Anatomy 2.1 Nervous Flashcards
What is the structural aspect of the nervous system?
CNS (brain and spinal cord) and the PNS (remainder of nervous system outside of the CNS)
What is the functional aspect of the nervous system?
Somatic nervous system and Autonomic nervous system
Neurons
Structural and functional units of the nervous system specialized for rapid communication
What is a neuron composed of?
Cell body with processes called dendrites and axons
What do dendrites and axons do?
Carry impulses to and away from the cell body
Neurolglia
Support the neurons
What is the principal role of the CNS?
Integrate and coordinate incoming and outgoing signals and carry out higher mental functions (thinking and learning)
What do the meninges and cerebrospinal fluid do?
Surround and protect the CNS
What does the PNS consist of?
Nerve fibers and cell bodies outside the CNS
What do the nerve fibers and cell bodies of the PNS do?
Conduct impulses to or away from the CNS
Nerve fiber
Consists of an axon, its neurolemma, and surrounding endometrial connective tissue
What does a neurolemma of myelinated nerve fibers consist of?
Schwann cells that make up a series of
What does a neurolemma of unmyelinated nerve fibers consist of?
Schwann cells that do not make up any series
What does a nerve consist of?
Bundle of nerve fibers outside the CNS
Connective tissue coverings that surround and bind the nerve fibers and fascicles together
Blood vessels that nourish the nerve fibers and their coverings
What are the types of connective tissue coverings?
Endoneurium
Perineurium
Epineurium
Endoneurium
Delicate connective tissue surrounding the neurilemma cells and axons
Perineurium
Dense connective tissue that encloses a fascicle of nerve fibers
What does the Perineurium provide?
Effective barrier against penetration of the nerve fibers by foreign substances
Epineurium
Thick connective tissue sheath that surrounds and encloses a bundle of fascicles
What does the Epineurium form?
Outermost covering of the nerve and includes fatty tissue, blood vessels, and lymphatics
What does the anterior (ventral) nerve root consist of?
Motor (efferent) fibers
What does the posterior (dorsal) nerve root consist of?
Sensory (afferent) fibers
Somatic motor fibers
Transmit impulses to skeletal (voluntary) muscles
Visceral motor system
Information coming in from the organs
Visceral motor fibers
Transmit impulses to smooth (involuntary) muscle, cardiac muscle, and glandular tissues
Special sensory fibers
For the special senses (smell, sight, hearing, balance, taste)
Sympathetic nervous system
Fight or flight
Parasympathetic nervous system
Calms body down
Nociception
Pain stimuli (processed output of brain)
What type of touch does the somatosensory system have?
Discriminative touch (touch, pressure, flutter, vibration)
What is the position proprioception in the somatosensory systems?
Static forces (muscle length and tension, joint pressure)
What is the movement proprioception in somatosensory systems?
Dynamic forces (muscle length and tension, joint pressure and angle)
Cutaneous receptors
Unencapsulated (crude touch, pain, temperature)
Proprioceptive receptors
In muscles, tendons, joint ligaments, and joint capsules (muscle spindle and Golgi tendon)
Muscle spindle (excitatory)
Proprioceptor that monitors and signals muscle stretch (muscle length)
Golgi tendon organ (inhibitory)
Proprioceptor that monitors and signals muscle contraction against a force (muscle tension)
What happens when there is damage to the CNS?
Destruction of tracts in CNS
Lesion
Any type of damage to a neuron that causes the electrical information to not transmit properly
Crude touch
Itch
Tickle
Pleasant contact
Pleasant pressure
Discriminative touch
Contact
Vibration
Pressure
Stretch
Position (static) proprioception
Muscle length
Muscle tension
Joint tension
Joint angle
Movement (dynamic) proprioception
Muscle length
Muscle tension
Joint tension
Joint angle
Free nerve ending
Nociception
Temperature
Crude touch
Merkels disk
Discriminative touch (pressure)
Meissners corpuscle
Discriminative touch (vibration low frequency)
Ruffinis ending
Discriminative touch (stretch)
What are the elements of the somatosensory system?
Integumentary, muscular, and skeletal system
Pacinian corpuscle
Discriminative touch (vibration high frequency)
Hair follicle nerve ending
Discriminative touch (movement of hair)
Where are Ruffini like found?
Joint capsules
What is Ruffini like stimulus?
Joint position
Where are Pacinian like found?
Joint capsules
What are Pacinian like stimulus?
Joint movement
