Sensory Part 1 Flashcards
Grouping of receptor types
- type of stimuli received
- time until sensory adaption occurs
What are the 6 different types of stimuli?
- chemoreceptors
- mechanoreceptors
- photoreceptors
- thermoreceptors
- nociceptors
- baroreceptors
2 types of time to sensory adaption:
- tonic receptors (always on)
- phasic receptors (active with stimulus change)
What are some examples of sensory adaptation?
- hum of projector
- feeling of feet on floor
- cold water in pool
Paths to sensory cortical regions (3):
- olfactory pathways from the nose project through the olfactory bulb to the olfactory complex
- most sensory pathways project to the thalamus. The thalamus modifies and relays info to cortical centers
- equilibrium pathways project primarily to the cerebellum
What are examples of chemoreceptors? (4)
- peripheral chemoreceptors
- central chemoreceptors
- olfactory receptors
- gustatory receptors
Where and what are peripheral chemoreceptors?
-aortic and carotid bodies
- monitor blood pH, CO2, and O2
Where and what are central chemoreceptors?
- in CNS
- monitor CSF and blood CO2 in medulla oblongata
a. medulla oblongata
b. CSF
c. blood-CSF barrier
d. capillary blood
central chemoreceptors location
Functions of the medulla oblongata
ANS control
1. cardiovascular control center (regulate HR & strength of contraction)
2. vasomotor control center (distribution of blood flow)
3. respiratory control center (rate of breathing)
Olfaction function:
important for communication
1. don’t need line of sight
2. function at night and far way
3. signal remains after you leave
What type of neuron are olfactory cells?
bipolar neurons
a. olfactory tract
b. cribriform plate of ethmoid
c. nasal conchae
d. olfactory epithelium
e. olfactory bulb
a. olfactory nerve (CN I)
b. ACE2 basal cell
c. ACE2 sustentacular cell
d. sensory cell
e. olfactory cilia
What is special about olfactory cilia?
they have a high surface area
a. cribriform plate of ethmoid
b. lamina propria (areolar)
c. olfactory epithelium
Where do mucous membranes line?
- respiratory
- urinary
- reproductive
- digestive passages
Many olfactory cells synapse into a single mitral cell in the olfactory bulb. This is an example of?
convergence
Where do odorants bind?
they bind to receptors on cilia of olfactory receptor cells
How do we distinguish around 10,000 odors?
- we have only 400 active genes, which each detect a few similar odorants with each olfactory cell having only one receptor type
- combo of odorants determines odor (like letters in alphabet
Olfaction bypasses the thalamus and goes directly to olfactory cortex T/F
true
Why do older people wear a lot of perfume and cologne?
olfactory cell replacement declines with age and sensitivity to smell diminishes
Why is a bloodhounds olfaction so good?
- 230 million olfactory cells in olfactory epithelium (humans 6 million)
- wrinkled muzzle traps scent particles
- ears flap on ground and waft scent to nose
- bred to smell rabbits
- other benefits (olfactory bulb larger, olfactory recess, lamina transversa, nostrils)
Dogs cannot smell cancer on urine or breath. T/F
False - dogs can smell cancers because of the metabolism of diseaced cells that produce unique VOCs
Review VNO
How do fish taste?
touch on outside of body
What are the 4 types of papillae:
- vallate
- foliate
- filiform
- fungiform
Vallate papillae
- largest papillae
- have the most taste buds
- “v” at back of tongue
Foliate papillae
only have buds in children
Filiform papillae
- lack taste buds
- touch sensation
Identify the papillae
fungiform
Identify the papillae
filiform
Identify the papillae
foliate
Identify the papillae
vallate
Where are other taste buds that are not on the tongue?
cheek, palate, pharynx
Where are tasted buds on the papillae?
on the side
What is a taste bud made up of?
many taste cells
What are the cells of the taste bud?
- sustentacular
- gustatory
- basal
What are the three cranial nerves that taste goes through?
- facial
- glossopharyngeal
- vagus
What are taste cells specific for and are there taste specialization?
each taste cell is specific to one taste/”flavor” - there are no regional specializations
What are the specific tastes of taste buds? (6)
sweet, umami, bitter, sour, salt, water
What describes umami?
savory/meaty
Why is bitter the most sensitive taste?
important to identify spoiled food/natural poisons (arsenic)
Where is the water receptor?
on back of pharynx
What are the two sensory nerves for gustation?
facial & glossopharyngeal
Where does most food flavor come from?
olfaction
What are the two types of cutaneous mechanoreceptors with examples?
- laminated with collagen (Meisner’s & Pacinian corpuscles)
- non-laminated (free nerve ending, Merkel’s cells, Ruffini endings)
Meissner’s corpuscle
- allow fine touch - laminated
- dense in fingertips, eyelids, soles of feet, genitalia, and nipples
- respond to flutter & stroking movement
rapidly adapting (stop sensing) - detect light pressure - found just under epidermis
Pacinian corpuscle
- deep touch - laminated
- sense vibrations
- common in fingertips, genitalia, and periosteum
- lamination prevents stimulation except for direct contact
rapidly adapting - detect deep pressure - found in subQ
Merkel’s cells
-sense steady pressure and texture
slowly adapting (continuously sense) - detect light pressure - found just under epidermis
Ruffinis endings
- detect skin stretch
slowly adapting - detect deep pressure - found in dermis
Examples of free-nerve endings
- hair follicle receptors
- thermoreceptors
- nociceptors
Hair follicle receptors
sense wind blowing by hair follicle base vibrations - senses hair movement
What responds to noxious stimuli?
free-nerve endings of nociceptors
What do thermoreceptors respond to?
changes in temperature
What are two foods/flavors that trigger thermoreceptors?
menthol & capsaicin
Why does spicy food burn going in and out?
2 types of nociceptors somatic (causes anus to burn from feces and on tongue and pharynx as thermo and nocio triggered) and visceral (intestines) - in your intestines there are physiological responses but don’t notice it … such as digestion speeds up, immune responses, can reduce inflammation
What animal is immune to the spice of capsaicin and why?
birds - they don’t have nociceptors in their mouths - encourages seed dispersal
Two factors of proprioception:
muscle spindles & golgi tendon organ
How do muscle spindles aid in proprioception?
- detect stretch of muscle
- considers speed of stretch
How do golgi tendon organs aid in proprioception?
- detect tendon stretch
- monitor tension
Who has lateral lines?
- agnathans
- condricthyes
- actinopterygians
What do lateral lines do?
- give fish sense of touch or movement in the water
- “distant touch”
How do lateral lines work?
openings in scales go into lateral lines - vibration of water sends it into lateral line - neuromasts detect water vibrations - within neuromasts there are multiple hair cells with cilia projections and a cupula (gelatinous) cap that moves over cilia - all this triggers afferent neurons
What are the two types of cilia projections in neuromasts? And what is their composition?
- stereocilia (short)
- kinocilium (long)
- 9+2 microtubule structure
What can fish determine with their lateral lines and how?
- which way the water is moving
- constant action potential = no movement/vibrations
- increase AP firing - movement from one direction
- decrease AP firing - movement from opposite direction
What is this and identify its parts?
Neuromast
a- cupula
b- kinocilium
c- stereocilia
d- hair cell
e- sustentacular cell
f- afferent lateralis neuron
g- efferent lateralis neuron
Why is electroreception important and what is it?
water conducts electricity - fish can detect electrical activity (heart always beating even if not moving) to find food/hunting
Who has electroreception?
- agnathans
- condricthyes
- actinopterygians
- platypus
What anatomical part does electrical detections?
ampullae of lorenzini (1000s of ampullae - hair cells detect voltage changes in seawater)
What have humans invented that uses the idea of electroreception?
electrocardiomyopathy
What are the 2 functions of the auditory system?
- hearing
- equilibrium
What are the 4 functions of hearing in the auditory system?
- detecting sound
- localizing sound
- pitch
- loudness
What are the 2 functions of equilibrium in the auditory system?
- rotation of the head
- linear acceleration & deceleration
Wavelength
length from wave to wave part per time
Frequency
how frequent from peak to peak (increase freq. = high pitch; decrease freq. = low pitch)
Amplitude
how high peaks go relative to the trough (high amp. = loud; low amp. = quiet)
What are the three major parts of the ear anatomy?
- external ear (pinna)
- middle ear (ear drum & ossicles)
- internal ear (vestibule & cochlea)
What does ear wax (cerumen) do for the ear?
prevents bacterial growth
Why do ears pop?
difference in external ear pressure & eustachian tube - as we increase external canal pressure the middle ear still has previous pressure - popping equalizes this pressure
What are the three ossicles of the middle ear?
malleus, incus, stapes
What are the two muscles of the middle ear?
tensor tympanii, stapedius
What are the function of ear ossicles?
- transmit sound to oval window
- transform sound waves into fluid waves
- amplify the sound
