Chapter 19: Senses: General and Special Flashcards
Differentiate between tonic and phasic receptors.
Tonic Receptors:
- Continuous
- Involved with maintaining balance
Phasic Receptors:
- Detect changes in stimulus
- Signal increased pressure on our skin when pinched
- Can undergo adaptation: reduction in sensitivity to continually applied stimulus
ie. when you put on a shirt you first notice it but after a few minutes you don’t notice it anymore
List and describe the 6 receptors that are named for their stimulating agent.
- Chemoreceptors: detect chemicals in fluid
- Thermoreceptors: detect temp change
- Photoreceptors: detect changes in light (intensity, color, movement)
- Mechanoreceptors: detect physical changes in touch, pressure, vibration, and stretch
- Baroreceptors: detect pressure changes in the body
- Nociceptors: detect tissue damage and pain caused by internal and external stimuli
Discuss the differences between phantom pain and referred pain.
Phantom pain:
- sensation associated with a part of the body that has been removed , usually an amputated limb
Referred pain:
- impulses from certain viscera are perceived as originating not from the organ but in a dermatome of the skin
- ie. heart attack: pain felt in the left arm
Discuss proprioceptors/proprioception.
- found in muscles, tendons, joints
- detect body and limb movements, muscle contraction, and stretch
- Awareness of their position and state of contraction of skeletal muscles
(Knowing where and in what position your body parts are in without looking.)
Describe a receptor.
- Range from simple to complex
- Monitor internal and external conditions and send that info to the CNS
- They make us aware of stimuli
Describe a receptive field.
- the entire area through which the sensitive ends of the receptor cell are distributed
- the larger the receptive field, the harder is to pin point exact location of the stimulus and vice versa (smaller receptive field, easier it is to pin point location of stimulus)
List and describe the two types of receptors.
- General senses
temp, pain, pressure, touch, stretch - Special senses
gustation (eating and feeling full), olfaction, vision, equilibrium, audition (hearing)
Discuss tactile receptors and understand what kind of receptors these are.
(Diagram Pg. 566)
- Mechanoreceptors! that react to touch, pressure, and vibration
- Location: dermis and subcutaneous tissue
- 2 Types:
1. Unencapsulated - ends NOT wrapped in connective tissue; free nerve endings deep in epidermis
2. Encapsulated - ends ARE wrapped in connective tissue;
krause bulbs, lamellated corpuscles, ruffani corpuscles, tactile corpuscles
Where are gustatory receptors found and what types of sensations do they detect?
(Diagram Pg. 567)
- housed in specialed taste buds on the surface of the tongue
- taste buds are on papillae on the tongue
4 types of papillae
1. Filiform- Anterior 2/3 of tongue
- No taste buds; no sensory role
- Fungiform
- Tip and side of tongue
- Contain a few taste buds - Vallate
- Least numerous and largest
- V-shaped arrangement, posterior part of tongue
- Most of our taste buds are housed here - Foliate
- Not well developed on human tongue
- A few during infancy and early childhood
5 Basic Taste Sensations:
salty, sweet, sour, bitter, umami
Nerves Associated: CN VII (facial) and CN IX (glossopharyngeal)
Discuss olfaction and the innervation for this sense.
Diagram Pg. 569
3 Cell Types:
- Olfactory Nerves - detect odor
- Supporting Cells - maintain receptors
- Basal Cells - replace olfactory epithelium
Describe and be able to label the structures of the eye.
Diagram Pg. 573
- Visual receptors detect light, color, and movement
- Accessory structures provide covering for the eye, prevent foreign objects from entering, keep eye moist, clean and lubricated
3 Tunics
- Fibrous Tunic
- cornea (transparent, avascular)
- sclera (white part of eye) - Vascular Tunic
- choroid (large capillary network)
- ciliary body (ciliary muscles and processes)
- iris - Neural Tunic
- Retina
Optic Disc - Blind spot (lacks photoreceptors)
Fovea Centralis - Area of sharps vision
2 Cavities/3Chambers
- Anterior Cavity (anterior to lens, posterior to cornea)
- Anterior Chamber (between iris and cornea)
- Posterior Chamber (between iris and the lens)
- Posterior Cavity (posterior to lens, anterior to retina)
- Vitreous Chamber
2 Types of Fluid
- Aqueous Humor
- Located in anterior cavity
- Removes waste and helps maintain chem environment of the eye - Vitreous Humor
- Located in posterior cavity
- Gelatinous
Photoreceptors:
Rods - black and white
Cones - colors
Understand the visual pathways. (Pg. 581)
Describe and be able to label the structures of the ear.
Diagram Pg. 573
3 Sections of the Ear
1. External Ear
- Auricle and external acoustic meatus
2. Middle Ear
- Tympanic cavity (air filled)
- Auditory Ossicles
- Malleus (hammer): articulates w/ tympanic membrane
- Incus (anvil): articulates with malleus and stapes
- Stapes (stirrup): articulates with round window
- Auditory tube: allows for pressure equalization
3. Inner Ear
- Bony Labyrinth
- Vestibule (utricle and saccule, with otolithic membrane and otoliths)
- Semicircular canals
(together these 1st two are called “vestibular complex”)
- Cochlea (cochlear duct)
- Membranous Labyrinth (within bony)
- receptors for equilibrium and hearing
- membrane and fluid filled spaces and tubes
Equilibrium
Head movement causes endolymph to push against cupula which bends the sterecilia and initiates a nerve impulse
Spiral organ (organ of Corti)
- responsible for hearing
- located within cochlear duct and detects movement of endolymph
- sterecilia of the hair cells project into tectorial membrane (gelatinous mass)
Perilymph is found in the space between the bone labyrinth and the membranous labyrinth.
Endolymph is found in the bony labyrinth.
