PNS & Sensory Systems Flashcards
Sensory divison
Receptors detect stimuli and transmit
Motor Division
Brain sends signal to activate structures
Name 2 subdivisions of the motor division
Somatic and Autonomic
Sympathetic division
Fight or flight repsonse
Parasympathetic division
Rest and digest response
Endoneurium
Surrounds each individual axon
Perineurium
Surrounds group of axons (fascicles)
Epineurium
Surrounds nerve
How many pairs of cranial nerves are there
12
How many pairs of spinal nerves are there
31
Where do the spinal nerves leave the spinal cord through
Intervertebral foramen
Where do sensory neurons enter the spinal cord
Dorsal nerve root
Where do motor axons leave the spinal cord
Ventral nerve root
Name the 4 major plexuses
Cervical, brachial, lumbar, sacral
Cervical Plexus: location and what does it branch into?
In the neck; branches into Phrenic nerve and nerves in posterior head and trunk
Brachial Plexus: location and what does it branch into?
In the neck; branches into nerves that service the arms (radial, axillary, and ulnar)
Lumbar Plexus: location and what does it branch into?
In the lumbar region; branches into nerves that service the pelvis and legs (femoral and saphenous)
Sacral Plexus: location and what does it branch into?
Lumbar and sacral spinal nerves; branches into nerves that service the leg (sciatic nerve, which branches into tibial and fibular)
Intercostal Nerves
Axons from thoracic spinal nerves that extend to area around ribs
What is the primary control of homeostasis
Autonomic Nervous System
What does the ANS have control over (is it voluntary or involuntary)
INVOLUNTARY control over cardiac muscle, smooth muscle, and glands
What kinds of threats can be made to the sympathetic division of the ANS
Physical or emotional
What does the body need to fight or run from threats made to the sympathetic division of the ANS
ATP, oxygen & glucose, and blood
Name 5 physiological responses in the sympathetic division of the ANS
Breathing rate increases, HR increases, blood vessels going to skeletal muscle dilate, sweating increases, and pupils dilate
What 2 things happen in the parasympathetic division of the ANS
Breathing and HR lower and more blood goes to digestive organs
Sensation
Stimulus stimulates a sensory receptor
Perception
Brain processes information
Name the 3 types of sensory receptors
Free nerve ending, encapsulated ending, and specialized receptor cells
Free nerve ending
Dendrites embedded in tissue (ex: pain and thermoreceptors)
Encapsulated ending
Dendrites encapsulated in connective tissue
Specialized receptor cells
Modified neurons to detect a specific type of stimulus
Name the 6 types of specialized receptor cells and what they do
Chemoreceptors (respind to chemical stimuli), osmoreceptors (changes in body fluid solute concentrations), nociceptors (chemicals released from tissue damage), mechanoreceptor (respond to touch pressure and vibration), thermoreceptor (temperature changes), and photoreceptors (detect light energy)
General sense
Receptors distributed throughout the body
Somatosensation
Touch, pressure, vibration, itch, muscle stretch, tickle, and pain
Proprioception and kinesthesia
Body movement
Visceral sense
Sensation associated with organs
Special sense
Specific organ devoted to sensation (ex: eyes, ears, mouth and nose)
Palpebral conjunctiva
Thin membrane that lines inner surface of eyelid and extends over white areas of the eye (sclera)
Lacrimal gland
Produces tears
Lacrimal duct
Tears drain
Extraocular (extrinsic) muscles
Skeletal muscles that move the eye around
Firbous tunic
Consists of the sclera and cornea
Vascular tunic
Consists of the blood vessels and the choroid
Neural/sensory tunic
Contains photoreceptors and retina
Ciliary body; definition and functions
Attached to the lens; contracts and pulls the lens to change the shape for near and far vision and bends light to focus on retina
Iris
Constricts and relaxes to change the shape of the pupil
Anterior compartment (between cornea and lens) is filled with _________ humor. Posterior compartment (behind lens) is filled with ________ humor.
Aqueous; vitreous
Optic disc
Where blood vessels and neurons enter and leave the eye
Rods
More active in low light, more sensitivity than cones, cannot detect color
Cones
Only active in bright light, can detect color, required for visual acuity
Auricle
Ear
External auditory meatus
Ear canal, runs through the temporal bone
Tympanic membrane
Between external and middle ear
Cochlea
Has sensory receptors needed for hearing
How do we hear different sounds
Different frequencies of soundwaves stimulate different areas of the organ of Corti
Where are the taste buds located
Papillae
Name what each chemical stimulates for taste: glucose, hydrogen and acids, sodium, alkaloids, glutamate
Glucose: sweet Hydrogen and acids: sour Sodium: salty Alkaloids: bitter Glutamate: umami (savory)
