Exam 1: General and Special Senses Flashcards
Distinguish between the general senses and the special senses.
General Senses
- receptors widely distributed throughout the body
- Individual cells
- Exteroception:
- Skin
- Surface
- Touch and pressure, temp., pain
- Interoception (visceroception)
- Inside
- Internal organs (stomach, gallbladder)
- Inside
- Proprioception
- In between
- Muscles, tendons, bones
- Body position
- In between
Distinguish between the general senses and the special senses.
Special Senses
- More specialized receptors and are confined to structures in the head such as the eyes and ears
- Organ (nose, ear)
- sense of smell; sense of taste; sense of hearing; sense of sight
Name five types of sensory receptors, explain the general function of each, and describe how stimulation of a receptor leads to the generation of sensory impulses (review Nervous System I).
- Chemorectpros
- nociceptors
- Thermoreceptors
- Mechanoreceptors
- Photoreceptors
Name five types of sensory receptors, explain the general function of each, and describe how stimulation of a receptor leads to the generation of sensory impulses (review Nervous System I).
Chemoreceptors
- General function:
- sensory receptor that detects certain chemical stimuli in the environment.
- how stimulation leads to impulses:
- respond to changes in the concentration of chemicals
in internal organs: decect change in blood concentrations (O2, H+, glucose and others)
ex: Smell and taste
In nose and internal organs
Name five types of sensory receptors, explain the general function of each, and describe how stimulation of a receptor leads to the generation of sensory impulses (review Nervous System I).
Nociceptors
- General function:
- Deformation/ displaced- respond to tissue damage
- How stimulation of a receptor leads to an impules:
- Can be triggered by different things
- Chemical (like to be inside; chemicals spill out of cells)
- mechanical
- Can be triggered by different things
Name five types of sensory receptors, explain the general function of each, and describe how stimulation of a receptor leads to the generation of sensory impulses (review Nervous System I).
Thermoreceptors
- General function:
- sense change in temperature
- How stimulation of a receptor leads to an impules:
- temperature change
warm and cold receptors
Name five types of sensory receptors, explain the general function of each, and describe how stimulation of a receptor leads to the generation of sensory impulses (review Nervous System I).
Mechanorecpetors
- General function:
- sense mechanical forces by detecting changes that deform the receptor
- How stimulation of a receptor leads to an impules:
- physical contact (Touch)
- physical displacement
Ex: Measure blood pressure, skin (physical contact), ear (balance, sound), muscle length and tension
Name five types of sensory receptors, explain the general function of each, and describe how stimulation of a receptor leads to the generation of sensory impulses (review Nervous System I).
Photoreceptors
- General function:
- respond to light
- How stimulation of a receptor leads to an impules:
Light (eye)
rods and cones
- Sensory impulses table 12.1; review chapter 10 pg. 377
- Axon to brain
- Hearing- temporal
- Vision-occipital
- ___-pariatal
Differentiate between sensation, perception, and projection.
Sensation
- Occurs when threshold is reached and action potentials cause the brain to become AWARE of that sensory event
- “smells good”
- Ex: vision- round object
Differentiate between sensation, perception, and projection.
Perception
Brain interprets sensory impulse
Identified the source
ex: basketball (kind)
Differentiate between sensation, perception, and projection.
projection
Brain projects sensation back to its apparent source
Where is it coming from?
Important for general senses; pinpoint the region of stimulation
Ex: eyes
Describe sensory adaptation and distinguish between central and peripheral adaptation.
- Getting used to something because of repeated stimulation
- Change (odor, temperature)
- Adapt: mechanoreceptors, chemoreceptors, thermoreceptors
- Don’t adapt: photoreceptors, nociceptors (pain)
- Peripheral
- Receptor- hyperpolarize, change threshold (achieve threshold less) as long as constant signal
- Central:
- Alter at synapse- block neurotransmitter (postsynaptic may not achieve threshold)
Describe the roles of ___, ___, and ___ in the senses of touch and pressure. Table 12.2; figure 12.1
- free nerve endings
- tactile (Meissner’s) corpuscles
- lamellated (Pacinian) corpuscles
Role of: free nerve endings
- function:
- detect changes in pressure
- sensation:
- touch, pressure
- sensation:
- detect changes in pressure
-
role:
- responsible for the sensation of itching
Role of: tactile (Meissner’s) corpuscles
Touch receptor- fine touch- distinguish touch
- Right under epidermis
- Nerve embedded in it
- Fingers, lips
- Function:
- detect objects moving over the skin
- sensation:
- touch and texture
- sensation:
- detect objects moving over the skin
Role of: lamellated (Pacinian) corpuscles
- Organ; connective tissue
- Pressure receptor
- Function:
- detect changes in pressure
- sensation:
- deep pressure, vibrations, fullness in viscera
- ex:
- sensation:
- detect changes in pressure
Dermis (skin), also in internal organs (ex: pancreas)
Stomach ache- really stomach stretched and pancreas is squished
Describe the roles of warm receptors and cold receptors in the sense of temperature.
- Warm receptors (77°F-113°F) (25C-45C)
- respond to warm temperatures
- close to 113- trigger pain receptores (buring sensation)
- respond to warm temperatures
- Cold receptors (50°F-68°F) (10C-20C)
- respond to cold temperatures
- below 50- trigger pain receptors- freezing sensation
- respond to cold temperatures
- In between- (68°F-77°F)
- No different than skin (normal skin temperature)
- Different cobinations of recepters- both adapt
Describe the role of nociceptors in the sense of pain.
- Don’t adapt
- Free nerve endings
- Skin, internal tissue (lack in brain)
- Protect
- Mechanical and chemical
- role: detect tissue damage
Describe visceral pain and the phenomenon of referred pain. Figures 12.2-12.3
Visceral Pain
Pain receptors are the only receptors whose stimulation produces sensation
Describe visceral pain and the phenomenon of referred pain. Figures 12.2-12.3
referred pain
Coming from some part of body other than part being stimulated
Ex: pain in left arm
Share nerve pathways (brain can’t determine origin), so it projects where pain began
Distinguish between fast and slow pain pathways, and describe how pain awareness may be altered.
Fast pain pathways
A-delta fibers
Myelinated- impulses rapidly
Acute pain
Sharp, immediate
Exact location (pinpoint)
Distinguish between fast and slow pain pathways, and describe how pain awareness may be altered.
Slow pain pathways
C fibers
Unmyelinated- conduct impulses slowly
Chronic pain
Sore, achy (next day), dull, delay
Broad section
Distinguish between fast and slow pain pathways, and describe how pain awareness may be altered.
pain awareness
- Thalamus
- Make it here before have sensation
- Cerebral Cortex (parietal lobe)
- Interpret and preserve what kind it is
- Natural analgesics- minimize pain- similar idea of adaptation
- Enkephalins and serotonin
- Inhibit presynaptic neurons in dorsal horn
- supress acute and chronic pain impulses
- Alter what happens at synapse
- Endorphins
- Higher up in brain- Pituitary gland, hypothalamus
- relay pain info
- Poppies- work same way
Describe the roles of muscle spindles and Golgi tendon organs in proprioception.
Proprioception
proprioceptors are mechanorecptiors that send information to the CNS about body position and the length and tension of skeletal muscle
Describe the roles of muscle spindles and Golgi tendon organs in proprioception.
Muscle spindles
detect changes in muscle length
Respond to stretch- muscle relaxed
Stretch reflex- stimulus
Bicep (when straighten arm)
end of a sensory nerve fiber wrapped around it:
Describe the roles of muscle spindles and Golgi tendon organs in proprioception.
Golgi Tendon
detect changes in muscle tension
-*9Tension in tendon when contracted
Triceps (when straighten arm)
are in tendons close to their attachment to muscles\
Describe the sense of smell, including the roles of ciliated bipolar neurons and the olfactory nerve.
Olfactory organs figure 12.5 and 12.6
- Ethmoid bone, nasal cavity
- Supporting columnar epithelial cells- Olfactory epithelium
- Replaced
Olfactory nerve pathways to limbic system
- Nerve pathway- neuro signal to limbi system (tied to emotion)
- Protective- memories
Olfactory stimulation- 10,000 different smells
- Olfactory code
- Receptors exposed to environment
- Can replace self (damage, exposed)
- As age not replaced as rapidly- so smell decreases
- Smell and taste coordinate
Ciliated Bipolar neurons
Olfactory receptor cells
- Ciliated bipolar neurons; 400 different types
- Role: cilia project into the nasal cavity and are the sensitive portion of receptor cells
- Odorant molecule bind, depolarizing cells, generating action potentials
Describe how the olfactory code allows us to distinguish specific odors.
Subpopulations all different
Probably stimulate more then 1 receptor
Describe the sense of taste, including the roles of taste buds and the taste nerve pathways.
Nerve pathway
- sensory impulses from taste receptor cells conduct impuleses into the medulla oblongata
- Facial, glossopharyngeal, vagus nerves
- then impulses ascend to the thalamus and are directed to the gustatory cortex of the verebrum (located in the insula) (parietal lobe)
Role of taste buds
special organs of taste
each taste bud includs group of taste cells that function as sensory receptors (taste receptors)
- Taste buds ~10,000 on depressions
Receptors are protected
Supporting cells
Taste hairs