ANAPHY: U7.1 Nervous System (Central Nervous System)

SHEM

Acronym to remember functions of the Nervous System

Sensation, Homeostasis with electrical signals, Emotions & higher mental functions, Muscle & gland activation

What are the functions of the Nervous System

SIM

Acronym to Remember Roles for the Nervous System

Sensory Input, Integration, Motor Output

Roles for the Nervous System

Sensory Input

Role of the nervous system in which information is gathered and changes inside and outside the body are monitore

integration

Role of the nervous system to process and interpret sensory input and decide if action is needed

Motor Output

Role of the nervous system to respond to integrated stimuli, activating the muscles or glands

Central & Peripheral Nervous System

2 Structural Classifications of the Nervous System

Brain & Spinal Cord

What organs are included in the central nervous system?

Dorsal Cavity

What cavity is the central nervous system located?

Act as the command center that takes in information and gives instruction

What is the function of the Central Nervous System?

Nerves outside the brain and spinal cord

What are included in the Peripheral Nervous System?

Act as the communication lines

What is the function of the Peripheral Nervous System?

Sensory (Afferent) & Motor (Efferent) Division

What are the two main divisions of the Peripheral Nervous System?

Carry information towards the central nervous system

What is the function of the sensory (afferent) division of the Peripheral Nervous System?

Carry impulses away from the central nervous system

What is the function of the motor (efferent) division of the Peripheral Nervous System?

Somatic nervous system and Autonomic Nervous System

What are the two subdivisions of the motor (efferent) division of the Peripheral Nervous System?

Somatic Nervous System

Voluntary Peripheral Nervous System

Autonomic Nervous System

Involuntary Peripheral Nervous System

Skeletal Muscles

What muscles do the Peripheral Nervous System control?

Sympathetic & Parasympathetic Autonomic Nervous System

What are the subdivisions of the Autonomic Nervous System?

Sympathetic Autonomic Nervous System

Subdivision of the Autonomic Nervous System that is the “fight-or-flight” response to unusual stimulus, due to the E’s (exercise, excitement, emergency, and embarrassment

exercise, excitement, emergency, embarrassment

E’s of the Sympathetic ANS

Parasympathetic Autonomic Nervous System

Subdivision of the Autonomic Nervous System that is responsible for housekeeping activities, conserving and energy and helping maintain daily necessary body functions

Digestion, defecation, diuresis

D’s of the Parasympathetic ANS

Cardiac and smooth muscles, glands

What does the Autonomic Nervous System control?

Neuroglia

Neuroglia or Neuron: Which one divides?

Neuroglia

Neuroglia or Neuron: Which one is usually involved in brain tumors?

Gliomas

What are brain tumors usually?

MEAO SS

Acronym to Remember the 6 Types of Support Cells of the NS

Microglia, Ependymal Cells, Astrocytes, Oligodendrocytes, Schwann Cells, Satellite Cells

6 Types of Support Cells of the Nervous System

Microglia, Ependymal Cells, Astrocytes, Oligodendrocytes

4 Support Cells of the CNS

Schwann Cells & Satellite Cells

2 Support Cells of the PNS

Microglia

Type of support cell in the CNS that protects the CNS from infection and becomes phagocytic in response to inflammation

Ependymal Cells

Type of support cell in the CNS that line the ventricles of brain and central canal of spinal cord; circulates and produces cerebrospinal fluid

Astrocytes

Type of support cell in the CNS that provides structural support, regulates neuronal signaling, and helps with neural tissue repair

Schwann Cells

Type of support cell of the PNS that form the myelin sheath in a jelly-roll like fashion

Satellite Cells

Type of support cell of the PNS that provide support and nutrition to neurons and protects the neurons from heavy metal poisons

Oligodendrocytes

Type of support cell of the CNS that forms myelin sheath in the central nervous system

Neurons

Cells specialized to transmit messages

Cell Body and Processes

2 Major Regions of Neurons

Nucleus (Metabolic Center of the Cell) & Large Nucleolus

What does the cell body contain?

Processes

One of the major regions of neurons that has fingers that extend from the cell body

Dendrites & Axons

What is included in the processes?

Dendrites

Process that conducts impulses towards the cell body

Axons

Process that conducts impulses away from the cell body

Axonal Terminals

Axons: What do axons end in?

Contain vesicles with neurotransmitters

Axons: What do axonal terminals contain?

Synaptic Cleft

Gap between adjacent neurons?

Synapse

Junction between nerves?

Schwann Cells & Nodes of Ranvier

2 Types of Nerve Fiber Coverings

Nodes of Ranvier

Gaps in myelin sheath along axon?

Multiple Scleroses

Autoimmune disease in which the myelin sheath is destroyed and the myelin sheath hardens?

Gray Matter

Cell bodies and unmyelinated fibers?

Nuclei

Clusters of cell bodies within the white matter of the CNS?

Ganglia

Collections of cell bodies outside the CNS?

Sensory/Afferent Neurons & Motor/Efferent Neurons

2 Classifications of Neurons

Sensory Receptors

Where do sensory/afferent neurons carry impulses from?

From the CNS to muscles and glands

Where do motor/efferent neurons carry impulses from and to?

Interneurons/Association Neurons

Type of neuron found in neural pathways in the CNS and connects sensory and motor neurons?

Irritability & Conductivity

Two ways neurons function?

Irritability

Neuron function which is the ability to respond to stimuli.

Conductivity

Neuron function which is the ability to transmit an impulse.

Depolarization, sodium (Na+) enters, exchange of ions initiates action potential

Three steps to starting a nerve impulse.

Potassium ions rush out and sodium ions rush in

What depolarizes the membrane?

Sodium-potassium pump

Pump requiring ATP?

Myelin sheath

Impulses travel faster when fibers have a ___ ___. 

Electrochemical Event

Term for when impulses are able to cross the synapse to another nerve.

Axon Terminal

Where is the neurotransmitter released from?

Dendrite

What of the next neuron is stimulated by the neurotransmitter?

Action potential

What is started in the dendrite?

Alcohol, sedatives, anesthetics, cold continuous pressure

What are the ways that conduction is slowed?

Reflex

Rapid, predictable, and involuntary responses to stimuli

Reflex Arc

Direct route from a sensory neutron, to an interneuroun, to an effector

Sensory receptor, afferent neuron, efferent neuron, efferent organ

What are the components of a 2-neuron reflex arc?

Knee-jerk reflex

What is an example of a 2-neuron reflex arc?

Autonomic and somatic reflexes

Two types of reflexes?

Smooth muscle regulation, heart and blood pressure regulation, regulation of glands, digestive system regulation

What are autonomic reflexes able to do?

Activation of skeletal muscles

What are somatic reflexes able to do?

Embryonic neural tube

Where does the CNS develop from?

Brain and spinal cord

What does the neural tube develop into?

Ventricles (four chambers in the brain)

What does the opening of the neural tube become?

Cerebrospinal fluid

What are the ventricles of the brain filled with?

Cerebral hemispheres/cerebrum, diencephalon, brain stem, cerebellum

4 regions of the brain

Cerebrum

Region of the brain that includes more than half of the brain mass, largest and most complex area of the brain

Ridges (gyri) & grooves (sulci)

What makes up the surface of the cerebrum?

Fissures (deep grooves)

What divides the cerebrum into lobes?

Longitudinal fissure

Fissure that separates the hemispheres?

Frontal, parietal, occipital, and temporal lobes

4 lobes of the cerebrum

Frontal Lobe

Lobe of the brain that is the primary motor area (sending impulses to skeletal muscle), helps in our ability to speak (includes Broca’s area), intellectual and psychic functions

Temporal Lobe

Lobe that acts as the gustatory, auditory, olfactory area

Occipital Lobe

Lobe that acts as the visual area

Parietal Lobe

Lobe that senses sensations (pain, hot and cold, touch, and speech and reading

Speech/language region, language comprehension region, general interpretation region

Interpretation areas of the cerebrum

Gray and white matter

2 Layers of the Cerebrum

Gray Matter

Outer layer of the cerebrum

White matter

Layer that are the fiber tracts within the gray matter 

Thoughts and voluntary actions

What does gray matter initiate?

Corpus callosum that connects the brain hemispheres

What is an example of white matter?

Diencephalon

Region of the brain that sits on top of the brain stem and is enclosed by the cerebral hemispheres