Module 12: Neurological System (Part 01) Flashcards
This system is the master controlling and communicating system of the body.
Nervous System
This detects external and internal stimuli.
Sensory Input
This processes and responds to sensory input.
Integration
What are the functions of the nervous system?
(1) Sensory Input - detects external and internal stimuli
(2) Integration - processes and responds to sensory input
(3) Control of Muscles and Glands
(4) Homeostasis is maintained by regulating other system
(5) Center for Mental Activities
what is the central nervous system composed of?
(1) Brain
(2) Spinal Cord (covered by the vertebra, it has nerves or appendages sticking out continously)
What is the peripheral nervous system composed of?
(1) Cranial nerves
(2) Spinal nerves
What are the two (2) anatomical divisions of the nervous system?
(1) Central Nervous System
(2) Peripheral Nervous System
This anatomical division of the nervous system is composed of the brain and the spinal cord. It is encased in bone (skull and vertebra). It also contains nerves and nerve endings.
Central Nervous System (CNS)
This anatomical division of the nervous system is composed of the nervous tissue outside of the CNS. It consists of sensory receptors and nerves. This cannot work on its own (needs receptors or connection).
Peripheral Nervous System (PNS)
What is the function of the Peripheral Nervous System (PNS)?
This acts as “information highway” which detects stimuli and transmits information as well as receive information to and from the CNS.
What is the function of the Central Nervous System (CNS)?
It processes, integrates (analysis or quick response), stores, and responds to information from the PNS.
What happens when the patient is quadriplegic?
The CNS of the quadriplegic patient can solely process information from the PNS but no longer integrate movement; hence the paralysis.
What are the two (2) divisions of the PNS?
(1) Sensory Division
(2) Motor Division
This transmits action potentials from sensory receptors to the CNS (sensations - touch, hear, eyesight etc.). This pertains to the input.
Sensory Division
This carries action potentials away from the CNS in cranial or spinal nerves. This pertains to the output or response.
Motor division
What are the two (2) subdivisions of the motor division?
(1) Somatic nervous system (SNS)
(2) Autonomic nervous system (ANS)
This subdivision of the motor division innervates the skeletal muscle. (soma = means body hence action of the skeletal muscle)
Somatic Nervous System
This subdivision of the motor division innervates the cardiac muscle, smooth muscle and glands (negative feedback). It has three subdivisions. This is important for the sustenance of life. (autonomic = automatic like heart pumping).
Autonomic Nervous System (ANS)
What are the three (3) subdivisions of the Autonomic Nervous System (ANS)?
(1) Sympathetic Division
(2) Parasympathetic Division
(3) Enteric nervous system
This is the most active during physical activity (fight or flight division).
Sympathetic division (For example: burning your hand (automatic response)
This regulates resting functions (rest and digest division).
Parasympathetic division (this balances your sympathetic division)
This controls the digestive system.
Enteric nervous system
Explain the Nervous System in terms of its division and subdivisions.
(1) Sensations (touch, sight, etc.) initiates from the Sensory Division
(2) Through the transmission of the sensations by the sensory receptors, the action potentials convey it to the nervous tissue (peripheral nervous system) to the brain (central nervous system)
(3) The brain sends signals to the action potentials of the PNS wherein it perceives the need for movement (motor division).
(4) Both autonomic (increase in heart rate and blood pressure etc.) and somatic nervous system will respond simultaneously,
(5) The response of the autonomic nervous system may fall under sympathetic, parasympathetic, and enteric)
Explain the Nervous System when you are hiking.
(1) Stimulus (input) - snakes
(2) Sensory division conducts action potentials from the periphery to the CNS
(3) The CNS processes and integrates information, initiates responses and carries out mental activity (interpretation as harmful)
(4) Motor division conducts action potentials from the CNS to the periphery
(4) Somatic Nervous System (prompts you to run from the snake) and the Autonomic Nervous System (causes your heart rate and blood pressure to go up)
What are the two (2) principle cell types of the nervous system?
(1) Neurons
(2) Neuroglia or Glial cells
These are excitable cells that transmits electrical signals. This electrical signal are called action potential
Neurons
These are non-neural cells, “helper cells” that surrounds neurons. It accounts for over half of the brain’s weight
Neuroglia or Glial cells (They are different glial cells in the CNS and PNS or the brain and the spine)
How many glial cells are in one neuron?
6 to 60 glial cells
How many Neuroglia or Glial cells are in the extracellular space?
Less than 20%
What happens when there are no Neuroglia or Glial cells in the neurons/
Without the support, all things will fall apart from the neurons since neurons have to be fed (due to the connection of the glial to the capillary), cushioned, and protected from foreign substances.
Explain the structure of the neurons.
Neuron has high nucleus in the middle and a long tail and have synapses at the end. They have one (1) cell.
Explain the structure of the glial cells.
Glial cells are connected to the axon and dendrites of the neurons (oligodendrocytes, microglia, and astrocyte).
These are cells that receive stimuli and transmit action potentials. It is all over the body from the tip of our finger, ears, etc.
Nerves
This is the primary site of protein synthesis. This is where the nucleus and other organelles is.
cell body (soma)
These are short, branched cytoplasmic extensions of the cell body that usually conduct electric signals toward the cell body. (they are electrically charged). It is the source of connection of the other nerve ending.
Dendrites (input)
These are cytoplasmic extension of the cell body that transmits action potentials to other cells. It connects to the muscle involved.
Axon (output)
Explain the structure of the neuron
(1) There is neck called the trigger zone that is where axon starts where the ATP is transmitted.
(2) Outside layer is called the Schwann Cells which is the protector of neuron, wraps around neurons and this can only be seen in the cell of PNS and not the CNS.
(3) Some (not all) have collateral axon to increase the connection.
(4) Presynaptic terminals are little tiny things that are extended out of the axon
(5) Nucleus contains the RNA and the DNA
These are known as the outside layer and the protector of neuron, wraps around neurons and this can only be seen in the cell of PNS and not CNS
Schwann Cells
This is the breathing part of the cells (oxygen).
Mitochondria
This neuron has many dendrites and an axon.
Multipolar Neuron
This neuron has a dendrite and an axon.
Bipolar Neuron
This neuron has an axon and no dendrites. However, its axon is two-way.
Unipolar Neuron
This neuron has dendrites and an axon. However the dendrites are separated from the axons.
Pseudo-unipolar Neuron
This structure of the neuron contains the nucleus and a nucleolus. This is the primary site of protein synthesis. This is where the Golgi apparatus, mitochondria and other organelles.
Cell body (soma)
Explain the nature of the Cell body (soma)
It has no centrioles (hence it is amitotic in nature). It is not multiplying or dividing in nature (cell division).
What are the clusters of cell bodies called in the CNS?
Nuclei (nucleus)
What are the clusters of cell bodies called in the PNS?
Ganglia (presynaptic ganglion: has dorsal and ventral coordinating to what position it is staying on the spine)
Explain the nature of the cell bodies in the brain (nuclei).
They are found in the gray matter
Where are the myelinated axons found, in gray or white matter?
White matter
This contains the myelinated axons or myelin sheathes.
White Matter
This contains the cell bodies, dendrites, unmyelinated axons, axon terminals and microglia.
Gray Matter
This is the part of the neuron where the axons originates. This is where the action potentials are generated; hence it is important because it is the start of the sensory input
Trigger Zone
This is generated from the trigger zone.
Action potentials.
These are slender processes of uniform diameter; may vary in length from a few millimeter to more than a meter. Usually, there is only one unbranched axon per neuron. This is the one transmits electrical signals first.
Axons (Nerve fibers)
This is called when rare branches are present in the axons.
Collateral Axons
These are the branched terminus of an axon (10,000 or more). The one the gives the output from the action potential and neurotransmitter from the axon which have many. Most of the drugs are based on the neurotransmitter.
Presynaptic Terminal
This is the junction between a nerve cell and another cell may be a muscle or any organ (can be sympathetic or parasympathetic).
Synapse
What are the bundles of axon processes in the CNS called?
Nerve Tracts
What are the bundles of axon processes in the PNS called?
Nerves
These cells provide a supportive scaffolding for neurons (connection). They also segregate and insulate neurons. They guides young neurons to the proper connections. They promote health and growth (neurotransmitters degrade as they age or if diagnosed with conditions like diabetes).
Glial Cells (Helpers or Supporting Cells)
What are the functions of the Glial Cells (Helpers or Supporting Cells)?
(1) Support and brace neurons and blood vessels. (Anchor neurons to their nutrient supplies)
(2) Influence the function of the blood-brain barrier (Mostly Astrocytes). (It means protection of the brain like placenta it is the barrier to protect the fetus. But some still passes like marijuana and cocaine, nicotine as they are too strong to be blocked.)
(3) Guide migration of young neurons
(4) Process substances
a. Mopping up leaked potassium ions (phagocytosis)
b. Recycling neurotransmitter
(5) Isolate damaged tissues and limit the spread of inflammation.
This is the protection of the brain that impedes the permeability of chemicals.
Blood Brain Barrier (But some still passes like marijuana and cocaine, nicotine as they are too strong to be blocked.)
What are the different glial cells in the CNS?
(1) Astrocytes
(2) Microglial
(3) Ependymal Cells
(4) Oligodendrocytes
What are the different glial cells in the PNS?
(1) Satellite cells
(2) Schwann cells
The most abundant, versatile and highly branched. They cling to neurons and their synaptic endings and cover capillaries.
They have a lot of dendrites as well as another axons and they cover capillaries (they support neurons and blood vessels).
Astrocytes
What are the functions of the astrocytes?
(1) Support and brace neurons and blood vessels (Anchor neurons to their nutrient supplies)
(2) Influence the function of the blood-brain barrier (Mostly Erythrocytes) (It means protection of the brain from infection)
(3) Guide migration of young neurons
(4) Process substances
a. Mopping up leaked potassium ions
b. Recycling neurotransmitter (bring it back to the axons)
(Garbage collector to have balance inside and outside)
(5) Isolate damaged tissues and limit the spread of inflammation
Explain the structure of the astrocyte
It has a dendrite connected to the cell body itself, it is wrapped around to the capillaries.
They range in shape from squamous to columnar may are ciliated. They also cover the choroid plexus and generates CSF for moisture. They line the ventricles of the brain and the central canal of the spinal cord.
Ependymal Cells
These constitute glial cells to produce cerebrospinal fluid (CSF).
Specialized Choroid Plexus
(Feeds and keeps the moisture in the brain; The movement of it is because of the cilia)
How does the cerebrospinal fluid (CSF). circulate?
Helps to circulate CSF using their cilia
(Spinal cap for meningitis – when the patient is diagnosed with that, the CSF changes in color)
These are small ovoid cells with spiny processes. It performs phagocytic actions because it engulfs the invader like virus. They look like white blood cells; it tries to clean the bacteria they see.
Microglia
These monitor the health of neurons.
Phagocytes
These cells form myelin sheaths around the axons of several CNS neurons. These are important for the insulation of dendrites and neurons.
Oligodendrocytes
Explain the structure of oligodendrocytes
(1) It has their own nucleus; the layer must be maintained to insulate the dendrites and neurons.
(2) It wraps around the axon of neurons.
Reminder: When oligodendrocytes are thicker the degree of transmission of electrical impulses is stronger