SENSORY SYSTEM (SIMPLIFIED) Flashcards
Free nerve ending
Dendrites embedded in tissue and receives sensation (pain, temperature)
Encapsulated ending
Sensory nerve endings encapsulated in connective tissue and enhances sensitivity (pressure, touch)
Specialized receptor cell
Distinct structrural components to interpret specific stimulus (light; photoreceptor)
Exteroreceptor
Located near stimulus on external environment (somatosensory receptor on skin)
Intereoceptor
Interprets stimuli from internal organs and tissue (detect blood pressure)
Proprioceptor
Receptor located near moving part of body, interprets position of tissues as it moves
Chemoreceptor
Chemical stimuli (taste, smell)
Osmoreceptor
Respond to solute concentration of body fluid
Nocioreceptor
Pain
Mechanoreceptor
Physical stimuli (sound; low freq vibration 5-15 hz, balance)
Thermoreceptor
Temperature
Photoreceptor
Light
General sense
Sense that is distributed throughout body with receptor cells within structures of other organs (touch, proprioception, balance)
Special sense
Sense with specific organ (eye, tongue, ear)
Somatosensation
Group of sensory modalities of vibration, pressure, touch, light, temperature, pain
Cutaneous receptors
Part of the somatosensory system with receptors located in skin
2 types of somatosensory signals
Pain and temperature
Bulbous corpuscle
Found in dermis and joint capsules detect stretch
Lamellated corpuscle
In dermis, subcutaneous tissue and detect high freq vibration ~250hz
Tactile corpuscle
In papillary dermis (fingertips and lips) and detect light touch vibrations below 50hz
Hair follicle plexus
Wrapped around hair follicle in dermis and detect movement of hair
Muscle spindle
With skeletal muscle fibres and detect muscle contraction and stretch
Tendon stretch organ
In line with tendon and detect stretch of tendons
Papillae
Raised bumps with taste bunds containing gustatory receptor cells
Pathway of gustation
Sensory neuron –> medulla (increased saliva and gastric juice) –> thalamus –> cerebrum (taste perceived)
Surface of tongue structure
Oral cavity lined by stratified squamous epithelium
Where are olfactory receptor neurons found
Small regions of walls of superior nasal cavity
Superior nasal cavity structure
Olfactory epithelium and contain bipolar sensory neurons
Olfacory sensory neuron structure
Dendrites extending from apical surface of epithelium into mucus lining the cavity
Where can olfactory tract project
Extends from basal surface of epithelium through skull opening and connect to olfactory bulb to connect to cerebral cortex, temporary lobe, limbic system or hypothalamus
Limbic system and hypothalamus significance in olfactory
Smell becomes associated with long term memory and emotional responses