Senses- Test 9 Flashcards
What are the Five senses
Touch
Tearing
Sight
Taste
Smell
Funcyion of chemoreceptors
Detect Oxygen/ph and some organic molecules
Mechanoreceptors detect
Pressure
Vibration
Acceleration
Sound
Cell stretch is detected by
Osmoreceptors
Difference between photoreceptors and thermorecepetors
Photo- photons of light
Thermo- degree of heat
Pain and noxious stimuli are detected by
Nocireceptors
Four types of stimuli
Visual
Auditory
Olfactory
Gustatory
List examples of disease of eye
Diabetic retinopathy
Cataracts
Colour blindness
Dry eye
Glaucoma
What is the difference between normal retina and diabetic retinopathy
Diabetic has haemorrhages with abnormal growth of blood vessels
Aneurysms cotton wool spots
Describe the difference between sense and perception
Sense is physicochemical, process of sensing environment
Perception is psychological a way of interpreting these signals
List the process of interpreting info
Sensory process project to thalamus
Thalamus relays to visual cortex
Outer region of cerebral cortex linked to visual function
List the functions of thalamus
Act as translator
Inputs processed here
Sense info relayed to the cerebral cortex
What is rubins vase
Cognitive optical illusion of mental choice of two interpretations
Explain the figure ground concept
Concept where its impossible to interpret two images at the same time
Explain the motion after effect
Staring consistently at movement in particular direction adapts your visual neurone encoding one motion direction.
As a result stationary scene look like moving
In the absence of image motion neurons, what will happen after staring at moving object
Equal response, when looking away, picture will look still rather than moving
What are the 3 concentric layers of eye
Outer layer- cornew
Middle iris ciliary body
Inner layer - retina
Function of outer layer
Cornea & sclera
Cornea protective epi layer
Sclera tough connective tissue know as white of eye
Function of middle layer
Iris and ciliary body made of ciliary muscle and process.
Choroid beneath sclera absorbing light and prevents reflection
Function of inner layer
Retina containing photoreceptors
Role of lens
Convex shaped lens bend light to focus on retina
- Lens =Light
-muscle = far/close*
Role of ciliary muscle
-**Change lens shape ***
by relaxing and contracting muscle
Role of sclera
White connective tissue
Role of retina
Contain photoreceptors
Role of fovea
Central point of the retina
Role of optic disk
Blind spot where optic nerve and vessels leave
Complete the sentence
In normal vision, light from image focused by lens
Falls on back of retina and image seen in focus
What happens to light before striking on retina
Modified
How is light modified before striking retina- describe in detail
First modulated by pupils (bright narrow/ dark open)
Second accommodation- lens changes shape to adjust refractive power so image focuses
Compare how the ciliary muscle contracts and relaxed in relation to objects
Ciliary muscle contracts - lens rounded to focus close objects
Ciliary muscle relaxed - lens elongated to visualise fat objects
The iris consists of 2 smooth muscle, explain how they change and their nervous stimulation
Inner circular - constriction - parasympathetic stimulation
Outer radial- dilation- sympathetic stimulation
Pigments in the eye are caused by what
Melanocytes
Which nervous system control accommodation mechanisms
Parasympathetic
What happens to the eye when there is NO parasympathetic stimulation
Ciliary muscle relaxed
Lens flattened
Ligaments pulled tight
What happens to the eye when THERE IS parasympathetic stimulation
Ciliary muscle contracts
Lens round
Ligaments slackened
Describe the pupil reflex
Consensual response used to asses integrity of sensor and motor function
In response to the pupil reflex, what will happen when light is exposed to one eye
Both pupils constrict
In response to pupil reflex, what would happen in an abnormal situation when light is shone in one eye
Second eye does not respond- sign of ocular motor nerve damage
What are the two visual fields and what are they responsible for
Binocular field- left and right field overlap
Monocular - visual field for one eye
How is image projected
Upside down on retina and brain reverses image
What are the 3 layers of retina and what are they responsible for
Inner - ganglions
Middle- bipolar
Outer- photoreceptors rods and cones
Explain reverse layer order
Light pass through inner and then middle and blood before photoreceptors
In relation to vision, state function of rods and cones
Rods black and white
Cones colour
In relation to abundance in retina state difference between rods and cones
Rods higher abundance than cones in retina
In relation to concentration in retina state difference between rods and cones
Rods highest conc in periphery of retina
Cones highest conc in fovea
In relation to acuity, state difference between rods and cones
Rods low visua acuity
Cones high visual acuity
In relation to convergence with bipolar cell state the difference between rods and cones
Rods- high convergence with bipolar cell
Cones- low
In relation to light conditions, describe the difference between rods and cones
Rods low light
Cones high light
In relation to sensitivity describe the diff between rods and cones
Rods high sensitivity
Cones low sensitivity
State the ration between bipolar cells AND
Rods
Cones
3 rods / 1 bipolar cell
1 cone/ bipolar cell
Describe what happens when rods are stimulated
In response to low light, rods stimulated, infor pooled and convergence
Complete sentence…
Signal summation leads to
Weak stimuli detection
Rods have…
High sensitivity
Low resolution
Explain first process of transduction
Light absorbed by photopigments
Rods - rhodopsin
Retinal - opsin
Cones- red green blue
Explain process of rhodopsin bleaching
Retinal absorbs light, changes shape + release opsin
Rhodopsin destroyed by bright light
When rhodopsin is destroyed by bright light, what makes new disks
Photorecptors
Three types of colour blindness
Tritanopia
Deuteronpia
Propanolia
Defects in tritanopia
S cone
Blue yellow defect
Defects in deutronpia
M cone defect green yellow red
Defects in propanolia
i cone
Green yellow red defect with reduced intensity
How many cranial nerves does the eye have
6
Optic nerve functions
Nerve 2
Sense incoming images and light disples on retina
Send infor to cerebral cortex
Autonomic - change pupil size
Oculomotor nerve 3 functions
Motor innervation of extraocular muscle
Autonomic- constriction of muscle
Trochlear nerve 4
Motor innervation
Only innervates superior oblique muscle
Trigeminal 5
3 branches-
Opthalmic sensory innervation of eye
Afferent part of corneal
Lacrimation reflex
Abductees nerve 6
Innervate 1 muscle
Lateral rectus
Facial nerve 7
Eye closure
Blinking by motor innervation of orbicularis oculi muscle
Sensory efferent outpu for corneal & lacrimation reflex of eye
How many muscles does eye have
6
Superior oblique
Downward and outward movement
Superior rectus
Upward movement
Lateral rectus
Outward movement
Medial rectus
Inward movement
Inferior rectus
Downward movement
Inferior oblique
Upward and outward movement
List the different layers of the skin in order
Epidermis
Dermis
Fat
Example of diseases of the skin
Roscaea
Acne
Eczema
Melanoma
Summarise the function of the skin
Protection- bio/chem/physical
Thermoregulation
Sensory
Vitamin d
Excretion of waste products
Absence of skin will result in
Extreme water loss
Explain how the layers of the skin are presented
Epidermis Superficial
Dermis. Deep layer
Hypodermics. Deepest layer with loose connective and adipose tissue
List the layers of the epidermis in order
Cornem
Lucidem
Granulosm
Spinosum
Basale
Function of cornem
Superficial layer
Withstand damage
Non nucleated and fulled with squames
What are squames
Soft keratin filaments
Explain lucidem
Clear layer
Between granulosm and cornem
Has keratin and devoid of nuclei
Explain granulosm
Granular layer
Become flattened from spinosum
Form 2-3 layers of pyknotic cells
What is pyknosis
Apoptosis and necrosis causing nuclear material to condense
Explain spinosum
Come from basale
Post mitotic cells
4-6 layers of cuboidal flattened cells
Explain basale/ germinatium
Continuous mitosis
Stem cells
Containf melanocytes
Act as dermi epidermal junction
How are cells of stratum basale held
Anchored to adjacent cells via desmosomes and to basement via hesmisdosomes
What are keratinocytes
Squamous epithelial cella originating from basal stem cells continuously maturing from basal to corneum and desquamate
What are melanocytes
Synthesise melanin that gives colour and protects from UV light
What are langerhan cells
Antigen presenting cells
What are merkel cells
Mechanoreceptors
Recall the steps of keratinisation in order
Dermis basale
Spinosum
Granulosm
Lucidem
Corneum
What does the dermis contain
Collagen & elastic fibres held by glycoproteins and glycoaminoglycans
Describe how the connective tissue is made for function
Strong enough but allows epidermal appendages neurovasculture and lymphatics to pass through
Recall the cell types in the dermis
Permanent - muscle wnd nerves
Migratory Immune
What is the subcutaneous tissue called
Hypodermis
What rests on the hypodermis
Dermis
Role of the dermis
Superficial facial sheath with adipose tissue
Role of the dermis
Superficial facial sheath with adipose tissue
Whats the role of the dermis
Superficial facial sheath with adipose tissue
Role of fascia
Reduce friction between dermis and deeper musculature
Role of adipose tissue
Thermoregulatory mechanism as well as disperse forces
What holds the hair
Hair follicle
Role of papilla
Provide blood and nerve supply for growing hair
What does each hair have
Sebaceous gland and 2 pili muscle
Function of hair
Protection and sensing
Psoriasis
causes
Chronic
Adults
Gene’s environment and autoimmune
Eczema condition
Transient
Children
Genes
Environemnt
Allergies
What are cytokines peoduced by
Immune system and keratinocytes
Explain the process of skin inflammation
Dendrites stimulate t cells
T cells activate keratinocytes
Keratinocytes activate cytokines, chemokine and antimicrobial properties
Leads to dysregulated proliferation and differentiation of keratinocytes
Types of wound healing
Inflammatory
Proliferation
Remodel
Role of peripheral mechani receptors
Detect displacement / velocity and acceleration of skin and internal organs
Provide info about location duration and intensity of stimulus
What are mechanoreceptors important for
Social
Manual dexterity
Locomotion
From mechanoreceptors, where is info relayed to
Thalamus
Explain the term adaptation of skin receptors
Tendency of receptor to respond less strongly to a sustained stimulus
Example of slow adapting and where rheyvare found
Merkel discs
Tips of fingers
Ruffini endings
Subcutaneous and connective nerve tissue- stretching
Example of rapidly adapting and where theyre found
Adapt quickly
Hair follicle
Sense fine movements of hair on skin
Function of pacinian corpuscle
Mechanoreceptors sensitive to mechanical pressure and vibration
Where does pacinian corpuscle exist
All over
Within joints
Periosteum
Connective tissue
Internal organs
Explain the structure of pacinian corpuscle
Concentic lamellar extending from schwann cell
Separated by small saca filled with lymph like fluid
Recall information about meiseen corpuscle receptors
Tactile corpuscles
Found in dermal papillae of hairless skin
Nerve endings sensitive to light pressure
Manipulate fine objects with precision
Complete sentence
Hairy skin can be
Both hairy or glabrous
Mechanoreceptors found in both
True or false
Merkel is involved with fine touches throughout body
False
Causes of psoriasis
Trauma
Drugs
Infections activate T cells in basale and spinosum
As result cytokines UPregulate cell cycle of ketatinocytes= epidermis sheds every 4 days instead of 26
What type of disease is albinism
Congenital or acquired disease due to hypo/hyper pigmentation
Causes of albinism
Absence of pigment due to abnormalities of tyrosinase needed for melanin production
What can albinism also lead to
Lack colour in iris
Photophobia
Increase risk of cancer
Seb glands responsible for
Discharge of oily secretion s
Sebum production
Keratinocytes
Most abundant
Langerhans
Melaonsytes
Adipocytes
Merkel
Present
Epidermis
How is vitamin d absorbed
Epidermis under influence of uvb
List examples of ear diseases
Noise induced hearing loss
Wax
Tiniitus
Menieres disease
Recall the two sensory physiologies
Sensation- processing of environment - physicochemical
Perception- interpret- psychological
What dies the thalamas act as
Translator, inputing processed signals, relaying info to cerebral cortex
What are sound waves
Air molecules put into motion
Travelling wave of oscillating pressure
Define sound
Pressure disturbance originating from vibrating object
Hows pitch measured
Wavelength and frequency
How loudness measured
Amplitude and intensity
Relationship between frequency and pitch
High frequency
Hugh pitch
How does brain tranlsate frequency
Into pitch
What is the ear canal sealed to
Tympanic membrane
Describe the tympanic membrane
Thin translucent commective tissue
Aka ear drum
Where is eustachain tube connected to
Pharynx
Describe middle ear
Small air filled mucosa lined cavity with bony boundaries
List the 3 bones in ear
Malleus
Incus
Stapes
Role of eustachian tube
Opens transiently to allow pressure reequibilration
What will happen if pressure is unequal in ear
Rupture of tympanic membrane
Infection of otitis media aka…
Middle ear infection
Glue ear
Bacteria trapped
Middle ear bone damaged
Invade the cochlea
Three types of hearing loss
Conductive
Sensoineural
Central
Conductive hearing loss
Sound XXX transmitted from external to middle ear= tympani XXX vibrate
Ear wax
Otitis media
Perforated ear drum
Disease trauma=otosclerosis= hardening of ossicles
Types of sensoineural hearing loss
Hair less damage
Noise damage
Inflammation damage
Central hearing loss
Neural pathway damage
Comgenital
Stroke
Trauma
Types of tinnitus
Objective- hear sound emitted from ear
Subjective only heard by affected person
Role of inner ear
Fluid filled , oval window keeps fluid separate from air folled sacs, located deep with temporal bine behind eye socket
2 sections of inner ear
Bony labrynth- complicated maze filled with fluid
Membrane tube- surrounded by endolymph fluid
3 major structures of ear
Cochlea- sensory
Vestibule& semicircular canal- sensory transducer for equilibrium function
Branches of cranial nerve- inner ear to brain
Structure and function of organ of coti
3 rows of inner hair& 1 row of inner hair
Vibrate bc of sound waves= band stereo cilia via electromechanical force
Perception of loudness
+ intensity=+ loudness=+ vibrations if basilar membrane=+ bending of stereocilia=+ no of k channels=+ generator potential=+ neurotransmitter release =+ frequency of AP
Louder noise ====
Increase of action potential
What can humans hear
12-20,000
Linked to age
Old age harder to hear +++ frequency
High frequency ==
Xx transmit far= maximum displacement of basilar membrane @ oval window
Low frequency==
Transmit further= max displacement @ bas membrane @ distal helicotrema
Distal end hair activated
Low pitch
Hair calle activated by
High pitch
Spatial coding
Differential response due to spatial coding
Sensory perception involves
Cochlear
Auditory complex
CN VIII is also known as
Auditory nerve
Role of vestibulary system
Maintain balance via vestibulocochlear nerve
Sacs in the vestibular labrynth
Utricle and saccule
Vestibular labrynth can also be known as
Organ for balance
Cochlear labrynth can also be known ad
Organ for hearing
Hearing is..
Our perception of sound