Endocrine system: basics Flashcards
What is the nervous system divided into?
The peripheral (PNS) and central (CNS) nervous system
What is the CNS made of?
The brain and spinal cord
Label the diagram
What nerves take information into and out of the brain?
Afferent = into the brain (FYI remember it as info ‘arrives’ at the brain)
Efferent = out of the brain (remember it as info ‘exits’ the brain)
What are the two types of efferent nerves?
Somatic and autonomic neurons
What is the difference between Somatic and autonomic neurons?
Somatic are voluntary and control skeletal muscle, autonomic are involuntary and control cardiac muscle, smooth muscle and glands
What systems make up the autonomic system?
The sympathetic and parasympathetic systems
Label the diagram
Label the diagram
What do schwas cells do?
They myelinated individual axons or support multiple unmyelinated axons in the PNS
What do axon terminals do?
They interact with other nerves or tissue
Label the diagram, what is it?
A snapse
Where is the Synapse located?
At the end of axon terminals
How do the pre and post synaptic neuron communicate? What is communication between them?
By neurotransmitters
The pre-synaptic neuron causes the post-synaptic neuron to produce an AP
Explain the steps of how the pre and post synaptic neuron communicate
1 - An action potential goes down the pre-synaptic neuron
2 - The action potential changes the structure of the voltage gated Ca2+ channel allowing Ca2+ to go into the synaptic bulb
3 - The Ca2+ in the synaptic bulb causes the synaptic vesicles which contain neurotransmitters to bind to the surface of the pre-synaptic neuron and release the neurotransmitters
4 - The neurotransmitter then acts on the ligand gated post-synaptic receptors allowing Na2+ into the cell
5 - The influx of Na2+ depolarises the post-synaptic neuron causing an action potential
What is the alarm response associated with?
Exercise, emotion and excitement
What is the relaxation response associated with?
Repletion, rest and relaxation
What are the signs of an alarm response? What does each response allow?
(Learn at least 4 of them)
- Heart: has increased rate and force of contraction (increased physical capabilities)
- Skin: contraction of arrector pili muscle (i.e. hair stand up for increased cooling ability)
- Dilation of pupils (get more visual info in)
- Decrease salivation and digestion (energy directed to movement)
- construction in blood vessels especially in the skin (more blood for the necessary organs [i.e. muscles, brain…])
- dilation of the bronchi (get more O2 in)
- Increased blood sugar from liver (more energy to do work)
- Increased blood pressure and water retention (greater nutrient exchange)
What are the signs of a relaxation response?
(Learn at least 4 of them)
- Decreased rate and force of heart contraction
- Contraction of pupils
- Increased salivation
- Dilation of peripheral blood vessels
- Increased digestion
- Constriction of bronchi
What controls the alarm and relaxation responses?
Alarm = Sympathetic system
Relaxation = Parasympathetic system
What are the sensory inputs for autonomic and somatic nervous systems?
Autonomic: Mainly interceptors (i.e. internal sensing)
Somatic: Special and somatic senses
What are the controls of output for autonomic and somatic nervous systems?
Autonomic: Involuntary from the limbic system, hypothalamus, brain stem and spinal cord
Somatic: Voluntary from the cerebral cortex
What are the motor neurone pathways for autonomic and somatic nervous systems?
Autonomic: Two neuron pathway (i.e. pre and post ganglion)
Somatic: One neuron pathway
What are the neurotransmitters for autonomic and somatic nervous systems?
Autonomic: Acetylcholine and norepinephrine
Somatic: Acetycholine
