General and special senses Flashcards
1
Q
Brain receives information about the environment and the body
A
Senses
2
Q
process initiated by stimulating sensory receptors and perception
A
Sensation
3
Q
conscious awareness of those stimu
A
Perception
4
Q
Five recognized senses:
A
- Smell
- Taste
- Vision
- Hearing
- Touch
5
Q
Senses are divided into two:
A
- General senses
- Special senses
6
Q
- Nerve endings or specialized cells capable of responding to stimuli by
developing action
A
Sensory receptors
7
Q
Receptors:
A
- Mechanoreceptors – respond to mechanical stimuli; bending and
stretching - Chemoreceptors – respond to chemicals.
- Photoreceptors – respond to light
- Thermoreceptors – respond to temperature changes
- Nociceptors (noceo = to injure) – – respond to stimuli that result in the
sensation of pain
8
Q
are widely distributed across various parts of the body and are categorized as either Somatic or Visce
A
General senses
9
Q
Categories of senses
A
A. Somatic Senses
* Touch
* Pressure
* Proprioception (sense of body position)
* Temperature
* Pain
B. Visceral Senses
* Pain
* Pressure
10
Q
General senses (List)
A
- Light touch or tactile discrimination
- Pressure
- Touch
- Pain
- Temperature
- Limb position
11
Q
Meissner’s corpuscles
A
– Light touch
12
Q
Hair follicle nerve ending
A
– Light touch
13
Q
Merkel’s tactile disc
A
Touch
14
Q
Pacinian corpuscle
A
Pressure
15
Q
Krause end
A
Cold
16
Q
Ruffini’s nerve ending
A
Heat/warmth
17
Q
Free nerve
A
Pain
18
Q
Muscle spindle
A
Proprioception
19
Q
Golgi tendon organ (Tendon spindle)
A
Proprioception
20
Q
Receptors (List)
A
- Meissner’s corpuscles – Light touch
- Hair follicle nerve ending – Light touch
- Merkel’s tactile disc – Touch
- Pacinian corpuscle – Pressure
- Krause end – Cold
- Ruffini’s nerve ending – Heat/warmth
- Free nerve – Pain
- Muscle spindle – Proprioception
- Golgi tendon organ (Tendon spindle) – Proprioception
21
Q
General Sense Pathways (N simula)
A
- First-order neuron (N1): Sensory neuron that receives the initial
stimulus. - Second-order neuron (N2): Association neuron.
- Third-order neuron (N3): Transmits sensory information to the cortex
22
Q
Ascending Fiber Tracts (4 sila)
A
- Anterolateral System
- Pathways to the Cerebellum
- Cuneocerebellar Tract
- Posterior Column
23
Q
Anterolateral System (2 sila)
A
➢ Lateral Spinothalamic Tract – For pain and temperature (except head).
➢ Anterior Spinothalamic Tract – Crude touch or light touch (except head).
24
Q
Pathways to the Cerebellum (2 sila)
A
➢ Posterior Spinocerebellar Tract –Unconscious proprioception
from lower limbs.
➢ Anterior Spinocereb
25
Unconscious proprioception from the upper
body
Cuneocerebellar Tract
26
– For conscious proprioception,
deep pressure, and discriminative touch.
Posterior Column (Dorsal Column)
27
Categories of Posterior Column (Dorsal Column) (2 sila)
- Gracile fasciculus – Lower extremities.
- Cuneate fasciculus – Upper extremities.
28
Ano ang Pain and Temperature Pathway and receptor
* Pathway: Lateral Spinothalamic Tract
* Receptors: Free nerve endings, Krause end bulb, Ruffini’s corpuscle
29
senses pathways of Pain and Temperature Pathway
o N1 - Dorsal Root Ganglion
o N2 - Dorsal horn cells (spinal cord), axons cross to the opposite
side and ascend.
o N3 - Ventroposterolateral nucleus (thalamus), terminating in
Brodmann’s area 3,1
30
Ano ang Crude Touch Pathway (Light Touch, Pressure) and receptor?
* Pathway: Ventral/Anterior Spinothalamic Tract
* Receptors: Meissner's corpuscle, Merkel's disc, Hair follicle nerve ending
31
senses pathways of Crude Touch Pathway (Light Touch, Pressure)
o N1 - Dorsal Root Ganglion
o N2 - Laminae VI, VII, VIII; fibers cross to the opposite side.
o N3 - Ventroposterolateral nucleus of the thalamus, ending in
Brodmann’s area 3,1,2.
32
what are Discriminative Touch, Deep Pressure, and Proprioception Pathway and receptor
* Pathway: Dorsal Column/Medial Lemniscal System
* Receptors: Pacinian corpuscle, Meissner’s corpuscle, Muscle spindles, Tendon spindles
33
Senses pathway of Discriminative Touch, Deep Pressure, and Proprioception Pathway
o N1 - Dorsal Root Ganglion; fibers ascend as fasciculus gracilis or fasciculus cuneatus.
o N2 - Synapse in nucleus gracilis or cuneatus, cross at the medial lemniscus.
o N3 - Ventroposterolateral nucleus of the thalamus, ending in Brodmann’s area 3,1,2.
34
Clinical Signs of Injury to the Lemniscal Pathway
Inability to recognize limb position
Astereognosia
Loss of vibration sense
Loss of two-point discrimination
Positive Romberg’s Sign
35
What is Astereognosia?
Inability to identify objects by touch
36
What is Positive Romberg’s Sign?
Increased body sway with eyes closed
37
Unconscious Proprioception Pathways
Anterior Spinocerebellar Tract -Lower extremity group proprioception
Posterior Spinocerebellar Tract – Individual muscle proprioception in lower extremities
Cuneocerebellar Tract – Upper extremity muscle proprioception
38
what is Pyramidal System?
Controls skilled voluntary movements.
39
Pathways of Pyramidal System (2 sila)
* Corticospinal Tract
➢ 90% of fibers cross in the medulla to form the Lateral Corticospinal Tract.
* Corticobulbar Tract
➢ Terminates at motor nuclei in the brainstem, supplying cranial
nerves.
40
What is the origin of Corticospinal Tract
: Primary motor cortex (Brodmann’s areas 4, 6)
41
what is the origin of Corticobulbar Tract
➢ Origin: Brodmann’s areas 4 and 8.
42
Clinical Correlations
- Upper Motor Neuron Lesions
➢ Spastic paralysis, hyperreflexia, positive Babinski sign.
* Lower Motor Neuron Lesions
➢ Flaccid paralysis, hyporeflexia, muscle atrophy, and positive
fasciculations.
43
What is extrapyramidal system
* Coordinates movements and postural adjustments.
44
What are the functions of . Extrapyramidal System
Functions:
* Smooth movement coordination with the pyramidal system.
* Control of automatic actions (e.g., smiling).
* Postural and muscle tone adjustments
45
Each eyeball is positioned in a bony depression in the skull called ____________?
Orbit
46
Only the _______________ of the eye’s surface can normally be seen
anterior one-sixth
47
Made up of the eyeball specialized for its ability to ______________
react to light
48
the stimuli for sense of vision, the light rays must pass through the different parts of the refractive media before reaching the retina.
eyeball
49
Parts of the eyeball
o cornea
o aqueous humor
o lens
o vitreous humor
50
Accessory structures of the eye which – protects, lubricate, move the eye
* Extrinsic Eye Muscles
* Eyelids - controlled by orbicularis oculi
* Conjunctiva - transparent covering of the eyeball
* Lacrimal apparatus
51
controlled by orbicularis oculi
Eyelids
52
- transparent covering of the eyeball
- Lines the eyelids and covers part of the white eye (sclera) infront o Secretes the mucus which helps to lubricate the eyeball and keep it moist
Conjunctiva
53
Anteriorly the eyes are protected by the ________ which meet at the medial and lateral corners of the eye, the medial and lateral canthus respectively
eyelids
54
- Projecting from the border of each eyelid
eyelashes
55
o Modified sebaceous glands associated with the eyelid edges
o Produce an oily secretion that lubricates the eyes
Meibomian Glands
56
Modified sweat glands between the eyelashes
Ciliary Glands
57
o Located above the lateral ends of each eye
o Continually release a dilute salt solution
that drain into the nasal cavity through the inferior meatus
Lacrimal glands
58
o not only moistens and lubricates the conjunctival sac but also reduces eye infections because it contains bactericidal
enzyme (lysozyme)
Lacrimal fluid
59
Lateral rectus moves eye
Laterally (nerve supply VI)
60
Medial rectus moves eye
Medially (nerve supply III)
61
Superior rectus moves eye
Upwards medially (III)
62
Inferior rectus moves eye
Downwards and medially (III)
63
Inferior oblique moves eye
upwards and laterally (III)
64
Superior oblique moves eye
Downwards and laterally (IV)
65
Protects the delicate inner structure of the eye and with the intraocular pressure maintain the shape and turgor of the eyeballmaintains
Fibrous Coat
66
posterior 5/6 - opaque, white of the eye
Sclera
67
Anterior 1/6 – Transparent
Cornea
68
➢ the outermost coat
➢ also called the fibrous tunic seen anteriorly as the “white of the eye”
➢ covered in the anterior part by the transparent conjunctiva
➢ densely packed collagenous fibers (type I collagen fibrils) – where tendons of extraocular muscles are attached
➢ pierced by optic nerve, ciliary nerves and blood vessels
Sclera
69
➢ The central transparent anterior portion of the eye covering the colored part of the eye which is the iris
Avascular and the central part depends on diffusion from aqueous
humor for its nourishment.
➢ Thicker than sclera with refractive power 2x as high as the lens
Cornea
70
DId you kwow?
One of the few organs that can be successfully transplanted from one person to another without the worry of rejection because it
has no blood vessels thus it is beyond the reach of the immune system is Cornea
71
o Concerned with nutrition of retina and production of aqueous humor
o Provides mechanisms for accommodation of the eyes for near vision and control of amount of light entering the eye
o Choroid
o Cilliar body
o Iris
Vascular and Muscular coat or UVEA
72
– most of the blood vessels are located on (eye)
Choroid
73
secretes aqueous humor (eye)
Cilliary body
74
Constric (eye)
- Increase in light
75
Relax (eye)
- decrease in light
76
➢ Middle coat of the eye
➢ Blood-rich nutritive tunic that contains a dark pigment that prevents light from the scattering inside the eye
Choroid
77
➢ A thickened part of the vascular layer (tunic) of the eye.
➢ Links the choroid to the circumference of the iris
➢ Contains the ciliary muscle, which aids in accommodation—the ability of the eye to focus on close objects
➢ Produce aqueous humor, which nourishes the eye and maintains intraocular pressure.
Ciliary body
78
When the ciliary muscle contracts, the lens becomes more convex, enhancing ___________
focus for nearby objects
79
Eye strain occurs with a focus less than 20 feet; beyond 20 feet, the eye muscles relax
wala lang
80
eye disease can cause vision loss if you are diabetic
Glaucoma
81
➢ Heavy pigmented colored part of the eye which is membranous
extension of the choroid
➢ Partially covers the lens, leaving around opening at the center called pupil
➢ With sphincter and dilator pupillae (constrict and dilate pupils)
Iris
82
2 smooth muslces
- Sphincter pupillae
➢ Circumferentially oriented fibers
➢ Constriction of pupil (parasympathetic)
➢ Constriction - miosis
- Dilator pupillae
➢ Radially oriented fibers
➢ Dilation of pupil (sympathetic)
➢ Dilation - mydriasis
83
What is Nerve Coat
o Retina
➢ Innermost layer where receptors for sense of sight are found
➢ The nervous coat of the eyeball containing the photoreceptor cells
84
Photoreceptor
* Rods
➢ stimulated by low intensity light
➢ For night vision (scotopic vision)
* Cones
➢ stimulated by high intensity light
85
– very sensitive and produces detachable signal on absorption of a single photon of light
Rhodopsin
86
what causes Night blindnes?
vitamin A deficiency
87
For day vision/ color vision (photopic vision) sensitive to blue, green, and red lights – 3 kinds provide basis for color vision
wala lang, bakit ba?
88
Refractive Media of the Eyes
➢ Transparent structures traversed by the light rays on the way to the photoreceptors of the retina
➢ These structures can bend or refract the light rays so the images can be focused on the retina
89
Refractive Media of the Eyes (parts)
o Cornea
o Aqueous humor (water) (in anterior and posterior chamber)
o Lens
o Vitreous humor
90
➢ transparent biconvex body situated immediately behind the pupil.
➢ shape changes during accommodation
➢ covered by a homogenous highly refractile capsule which is essentially an exceedingly thick basal lamina
Lens
91
➢ colorless, structureless. gelatinous mass with a glasslike transparency filling up the vitreous cavity between lens and retina.
➢ nearly 99% is water
➢ with liquid and solid phase
Vitreous humor
92
➢ photosensitive area
➢ with a circular depressed white area, optic disk or optic papilla where optic nerve exits and retinal vessels enter and leave
Pars Optica
93
contains nerve fibers but no photoreceptors and is insensitive to light. Called phya siologic blind spot.
Optic disk
94
lies on the superior bank of the calcarine cortex, receives the medial fibers of the visual radiations
Cuneus gyri
95
– lies on the inferior bank of the calcarine cortex, the medial fibers coursing in the visual radiations, which carry input from the upper
retina (i.e. the lower contralateral visual field), pass from the lateral geniculate body directly through the parietal lobe to reach the cuneus gyrus.
Lingual gyrus
96
nearsightedness; corrects with concave
Myopia
97
farsightedness; corrects with convex
Hyperopia
98
Parts of the ear Outer (external) ear
o Pinna or auricle
o External acoustic meatus
o Tympanic Membrane or Eardrum
99
Pinna or auricle
Shell-shaped structure surrounding the auditory canal opening
100
External Auditory Canal
➢ A short narrow chamber about 1 inch long by ½ inch wide
➢ Curved into temporal bone of the skull
➢ Skin of walls lined with ceruminous glands which secretes a waxy
yellow substance called ear wax, or cerumen
101
Tympanic Membrane or Eardrum
➢ A thin membrane separating outer from middle ear
102
Parts of the ear (middle ear/ tympanic cavity)
➢ A small, air filled cavity within the temporal bone
o Ossicles (malleus, incus stapes)
o Tensor tympani, stapedius
103
Medial Boundary
➢ A bony wall with 2 openings
o Oval window
o Round window
104
Lateral Boundary
➢ Tympanic membrane with handle of the malleus attached
105
Anterior Boundary
➢ Eustachian tube (connects middle ear and nasopharynx)
106
Posterior Boundary
➢ Mastoid process
107
Ossicles in the Middle Ear
➢ Malleus (hammer) attached to tympanic membrane
➢ Incus – anvil
➢ Stapes – stirrups, presses on the oval window of the inner ear
108
Middle ear part
Middle Ear or Tympanic Cavity
Medial Boundary
Lateral Boundary
Anterior Boundary
Posterior Boundary
Ossicles in the Middle Ear
109
Inner (internal) ear (labyrinth)
➢ Composed of 2 parts:
o Bony Labyrinth
o Membranous Labyrinth
110
Bony Labyrinth
➢ Wall is bony – temporal bone
➢ Fluid inside is perilymph (one of the two types of cochlear
fluids, the other being endolymph)
➢ Made up of:
▪ Cochlea – made up of scala vestibuli and tympani;
concerned with hearing
▪ Vestibule – concerned with static equilibrium
▪ 3 semicircular canals – concerned with dynamic
equilibrium
111
Membranous Labyrinth
➢ Found inside the bony labyrinth
➢ Wall is fibrous
➢ Fluid inside is endolymph (fluid contained in the
membranous labyrinth of the inner ear)
➢ Made up of:
▪ Scala media – inside bony cochlea
▪ Utricle & Saccule – inside bony vestibule
▪ 3 semicircular ducts – inside the semicircular canal
112
Organ of Corti
* Receptor for hearing
* Found in the cochlea
113
* A spiral bony canal turning 2 ¾ around a central bony axis (modiolus)
* A spial bony projection from modiolus (spiral lamina) makes also a 2 ¾ turns.
* Scala vestibuli and tympani contain perilymph. They communicate in heliotrema
* Scala media contains endolymph
o Incompletely divides the bony cochlea
➢ Scala vestibuli
➢ Scala tympani
Cochlea
114
* Composed of five filaments embedded in gelatinous matrix rich in
mucopolysaccharides
* Secreted at the upper surface of interdental cells
Tectorial membrane
115
Hearing loss of any degree
Deafness
116
2 types of deafness
* Conduction Deafness
➢ Results when something interferes with conduction of sound
vibrations to the fluids of the inner ear
➢ Involves diseases of external and middle ear
o Impacted Cerumen
o Otosclerosis
o Rupture of Eardrum
o Otitis Media
* Sensorineural Deafness
➢ Results from degeneration or damage to receptor cells to cochlear
nerve, or to neurons of auditory cortex
o Old age
o Extended listening to excessively loud sounds
o Intake of ototoxic drugs like streptomycin, quinine, aspirin
117
Test to distinguish sensorineural from conduction deafness
Weber’s Test
➢ The base of the vibrating tuning fork is applied in the midline
Rinne’s Test
➢ The base of the tuning fork is placed over the mastoid process of the skull
➢ When it can no longer be heard, it is removed and then is held in front of the ear
118
Weber’s Test
o Normal Individual - sound appears to be in the midline
o Conduction Deafness - sound appears louder in the affected ear
o Sensorineural Deafness - sound appears louder in the normal ear
119
Rinne’s Test
o Normal Individual - continues to hear by air conduction after bone
conduction ceases; air conduction is greater than bone
conduction
o Conduction Deafness - bone is greater than air conduction
o Sensorineural Deafness - both are diminished but air conduction
remains better than bone conduction
120
Vestibular Sense / Apparatus
* Consists of receptors located in the inner ear on both sides of the head
* 8th cranial nerve transmits the vestibular information (for equilibrium) from the receptors to the CNS
121
What area the function o fVestibular Sense / Apparatus
* Maintains body balance
* Coordinates eye, head and body movements
* Permits the eyes to remain fixed on a point in space as the head moves
122
* vestibule and the semicircular canals are components of the bony
labyrinth associated with balance
Vestibule Organs
123
Receptors od vestibular sense/ apparatus
* Cristae Ampullaris
➢ found in the dilatations of semicircular ducts called ampulla
➢ stimulated by angular acceleration
➢ contains gelatinous substance called cupula
* Macula
➢ found in the vestibule
➢ stimulates by linear acceleration
➢ contains gelatinous substance called otolithic membrane
124
Dynamic Function
* Mediated largely by the semicircular canals
* Can detect motion of head in space
125
Static Functions
* Mediated mostly by the utricle
* Allow detection of the position of the head in relation to gravity
* Important in control of posture
126
Chambers of Vestibule
Utricle
Saccule
Endolymphatic duct
127
– largest membranous component of the vestibular system
Utricle
128
- spherical and smaller communicates with the cochlear duct through the short narrow ductus reunions and with the utricle through the utriculo-saccular duct
Saccule
129
– tubular evagination of the utriculo-saccular duct; it terminates as a blind expansion called the endolymphatic sac
Endolymphatic duct
130
Vestibular Nuclei
* Superior – vestibular nucleus of Bechterew
* Inferior – descending spinal
* Medial – vestibular nucleus of Schwalbe
* Lateral – vestibular nucleus of Deither
131
what is the receptor of Olfactory Sense / Apparatus
olfactory epithelium located in the upper 1/3 of each nasal mucosa
132
what is the receptor of Gustatory Sense / Apparatus
: taste buds
133
➢ Most are localized in the tongue
➢ A few are found on the soft palate, inner surface of the cheeks, walls of oropharynx
➢ Cylindrical taste bud is composed of many sensory gustatory cells that are encapsulated by supporting cells
➢ Are found on the sides of the circumvallate and on the more numerous fungiform papilla
Taste Buds
134
➢ Opening in the taste buds where the gustatory hairs (sensitive portion
of receptor cell) pass through
➢ Dorsal surface of tongue is covered with small peg-like projections or
papillae
Taste Pore
135
Four types of Papillae
* Circumvallate – with taste buds
* Fungiform – with taste buds
* Foliate – with taste buds
* Filliform – contains only gustatory cells
136
4 basic modalities of taste are sensed acutely In particular regions of the tongue
* Sweet – tip of tongue
* Bitter – back of tongue
* Salty – over most of the tongue
* Sour – sides of tongue
137
➢ respond to substances such as sugars, saccharine, and some amino
acids
Sweet Receptors
138
➢ respond to alkaloids
Bitter Receptors
139
➢ respond to metal ions in solution
Salty Receptors
140
➢ respond to hydrogen ions (h+), or the acidity of the solution
Sour Receptors
141
Termination of the gustatory pathway
* area located in the opercular part of the post central gyrus (Brodmann’s
Area 43)
