Learning Outcome 10 General and Special Senses Flashcards
What three types of stimuli do receptors respond to?
(1) a neuron that has a free nerve ending, with dendrites embedded in tissue that would receive a sensation
(2) a neuron that has an encapsulated ending in which the sensory nerve endings are encapsulated in connective tissue that enhances their sensitivity
(3) a specialized receptor cell, which has distinct structural components that interpret a specific type of stimulus
What is a sensation?
Sensation is the activation of sensory receptor cells at the level of the stimulus.
Perception vs projection
Perception is the central processing of sensory stimuli into a meaningful pattern. Perception is dependent on sensation, but not all sensations are perceived.
What is adaptation?
Sensory receptors becoming less responsive/sensitive as the stimulus continues over time
What two types of sensory receptors are there?
General Sense Receptors - Somatic (Skin, mucous membranes, tendons, joints) and Visceral (walls of internal organs)
Special Sense Receptors - Specialized complex sensory organs. Involved in gustation, vision, hearing and equilibrium
What types of receptors are there based on function?
-chemoreceptor, interprets chemical stimuli, such as an object’s taste or smell. -Osmoreceptors respond to solute concentrations of body fluids.
- nocicepto, pain is primarily a chemical sense that interprets the presence of chemicals from tissue damage, or similar intense stimuli, through a
- mechanoreceptor. Physical stimuli, such as pressure and vibration, as well as the sensation of sound and body position (balance)
-thermoreceptor , physical stimulus that has its own type of receptor is temperature, which is sensed through a thermoreceptor that is either sensitive to temperatures above (heat) or below (cold) normal body temperature.
What types of receptors are there based on structure?
-Free nerve ending
-Encapsulated nerve ending
-Specialized receptor cell
What are the four components of a sensory mechanism?
- Stimulus (Change in internal environment activates sensory receptor)
- Sensory Receptor (Converts stimulus to electrical impulse (AP))
- Sensory Pathway (Conduction occurs along a neural pathway to the brain
- Sensory Area (Cerebrum) (Receives and integrates the nerve impulse into a sensation)
Where are taste buds found? What are the three types of cells found in taste buds?
-Papillae
-Gustatory Cells, Supporting Cells, Basal Cells
What are the five primary taste sensations? What does umami mean?
-sweet, salty, sour, and bitter.
-Umami is a Japanese word that means “delicious taste,” and is often translated to mean savory
Which cranial nerve detects taste from the anterior two-thirds of the tongue?
Facial Nerve (CN VII)
What cranial nerve detects taste from the posterior one-third of the tongue?
Glossopharyngeal (CN IX)
Where areas of the brain do gustatory impulses reach?
-Primary gustatory cortex located in the parietal lobes and insula
(Impulses reach medulla oblongata, pass through the thalamus, then to the primary gustatory cortex)
What are the two types cells found in the olfactory epithelium? Which ones contain chemoreceptors?
- bipolar sensory neurons/olfactory sensory neuron
-chemoreceptors (odorant gaseous molecules)
What is the sensory mechanism for olfaction? Which cranial nerve do impulses travel along?
The sensory mechanism for olfaction is the olfactory nerve, also known as cranial nerve I (CN I), which is responsible for the sense of smell
-Travel DIRECTLY to the cerebrum, they
DO NOT pass through the thalamus
What is Olfaction?
Like taste, the sense of smell, or olfaction, is also responsive to chemical stimuli. The olfactory receptor neurons are located in a small region within the superior nasal cavity
What are the two areas where olfaction reaches the brain?
- Olfactory bulbs (inferior to frontal lobes)
- Primary olfactory cortex (temporal lobes
What is Audition?
audition (Hearing) , is the transduction of sound waves into a neural signal that is made possible by the structures of the ear
What are the three regions of the ear?
- External Ear
- Middle Ear
- Inner Ear
What are the components of the middle ear?
-Tympanic Cavity
-Auditory (euschian tube)
-Auditory Ossicles
What are the components of the internal ear?
Bony Labyrinth - Vestibule, Cochlea, 3 semicircular canals
Membranous Labyrinth - Cochlear, Utricle, Saccule, Semicircular Duct
What is the function of the auricle (pinna)?
Auricle (Pinna) - Protect ear canal/collect sound waves traveling through air & direct them to the EAM.
Which part of the ear produces cerumen? What is the purpose of cerumen?
What type of tissue lines the tympanic membrane on the inside and on the outside?
(Eardrum)
Outer - Epithelial Layer
Inner - Mucosa (Endodermal)
What are the three auditory ossicles in order from lateral to medial? What is their purpose?
by three small bones called the ossicles - purpose is to transfer and amplify air vibrations into the inner ear to be processed as sound
-malleus (hammer)
- incus (anvil)
-stapes (stirrup)
What is the difference between the oval window and the round window?
-The oval window is located at the beginning of a fluid-filled tube within the cochlea called the scala vestibuli. The scala vestibuli extends from the oval window, travelling above the cochlear duct, which is the central cavity of the cochlea that contains the sound-transducing neurons. (vibrations)
-round window, which is covered by a membrane that contains the fluid within the scala. (fluid)
What are the three components of the inner ear?
Cochlea: The snail-shaped organ of hearing that converts sound waves into nerve signals
Semicircular canals: Fluid-filled tubes that sense head rotation and help with balance
Vestibule: The central cavity of the inner ear that helps with balance and equilibrium
What part of the inner ear is filled with perilymph?
scala tympani and scala vestibuli of the cochlea
