Anatomy Flashcards
What is proprioception
The ability to sense stimuli with the body in regard to position, motion and equilibrium
List the components of the reflex arc
- Receptor
- Sensory
- Integration centre
- Motor neuron
- Effector
Where is the receptor found
It is at the site of stimulus action
What do sensory neurons do
They transmit afferent information to CNS
What is the integration centre
One or more synapses in the CNS
What does the motor neurone do
It conducts efferent impulses to the effector Organ
What is an effector
A muscle fibre or gland that responds to impulses
List the 5 conscious modalities
- Touch
- Auditory
- Sight
- Smell
- Taste
List the 5 subconscious modalities
- Pain
- Balance
- Body position
- Movement
What does sensory transduction require
Requires detection to changes in the environment (Stimuli)
What is sensory induction
Environmental signals being converted into electrochemical
How is a stimulus detected
Sensory receptors/ neurones detect changes in the environment
What is necessary to be able to detect a small stimulus
Amplification
What does localised depolarisation trigger
Triggers an action potion to propagate to the central nervous system via afferent fibres
What is the magnitude of receptor potential dependent on
Stimulus strength
How can sensory receptors be classified
- Location
- Function
- Fast or slow adapting
How do we classify sensory receptors by location
- Exteroceptors
- Interoreceptors
- Proprioceptors
Describe Exteroceptors
Sensitive to stimulus outside the body
Describe Interoreceptors
They respond to stimuli within body
Describe Proprioceptors
Advice the brain of body movements
How do we classify sensory receptors by function
- Mechanoreceptors
- Proprioceptors
- Thermoreceptors
- Chemoreceptors
- Noiciceptors
- photoreceptors
What do mechanoreceptors detect
Detect touch, pressure. vibration and stretch
What do Proprioceptors detect
Position
What do thermoreceptors detect
Detect temperature changes
What do photoreceptors detect
Detect light energy
What do chemoreceptors detect
Detect chemical stimuli
What do Nociceptors detect
Detect pain
What are fast adapting neurones
Their response declines rapidly with continuous stimulation
What is another name for fast adapting neurones
Phasic receptors
What are slow adapting neurones
They continue to respond as long as the stimulus is there
What is another name for slow adapting neurones
Tonic receptors
Give an example of a fast adapting neurone
Thermoreceptors
Give an example of a slow adapting neurone
Pain receptors
Where are mechanoreceptors found
Present under fingertips and respond to mechanical forces
What do mechanoreceptors cause
Membrane distortion in receptive endings opening ion channels
Name the different types of sensory receptors
- Free sensory endings
- Root hair plexus
- Merkel disks
- Pacinian corpuscles
- Ruffini corpuscles
- Messner’s corpuscles
- Krause’s End Bulbs:
Describe Free sensory endings
Unencapsulated free end sensory swelling with distal knob like swellings
WhIch location class can free sensory endings fall under
Exteroceptors,
interoreceptors,
proprioceptors
Which function class can sensory endings fall under
Nociceptors (pain),
chemoreceptors,
thermoreceptors
mechanoreceptor
Where are free sensory endings found
Most internal tissues (mostly in connective tissue)
Describe root hair plexus
Modified unencapsulated free nerve endings that entwine into hair follicles
WhIch location class can root hair plexus fall under
Exteroceptors
Which function class can root hair plexus fall under
Mechanoreceptors
Where are root hair plexus found
In and surrounding hair follicles
Describe merkel disks
Unencapsulated free nerve endings attaching to deep epidermis
WhIch location class can Merkel disks fall under
Exteroceptors
Which function class can Merkel disks fall under
Mechanoreceptors
Where are Merkel disks found
Base of epidermis and sweat ridges of fingertips
What is the function of Merkel disks
Gather information regarding pressure and texture of touch
Describe Pacinian corpuscles
Single nerve cell surrounded by 60 layers of Schwann cells
WhIch location class can Pacinian corpuscles fall under
Exteroceptors, interoreceptors & some proprioceptors
Which function class cam Pacinian corpuscles fall under
Mechanoreceptors
Where are Pacinian corpuscles found
Dermis and subcutaneous layers of skin (fingers, soles, genitalia, nipples)
What is the function od Pacinian corpuscles
Sensitivity to pressure pain and stretch