Autonomic Nervous System, Sensory, Motor, and Integrative Systems, The Special Senses
What are two types of Neurotransmitters used in ANS
2. All preganglionic fibers, some postganglionic fibers of sympathetic system, muscarinic, and parasympathetic.
3.activates cholinergic receptor.
4. Sympathetic postganglionic neurons that innervate most sweat glands
1. Nuerotransmitter released by cholinergic
1. Most sympathetic postganglionic neurons
-- Adrenergic Neurons – Norepinephrine (NE) aka Noradrenalin
3. released by most sympathetic post ganglionic fibers.
a. The first of the two motor neurons in any autonomic pathway
b. Cell body is in the brain or spinal cord – axon exits the CNS as part of the cranial or spinal nerve
c. Origin in lateral horn of gray matter of CNS
d. Short and myelinated
e. Most synapse in ganglia adjacent to CNS
f. Release Acetycholine
g. Most synapse in ganglia adjacent to CNS.
a. The second neuron in the autonomic motor pathway
b. Lies entirely outside the CNS in the PNS – Cell body and dendrites are located in the autonomic ganglion.
c. Extend from ganglia to target tissue
d. Long and unmyelinated
e. Typically release Catecholamine
What is the Thoracolumbar division?
Also known as (Sympathetic Division)
a. Fight or Flight Division
b. Activity results in increased alertness and metabolic activities to prepare the
body for an emergency situation
c.Axons of the sympathetic preganglionic neurons are thoracolumbar outflow.
What is the Craniosacral Division?
Also known as (Parasympathetic Division)
a. Rest and Digest Division
b. Activity conserve and restore body energy during times of rest or digesting a meal.
c. axons of the parasympathetic ganglionic neurons are the craniosacral outflow.
Nerve X (10).
1. Vagus (Nerve X) have preganglionic axons that leave the brain as part of the vagus nerve carry nearly 80% of the total craniosacracl flow.
2. Vagal axons extend to many terminal ganglia in the thorax and abdomen.
3. As the vagus nerve pass through the thorax it sends axons to the heart and the airways of the lungs. In the abdomen, it supplies the liver, gallbladder, stomach, pancreas, small intestine, and part of the large intestine.
4. Located in parasympathetic.
Where is the origin of the sympathetic preganglion neurons?
Cell bodies are located in the lateral horns of the gray matter in the 12
thoracic segments and the first two (sometimes three) lumbar segment of the
spinal cord (T1-L2)
What are the effectors of the ANS?
Which nervous system is voluntary?
Somatic Nervous System
Which nervous system is involuntary?
Autonomic nervous system
What is the neurotransmitters of the preganglionic neurons?
What is dual innervation?
1.Most organs are able to receive impulses from both sympathetic and parasympathetic neurons.
2. Typical of most viscera.
3. Tunica media of blood vessel is only sympathetic
1.Major control and integration center in ANS.
2.Regulates the autonomic nervous system
3.receives sensory input related to visceral functions, olfaction (smell) and gustation (taste)
4. Output of the hypothalamus influences autonomic centers in both the brain stem and the spinal cord
5.Connected to both sympathetic and parasympathetic divisions by axons of neurons.
6. The posterior and lateral parts of hypothalamus controls the sympathetic.
7.The anterior and medial parts control parasympathetic
What is the sympathetic trunk ganglia?
Also called (Paravertebral Ganglia)
a. Lie in a vertical row on either side of the vertebral column (lateral to spinal cord)
b. Extends from the base of the skull to the coccyx.
What are the activities of the Parasympathetic Division?
Its activities conserve and restore body energy during times of rest or digesting a meal; the majority of its output is directed to the smooth muscle and glandular tissue of the gastrointestinal and respiratory tracts. Conserves energy and replenishes nutrient stores
Insulin is activated by what system?
Autonomic nervous system--Parasympathetic
What does the acronym for SLUDD stand for?
FIVE parasympathetic response.
What is the job of the parasympathetic?
1.Enhances rest and digest activities
2.Supports body functions that conserve and restore body energy during rest and recovery
3.reduce body functions that conserve and restore body energy during rest and restore
4. decrease heart rate, decrease diameter of airways ans decrease diameter of pupils
Skeletal muscle activity is activated by?
Somatic nervous neurons or Somatic Nervous System
What is the structural makeup of Pacinian (Lamellated) Corpuscles and the sensory classification? What does it feel?
Large ovallayered structure composed of a multilayered connective tissue capsule that encloses a dendrite.
-Pressure / Vibrations (fast)
classified on morphology
What is the structural makeup of Meissner Corpuscles (corpuscles of touch) and the sensory classification? What does it feel?
An egg shaped mass of dendrites enclosed by a capsule of connective tissue in dermal papillae of hairless skin
-Touch / Pressure / Vibrations (slow)
-on the surface
-root hair plexus touch
-rapidly adapting touch receptors
What is the structural makeup of Ruffni corpuscles (Type II cutaneous mechanoreceptors) and the sensory classification? What does it feel?
Elongated capsule surrounds dendrites deep in the dermis and in ligaments and tendons
-Stretching of skin
-slow adapting touch receptor
What is the structural makeup of hair root plexus and the sensory classification? What does it feel?
Free nerve endings wrapped around hair follicles in skin
-rapidly adapting touch receptors found in hairy skin
What is the structural makeup of nociceptors and the sensory classification? What does it feel?
Free nerve endings found in every tissue of the body except the brain
-classification: type of stimulus detected
What is the structural makeup of free nerve endings and the sensory classification? What does it feel?
Bare dendrites associated with pain, thermal, tickle, itch, and some touch sensations that lack any structural specializations that can be seen under a microscope
-classification based on morphology
What is the structural makeup of proprioceptors and the sensory classification? What does it feel?
Located in muscles, tendons, joints and inner ear; provide information about body position, muscle length and tension, position and motion of joints and equilibrium (balance)
-Muscle Tendons = Muscle Length
-Tendon Organs = Muscle tension
-Joint Kinesthetic = Joint position and movement
--Allows us to know where our head and limbs are located , how they are moving, without looking at them.
--Allow weight discrimination
--Classified by location of receptors activating stimuli
What is the structural makeup of Thermoreceptors and the sensory classification? What does it feel?
Free nerve endings n skin and mucous membranes of the mouth, vagina and anus.
-feels warm and cold
-classified by types of stimulus detected
What are mechanoreceptors?
Detect (sensitive to) mechanical stimuli such as deformation, stretching, or bending of cells.
-Touch, pressure, vibration, proprioception, hearing and equilibrium
-Monitor stretching of blood vessels and internal organs---some kind of movement
What are Nociceptors?
Respond to painful stimuli resulting from physical or chemical damage to tissue
-Found in all tissue but the brain
-exhibit very little adaption
What are osmoreceptors?
Sense osmotic pressure of body fluids
What are photoreceptors?
Detect light that strikes the retina of the eye
what are chemoreceptors?
-And body fluids
What are thermoreceptors?
a. free nerve endings that have receptive fields about 1mm in diameter on the skin surface
b. Cold receptors are located in the stratum basale of the epidermis
-temp 10 and 40 C(50-105) activate cold receptor
c.Warm receptors are not as abundant as cold, are located in dermis
-activated by temps32-48C (90-118)
-temps below 10 and above 48 stimulate pain.
What are Muscle spindles?
-Sensory nerve endings wrap around central area of encapsulated intrafusal muscle fibers within most skeletal muscles.
-the proprioceptors in skeletal muscles that monitor changes in the length of skeletal muscles and participate in stretch reflexes.
-each muscle spindle consist of several slow adapting sensory nerve endings that wrap 3- 10 specialized muscle fibers
What is Accomodation?
Increase in the curvature of the lens for near vision.
--accomodation ceases at near point of vision
What is adaptation?
the generator potential or receptor potential decreases in amplitude during maintained, constant stimulus.
--causes the frequency of nerve impulses in the first order neuron to decrease.
---the perception of a sensation may fade or disappear even though the stimulus persists.
Olfactory receptors-type, where, shape
1. (Smell) – Are the first-order neurons of the olfactory pathway (bipolar).
--Each olfactory receptor is a bipolar neuron with an exposed knob-shaped dendrite and an axon projecting through the cribriform plate and ending in the olfactory bulb.
---The olfactory receptors are found on the olfactory hairs which originate from the dendritic ends.
Gustatory receptors-type, where, shape
-located in the taste buds
-surrounded by supporting cells
-single long microvillus, gustatory hair projects from each receptor cell through taste pore.
-has life span of 10 days
-at the base the gustatory receptor cells synapse with dendrites of the first order neurons that form the first part of gustatory pathway.
Nerves of the gustatory pathway
-contain axons of the first-order gustatory neurons that innervate taste buds.
--Facial Nerve (VII)
--glosspharyngeal nerve (IX)
--Vagus nerve (X)
---From the taste buds, nerve impulses propogate along the 3 cranial nerves to the gustatory nucleus in the medulla oblongata.
---located in lungs, tongue, bronchial tract, pharynx
Facial Nerve(VII) gustatory pathway
serves taste buds in the anterior two thirds of the tongue
glosspharyngeal Nerve (IX) gustatory pathway
serves taste buds in the posterior one third of the tongue.
Vagus Nerve (X) gustatory pathway
serves taste buds in the throat, and epiglottis
What does the nasolacrimal duct do?
1.Carries lacrimal fluid into the nasal cavity just inferior to the inferior nasal concha.
2. secrete tears.
What does the lacrimal canal do?
conducts fluid from lacrimal puncta to lacrimal sac
-leads into lacrimal sac
WHat does lysozymes do?
1.Inhibits bacterial growth.
2. A protective bactericidal enzyme.
3. Fluid protects, cleans, lubricates and moistens the eyeball
What is the sclera and what does it do?
Layer of the fibrous Tunic
1.The white of the eye, is a layer of dense connective tissue made up mostly of collagen fibers and fibroblasts.
2. Covers the entire eyeball except the cornea;
3.it gives shape to the eyeball, makes it more rigid, protects its inner parts, and serves as a site of attachment for the extrinsic eye muscles
What is the cornea and what does it do?
Layer of the fibrous tunic
1. Is a transparent coat that covers the colored iris.
2. Because it is curved, the cornea helps focus light onto the retina.
3. Its outer surface consists of nonkeratinized stratified squamous epithelium. The middle coat of the cornea consists of collagen fibers and fibroblasts, and the inner surface is simple squamous epithelium.
What is the conjunctiva and what does it do?
(small bump) – A thin, protective mucous membrane composed of nonkeratinized stratified squamous epithelium with numerous goblet cells that is supported by areolar connective tissue
What is the vitreous (body) humor and where is it located?
1.A transparent jellylike substance that holds the retina flush against the choroid, giving the retina an even surface for the reception of clear images.
2.Fills the posterior cavity
3. helps maintain shape of eyeball
4. Refracts light and not replaced.
What is the aqueous humor and where is it located?
1. A transparent watery fluid that nourishes the lens and cornea
2.Located in chamber of anterior cavity
3. Production and flow of aqueous humor
---ciliary process-->posterior cavity-->pupil-->anterior cavity-->canal of schlemm(scleral venous sinus)
4.Drains out of scleral venous sinus
5. replaced every 90 minutes
6. Helps keep eye inflated
7. Refracts light
8. contains some nutrients
What is the lens and what does it do?
1. Transparent organ constructed of proteins (crystallins)
2. located behind the pupil and iris within the cavity of the eyeball and helps focus images on the retina to facilitate clear vision.
3. located with in a capsule-held in place by suspensory ligaments.
4.Lens elastic, can change shape (concave-diverges light) (convex-converges light)
What is refraction?
1. A bend at the junction between 2 substances.
2.When light rays traveling through a transparent substance (air) pass into a second transparent substance (water), they bend at the junction between the two substances.
3.lens accomplish 25% of light refraction
4.cornea accomplish 75% of light refraction
Adaptation to light
1.Bleaching of rods exceeds regeneration in light.
2.Regeneration in cones keeps pace with bleaches reception of bright light.
3.Occurs when you emerge from dark surroundings (tunnel) into the sunshine.
4. Visual system adjusts in seconds to the brighter environment by decreasing its sensitivity.
Adaption to dark
1. photopigments of cones do not bleach.
2. Rhodopson of rod regenerates as light dims.
3.Occurs when you enter a darkened room (theater). 4.Visual system increases sensitivity slowly over many minutes.
The single type of photopigment in rods.
A glycoprotein associated with vision
-contribute to the optic nerve fibers which carry impulses to the brain
-layer of retinal neurons
--receive neurotransmitters and conduct an impulse to ganglion cells.
--layer of retinal neuron has horizontal cells amacrine cells
rods and cones
detect light and stimulate bipolar cells by releasing a neurotransmitter
layer of retinal neuron
External ear (outer ear)
Consists of the auricle, external auditory canal, and eardrum
a. Auricle (Pinna) – is a flap of elastic cartilage shaped like the flared end of a trumpet and covered by skin
b. External Auditory Canal – is a curved tube about 2.5 cm long that lies in the temporal bone and leads to the eardrum
c. Eardrum (Tympanic Membrane) – is a thin, semitransparent partition between the external auditory canal and the middle ear
Middle ear (tympanic cavity)
1.Is a small, air-filled cavity in the petrous portion of the temporal bone that is lined by epithelium.
2.It is separated from the external ear by the tympanic membrane and internal ear by thin bony partition that contains two small membrane-covered openings, the oval window and the round window
The oval central portion of the bony labyrinth.
Sac located in the membranous labyrinth in the vestibule connected by a small duct.
--chambers arising from the semicircular ducts.
Sac located in the membranous labyrinth in the vestibule connected by a small duct.
--chamber arising from the semicircular ducts
--contain macula(sense organ for static equilibrium)
bony spiral canal located in the membranous labyrinth in the vestibule.
--Anterior to the vestibule (snail shaped) bony spiral canal and makes almost three turns around the central bony core.
--Coiled tube divided by a bony shelf into two compartments 1) Scala vestibule 2) scala tympani
Located in the labyrinth
--stationary endolymph promotes bending of hair cells.
--all structures membranous labyrinth is filled with endolymph
a ringing, roaring or clicking in the ears.
projecting superiorly and posteriorly from the vestibule are the three bonystructures named anterior, posterior, and lateral semicircular. filled with perilymph.
-an inflammation of the conjunctiva when caused by bacteria such as pneumococci, stephlococci or haemophilis influenzae.
-it is very contagious and more common in children
-may also be caused by irritants such as dust, smoke, or pollutants in the air, in which case it is not contagious.
night blindness-inability to see well at low light levels
-prolonged vitamin A deficiency and the resulting below amount of rhodopsin may cause night blindness
occurs very rapidly, usually 0.1 second after a stimulus is applied because the never impulses propagate along medium-diameter myelinated A fibers.
-also called acute, sharp, or pricking pain
-not felt in deeper tissue.
-begins a second or more after a stimulus is applied gradually increases over a period of seconds and minutes.
-conducted along small diameter,unmyelinated C fibers
-burning, aching, throbbing pain
-occur in skin and deep tissue and internal organs
Types of cone receptors
Cone cells are densely packed in the fovea centralis a 0.3 mm diameter rod-free area with very thin, densely packed cones, but quickly reduce in number towards the periphery of the retina. There are about six to seven million cones in a human eye and are most concentrated towards the macula.
--The first responds the most to light of long wavelengths, peaking at a reddish colour; this type is sometimes designated L for long.
-- The second type responds the most to light of medium-wavelength, peaking at a green colour, and is abbreviated M for medium.
--The third type responds the most to short-wavelength light, of a bluish colour, and is designated S for short.
Types of rods and photo pigment
1. each photopigment is a combination of retinal and one of the opsins
2. Photopigment for rods is rhodopsin
3. rods involved primarily with "noncolor vision" can absorb blue-green light
calcium carbonate particles in membrane.
--extends over the entire surface of the otolithic membrane.
lips, face, tongue, and hand-provide input to large regions in the somatosensory area.
--trunk and lower limbs project to smaller cortical regions
--expand or shrink depending on the quantity of sensory impulses received from the body part
what does the lacrimal duct do?
Empty tears onto the surface of the conjunctiva of the upper lid.