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
These cells form a myelin sheathe around part of the axons of a PNS neuron. In this, there is a node of Ranvier (periodic gap in the insulating sheath (myelin) on the axon of certain neurons)
Schwann Cells
These cells support and nourish neuron cell bodies within ganglia. (Covers the neural cell body)
Satellite cells
These are the plasma membrane of Schwann cells or Oligodendrocytes that repeatedly wraps around a segment of an axon to form the myelin sheath.
Myelinated Axons
What are the myelin made up of?
Schwann cells (PNS) or Oligodendrocytes (CNS)
This is the whitish, fatty (protein lipid) segmented sheathe around most long axons.
myelin (provides insulation)
What are the functions of the myelin?
(1) Protect the axon
(2) Electrically insulate fibers from one another
(3) Increases the speed of nerve impulse transmission.
(a) The thicker the myelin sheath, the stronger the nerve impulses
What happens when you have a weak or sick myelin?
If myelin is sick, you will become numb in your limb and you will not be able to walk properly (multiple sclerosis); neuropathy (No feelings); don’t feel the sharp objects.
These are the gaps in the myelin sheath.
Node of Ranvier (It has no myelin sheath)
These rest in invaginations of Schwann Cell (PNS) or the Oligodendrocytes (CNS). They conduct action potentials slowly.
Unmyelinated Axons
Nervous tissue can be grouped into what?
(1) White Matter
(2) Gray Matter
These consists myelinated axons. They propagate action potentials because the more myelin, the more electrical impulses are transmitted.
White Matter
What does the White Matter form in the CNS and PNS respectively?
Nerve Tracts and Nerves
These are collections of neuron cell bodies or unmyelinated axons.
Gray matter
What does the Gray Matter form in the CNS and PNS respectively?
Cortex and Nuclei; Ganglia
These synapse with neuron cell bodies, which are functionally the site of integration in the nervous system
Axons
The electric signals produced by cells are called ________________.
Action Potentials (source of energy of electrical signals; everything we do like contraction and secretion is brought about by action potentials)
Explain the use of action potentials.
(1) When action potentials are received from sensory cells it can result in the sensation of sight hearing, and touch.
(2) Complex mental activities such as conscious thought, memory, and emotion results from action potentials
(3) Contraction of muscles and the secretion of certain glands occur in response to action potentials.
Where does electrical properties of cells result from?
(1) Ionic concentration difference across the plasma membrane
(2) permeability characteristics of the plasma membrane (neurons have more gates and channels; a. The pores is where the Sodium and potassium exchanged)
What ions are involved in the production of action potentials?
(1) In ATP, there are only three ions that are important, Na, K, MG
(2) In action potential it needs more; Ca, Cl and other negatively charged of proteins are also involved.
These ions are in much greater concentration outside of the cell than inside.
(1) Sodium Ions (Na+)
(2) Calcium Ions (Ca2+)
(3) Chloride Ions (Cl-)
These ions are in much greater concentration inside of the cell than outside.
(1) Potassium Ions (K+)
(2) Negatively Charged Proteins
(sodium ions and potassium ions are equal in neurons)
These are synthesized inside the cell and cannot diffuse out of it.
Negatively charged proteins
The permeability characteristics of the plasma membrane are determined by what?
(1) Leak Channels (always open)
(2) Gated Ion Channels (voltage-gated)
These moves ions by active transport. Potassium ions are move into the cell and Na+ are moved out of it (PISO).
Na+ - K+ pump
Explain the nature of the Leak Channels (always open)
Potassium ion leak channels are more numerous than Na+ leak channels; thus, the plasma membrane is more permeable to K+ than to Na+ when at rest
These Include ligand-gated channels, voltage-gated channels, ion channels and other gated-ion channels
Gated Ion Channels (voltage-gated) - for electrical impulses
Explain the nature of Na+ - K+ pump
(1) The negatively charged proteins are always inside of the cells; hence, they are always intracellular
(2) Every 1 K gets out, 1 K gets in
This is the charge difference across the plasma membrane when the cells is not being stimulated. The inside of the cell is negatively charged compared with the outside of the cell.
Resting membrane potential
Explain the nature of the resting membrane potential.
(1) Due mainly to the tendency of positively charge K+ to diffuse out of the cell.
(2) Opposed by the negative charge that develops inside the plasma membrane.
(Action potentials I ATP only acts when there is sensation or sensory input like ears)
(3) In this, negatively charged ions inside the plasma membrane are usually sodium and chloride, the positive ions are usually potassium. (There has to be an equal number of both positively and negatively charged ions).
What happens when the stimulus occur consecutively?
The person will lose action potentials or neurotransmitters.
How does the resting membrane potential occur?
(1) Potassium ions diffuse out of the cell because there is greater concentration of K+ inside than outside of the cell
(2) Potassium ions move into the cell because the positively charged ions are attracted to the negatively charged proteins and anions
(3) the resting membrane potential is established when the movement of K+ out of the cell is equal to the movement into the cell.
These are larger changes in the resting membrane potential that spread over the entire surface of the cell. This occur in an all or none fashion and are in the same magnitude no matter how strong the stimulus is.
Action Potentials
This is the level of graded potential that causes the depolarization of the plasma membrane.
Threshold
What is the ideal threshold to be attained by action potentials?
-70mV
How many millivolts is required for the action potentials to occurs in an all-or-none fashion and are the of the same magnitude, no matter how strong the stimulus?
(+20 mV)
What are three phases of the action potentials?
(1) Depolarization Phase
(2) Repolarization Phase
(3) Afterpotential
This happens when the inside of the membrane becomes more positive.
Depolarization Phase
Explain the nature of the Depolarization Phase
Na+ diffuses into the cell through voltage=gated ion channels. The sodium phase should be at least be -70mV.
This occurs when there is the return of the membrane potential toward the resting membrane potential.
Repolarization Phase
Explain the nature of the Repolarization Phase
(1) Voltage-gated Na+ channels close
(2) Voltage-gated K+ channels open and K+ diffuses out of the cell
o Downward tract of AP
o Potassium Phase
o Maximum is +20
This is known as the brief period of hyperpolarization following repolarization
Afterpotential (lower than the -70)
What are the characteristics of Action Potentials?
- Action potentials are produced when a graded potential reaches threshold.
- Action potentials are all-or-none.
- Depolarization is a result of increased membrane permeability to Na+ and movement of Na+ into the cell. Activation gates of the voltage- gated Na channels open.
- Repolarization is a result of decreased membrane permeability to Na and increased membrane permeability to K+, which stops Na+ movement into the cell and increases K movement out of the cell. The inactivation gates of the voltage-gated Na channels close, and the voltage-gated K+ channels open.
- No action potential is produced by a stimulus, no matter how strong. during the absolute refractory period. During the relative refractory period, a stronger-than-threshold stimulus can produce an action potential.
- Action potentials are propagated, and for a given axon or muscle fiber the magnitude of the action potential is constant.
- Stimulus strength determines the frequency of action potentials.
What are the two (2) types of refractory period?
(1) Absolute Refractory Period
(2) Relative Refractory Period
This is the time during an action potential when a second stimulus (no matter how strong) cannot initiate another action potential.
Absolute Refractory Period (there is no longer enough neurotransmitters; hence there are no action potentials)
This is the time during which a stronger-than-threshold stimulus can evoke another action potential
Relative Refractory Period
These are the ends of the axons. The junction between two cells where communication takes place.
Synapse
These kinds of synapses transmits signal towards the synapse.
Presynaptic Cells
These kinds of synapses receives the signal
Postsynaptic cells
What are the two (2) types of synapses?
(1) Electrical Synapse
(2) Chemical Synapse
What are the three (3) anatomical parts of a chemical synapse?
(1) presynaptic cells
(2) Postsynaptic cells
(3) Synaptic cleft
These are the enlarged ends of the axons that contain synaptic vesicles. This is where the exchanged of neurotransmitters happen (the neurotransmitters that weren’t engulfed by the postsynaptic membranes are transmitted back to it)
Presynaptic Terminals
This is a space, separates the presynaptic and post synaptic membrane, It contains the calcium channels.
Synaptic cleft
These contain receptors for the neurotransmitter. They usually has the pores necessary for exchange of neurotransmitter
Postsynaptic cells
This is important in electrical signals as they are responsible for releasing neurotransmitter.
Calcium
Explain the chemical synapse activity.
(1) Action potentials arriving at the presynaptic terminal cause voltage gated Ca2+ channels to open.
(2) Calcium ions diffuse into the cell and cause synaptic vesicles to release neurotransmitter.
(This is important to have communication.)
(3) Neurotransmitters diffuse from the presynaptic terminal across the synaptic cleft
(4) Neurotransmitter combine with their receptor sites and cause ligand-gated ion channels to open. Ions diffuse into the cell or out of the cell and cause a change in membrane potentials (they maintain that equal amount of the positive and negative ions that surround the membrane)
a. If there is too much, there is another opening like acetylcholine to get it
This hormone is involved in mood, anxiety and sleep induction. Elevated levels of this may lead to schizophrenia (delusions, hallucinations, and withdrawal). Medications like Prozac are used to treat depressive and anxiety disorders.
Serotonin
This medication is used to augment the levels of serotonin in the cell membrane, used to treat anxiety, OCD, and depressive symptoms.
Selective- Serotonin- Reuptake Inhibitor
What is the effect of serotonin and where is its site of release?
Generally inhibitory; CNS synapses
This is a neurotransmitter that is released in selected CNS synapses and some ANS synapses, which can be inhibitory or excitatory. It is stimulated excessively due to drug addiction.
Dopamine (Parkinson’s disease - depression of voluntary motor control - it results due to destruction of dopamine secreting neurons
How is drug addiction and dopamine related?
(1) Drug addiction causes over release of dopamine
(2) Drug do not allow the opening of presynaptic for the excess neurotransmitter, dopamine remained only in the cleft-
This is a neurotransmitter that is released in CNS synapses that has an inhibitory effect. It is known as a pain reliever type of neurotransmitter.
Gamma-aminobutyric acid (GABA) - Drugs that increase GABA function have been used to treat epilepsy, which is the excessive discharge of neurons.
How is GABA and marijuana related?
(1) Marijuana (causes increment in levels of dopamine) blocked the GABA
(2) GABA control the dopamine which is an excitatory to make us feel better and it relieves our pain
What does GABA inhibit?
(1) Dopamine
(2) Serotonin
This is a neurotransmitter that is released in descending pain pathways which has an inhibitory effect.
Endorphins - the opiates morphine and heroin bind to endorphin receptors on presynaptic neurons and reduce pain by blocking the release of a neurotransmitter
This is important to regulate blood pressure and the constriction of our blood vessels.
Nitric Oxide
This is countered by caffeine and it is responsible to allow the person to sleep and feel drowsy.
Adenosine (if adenosine is continously blocked, it entails more caffeine to make you feel better)
What are the two (2) Types of postsynaptic potentials?
(1) Excitatory Postsynaptic Potentials (ESP)
(2) Inhibitory Postsynaptic Potentials (ISP)
This is a depolarizing graded potential of the postsynaptic membrane
Excitatory Postsynaptic Potentials (ESP) - Excitatory are norepinephrine and epinephrine, adrenaline, dopamine, acetylcholine
This is a hyperpolarizing graded potential of the postsynaptic membrane
Inhibitory Postsynaptic Potentials (ISP) - Inhibitory GABA, endorphin, serotonin
This decreases neurotransmitter release
Presynaptic inhibition
This increases neurotransmitter release
Presynaptic facilitation
What are the three (3) types of neuronal pathways and circuits?
(1) Convergent Pathways
(2) Divergent Pathways
(3) Oscillating Circuits
This neuronal pathway have many neurons synapsing with a few neurons.
Convergent Pathways
This neuronal pathway have a few neurons synapsing with many neurons.
Divergent Pathways
This neuronal pathway have collateral branches of postsynaptic neurons synapsing with presynaptic neurons
Oscillating Circuits (either left or right)
Explain the structure of the Somatic Nervous System (SNS)?
(1) Cell bodies of somatic neurons are located in the CNS
(2) Their axons extend to skeletal muscles where they have an EXCITATORY EFFECT
(3) They are usually controlled consciously
Explain the structure of the Autonomic Nervous System (ANS).
(1) Cell bodies of the preganglionic neurons are located in the CNS
(2) Their axons extend to the ganglia where they synapse with postganglionic neurons.
(3) The postganglionic axons can have an excitatory or inhibitory effect on
o Smooth muscle (like the uterus and the urinary bladder)
o Cardiac muscle
o Glands
(4) Usually controlled unconsciously (you do not notice that it is happening, like diagnosing people with hypertension)
Is mucus production sympathetic or parasympathetic? Accumulation of the mucus will lead to enema
Sympathetic
Explain the difference between the SNS and ANS?
Somatic is directed to the muscle while autonomic passes from preganglionic neuron, autonomic ganglion, to postganglionic (the electrical impulses coming the gray matter of the spine (dorsal), passes through an autonomic ganglion (sympathetic ganglion - transmits the electrical signals to a post ganglionic neurons then to the target organ (smooth muscle).
What are the three (3) subdivisions of the AN/S?
(1) Sympathetic Division
(2) Parasympathetic Division
(3) Enteric Nervous System
(a) Sympathetic and Parasympathetic divisions also act in the enteric, increase in secretion of hormone (sympathetic)
Sympathetic and Parasympathetic divisions differ structurally in what?
(1) Location of their preganglionic neuron cell bodies within the CNS
(2) Location of their autonomic ganglia (PNS - connected through the entire spine)
The cells have bodies that are in the lateral horns of the spinal cord gray matter from T1 to T2
Preganglionic cell
These cells pass through the ventral roots to the white rami communicates to the sympathetic chain ganglia. From there, four courses are possible
Preganglionic axons
In the Parasympathetic Division explain where the - Preganglionic cell bodies can be located?
Preganglionic cell bodies are in nuclei in the brainstem or the lateral parts of the spinal cord gray matter from S2 to S4
In the Parasympathetic Division explain how preganglionic axons travel?
(1) Preganglionic axons from the brain pass to ganglia through cranial nerves
(2) Preganglionic axons from the sacral region pass through the pelvic splanchnic nerves to the ganglia
- Preganglionic axons pass to terminal ganglia within the wall of or near the organ that is innervated
The bladder expansion and the contraction of the sphincter is parasympathetic or sympathetic?
Parasympathetic
The storage of the bladder that prompts the contraction of the sphincter is parasympathetic or sympathetic/
sympathetic
This subdivision of the autonomic nervous system consist of nerve plexuses within the wall of the digestive tract.
Enteric Nervous System
What are the contributions of the Enteric Nerve System (ENS( from three sources?
(1) Sensory neurons that connect the digestive tract to the CNS
(2) ANS motor neurons that connect the CNS to the digestive tract
(3) Enteric neurons, which are confined to the enteric plexuses
These are a are group of nerves that work together with PNS; they have specific tract.
Plexuses
Explain the division of autonomic nerve fibers
(1) Sympathetic, parasympathetic, and sensory neurons intermingle in autonomic nerve plexuses
(2) Sympathetic axons reach organ through spinal, sympathetic and splanchnic nerves
(3) Parasympathetic axons reach organs through cranial and pelvic splanchnic nerves
(4) Sensory neurons runs alongside sympathetic and parasympathetic neurons within nerves and nerve plexuses
What are the organs that are sympathetic?
(1) Adrenal Medulla (This is due to their capacity to produce or secrete steroids which are anti-inflammatory. Moreover, when the person is under stress, cortisol levels go up.)
(2) Arrector Pili Muscles (This is found in the integumentary; in charge of goosebumps - sympathetic)
(3) Sweat Glands (men sweat more because the have more muscle)
(4) Most Blood Vessels (because they allow the movement of the blood.
What are the organs that are parasympathetic?
(1) Esophagus (esophageal glands)
(2) Stomach (gastric glands) - the rest of the gastric glands can either be sympathetic or parasympathetic) - entirely enteric
(3) Intestines
(4) Pancreas (there are areas in the pancreas that are sympathetic like those that excrete insulin and acini (islet of Langerhans - not entirely enteric
(5) Gallbladder
(6) Pancreato-biliary ducts
What are the functions of the Enteric Nervous System (ENS)?
(1) Control motor function
(2) Local blood flow
(3) Mucosal transport
(4) Secretions of enzymes and hormone (fasting - ketotic reaction - salivating - parasympathetic)
(5) Modulates immune system and endocrine functions
What are the target organs of the ENS in the digestive system?
(1) Esophagus
(2) Stomach
(3) Intestines
(4) Pancreas
(5) Gall bladder
(6) Pancreato-biliary ducts (amylase - released in the blood)
What are the processes involved in the Enteric Nervous System (ENS)
(1) Secretion
(2) Digestion
(3) Motility
(4) Inflammatory response (lymph glands that protect us from virulent bacteria)
This neurotransmitter from the ANS is released by cholinergic neurons
Acetylcholine (preop medication is given prior to surgery to prevent saliva from moving down to your lungs)
What neurons fall under acetylcholine?
(1) All preganglionic neurons
(2) All parasympathetic postganglionic neurons
(3) Some sympathetic postganglionic neurons
This neurotransmitter from the ANS is released by adrenergic neurons.
Norepinephrine (or epinephrine) - important to increase heart rate and is entailed for survival
What neurons fall under Norepinephrine (or epinephrine) ?
Most sympathetic postganglionic neurons
What receptors does Acetylcholine bind to?
(1) Nicotinic receptors
(2) Muscarinic receptors
they came from post ganglionic neurons because they are the ones accepting the receptor
These receptors are found in the postganglionic neurons and have an excitatory effect.
Nicotinic receptors
These receptors are found in all parasympathetic effector organs and some sympathetic effector organs. They have an excitatory or inhibitory effect.
Muscarinic receptors (every organ has their own receptor as well)
What receptors do the norepinephrine and epinephrine bind to?
Alpha and Beta adrenergic receptors
They are found in most sympathetic effector organs. They are sent out to the heart and the blood pressure. They have an excitatory and inhibitory effect.
Alpha and Beta adrenergic receptors (all medications that end with olol, they are blocked by hypertensive drugs; they counter the effects of high blood pressure)
headache may be due to hyperosmolar or due to hormones to avoid nausea
This is used to control hypertension
Alpha 1 Blocker
These control most of the activity of visceral organs, glands, and blood vessels.
Autonomic Reflexes
What influences autonomic reflex activity?
(1) Autonomic reflex activity can be influenced by the hypothalamus and higher brain centers
(2) The sympathetic and parasympathetic division can influence the activities of the enteric nervous system through autonomic reflexes
How can the ENS function independently?
The enteric nervous system can function independently of the CNS through local reflexes (The area around it are continuously producing the stimulus like the food we eat to enable the ENS to start working)
Explain the nature of the heart in terms of parasympathetic and sympathetic.
Glossopharyngeal gets stimulated hence stimulating the heart because its near the crocin (vagal nerve is important to keep your heart rate at a certain level)
(1) Sympathetic - increases
(2) Parasympathetic - decreases
What are the functional generalizations about the ANS?
(1) Both divisions of the ANS produce stimulatory and inhibitory effects
(2) Most organs are innervated by both divisions
o Usually each division produces an opposite effect on a given organ
(3) Either division alone or both working together can coordinate the activities of different structures
(4) The sympathetic division produces more generalized effects (heart rate, blood pressure) than the parasympathetic division
(5) Sympathetic activity generally prepares the body for physical activity (flight or fight system)
(6) Parasympathetic activity is more important for resting conditions (rest and digest)
The stimulation of salivation is parasympathetic or sympathetic
Parasympathetic
