
1.Impulse is received by dendrite of neuron
2.Neuron changes from negatively charged to positively charged for 1m/s
3.Creates electrical impulse which is called axon potential
4.Travels through cell body along axon to axon terminal
5.
What is the process of synaptic transmission?
-When electrical signal (action potential) reaches the axon terminal of the presynaptic neuron, it triggers vesicles.
-These are tiny sacs with chemicals that are called neurotransmitters.
These fuse with the presynaptic membrane and release their neurotransmitters into the synapse
-Then they diffuse across the synapse towards the receiving neuron.
-Then bind with receptor sites on the dendrites of postsynaptic neuron
-These receptor sites are Specialized to bind with certain neurotransmitters
-Causes either an excitatory or inhibitory response to occur in the postsynaptic neurons .
-Then neurotransmitters are released from receptors
-Either broken down by enzymes or taken back up to presynaptic neuron for reuse (reuptake)
What are excitatory neurotransmitters and an example?
-Make the post synaptic more likely to fire
-Neurotransmitters ‘on switches’-continue the excitatory/arousal message
E.G noradrenaline binds to the postsynaptic receptors which will cause an electrical charge in the cell membrane
What are inhibitory neurotransmitters and an example?
-Make them less likely to fire
-if an inhibitory neurotransmitter like GABA binds to the post-synaptic receptors it will result in an inhibitory post-synaptic potential (IPSP), which makes the post-synaptic cell less likely to fire.
-nervous systems ‘off switches’ as they inhibit/reduce the activation of certain neural pathways
What is the autonomic system responsible for?
Vital functions such as heart rate,breathing,digestion and sexual arousement
What is the main role of the peripheral nervous system?
Transmits messages through neurons
What is the role of the semantic system?
-Receives information from senses and transmits to CNS
-Transmits info from CNS to direct movement of muscles
What gland releases the hormone melatonin?
Pineal
What are the main differences between the endocrine system and the nervous system?
Endocrine:
Chemical messengers
Long lasting effects
More permanent and wide
Takes longer
Nervous
Electrical impulses
Short lived
Quick
Temporary and localised
What happens during flight or fight response?
-hypothalamus triggered
-sympathetic branch of ANS activated
-Adrenal medulla (within adrenal gland) secretes the hormone adrenaline
-Adrenaline is a hormone responsible for getting the body ready for action
-Adrenaline produces bodily changes associated with flight or fight response
-parasympathetic branch of ANS activated
What is the role of the spinal cord?
Extension of brain/transports messages to and from brain to peripheral nervous system/responsible for reflexes
What is the Order from stimulus to response?
Stimulus-receptor-sensory-relay-motor-effector-response
What is the myelin sheath?
-Fatty layer
-protects the actor axon and speeds up electrical transmission of the impulse
Little gaps segmented
What are terminal buttons?
Communicate with the next neuron in the chain across a gap known as a synapse
What is the process of electric transmission in simple terms?
Resting state=negatively charged cell
Stimulus activates neuron=inside becomes positively charged
Action potential occurs
Electrical impulse is created
What is the process of chemical transmission?
-Electrical impulse travels along the axon of a transmitting neuron
-Causes the presynaptic neuron to release chemical messengers called neurotransmitters from presysnaptic vesticles
-These chemical diffuse across the synapse and bind to receptor sites on the postsynaptic neuron
-The chemical message is then converted back into an electrical impulse and the message continues to next neuron in the chain
-The neurotransmitters are reabsorbed into the presynaptic neuron once they have conveyed the impulse to the next neuron.
Name all the different facts about neurotransmitters.
-Chemicals that diffuse across the synapse to the next neuron in the chain
-postsynaptic receptor site
-conversion of chemical message to electrical impulse
-each neuron transmitter fits perfectly into a receptor’s
-each neurotransmitter has a specific function e.g acetylcholine makes muscles contract.
What is the function of the pituitary gland?
Stimulates ovaries to produce oestrogen and progesterone
Stimulates the testes to produce testerone and sperm
What is the function of ovaries?
To regulate the menstrual cycle
What is the role of the testes ?
Development of internal and external male genitalia
Muscle growth
What is the role of the pineal gland?
Regulates the wake sleep cycle
What is the role of the andrenal gland?
Produces the flight or fight response
What is the role of pancreas and what hormones does it produce?
Regulates blood sugar levels
Insulin and Glucagon
