Nervous System Flashcards
The communication system
Nervous System
Receive signals from and sending commands to different arras of the body
Nervous System
Major functions of Nervous System
- Receiving sensory input
- Integrating information
- Controlling muscle and glands
- Maintaining homeotstasis
- Establishing and maintaining mental activity
Can sitmulate or inhibit the activities of other systems to help main a constant internal environment
Nervous system
Two major division of nervous system
CNS
PNS
Contains the brain and spinal cord
CNS
Consists of all nervous tissue outside the CNS (nerves and ganglia)
PNS
Also called as the “Afferent Division”
Sensory Division
Conducts action potentials from sensory receptors to the CNS
Sensory Division/ Afferent Division
Neurons that transmits action potentials from the periphery to CNS
Sensory neurons
Also called as “Efferent division”
Motor division
Afferent means
Towards
Efferent means
Away
Neurons that transmits action potential from the periphery to the cns
Sensory neurons
Neurons that transmit action potential from the cns to periphery
Motor Neurons
Effectors controlled by the motor division
Muscle tissue and glands
Transport action potential from the CNS to skeletal muscles
Somatic nervous system
Transport action potential from the CNS to cardiac muscle, smooth muscle, and glands
Autonomic nervous system
Unique subdivision of PNS that has both sensory and motor
Enteric Nervous System
It is also called as nerve cells
Neurons
Receive stimuli, conduct action potentials, and transmit signals to other neuron or effector organs
Nuerons / nerve cells
Three parts of neuron
Cell body
Dendrites
Axon
Contains one nucleus and processes stimulus
Cell body
Extension of the neuron cell body; receive stimulus
Dendrites
Branching cytoplasmic extensions
Dendrites
Single long cell process; transmit stimulus to a gland, muscle, organ, or other neuron
Axon
The area where the axon leaves the neuron cell body
Axon Hillock
Branches of axons
Collateral axons
Highly specialised insulating layer of cells
Myelin sheath
The types of neurons
Multipolar neurons
Bipolar neurons
Pseudo-unipolar neurons
Have many dendrites and one axon
Multipolar Neuron
Have 2 processes: 1 dendrite and 1 axon
Bipolar Neuron
a single process that divides into 2 processes
Pseudo-unipolar Neuron
Supportive cells of cns and pns
Glial Cells / Neuroglia
Do not conduct any action potentials; enhance neuron function
Glial Cells / Neuroglia
Fatty, protecting wrapping around axons that are formed by PNS and CNS
Myelin Sheaths
What is OLIGODENDROCYTES
CNS
SCHWANN CELLS
PNS
Fight or flight system
Sympathetic
Resting and digesting system
Parasympathetic
Major supporting cells in the CNS
Astrocytes
Can stimulate or inhibit the signaling activity of nearby neurons
Astrocytes
Astrocytes participate with the blood vessel endothelium TO FORM A PERMEABILITY BARRIER
Blood brain barrier
Help limit damage to neural tissue
Astrocytes
Produce cerebrospinal fluid
Ependymal cells
Act as immune cells of CNS
Microglia
Provides insulating material that surrounds axon
Oligodendrocytes and Schwann Cells
Axons with myelin sheaths are called
Myelinated Axon
Gaps in the myelin sheath
Nodes of Ranvier
Communication among neurons
Neural signaling
Action potentials are conducted SLOWLY because in travel along the entire axon
Unmyelinated Axon
Action potentials are conducted RAPIDLY by salutatory conduction
Myelinating Axons
Groups of neuron cell bodies and their dendrites, where there is a little myelin
Gray Matter
Bundles parallel of axon with their myelin sheath, which are whitish color
White Matter
Gray matter on the surface of the brain
Cortex
A cluster of neuron cell bodies in PNS
Ganglion
Found on the CNS which propagate action potential from one area of the cns to another
Nerve Tracts / Conduction Pathways
Bundles of axons located in the PNS
Nerves
A type of neuron found in special sense organs, such as eye and nose
Bipolar Neuron
Single cells surrounding axons
Schwann cells
Uneven distribution of charge
Polarized cell membrane
Appears to have an axon and no dendrites
Pseudo-unipolar neuron
Unstimulated cell, the uneven charge distribution
Resting membrane potential
Greater permeability of the cell membrane to K+ than to Na+
True
Two basic type of ion channels
Leak channels
Gated channels
A channel that is always open
Leak channel
The resting membrane potential is established when the movement of K+ out of the cell is EQUAL to the movement of K+ into the cell
True
Opened by neurotransmitters or other chemicals
Chemically gated channels
Opened by a change in membrane potential
Voltage gated channels
The inward movement of Na+ makes the inside movement of Na+ makes the inside of the membrane POSITIVE
Depolarization
Constitution of depolarization and repolarization
Action Potential
Most often reached at axon hillock
Threshold
The charge on cell membrane briefly becomes MORE NEGATIVE than the resting membrane potential
Hyperpolarization
Occurs in unmyelinated axons
Continuous conduction
Occurs in myelinated axons
Saltatory Conduction
A junction where axon of one neuron interacts with another
Synapse
Three major components of synapse
Presynaptic Terminal
Postsynaptic Membrane
Synaptic cleft
End of the axon; has synaptic vesicles that store neurotransmitters
Presynaptic terminal
Membrane of the dendrite or effector cell
Postsynaptic membrane
Space separating the presynaptic terminal and postsynaptic membrane
Synaptic cleft
What is stored in synaptic vesicles?
Neurotransmitters
The chemical messengers
Neurotransmitters
The inside of postsynaptic cells tends to become MORE NEGATIVE
Hyperpolarized
Associated with the decrease in acetylcholine-secreting neurons
Alzheimer disease
Increase the release and block the reuptake of norepinephrine
Coccaine and amphetamines
It is involved in mood, anxiety, and sleep induction.
Serotonin
Used to treat depression and anxiety disorders
Prozac
Meaning of gaba
gamma-aminobutyric acid
Involuntary reactions in response to a stimulus
Relfexes
Allow a person to react to stimuli more quickly
Reflexes
The neuronal pathway by which a reflex occurs
Reflex arc
Basic functional unit of nervous system
Reflex arc
Five basic components of reflex arc
Sensory receptor
Sensory neuron
Interneuron
Motor neuron
Effector organ
Pick up the stimulus
Sensory receptor
Afferent: send stimulus to interneurons in spinal cord
Sensory Neurons
Efferent; send response to effector
Motor neuron
What are the effector organ?
Muscle tissue and glands
Two types of neuronal pathways
Converging pathway
Diverging pathway
Two or more neuron synapse with same neuron
Converging pathway
The axon from one neuron divides and synapses with more than one neuron
Diverging pathway
Allows the integration of multiple subthreshold local potentials
Summation
Extends from the foramen magnum to the 2nd lumbar vertebra
Spinal cord
Inferior end of the spinal cord that resembles a horse’s tail
Cauda equina
At the center of spinal cord that is shwped like LETTER H OR BUTTERFLY
Gray Matter
Dorsal?
Posterior
Ventral?
Anterior
Fluid filled space in the center of the cord
Central canal
Conduct action potentials toward the brain
Ascending tracts
Conduct action potentials away the brain
Descending tracts
Simplest reflex
Stretch flex
Simplest reflex
Stretch flex
Called the patellar flex
Knee-jerk reflex
Stretching of the quadriceps femoris muscle
Knee-jerk reflex
Called the flexor reflex
Withdrawal reflex
Contains pain receptors as its sensory receptors, if stimulated, reflex occurs
Withdrawal reflex
The function is to remove a limb or another body part from a painful stimulus
Withdrawal reflex
The function is to measure the posture maintenance and coordination of muscle activity
Knee-jerk reflex
Spinal cords from union of dorsal and ventral roots
Spinal nerves
How many pairs of spinal nerves?
31
Area of skin applied with sensory innervation by a pair of spinal nerves
Dermatome
Neurons of spinal nerves come together and intermingle
Plexus
3 major plexus
Cervical Plexus
Brachial Plexus
Lumbosacral Plexus
Spinal nerves T2 through T11 do not join a plexus
True
A plexus: muscles of the pelvic floor and sensory cutaneous innervation to the skin over the coccyx
Coccygeal plexus
Innervates the diaphragm
Phrenic nerve
The ulnar nerve at this location is called
Funny bone
Major regions of the brain
Diencephalon
Brainstem
Cerebrum
Cerebellum
Connects the spinal cord to the remainder of the brain
Brainstem
What contains the brainstem?
Midbrain
Pons
Medulla oblongata
The brainstem controls the heart rate, blood pressure, and breathing
True
What cranial nerves located in the brainstem?
The first two cranial nerves
Most inferior portion of the brainstem and is continuous with the spinal cord
Medulla Oblongata
Contains the ascending and descending nerve tracts
Medulla oblongata
How many pounds is the brain?
3 pounds
Soft, wrinkled mass of tissue that is highly complex and adaptive
Brain
What part of brainstem has important reflex actions like vomiting, sneezing, coughing, and swallowing
Medulla oblongata
Two prominent enlargement at uppermost part (anterior)
Pyramids
A large tumor; a mass of blood that occurs as the result of bleeding into the tissue
Hematoma
Superior to medulla oblongata
Pons
Relay information/ functional bridge between cerebrum and cerebellum; arched footbridge
Pons
Superior to the pons
Midbrain
The smallest region of the brainstem
Midbrain
The 4 mounds is called
Colliculi
2 mounds; involved in visual reflexes and receive touch and auditory input
Superior colliculi
Major relay centers for auditory nerve pathways in CNS
Inferior Colliculi
Major relay centers for auditory nerve pathways in cns
Inferior colliculi
The black nuclear mass in the midbrain that is involved in regulating body movements
Substantia Nigra
This midbrain contains nuclei involved in coordinating eye movements and controlling pupil diameter and lens shape
Midbrain
A group of nuclei scaterred throughout the brainstem
Reticular formation
Its function is to regulates cyclical motor function (respiration,walking,chewing)
Reticulqr formation
Plays an important role in arousing and maintaining consciousness; in regulating sleep-wake cycle
Reticular activating system
Attached to brainstem
Cerebellum
Several large connections attached to brainstem
Cerebullar peduncles
Known as the LITTLE BRAIN
Cerebellum
Second largest part of the brain
Cerebellum
Responsible for coordination of movement
Cerebellum
Provide info about the position of the body parts
Proprioceptive neurons
Largest and most prominent part of the brain
Cerebrum
Part of the brain between brainstem and cerebrum
Diencephalon
Main components of diencephalon
Thalamus
Hypothalamus
Epithalamus
Largest part of diencephalon
Thalamus
Consist of cluster of nuclei shaped like yo-yo
Thalamus
Centrally connect the two large, lateral parts
Interthalamic adhesion
This part of the brain influences the mood and registers an inlocalized, uncomfortable perception of pain
Thalamus
Small area superior and posterior to thalamus
Consist of small nuclei; involved in the emotional and visceral response to odors and phineal gland
Epithalamus
An endocrine gland that influences the onset of puberty; role in controlling long term cycles
Pineal gland
Most inferior part of diencephalon
Hypothalamus
Plays a central role in maintaining homeostasis, control of body temp, hunger, thirst, sexual oleasures, rage, fear, relaxation after meal, contril secretion in pituitary gland
Hypothalamus
Contains several small nuclei
Hypothalamus
Funnel shaped stalk that controls the secretion of hormones from the pituitary gland
Infundibilum
Visible swelling; involved in emotional responses to odors and in memory
Mammillary bodies
Largest part of the brain
Cerebrum
The cerebrum is divided into left and right hemisphere by a ____
Longitudinal fissure
Numerous folds on cerebral cortex; increase the surface area of the cortext
Gyri
Intervenning grooves
Sulci
What are the type of lobes
Frontal lobe
Parietal lobe
Occipital lobe
Temporal lobe
Insula / fifth lobe
vital in control of voluntary motor functions, motivation, aggression, mood and olfactory
Frontal lobe
Consciously perceive most sensory information such as touch, pain, temperature and balance
Parietal love
Receivint and perceiving visual input
Occipital lobe
Lobe involved in olfactory and auditory sensations; plays an important role in memor6
Temporal lobe
Deep within lateral fissure; processes interoception
Insula/Fifth Lobe
Surface of cerebrum that is composed of gray mater
Cerebeal cortex
It separates the frontal and parietal lobes
Central sulcus
