What is the basic unit of the nervous system ? What encapsulates the individual myelinated axons?
The neuron (supported by neuroglia) - Endoneurium
What are the neuroglia of the CNS? What surrounds the individual fascicles?
-Astrocytes – Regulation of what comes in
-Microglia – Destroy pathogens and debris - Perineurium
-Oligodendrocytes – Provides insulating myelin sheath around axon
-Ependymal – Produce CS fluid
What surrounds the entire nerve?
What are the neuroglia of the PNS?
- Epineurium
-Schwann cells – Provide insulating myelin sheath around axon
-Satellite cells – Surrounds soma and regulates material exchange How many regions are in the brain?
What are chemical messengers known as? - Cerebrum, Cerebellum, Diencephalon, Mesencephalon, Pons, and
Medulla Ob.
-Neurotransmitters
What receives neurotransmitters on the post synaptic membrane? What is the function of cerebrum?
-Receptors - Conscious thought and higher learning (occipital, parietal, frontal, and
temporal
lobe)
What connects the two hemispheres together?
- Corpus callosum (nerve fibers) provides communication between hemispheres
What is grey and white matter?
White matter = myelinated neuronal
processes – connects regions of the brain
Gray matter = neuron cell bodies (unmyelinated)
What increases surface area? What are the different layers of the Meninges?
Gyri (gyrus) = fold, Sulci (sulcus)= valley - Pia mater (Deep), Arachnoid Mater (middle), Dura Mater (superficial)
The Dura Mater includes the periosteal and meningeal
What is the second largest region of the brain?
Cerebellum – monitor body position and coordinate movement O O On nce ne akes he ntomy inal T T A F
V Gery ood Vacations re A Heavenly
Contains the arbor vitae and the choroid plexus
What is the function of the Diencephalon (Forebrain) Some ay arry oney ut y S M M B M
Brother ays ig rains atter S B B M More
Thalamus = Interpreting sensory information
Hypothalamus = emotions, instincts, and link to endocrine system
What is the brain stem composed of? How many pairs of there of spinal nerves?
Mesencephalon (midbrain) = vision, hearing, motor control, sleep/wake, arousal/ alertness - 31 pairs of spinal nerves
Pons = relay station
Medulla oblongata = coordinate breathing and heart patterns, swallowing reflex What are dermatomes?
What does the cephalic ventricles produce and circulate? - A “zone” in the body that each spinal nerve serves.
They produce cerebral spinal fluid (CSF)
Where is most of CSF produced? The brachial plexus is a network of nerves that innervates
the shoulder, arm, and the hand
It is produced in the choroid plexus.
What are the different ventricle types?
Lateral ventricles, third ventricle, cerebral aqueduct, fourth ventricle,
lateral apertures, and the central canal
What are the two functions of the cornea? What are the three different types of ossicles?
Controls and focuses the entry of light into the eye, bends/refracts light The malleus, the incus, and the stapes
What muscle moves the eye inferior and laterally? Vibrations transfer from the ossicles to what in the inner
ear?
The superior oblique muscle Transferred to the cochlea
What muscle moves the eye superior and lateral? What detects sound in the cochlea?
The inferior oblique muscle The Organ of Corti (converts stimuli to action potentials)
What are the two cavities in the eye? What are the two structures that are responsible for
maintaining balance and equilibrium?
Anterior (aqueous) and posterior (vitreous) cavities
The vestibule (static equilibrium) and the semicircular canals
What are the three tunic layers?
The sclera, the choroid, and the retina (deep) What are the two major parts of the tongue?
Where is the blind spot (no cones or rods) located? The pharyngeal part and the oral part (corpus)
In the Optic disc
What location contains a high density of photoreceptor cells? What are the five basic tastes?
The fovea centralis Sweet, salty, sour, bitter and umami (deliciousness)
What is the external ear composed of?
cartilage
A comparatively simple automatic response to a stimulus What are the two structures in the muscle spindle?
A reflex Intrafusal fibers inside the extrafusal fibers
What are neural reflexes designed to do? What are the two motor neurons in the muscle?
spindle?
Maintain balance, protection, and carry out daily routines alpha-motor neurons innervate = intrafusal region
Gamma-motor neurons innervate = extrafusal region
What are the steps of the reflex arc?
1. Receptor 2. Sensory relay 3. Integration 4. Motor Command relay 5. Effector Receptors are ______, they convert stimuli to A.P.’S
What are the types of reflexes? transducers
Monosynaptic, polysynaptic, somatic, autonomic, and acquired Desensitization to constant stimuli is called
adaptation
What are the two classifications of sensory receptors?
Exteroceptors and Interoceptors (chemo, visceral stretch, and proprioceptors) The smaller and more dense the fields, the more
There are general and special (vision, hearing, equilibrium, taste, smell) sensitive
What should I be able to locate on the receptor structure? receptor fields
Free (naked) nerve endings – Least covering of nerve (very close to skin)
Merkel Cells – light touch (associated with free nerve endings)
Meissner’s corpuscles – detect lighter touch (encapsulated) spindle is compressed = fewer impulses sent to alpha -motor neurons
Pacinian corpuscles - Detects forceful pressure (deep) spindle is stretched = more impulses sent to alpha-motor neurons
What is the function of the muscle spindle?
SKELETAL MUSCLES CONTRACTION = SPINDLE STRETCHING
To monitor muscle position and to ensure it is not overstretched SKELETAL MUSCLES RELAX = SPINDLE COMPRESSION
