Lecture 4 - General Sensory Mechanisms Flashcards
What are the different types of sensory receptors?
L4 S4
- mechanoreceptors (includes hearing, equilibrium, and BP)
- thremoreceptors
- nociceptors (pain)
- electromagnetic receptors (rods and cones)
- chemoreceptors
What is meant by differential sensitivity?
L4 S8 LO1
Receptors are highly responsive to a single type of stimulus and almost non-responsive to others
What is meant by modality of a receptor and the labeled line principle?
L4 S8 LO1
Modality:
-principle type of stimulation
Labeled line principle:
-specificity of nerve fibers to transmit only one modality of sensation
What is adaptation?
L4 S8 LO1
Receptors partially or completely adapt to a constant stimulus after a period of time
What are the different mechanisms of mechanical stimulation?
L4 S11 LO1
- mechanical deformation
- exposure to a chemical
- change in temperature
- electromagnetic radiation
What is a receptor potential and what is its significance in generating an action potential?
L4 S12 LO1
Area of receptor with modality related ion channels generates a local potential in response to magnitude of the modality.
This local potential is decremental, so if strong enough, it may reach an area of the cell where it can create an action potential.
Differentiate between tonic and phasic receptors.
L4 S15 LO1
Tonic:
- slow adapting
- detect continuous stimulus
- transmit impulse if stimulus is present
Phasic:
- rapidly adapting
- non-continuous stimulus
- stimulated only with change in magnitude of stimulus
- transmission rate related to rate of stimulus change
What are the main types of nerve fibers?
L4 S16 LO1
Type A:
- large/medium-sized
- myelinated
- spinal nerves
- Type Ia, Ib, II, and III
Type C:
- small
- unmyelinated
- low velocity signal conduction
- most sensory fibers and all postganglionic autonomic fibers
- Type IV
Differentiate spatial summation and temporal summation.
L4 S19 LO2
Spatial:
-increasing signal strength is transmitted by using a greater number of nerve fibers
Temporal:
-increasing signal strength by increasing frequency of nerve impulses
What are the functional areas of a neuronal field?
L4 S22 LO2
Stimulatory field:
-area within the pool stimulated by incoming an nerve fiber
Discharge zone:
-all output fibers stimulated by incoming fiber
Facilitated/inhibition zone:
- neurons further from discharge zone that are facilitated by not excited
- either inhibitory or excitatory
What is a reverberatory circuit?
L4 S28 LO2
- positive feedback loop in a neuronal circuit
- can discharge repeatedly for a period of time from a single stimulation.
Differentiate between the types of senses.
L4 S33 LO3
Somatic:
- sensory information from all over the body
- includes mechanoreceptive, thermoreceptive, and pain
Special:
-includes vision, hearing, smell, taste, and equilibrium
Differentiate between the different types of sensation.
L4 S33 LO3
Exeteroreceptive:
-from the surface of the body
Proprioceptive:
- position sensation
- muslce/tendon sensation
- pressure sensation
- equilibrium
Deep:
-deep pressure, pain, and vibration
