CH 13-15 AP
What is an otolith?
crystals of calcium carbonate that move within the vestibule and activate the vestibular receptors when the head changes position
Compare and contrast the neurons used in these two systems (Parasympathetic and sympathetic)
he PNS controls homeostasis and the body at rest and is responsible for the body's "rest and digest" function. The SNS controls the body responses to a perceived threat and is responsible for the "fight or flight" response.
Pathway of sound waves
1. Sound waves (SW) enter the external acoustic meatus causing the tympanic membrane to vibrate. 2. Vibration is transmitted through the auditory ossicles (small bones in the inner ear) to the vestibule. 3. SW enter the fluid (endolymph) of the scala vestibuli and travel to the Cochlea
What neurotransmitter is needed to control the SNS?
Acetylcholine
Different humors and a disease that is associated with the aqueous humor?
Aqueous humor - fills anterior cavity- 98% water - continuously produced by the capillary body to nourish avascular eye structures and maintain eye pressure. Glaucoma: blocked drainage of aqueous humor increases pressure and causes compression of retina and optic nerve blindness Vitreous humor - fills posterior cavity- gelatinous consistency- maintains shape of the eye and protects the retina. Produced once in embryo lasts a life time. Lens separates internal cavity into anterior and posterior segments (cavities) Biconvex, transparent, flexible, and avascular Changes shape to precisely focus light on retina
List the 12 pairs of cranial nerves; designate which are motor, sensory, or mixed, and give the function of each.
Brain responsible with sensory and motor control associated with the head using only nerves 1. Olfactory nerves - sensory - function in smell. 2. Optic nerve - sensory - function in vision 3. Oculomotor - motor - eyelid and eye movement, control of iris and lenses 4. Trochlear - motor - movement of the eye 5. Trigeminal (tri-jem -e-nal) - mixed - sensory function in tear production and touch in scalp and face, motor function for chewing. 6. Abducens (ab - doo-senz) - motor - eye muscle movement 7. Facial - mixed - sensory for taste, motor for facial expression, tears and salivary glands 8. Vestibulocochlear - sensory - sense of balance and hearing 9. Glossopharyngeal - mixed- sensory conduct impulses from the pharynx, tonsils, tongue and carotid arteries, motor function in salivary gland and muscles in pharynx for swallowing 10. Vagus - mixed - sensory and autonomic motor figures function throughout the viscera of the thorax and abdomen. Somatic muscle movement for speech and swallowing 11. Accessory nerve - motor - movement of the soft palate, pharynx, larynx, neck and back 12. Hypoglossal - motor - tongue movement.
Know the different plexuses
Cervical plexus brachial plexus lumbar plexus sacral plexus
What happens to someone's vision with different shaped eyes?
Change in lens curvature allows for fine focusing
Describe a disease associated with lack of tear production.
Chronic Dry Eye Cause is unknown. Associated with computer use, lasik eye surgery, postmenopausal women, use with allergy medicine (anti-histamines) Results in improperly made tears or not enough tears. Complications are eye infections, scaring of the eye that could affect vision
Difference between night and color blindness?
Colour blindness Color-blindness is associated with missing cones. Night blindness Night-blindness can be caused by lack of vitamin A
What are the homeostatic imbalances in the ears?
Conduction deafness Sensorineural deafness Tinnitus Meniere's syndrome Hyper-secretion of growth hormone Hypo-secretion of growth hormones
Be able to discuss motion sickness, deafness, and tinnitus.
Conduction deafness? Blocked sound conduction to fluids of internal ear Impacted earwax, perforated eardrum, otitis media, otosclerosis of the ossicles Sensorineural deafness? Damage to neural structures at any point from cochlear hair cells to auditory cortical cells Tinnitus? Ringing or clicking sound in ears in absence of auditory stimuli due to cochlear nerve degeneration, inflammation of middle or internal ears, side effects of aspirin
What is refraction and what three parts of the eye that carry out refraction?
Cornea - Iris - Lens • Due to change in speed when light passes from one transparent medium to another
Roles of the Basilar Membrane and Hair cells
Depending on the frequency of the SW, different receptors cells (inner hair cells) on the basilar membrane within the Organ of Corti (deep in the Cochlea) will be activated and uptake calcium.
What does the autonomic nervous system control?
Exocrine glands, cardiac muscle, smooth muscle, and endocrine glands. Most visceral organs have dual innervation Dynamic antagonism allows for precise control of visceral activity Sympathetic division - activated during the "Flight, Fright and Fight. Increases heart and respiratory rates, and inhibits digestion and elimination Parasympathetic division - activated for "Rest and Digest" decreases heart and respiratory rates, and allows for digestion and discarding of wastes
Difference between amplitude and frequency?
Pitch (Frequency) The number of vibrations per second Amplitude The loudness of the note is related to the strength of its vibration.
How does the sensory information enters the spine, goes to the brain and back through the spine and out?
Information is delivered into the spinal cord through the axon terminals of sensory neurons. Once in the spinal cord, the information may flow to motor neurons then to interneurons that transmit the information to the brain.
How does the fluid affect the homeostasis of the eye?
Internal cavity filled with fluids called humors Aqueous humor - fills anterior cavity- 98% water - continuously produced by capillary body to nourish avascular eye structures and maintain eye pressure.
How is the NMJ a representative of Motor Control?
It's a chemical synapse between a motor neuron and a muscle fiber. It allows the motor neuron to transmit a signal to the muscle fiber causing muscle contraction. Muscles require innervation to function - and even just to maintain muscle tone, avoiding atrophy.
Which part of the brain has the most control over the autonomic system? Discuss how it is used.
It's controlled by hypothalamus. main integrative center of ANS activity Subconscious cerebral input via limbic system structures on hypothalamic centers Other controls come from cerebral cortex, reticular formation, and spinal cord
Know the external muscles of their eyes and the movement that they control.
Lateral rectus - moves eye laterally Medial rectus- moves eye medially Superior rectus - elevates eye and turns it medially Inferior rectus - depresses eye and turns it medially Inferior oblique - elevates eye and turns it laterally Superior Oblique - depresses eye and turns it laterally
Name and describe all the receptors in the peripheral nervous system
Mechanoreceptors—respond to touch, pressure, vibration, and stretch Thermoreceptors—sensitive to changes in temperature Photoreceptors—respond to light energy (e.g., retina) Chemoreceptors—respond to chemicals (e.g., smell, taste, changes in blood chemistry) Nociceptors—sensitive to pain-causing stimuli (e.g. extreme heat or cold, excessive pressure, inflammatory chemicals)
How is Voluntary control of the autonomic system used?
Mostly involuntary control instigated by hypothalamus but some voluntary control
What are the receptors used on the effectors of the autonomic nervous system?
Muscarinic receptors - Binds to these receptors. They are found on most Visceral effectors. Nicotine Receptors - nicotine binds to these. They are found on skeletal muscle and autonomic ganglia. Two types of receptors bind ACh - Nicotinic & Muscarinic Named after drugs that bind to them and mimic ACh effects Two major classes ; Alpha & Beta Effects of NE depend on which subclass of receptor predominates on target organ
What are the problems associated with eye shape and lens shape?
Myopia (nearsightedness) Focal point in front of retina, e.g., eyeball too long Corrected with a concave lens Hyperopia (farsightedness) Focal point behind retina, e.g., eyeball too short Corrected with a convex lens Astigmatism- Unequal curvatures in different parts of cornea or lens Corrected with cylindrically ground lenses or laser procedures
Where is the image perceived in the eye and how is this image taken to the brain?
Occurs when light meets surface of different medium at an oblique angle What in the eyeball is curved and refracts light? - Curved lens can refract light - Light that is refracted creates an inverted image
Which cranial nerves are part of the parasympathetic nervous system and their motor functions?
Oculomotor nerves - smooth muscle of eye Facial nerves - stimulate large glands in head Glossopharyngeal nerves - parotid salivary glands Vagus nerves - neck and nerve plexuses for ~ all thoracic and abdominal visceral • Serves pelvic organs and distal half of large intestine • Axons travel in ventral root of spinal nerves in sacral plexus
Know the effects of activation of receptors in both the parasympathetic and sympathetic nervous system?
Parasympathetic division: short-lived, highly localized control over effectors - ACh quickly destroyed by acetylcholinesterase Sympathetic division: longer-lasting, body wide effects - NE inactivated more slowly than ACh - NE and epinephrine hormones from adrenal medulla prolong effectsSympathetic division:
Explain how light is focused in a normal person?
Pathway of light entering eye: cornea, aqueous humor (anterior), pupil, lens, vitreous humor then, light enters the neural layer of retina and is conveyed to the photoreceptors Light refracted three times along pathway - Entering cornea - Entering lens - Leaving lens
What are the aspects of sensory perception?
Perceptual detection— ability to detect a stimulus (requires summation of impulses) - Magnitude estimation— intensity coded in frequency of impulses -Spatial discrimination— identifying site or pattern of stimulus (studied by two-point discrimination test)
Difference between pitch, tone and loudness
Pitch Perception of different frequencies Normal range 20-20,000 hertz (Hz) Higher frequency = higher pitch Amplitude Height of crests Loudness • perceived as loudness -Normal range is 0-120 decibels (dB) -Severe hearing loss with prolonged exposure above 90 dB Amplified rock music is 120 dB or more
General organization of the peripheral nervous system (PNS)
Provides links from and to world outside body All neural structures outside brain - Sensory receptors - Peripheral nerves and associated ganglia -Efferent motor endings
What is the somatosensory system? How is it organized?
Responds to stimuli outside of the body. Exteroceptors - Receptors in skin for touch, pressure, pain, and temperature Interoceptors (visceroceptors) - Sensitive to chemical changes, tissue stretch, and temperature changes inside the body Proprioceptors- Respond to stretch in skeletal muscles, tendons, joints, ligaments, and connective tissue coverings of bones and muscles to inform brain of body position
What are the three levels of Motor Control? What parts of the brain are involved in each part? What are the functions of each part?
Segmental Level (Automatic Response)- controlled by Spinal Cord known as reflexes Projection Level (Intermediate Response) - controlled by Brain Stem and Motor Cortex for posture, eye and head movements- also sends information to Precommand Level for integration. Precommand Level ( Apex Response) - controlled by Cerebellum and Basal Ganglia- fine tunes voluntary movement- sends signal back to projection level
What are the five components of the Reflex Arc?
Sensory receptor Sensory neuron Integration center Motor neuron Effector target
Know the parts of the vestibule and semicircular canals and their roles in the equilibrium pathway to the brain
Sensory receptors (crista ampullaris) located in a gel-like mass called an ampullary cupula One in ampulla of each semicircular canal Major stimuli are rotational movements
Describe the difference between static and dynamic equilibrium?
Static is the state of the head and body posture when the head and body are still and is detected using vestibular receptors Dynamic is the state of the head and body posture when the head and body are moving and is detected using semicircular canal receptors
What are the two components of the autonomic nervous system? Describe the relationship between these two systems?
Sympathetic and parasympathetic The SNS prepares the body for intense physical activity and is often referred to as the fight or flight response. The PNS has almost the exact opposite effect and relaxes the body and inhibits or slows many high energy functions.
What organs are controlled by the parasympathetic system?
The PNS; Controls eye, salivary glands, heart, lungs, stomach, pancreas, liver and gallbladder, bladder and genitals. The PNS controls homeostasis and the body at rest and is responsible for the body's "rest and digest" function. The SNS controls the body responses to a perceived threat and is responsible for the "fight or flight" response.
Compare and Contrast the structure and types of neurons needed between the somatic and autonomic nervous system?
The SNS has sensory and motor pathways, whereas the ANS only has motor pathways. The ANS control internal organs and glands, while the SNS controls muscles and movement.
What organs are controlled by the sympathetic system?
The SNS; eye, skin, salivary glands, lungs, heart, stomach, pancreas, liver and galbladder, adrenal glands, bladder and genitals The SNS; Control the internal organs to the brain by spinal nerves. When stimulated, the nerves prepare them for stress by increasing heart rate, increasing blood flow to muscles and decreasing blood flow to the skin.
Roles of Cornea, Iris, lens, retina, rods and cones in perceiving light.
The cornea is also a part of the outer layer. Embedded in the retina are millions of light sensitive cells, which come in two main varieties: rods and cones. Rods are used for monochrome vision in poor light, while cones are used for color and for the detection of fine detail. 1) Light passes through the cornea covering the eye which refracts it. 2) The iris regulates the size of the pupil which controls how much light is allowed to enter the eye. 3) Behind the pupil is the lens that focuses light (or an image) onto the retina
What are the functions of the dorsal and ventral roots and rami?
The dorsal and ventral rami contains nerves that provide visceral motor, somatic motor, and sensory information, with the dorsal ramus feeding the dorsal trunk (skin and muscles of the back) and the ventral ramus feeding the ventral trunk and limbs through the ventrolateral surface.
What is the effect of the nervous system? (Stimulatory or Inhibitory)
The effectors of the somatic nervous system are the skeletal muscles. The efferent neurons (also known as the motor neurons) of the somatic nervous system The effect is when its faced with a threatening situation, it makes sense that your heart rate and blood pressure will increase, breakdown of glycogen will occur (to provide needed energy) and your heart rate of respiration will increase. All of these are stimulatory. It has an opposite inhibitory function (dampens a response)
What does the somatic nervous system control?
The somatic nervous system is a component of the peripheral nervous system associated with the voluntary control of the body movements via the use of skeletal muscles.
What are receptors?
They are cells that detect stimuli There are many different types e.g. taste and sound receptors Receptors for both the static and dynamic equilibrium send signals to the cerebellum (reflex center) of the brain which allows the brain to signal the appropriate skeletal muscles with motor neurons. In addition, the brain responds to proprioceptive receptors that are used for determining body position located in the joints and neck. In addition, the brain responds to visual receptors that are used for spatial orientation.
How and where is sound processed in the brain?
Vesicles at the base of the receptors will release neurotransmitters which will stimulate sensory neurons along the cochlear branch of the vestibulocochlear nerve. The auditory cortex of the temporal lobe within the brain interrupts the sensory impulses.
What is pain tolerance?
When we feel pain, sensory receptors send a message to the a delta fibers and c fibers, to the spinal cord and brainstem, where its registered,then processed. • All perceive pain at same stimulus intensity • Pain tolerance varies • "Sensitive to pain" means low pain tolerance, not low pain threshold • Genes help determine pain tolerance, response to pain medications - Research to allow genes to determine best pain treatment
Discuss the role of biofeedback.
a process whereby electronic monitoring of a normally automatic bodily function is used to train someone to acquire voluntary control of that function. Awareness of physiological conditions with goal of consciously influencing them Biofeedback training allows some to control migraines and manage stress
How is light measured?
wavelengths
What are the different types of reflexes?
• Inborn (intrinsic) reflex - rapid, involuntary, predictable motor response to stimulus Example - maintain posture, control visceral activities - Can be modified by learning and conscious effort • Learned (acquired) reflexes result from practice or repetition Example - driving skills Reflex is named for the effector - Somatic Reflexes - skeletal muscle is the effector - Autonomic Reflexes - smooth muscles in visceral organs are the effectors.
The function of the lacrimal gland, what tears are made of and their function.
• Lacrimal gland and ducts that drain into nasal cavity • Lacrimal gland in orbit above lateral end of eye • Lacrimal secretion (tears) - Dilute saline solution containing mucus, antibodies, and lysozyme - Blinking spreads tears toward medial commissure - Tears enter paired lacrimal canaliculi via lacrimal puncta (PUNG-TA) -Then drain into lacrimal sac and nasolacrimal duct
What are the homeostasis imbalances: hyperalgesia, phantom limb pain, visceral pain, and referred pain?
• Long-lasting/intense pain— Hyperalgesia (pain amplification) - Condition that causes increased sensitivity to pain. - Modulated by NMDA receptors—allow spinal cord to "learn" hyperalgesia • Early pain management critical to prevent • Phantom limb pain - Felt in limb no longer present - Now use epidural anesthesia to reduce • Visceral Pain - Stimulation of visceral organ receptors - Occurs when pain receptors in the pelvis, abdomen, chest, or intestines are activated. • Referred pain - Pain from one body region perceived from different region - Visceral and somatic pain fibers travel in same nerves; brain assumes stimulus from common (somatic) region • E.g., left arm pain during heart attack
What does the sacral part of the nervous system control?
• Serves pelvic organs and distal half of large intestine • Axons travel in ventral root of spinal nerves in sacral plexus • Synapse with ganglia in walls of distal half of large intestine, urinary bladder, ureters, and reproductive organs
How do we perceive pain?
• Warns of actual or impending tissue damage protective action When we touch a hot stove, sensory receptors in our skin send a message to a detla fibers and c fibers, to the spinal cord and brainstem, then onto the brain where the pain is registered