special senses: Anna made Flashcards
(71 cards)
1
Q
sensation
A
- Stimulus we are consciously
aware of - Reaches cerebral cortex
2
Q
sensation characteristics
A
- Modality
Type of stimulus; what is
activating the receptor - Location
Site of receptive field - Intensity
How many neurons are firing - Duration
Length of signal transmission
3
Q
Sensory Receptors
A
- Respond to an external or internal stimulus
- Deliver information to CNS
- “Transducers”
Convert stimulus energy into electrical energy - Each type of receptor responds to a certain stimulus
4
Q
Chemoreceptors
A
detect chemicals
taste and smell
5
Q
thermoreceptors
A
Detect changes in temperature
- skin
6
Q
Photoreceptors
A
Detects changes in light, color, movement
7
Q
Mechanoreceptors
A
Detect distortions in cell membrane
- pressure
- vibration
8
Q
Nociceptors
A
Detect painful stimuli
9
Q
Receptive Field
A
- Area monitored by the receptor endings of a neuron
- Small receptive field: neuron detects stimuli over limited area; more precise perception
- Large receptive field: neuron detects stimuli over broader area; less precise perception
10
Q
Receptor Adaptation
A
Decreased sensitivity to continuous stimulus
11
Q
Tonic receptors
A
- Limited adaptation
- Respond continuously
- brain continues to be aware of this stimuli
ex: vestibular apparatus, pain receptors
12
Q
Phasic receptors
A
- Adapt rapidly
- Only respond to new stimuli
- brain does not continuously pay attention to stimuli
ex: (ex: pressure receptors)
13
Q
General sense
A
- Receptors distributed throughout the body
- Somatic sensory receptors
- Tactile receptors of skin;
proprioceptors
- Tactile receptors of skin;
- Somatic sensory receptors
- Visceral sensory receptors
- Found in walls of internal
organs- Monitor stretch, chemical
environment, temperature, pain
- Monitor stretch, chemical
- Found in walls of internal
14
Q
special sense
A
Specialized receptors in head
- Olfaction, gustation, vision, audition, equilibrium
15
Q
Exteroceptors
A
Detect stimuli from external environment
Skin, mucous membranes
Special sense receptors
16
Q
Interoceptors
A
Detect stimuli from internal organs
Visceral sensory receptors
17
Q
Proprioceptors
A
Detect body/limb movement
Somatosensory receptors of muscles, tendons, joints
18
Q
Tactile Receptors: Mechanoreceptors
A
- Detect distortion of cell membrane
- Abundant in skin and mucous membranous
- Encapsulated
Pressure, vibration - Unencapsulated
Hair movement, light touch, pain
19
Q
Proprioceptors: Mechanoreceptors
A
- Detect changes in body position and movement
Muscle spindle: detects stretch in muscle
Golgi tendon organ: detect tension in tendon
Joint kinesthetic receptor: detect stretch in articular capsule and ligaments
20
Q
Joint kinesthetic
A
detect stretch in articular capsule and ligaments
21
Q
Golgi tendon
A
detect tension in tendon
22
Q
Muscle spindle
A
detects stretch in muscle
23
Q
Referred Pain
A
- Signals from viscera perceived as originating in skin, muscle
- Many somatic and visceral sensory neurons send signals along the same ascending tracts within spinal cord
- Somatosensory cortex unable to determine true source
Heart attack pain may be referred to arm
Kidney/ureter pain may be referred to abdominal cavity
24
Q
Phantom Pain
A
- Sensation associated with removed body part
- Occurs following amputation of a limb
- Results from stimulation from remaining portion of limb along sensory pathway
25
Olfaction
* Detection of “odorants”
Chemicals in air detected by chemoreceptors
26
Olfactory epithelium
- lining of the nasal cavity
- chemoreceptors are Located in superior nasal cavity
- Bipolar olfactory receptor cells
- Olfactory “hairs” (cilia) house chemoreceptors
- Olfactory (Bowman) glands
- Produce mucus
27
Olfactory bulbs
- Ends of olfactory tracts
- Located under frontal lobes
- Synapsing between olfactory nerve axons and CNS olfactory tracts
- part of olfactory cranial nerve 1
28
Olfactory tracts
- Project to olfactory cortex (temporal lobe), hypothalamus, limbic structures
- part of olfactory cranial nerve 1
29
Gustation
* Taste
* Detection of “tastants”
* Chemoreceptors within papillae (taste buds) of tongue
30
Vallate papillae
Contain most of the taste buds
31
Fungiform papillae
Contain some taste receptors
32
Filiform papillae
- No taste receptors
- Help manipulate food
33
Foliate papillae
- side of anterior tongue lie flat
- some taste receptors
- not well developed
34
Taste Buds
* House taste receptors
- Gustatory cells
Detect tastants
Live 7-9 days
- Supporting cells
Sustain gustatory cells
Specific function unclear
- Basal cells
Neural stem cells that replace gustatory cells
35
Gustatory Pathway
* Facial nerve (CV VII)
* Glossopharyngeal nerve (CN IX)
* Sensory neurons from gustatory cells project to thalamus
* Thalamus then projects to gustatory centers in insula
* Five taste sensations
Sweet, salt, sour, bitter, umami
36
Vision
* Light processed by the eye and interpreted by the brain
* Optic nerve (CNII)
* Primary vision center in occipital lobe of cerebrum
37
Lacrimal glands
Produce tears
Moisten eye,
antibacterial effect
38
Eye Structure: Anterior cavity
- Anterior to lens
- Contains circulating aqueous humor
- Two chambers separated by iris
Anterior chamber
Posterior chamber
39
Eye Structure: Posterior cavity
Posterior to lens
Contains permanent vitreous humor
40
Vitreous humor/body
Gelatinous fluid in posterior cavity
Helps maintain eye shape
Keeps retina flush against back of eye
Produced during fetal development
41
Aqueous humor
Watery fluid in anterior cavity
Continuously produced by ciliary process
Nourishes lens and inner cornea
42
Fibrous Tunic
- Tough outer CT layer
- Sclera
- Cornea
43
Sclera
White of the eye
Maintains eye shape
Protects internal contents of
44
cornea
Anterior convex “window”
Covers iris and pupil
Refracts light
45
Vascular Tunic
Highly vascular
Choroid (“uvea”)
Ciliary muscles
Iris
46
Choroid (“uvea”)
Vascular network
47
Ciliary muscles
Changes shape of lens
48
iris
- Gives eye color
- Divides anterior and posterior chamber
- Opening in center of iris is pupil
- Controls pupil diameter
pupillary muscles dilate and constrict pupil
49
Retina
- “Neural layer”
- 3 sublayers
- Photoreceptor cell layer
- Bipolar cell layer
- Ganglion cell layer
50
Photoreceptor cell layer
Outermost retinal layer
Contains rods and cones
Rods detect black and white/night vision
Cones detect color recognition/bright light
51
Bipolar cell layer
Dendrites receive input from rods and cones
52
Ganglion cell layer
Innermost retinal layer
Axons join at optic disc to form optic nerve
53
Optic disc
No photoreceptors
“Blind spot”
Ganglion exons exit
toward brain
54
Macula lutea
Round region lateral to
optic disc
Contains fovea
Cone
55
Peripheral retina
- rods
56
Lens
- Changes shape to focus light on retina
Light refraction
Shape determined by ciliary muscle and suspensory ligaments
57
Optic chiasm
crossing of axons in visual pathway
58
Visual Pathways
* Photoreceptors in retina
* Optic nerve
* Optic chiasm (crossing of axons)
* Optic tract
* Lateral geniculate nucleus (LGN) of thalamus
* Occipital lobe
59
Hearing
Conversion of sound waves into neural impulses for CNS integration
60
Balance
Monitoring of head position
61
Auricle
- part of External ear structure
- Directs sound waves inward
- Elastic cartilage
62
External auditory (acoustic) meatus
- part of External ear structure
- “Ear canal”
- Extends to tympanic membrane
- Ceruminous glands secrete cerumen
- Ear wax
63
Tympanic cavity
- Auditory ossicles
- Malleus, incus, stapes
- Amplify sound waves and transmit to oval window
- Creates pressure waves in inner ear fluid
64
Name of bones tympanic cavity
Malleus, incus, stapes
65
Tympanic membrane
boundary between outer ear and inner ear
66
Inner ear
* Cochlea
* Vestibule
* Semicircular canals
* Eustachian (auditory) tube
- Extends from middle ear to back of nose
67
Cochlea
- Spiral organ
* Sensory structure for hearing
* Fluid-filled cochlear duct
* Hair cells with receptors on stereocilia
* Synapse with sensory neurons of cochlear nerve
- Signals sent through medial geniculate nucleus of thalamus
- Delivered to auditory cortex of temporal lobe
68
Hearing pathway after cochlea
-sound vibrations go into ear canal
- vibrates eardrum
- the Malleus, incus, stapes vibrate which amplify sound waves and transmit to oval window
-bump into fluid in cochlea
- Creates pressure waves in inner ear fluid
-Synapse with sensory neurons of cochlear nerve
- Signals sent through medial geniculate nucleus of thalamus
- Delivered to auditory cortex of temporal lobe
69
Equilibrium
* aka balance
* Awareness of head movement
* Vestibular apparatus
- Utricle, saccule, and semicircular canals
* Detect position of head and acceleration
70
Macula of Utricle and Saccule
* Macula is a gelatinise Membrane located in utricle and saccule
- Layer of hair cells with stereocilia (receptors) that extend into otolithic membrane
- Otoliths (calcium carbonate crystals) embedded in gelatinous membrane (Macula)
- Head movement causes crystals to move and activate receptors (stereocilia)
- Signal sent along vestibular nerve (CNVIII) to somatosensory cortex
71
Ampulla of Semicircular Canals
* Enlargement at base of semicircular canal
- Houses crista
Contains hair cells with stereocilia oriented in a consistent direction
- When head rotates fluid in canal pushes against cupula
- Detect acceleration and deceleration
- Signal sent to somatosensory cortex (CNVIII)
