Sensory, Motor & Intergrative Systems Flashcards
Describe how information flows as a sensory input
From the PMS to the CNS
Describe how info flows as a motor output
From the CNS to the PNS
What is a sensation?
Conscious or subconscious awareness of external or internal stimuli
What is perception?
Conscious awareness and the interpretation of meaning of sensations
What is sensory modality?
each unique type of sensation
What are general senses?
Somatic and Visceral
Senses detected by tiny receptors scattered on the skin, muscles, tendons, joints, CT & mucosa
What do somatic sensory receptors detect?
Pressure, pain, temperature, touch, vibration & proprioception
What do visceral sensory receptors detect?
Changes in the conditions within the viscera (internal organs)
May include stretch, chemical changes ect.
What are the special senses?
5
1) Sight
2) Hearing
3) Taste
4) Smell
5) Equilibrium
What is sensory selectivity?
Each sensory receptor can only detect a specific sense
Uour ears cannot taste your food
What are the stages in the production of a sensation?
4
!) Stimulation of the sensory receptor
2) Transduction of the stimulus
3) Generation of nerve impulses
4) Integration of the sensory input
What does transduction do to the stimulus?
Transduction turns the original stimulus into a graded potential
Thus changing chemnical energy into electrical energy
How does the generation of nerve impuses occur (stage 3)?
The graded potential must be large enough to stimulate an action potential
First order neurons from the PNS to the CNS
Describe how the sensory output is integrated (stage 4)?
Sensory nerve impulses are integrated by various portions of the CNS
Mainly the cerebral cortex
What is the function of sensory receptors?
Respond to stimuli by converting the original stimulus into a nerve impulse
What is a graded response or receptor potential
produced when the stimulus is adequit
What is adaption?
If a stimulus is continuous the magnitude of the receptor potential generated will decrease over time
Therefore a larger stimulus will be needed in order to get the same response
What are “rapidly adapting receptors”?
3
Touch
Pressure
Smell
What are “slowly adapting receptors”?
3
Pain
Body position
Chemical conditions of the blood
Where are somatic sensory receptors found in high density’s?
3
Lips
Tip of tongue
Tips of fingers
How do we classify sensory receptors by location in the body
(3)
Exteroceptors
Visceroceptors/interoceptors
Proprioceptors
Describe Exteroceptors
Found on or very near to the body surface
Detect stimuli from the external environmeny
Include receptors for special senses, cutaneous receptors for touch, pressure, pain & temperature.
Describe visceroceptors/interceptors
Found internally within the viscera
Found in BV’s, Muscles, NS & visceral organs
Monitors the bodies internal environment by detecting changes in chemicals, stretch, pressure & body temp
Also includes sensations of hunger & thirst
What are proprioceptors?
Specialized receptors
Found in skeletal muscles, joins, capsules, the inner ear & tendons ONLY
They respond to muscle stretch and movement to help orientate us in space
2 types
What are the types of proprioceptors?
2
1) Tonic proprioceptors
2) Phasic proprioceptors
What are tonic proprioceptors?
non- adaptive
they tell where the body is when the body is at rest (not moving)
What are phasic proprioceptors?
Rapidly adaptive
They tell where the body is while its moving
How are sensory receptors catagorized by the stimulus detected?
(5)
1) Mechanoreceptors
2) Chemoreceptors
3) Nociceptors
4) Thermoreceptors
5) Photoreceptors
Describe Chemoreceptors
Respond to chemical change
Used for detecting sensations of smell, detect blood sugar levels, blood, pH, and blood O2
What are nociceptors?
Respond to potentially damaging stimuli that result in pain
A defensive warning signal for the body
What are thermoreceptors?
Respond to changes in temperature
Help monitor core body temp. and the temp. on the skins surface
What are photoreceptors?
Respond to light energy
Found in the retina of the eye
In human eye–> can only respond to light energy on the “visible spectrum”
How are sensory receptors catagorized by structural complexity at the microscopic level?
(3)
Free nerve endings
Encapsulated nerve endings
Seperate cells
Describe free nerve endings
Simplest, most common foudn everywhere bare dendrites structural complexities visible under light microscore mostly respond to pain, temp, itching, tickleing, and some touch
What are encapsulated nerve endings?
Receptor structure is enclosed in a specialized CT capsule & has distinct structural complexities
Almost all are mechanoreceptors
ex. Pacinion corpuscle & meissners corpuscle
What is Pacinion corpuscle?
A lamellated receptor that detects deep pressure
What is Meissner’s corpuscle?
Detects tactile touch & discriminative touch
What are receptors that are special cells?
Used for detecting special senses
A seperate receptor cell synapses with a first - prder sensory neuron (chemical synapse)
Found in hair cells (hearing & equilibrium) gustatory chemoreceptors in taste buds, photoreceptors in the eye
What are the modalities that make up somatic sensations
4
Tactile (touch)
Temperature
Pain
Proprioception
What are tactile sensations sensed with?
2
Encapsulated –> touch, pressure, vibration –> use “A fibres”
Free nerve endings –> itch, tuckle, touch –> use “C fibres”
What are the rapidly adapting touch receptors?
1) Meissner’s corpuscle
2) Hair root plexuses
Describe Meissner’s corpuscles
Detect fine touch
Found in the dermal papillaw of hairless skin
Density distributed on hands, eyelids, tip of the tongue, lips, nipples, soles, and external genitalia
Describe hair root plexuses
Free nerve endings wrapped around hair follicles & detect movement of the hair caused by wind, water etc.
What are the types of slow adapting touch receptors?
2
Merkel Disc’s
Ruffini’s Corpuscles
What are merkel disks?
Free nerve endings with contacts to Merkel cells in the epidermis’ stratum basale.
They are type II mechanoreceptors that are densest in the lips, hands, fingertips, and external genetalia
What are Ruffini’s corpuscles?
A type II cuaneous mechanoreceptor
Found in ligaments, tendons, the deep portion od the dermis
densest on soles and hands
respond to stretching due to movement
Describe pressure
Not well localized precieved over a large surface
Produced as a result of a disturbance in deeper tissue (great force needed)
Type II mechanoreceptor such as a lamellated encapsulated nerve endings and touch corpuscles
Where are pressure receptors found?
1) dermis & subcutaneous layers
2) beneath the mucus & the serous membranes
3) aroud the muscles, joints % tendons
4) periostium
5) mammary gland & external genitalia
6) some Viscera (pancrea & bladder)
Describe Vibration
Felt by tactile receptors that produce a series of rapid, repeditory nerve impulses
Detect vibration = corpuscles of touch & the pacinan vibrations
Describe itch
Occus when certain chemicals in the body stimulate free nerve endings
These include: Bradykinins, protaglodins & other chemicals released during an inflammatory response
Describe tickle
Produced when someone touches you, stimulating free nerve endings & lamellated corpuscles.
Where are cold temp. receptors found?
Closer to the surface of the body because most of the time, cooling of the body is due to external influences.
Describe thermal/temperature sensations
Produced by thermoreceptors which respond to changing temperature
Where are warm receptors foud?
in the dermis because most of the time the body over heating is due to external influences
Send info via “C-Fibres”
They respond to 32°C to 48°C
Where are cold receptors found?
Epidermis (stratum basale)
Spend input via “B fibres”
React to 10°C-40°C
What are nociceptors?
Receptors that detect pain
Free of nerve endings
Do nociceptors display adaption?
Little to none
because a stimulation that could cause damage should NOT be ignored
What can activate nociceptors?
High intense stimulation of other receptors such as temperature, touch, pressure or chemical stimuli
What are the types of pain?
2
Fast pain
Flow pain
Describe fast pain
pain that is elicited within 0/sec of stimulation (immediately)
uses medium-diameter, myelinated neurons
Acute, sharp & pricking pain”
Not felt in deep tissues
What is slow pain
Pain that sets in/or more seconds after
Once started it will increase
Uses small-diameter, unmyelinated neurons
Described as chronic, burning, churning, & aching
Where is superficial somatic pain detected?
Cia the nocireceptors in the skin
Where is the deep somatic pain detected?
By the nociceoptors located in the deeper tissues, such as joints, tendons, fasia & skeletal muscles
Where does viscera pain arise from?
nocireceptors found in the visceral organs are stimulated & can be particularly difficult & hard to bear
What time of pain is easy/difficult to localize?
Fast paion = easy to localize
Slow pain = Can be localized well but over a larger area
Slow Visceral pain =- can be localized percisely but can be felt on the skin
What is proprioceptian?
Permits us to have knowledge of where our body uis located without visual clues
What determines the orientation of our head?
Determined by the hair cells int he inenr ear that detect where the head is in relation to the ground & the body
This is how we can perform complex skeletal movements & visual coordination (dressing, typing etc)
What is Kinaesthesia?
Perception of body movements
What are the types of preprioceptors?
3
Muscle Spindles
Tendon organs
Joint kinaesthic receptors
Decsribe: muscle spindles
Found in skeletal muscles & respond to the degree of stretch in those muscles & allow the brain to set muscle tone
Describe: Tendon organs
Found where a tendon is joined to a muscle
prevents the over-stretching/damage to the skin
Describe join kinasthetic receptors
Foud in the articular capsules of synovial join & respond tyo the pressure that is impacting the joint capsule itself.
