Chapter 12 A&P Flashcards
What does the nervous system do?
Primary communication and control system.
-Collects info
-Processes and evaluates info
-Initiates response to information
How does the nervous system collect information?
Through receptors
What does stimuli do?
Monitor changes in external and internal environment
What are the nerves called that initiate responses?
Effectors
What are three effectors?
Muscle tissue
Nerves
Glands
What are the two main divisions of the nervous system?
Central nervous system (CNS)
Peripheral nervous system (PNS)
Which division of nervous system are the brain and spinal cord a part of?
CNS (central nervous system)
What is part of the PNS? (peripheral nervous system)
- Spinal nerves
- Cranial nerves
- Ganglia
What are the two main divisions of the PNS?
Sensory (Afferent)
Motor (Efferent)
What are the two main divisions of the Motor (Efferent) nervous system?
- Somatic Nervous System (SNS)
- Autonomic Nervous System (ANS)
What are the 3 divisions of the ANS? (Autonomic Nervous System)
- Sympathetic
- Parasympathetic
- Enteric
What does the word “enteric” ALWAYS refer to?
Digestive organs
What does “soma” mean?
Body
Which sensory do we consciously perceive?
Somatic Sensory
(eyes, ears, nose, skin, etc)
Which sensory do we NOT consciously perceive?
Visceral Sensory
(Blood vessels, internal organs)
What does “visceral” mean?
Organs
What does “motor” mean?
Movement
Which motor refers to the voluntary skeletal muscle control?
Somatic motor
Which motor innervates/regulates cardiac and smooth muscle, and glands without conscious control?
Autonomic motor
What does “afferent” mean?
It is always sending messages towards the CNS.
What does “efferent” mean?
It is always sending messages away from the CNS.
What are the two cell types in the nervous tissue?
Neurons and Glial cells
What do Glial cells do?
Support and protect neurons
What cells in the nervous tissues DO NOT send any messages?
Glial Cells
Which cells are excitable and transmit electrical signals?
Neurons
What is the receiving portion of the neuron? (short processes)
Dendrites
What is the single long process on the dendrite?
Axon
What is the long process called on the axon?
Axon Hillock
What gives rise to side branches in the axon?
Axon collaterals
What do axon collaterals divide into?
Axon terminals
What do axon terminals turn into at the end?
Synaptic end bulbs / Synaptic knobs
What do Synaptic end bulbs/knobs contain?
Numerous synaptic vesicles
What do synaptic vesicles contain?
The neurotransmitter
Do neurons touch any other structures?
No
FYI Neuron
FYI
What do the interneurons do? (association neurons)
What does inter mean?
Facilitate communication between sensory and motor neurons
(This makes up 99% of your neurons!)
Very important to know!
What are most of the nervous system cells?
Glial Cells
What are astrocytes?
Starlike shape from surface projections
What is the “star-cell?”
Astrocytes
(star)(cell)
What is the BBB?
Blood Brain Barrier
-this controls the movement of substances exiting blood and entering the nervous tissue
Where do Ependymal cells line?
Internal cavities of the brain and spinal cord.
Which cell helps produce cerebrospinal fluid? (CSF)
Ependymal cells
What acts as the vacuum cleaner?
Microglia- it removes debris from dead or damaged tissue
What forms the myelin sheath by repeatedly wrapping around an axon?
Oligodendrocytes
What allows for faster action potential propagation through CNS?
Myelin Sheath
FYI
What do satellite cells do?
Regulate the exchange of nutrients and waste products.
What do Schwann cells do?
Ensheathe PNS axons to form myelin sheath
FYI- Myelination
What is myelination?
Process by which part of an axon wrapped in myelin.
What kind of matter does myelin create?
White Matter
What are the gaps between myelin called?
Nodes of Ranvier
FYI- White vs Grey Matter
What does “saltare” mean?
To jump
What happens in Saltatory Conduction?
Nerve signal jumps from node of ranvier to node of ranvier
What two things cause a faster nerve signal?
- Larger diameter of the axon
- Myelination of the axon
FYI
What are four facts about Action Potential?
- Occurs in a nerve
- AKA Nerve Impulse
- Very fast
- Electrochemical communication by neurons
FYI: Details of Action Potential (Drawn by Jenna, YT video Ch 12, Time stamp: 43:18)
https://www.youtube.com/watch?v=L3jiWrdsZJg
What does RMP mean?
Resting Membrane Potential
Ion within the nerve:
Potassium (K+)
Ion outside the nerve:
Sodium (Na+)
FYI
Action potentials can only occur if the membrane potential…
reaches threshold
The 5 steps of Action Potential
Very important, memorize these steps
- Resting Membrane Potential (RMP)
- Depolarization
- Repolarization
- Hyperpolarization
- Resting Membrane Potential (RMP)
What step is the neuron at rest?
RMP
-70mV
What happens in depolarization?
Inside of the cell becomes more positive.
- From -70 mV to +30 mV
- Na+ gates open
- K+ gates closed
What happens in repolarization?
Movement of K+ out of neuron due to K+ gates open
- Na+ gates closed
- Return to RMP (-70 mV)
What happens in hyperpolarization?
K+ gates are open longer than time needed to reestablish RMP
- Na+ still closed
- Inside of neuron briefly more negative than RMP
What do synaptic vesicles release?
Neurotransmitters
Calcium binds to synaptic…
Vesicles
FYI: Synaptic Messages
What are the two different postsynaptic potentials?
Excitatory (EPSP)
Inhibitory (IPSP)
Which PSP (postsynaptic potential) is hyperpolarizing?
Inhibitory
Which PSP (postsynaptic potential) is depolarizing?
Depolarizing
FYI: Summation
FYI:
