Flashcards in Autoendocrine System Deck (114)
What are the two parts of the nervous system?
CNS: Brain and spinal cord
PNS: nerves that go to different parts of the body (cranial and spinal nerves)
What is the CNS made up of?
Brain and spinal cord
What is the PNS made up of?
Nerves that go to different parts of the body from the spinal cord:
Cranial and spinal nerves
What are ganglia?
Some nerves come out from the spinal cord and go out to switching stations to connect with other nerves that go out to other tissues. These switching stations are called ganglia.
What are peripheral nerves?
Very fine nerves that go out to all our tissues in the periphery.
What do we call nerves that bring in information to the CNS?
Sensory (afferent) neurons
What do we call the nerves that go from our brain to our spinal cord to other nerves?
Motor (efferent) neurons
What are the two types of motor neurons?
What do somatic neurones innervate?
What is the autonomic system divided into?
Sympathetic and parasympathetic
What is the purpose of the autonomic nervous system?
To respond to changes in the circumstances.
What does the autonomic system innervate?
Cardiac muscle, smooth muscle and glands
Where do most cell bodies lie?
In the spinal cord
What is a myelin sheath?
Layers of insulation wrapped around some but not all axons.
What would we see if we sliced across an axon with a myelin sheath?
A cell type that strongly associates with the axon called Schwann cell that wraps layers of its membrane around the axon, which is full of a protein called myelin.
What is the function of the myelin sheath?
Insulates the axons so that the nerve impulse will travel along the axon and not diverge out to the sides.
How are unmyelinated axons associated with Schwann cells?
In not such an intimate way. Several axons are associated with a Schwann cell.
How does a synapse occur?
Electrochemical signal travels to knob, and changes the structure of transmembrane proteins so that calcium ions can move into the knob through voltage-gated calcium channels. The calcium ions trigger changes that cause vesicles containing neurotransmitters to move and fuse with the membrane of the presynaptic neurone and release the contents. Neurotransmitters travel across synaptic cleft and bind to receptors on postsynaptic membrane that causes these membrane proteins to change shape leading to sodium ion influx that changes the charge of that region.
When does a synapse occur?
Between two nerves
Between a nerve and a muscle
Between a nerve and a gland
What do nerves do?
Coordinate our actions and bodily functions.
What occurs to the heart, eyes, mouth, lungs, skin, gut, and blood during the alarm response?
Heart: increase rate and contraction force (BP increases)
Eyes: dilate pupils so we are more aware of our surroundings
Mouth: decrease saliva because digestion is not important
Lungs: dilate bronchi and faster breathing
Skin: constrict peripheral blood vessels (more blood pumped into muscles), contract arrector pili muscles, increase sweat secretion to cool body
Gut: decrease digestion
Increase blood sugar for more energy.
Increase blood pressure and water retention.
What happens during the relaxation response?
Heart: decrease rate and contraction force
Eyes: contract pupils
Mouth: increase saliva
Lungs: constrict bronchi
Skin: dilate peripheral blood vessels
Gut: increase digestion
What is the fight, flight, freeze response?
Once we sense a potential threat, our body responds with a chain of reactions. First, it activates the sympathetic autonomic nervous system. The brain sends an electrical signal to the adrenal glands which flood the body with adrenaline. This initiates a short term energy burst needed to respond to the emergency.
How long does the alarm response take?
What is the collective name for the responses due to different situations?
What is another name for autonomic?
What does the autonomic system control?
Body's internal responses
What are the two divisions of the autonomic nervous system?
Sympathetic and parasympathetic
What is the sympathetic division of the autonomic nervous system associated with?