Nervous System Flashcards
The body’s control center and communication network.
Nervous system
Directs the function of the different organs and systems of the body.
Nervous system
2nd important regulating system that works with the nervous system to regulate and maintain body’s homeostasis.
Endocrine system
The nervous system controls rapid _.
Electrical nerve impulses
The endocrine system produces _ that are released in blood which brings about its effect.
Hormones
Function of the NS: Uses sensory receptors to monitor changes.
Sensory input
Function of the NS: processes & interprets input & decide
Integration
Function of the NS: effects response
Output
What is under the structural NS?
CNS and PNS
What is under the functional NS?
PNS
What is included in the CNS and PNS?
CNS: Brain and spinal cord; PNS: Spinal nerves and cranial nerves
The PNS is divided into two, which are?
Afferent and efferent
The ENS is divided into?
Somatic and autonomic
The ANS is divided into?
Sympathetic and parasympathetic
Sensory information is integrated in order to generate a motor output.
Control center
PNS method of communication
Nerves
Afferent or?
Sensory
Efferent or?
Motor
Receptor to CNS
Sensory/afferent
CNS to muscle
Motor/efferent
To skeletal muscle (voluntary motion)
Somatic
To smooth and cardiac muscle (involuntary motion)
Autonomic
Rest and digest
Parasympathetic division
Fight and flight
Sympathetic division
Supports, insulates, and protects delicate neurons.
Neuroglia/glial cells
Neuroglia can conduct impulses.
False
Neuroglia has the ability to divide.
True
Most brain tumors are glial in nature.
True
Receive information & transmits biochemical information.
Neurons/nerve cells
The four types of CNS glial cells are?
Astrocytes, microglia, ependymal, oligodendrocytes
Star-shaped cells that wrap around nerve cells to form supporting network in the brain & spinal cord.
Astrocytes
Function in blood-brain barrier to prevent toxic substances from entering the brain.
Astrocytes
Attach neurons to blood vessels & tissues helping regulate nutrients & ions needed by the body.
Astrocytes
Most abundant and versatile neuroglia.
Astrocytes
Spider-like phagocytes that dispose debris, including braincells & bacteria.
Microglia
Glial cell that act in response to inflammation and injury.
Microglia
Line central cavities of the brain & spinal cord.
Ependymal
Their cilia helps circulate the CSF that fills cavities & forms protective cushion around CNS.
Ependymal
Line cerebrospinal fluid-filled cavities.
Ependymal
Looks like small astrocytes.
Oligodendrocytes
Wrap their flat extensions tightly around the nerve fibers, producing fatty insulating covering.
Oligodendrocytes
What does oligodendrocytes produce?
Myelin sheath
Fatty insulating covering
Myelin sheath
What are the two glial cells of the PNS?
Schwann cells and satellite cells
Form myelin sheaths around nerve fibers in the PNS.
Schwann cells
Surrounds the axon in PNS
Schwann cells
Provide protective, acts in cushioning cells.
Satellite cells
Surrounds the cell body of a neuron in PNS
Satellite cells
Highly specialized to transmit message (nerve impulse) from 1 part of the body to another.
Neuron
What do neurons transmit?
Message/nerve impulses
Structural and functional unit of the nervous system.
Neuron
Neurons are mitotic.
False
Part of the neuron with nucleus.
Cell body
Metabolic center of neuron.
Cell body
The nucleus of the cell body is transparent and contains the nucleolus.
True
The cytoplasm of the cell body contains usual organelles except?
Centrioles, because neurons are amitotic.
5 parts of the cell body: _?
Mitochondria, golgi bodies, lysosomes, neurofibrils, extensive rough ER
Network of threads important in maintaining the cell shape of the neuron cell body.
Neurofibrils
The granular structure in the RER of the cell body where protein synthesis occurs.
Nissl bodies/chromatophilic substances
What are the two processes or fibers?
Dendrites and axons
Small extensions projecting from the cell body.
Dendrites
Receptive areas of the neuron.
Dendrites
How many dendrites does a multipolar neuron have?
Many
Neuron process that convey incoming messages (electrical signals) towards the cell body.
Dendrites
Single, long extension of the cell body.
Axons
Conducting region of the neuron.
Axons
Generates electrical signals for communicating & conducting them away from the cell body.
Axons
Towards the cell body; away from the cell body.
Dendrites; axons
Where does the impulse start and go?
From the axon hillock (trigger zone) to terminal branches (secretory regions).
A long process or fiber that begins singly but may branch and at its end has many fiber extensions called?
Axonal terminals
Contact with dendrites of other neurons.
Axonal terminal
Where does the axon arises?
Axonal hillock
Axonal terminals contain hundred of tiny vesicles or membranous sacs that contain chemicals called?
Neurotransmitters
When impulse reach the axonal terminal, what will happen?
Stimulate the release of neurotransmitters into extracellular space.
Cytoplasm within the axon.
Axoplasm
A tiny gap that separates axial terminal from the next neuron.
Synaptic cleft
Functional junction
Synapse
Areas where terminal branches of axon are anchored but not touching the end of dendrites of the next neuron.
Synapse
Pre-synaptic cell
Sending
Post-synaptic cell
Receiving
Junction between two neurons.
Synapse
Gap between the pre-synaptic and post-synaptic cell.
Synaptic cleft
A component of the synapse.
Synaptic cleft
Composed of a pre-synaptic membrane, synaptic cleft, and a post-synaptic membrane.
Synapse
Involved in the conversion of electrical signals into chemical signals and transmission of the nerve impulses into an adjacent neuron.
Synapse
Involved in the transmission of nerve impulses between the membranes of two neurons.
Synaptic cleft
Whitish, fatty material which has a waxy appearance that covers nerve fibers.
Myelin sheath
Protects and insulates the fibers & increases transmission rate of nerve impulses.
Myelin sheath
Gaps or indentations in the myelin sheath formed by many individual schwann cells.
Nodes of ranvier
The nodes of ranvier allow ions to flow freely from?, which assists in developing action potentials for nerve transmission.
ECF to axons
Myelinated axons conduct action potentials more quickly. How fast do they conduct?
3-15 meters/sec
The CNS myelin sheath lacks?
Neurilemma
Cytoplasm outside the myelin sheath.
Neurilemma
Classification based on the number of processes extending from the cell body.
Structural
The structural classification of neurons includes?
Multipolar, bipolar, and unipolar
Groups neurons according to direction the nerve impulse is traveling relative to CNS.
Functional
3 functional classification of neurons?
Sensory, association, and motor neurons
Neuron that has many dendrites and one axon.
Multipolar
Most neurons in the brain and spinal cord are?
Multipolar
Neuron that has one dendrite and one axon.
Bipolar
Neurons rare in adults and found only in special senses.
Bipolar
Have 1 process extending from cell body. This process branches into a central branch (function as axon) & a peripheral branch (function as dendrite).
Unipolar
The branch that functions as _ enters the brain and spinal cord, the branch that function as _ connect to peripheral part of the body.
Axon, dendrite
Neurons carrying impulses from sensory receptors to CNS.
Sensory/afferent neuron
Cell bodies of sensory neurons are always found in?
Ganglion outside the CNS
Keeps us informed about what is happening both inside and outside of the body.
Sensory neuron
What type is sensory neurons according to its structural composition?
Unipolar
Simple types of sensory receptors seen in the skin.
Cutaneous sense organs/pain receptors
Simple types of sensory receptors seen in muscles and tendons.
Proprioceptors
What type is association neurons according to its structure?
Multipolar
Where are association neurons found in the body?
Brain and spinal cord
What do association neurons transmit?
Sensory impulse
Connects motor and sensory neurons in neural pathways.
Association neurons
What is done to the sensory impulse conducted to the brain/spinal cord by the association neurons?
Interpretation and processing
Nerves carrying impulses from CNS to viscera, muscles or glands.
Motor neurons
What type is motor neurons according to its structure?
Multipolar
Brings about reaction to the original stimulus.
Motor neurons
Myelinated axons
White matter
The matter that forms nerve tract in CNS.
White matter
Most nerves are _ matter.
White
Unmyelinated axons
Gray matter
Gray matter at the surface of the brain is called?
Cortex
Masses of gray matter
Ganglia
Areas of gray matter in the spinal cord is called?
Horn
Collection of cell bodies in CNS.
Nuclei
Collection of cell bodies in PNS.
Ganglion
Collection of axons/nerve fibers in CNS and PNS.
CNS: Nerve tracts; PNS: Nerves
Conduct impulse up the cord and concerned with sensation.
Ascending tract
Conduct impulse down the cord and concerned with motor function.
Descending tract
Descending tract is concerned with?
Motor function
Ascending tract is concerned with?
Sensation
What does being polarized mean in the physiology of nerve impulse?
The outer face of the membrane is slightly positive due to the chief extracellular ion sodium, whereas its chief intracellular ion is potassium.
What initiates depolarization?
Stimulus
How does the stimulus affect the nerve impulse?
Changes the permeability of the membrane, allowing sodium ions to diffuse rapidly inside the cell.
What does depolarization signify?
Due to the rapid diffusion of sodium ions into the membrane, the inside becomes more positive while the outside become more negative.
How is action potential initiated?
When depolarization causes membrane polarity to be completely reversed.
When an impulse reaches the axon terminal, what does it trigger to release?
Neurotransmitters like acetylcholine
Where is the neurotransmitters released into?
Synaptic cleft
What are the other neurotransmitters found in the body?
Epinephrine, adrenaline, norepinephrine, serotonin, dopamine, and endorphins
A rapid, predictable, and involuntary response to a stimuli.
Reflex
Allows us to respond more quickly than if we had to consciously think about what to do.
Reflex
Two types of reflexes
Somatic and autonomic
Include all reflexes that stimulate the skeletal system.
Somatic
Type of reflex involved when pulling the hand away from a hot object.
Somatic
Type of reflex that regulates the activity of smooth muscles, the heart and glands.
Autonomic
Type of reflex involved in the secretion of saliva (salivary reflex),changes in size of pupil (pupillary reflex).
Autonomic
The pathway that results in a reflex.
Reflex arc
Basic unit of the nervous system.
Reflex arc
Smallest and simplest pathway able to receive a stimulus, enter the CNS for interpretation, and produce a response.
Reflex arc
5 components of the reflex arc
Sensory receptor in the skin, sensory or afferent neuron, association or internuncial neuron within the spinal cord, motor or efferent organ, and effector organ.
