Lecture 7: Receptor Physiology

Question 1

________ is for information from the external world (hearing, vision , touch)

Answer 1

Exteroreceptor

Question 2

______ is for information from the musculoskeletal system ( deep sensation from the muscles, tendons, joints)

Answer 2

Propeioceptors

Question 3

_____ is for information from the internal organs

Answer 3

Interoreceptors

Question 4

Cranial nerves attach to _____
Spinal nerves attach to _____

Answer 4

Brain
Spinal cord

Question 5

_____ sensory : touch, pain, pressure, vibration, temp, and proprioception in skin, body wall, and limbs. Hearing, equilibrium, vision, smell

Answer 5

Somatic

Question 6

Somatic sensory and visceral sensory belong to ______ division

Answer 6

Sensory (afferent)

Question 7

_____ sensory: stretch, pain, temp, chemical changes, and irritation in viscera: nausea/hunger. Taste

Answer 7

Visceral

Question 8

Somatic motor and visceral motor belong to ____ division

Answer 8

Motor (efferent )

Question 9

____ motor: motor innervation of all skeletal muscles

Answer 9

Somatic

Question 10

______ motor: motor innervation of smooth muscle, cardiac muscle and glands: equivalent to autonomic nervous system. Divides into _____ division and ___ division

Answer 10

Visceral
Parasympathetic
Sympathetic

Question 11

__________is the link between the periphery and the CNS

Answer 11

Peripheral nervous system

Question 12

________ division : information from receptors about internal and external environment toward CNS-> sensory - somatosensory, visceral sensory

Answer 12

Afferent

Question 13

_____ division: response that controls the effectors (skeletal muscles, tissues, and other organs) -> motor- somatic motor visceral motor

Answer 13

Efferent

Question 14

Peripheral nervous system consists of _____ that carry information between the CNS and other parts of the body

Answer 14

Nerve fibres

Question 15

Sensory information can be integrated in the _______ or can travel directly to higher levels in the brainstem, and thalamus

Answer 15

Spinal cord

Question 16

_______ sensory neuron : afferent neuron with its peripheral receptor that first detects stimulus

Answer 16

1st order

Question 17

______ sensory neuron:
Located in the thalamus

Answer 17

3rd order

Question 18

____ sensory neuron:
Either in spinal cord or medulla, synapses with 3rd order neuron

Answer 18

2nd order

Question 19

Sensory information

______ - pain, temperature, tactile, proprioceptive ( from skin, muscles, joints, inner ear)

Answer 19

Somatic

Question 20

Sensory information :

_____ - pain, temperature, stretch, chemical, osmotic

Answer 20

Visceral

Question 21

Sensory information
________ - vision, hearing, balance , taste and smell

Answer 21

Special senses

Question 22

________ at peripheral endings of afferent neurons or receptor cells detect stimuli (change detected by body)

Answer 22

Sensory receptor

Question 23

________ conversion of different forms of energy into electrical signals (action potentials)

Answer 23

Sensory transduction

Question 24

_______ - different types of sensation (sound, light , taste, touch , pain )

Answer 24

Modality

Question 25

_______ : responsive to visible wavelengths of light

Answer 25

Photoreceptors

Question 26

_____ sensitive to mechanical energy

Answer 26

Mechanoreceptors

Question 27

_____: sensitive to heat and cold

Answer 27

Thermoreceptors

Question 28

______: sensitive to pain

Answer 28

Nociceptors

Question 29

_________ : sensitive to specific chemicals Include receptors for smell, taste and receptors that detect 02 and c02 concentration in blood and chemical content of digestive tract

Answer 29

Chemoreceptors

Question 30

_______: detect changes in osmotic pressure

Answer 30

Osmoreceptors

Question 31

_______ each type of receptor is specialized to respond to one type of stimulus. Requires the least amount of energy to activate that particular receptor- the form of energy which the receptor is most responsive

Answer 31

Adequate stimulus

Question 32

__________ - the sensation characteristic of each sensory neuron is produced by its adequate stimulus

Answer 32

Law of specific nerve energies

Question 33

Stimulus alters receptor’s permeability, usually by causing nonselective opening of all small _______ opening of all small ion channels •This change in membrane permeability can lead to the influx of _____ ions -> depolarizes the receptor membrane (usually)

Answer 33

Ion channels Sodium

Question 34

•This local depolarization (graded potential) is known as a __________in the case of a separate receptor, or a generator potential in the case of the specialized ending of a nerve fiber •Receptor or generator potential - graded potential whose amplitude and duration can vary - The stronger the stimulus, the greater the ________change and the larger the potential • Receptor potentials have no __________-> summation is possible with rapidly successive stimuli

Answer 34

Receptor potential Permeability Refractory period

Question 35

_____ receptors : do not adapt at all or adapt slowly Muscle stretch receptors, joint proprioceptors

Answer 35

Tonic

Question 36

_____ receptors: rapidly adapting receptors Tactile receptors in skin

Answer 36

Phasic

Question 37

A particular modality detected by a specialized receptor is sent over a specific afferent and ascending pathway to excite a defined area in the _________

Answer 37

Somatosensory cortex

Question 38

______: 1:1 association of receptor with a sensation -> labeled line coding

Answer 38

Somatosensory

Question 39

Most sensory pathways project to the_____. This modifies and relays information to cortical centres

Answer 39

Thalamus

Question 40

_______: the region f skin surface that the somatosensory neuron responds to

Answer 40

Receptive field

Question 41

The receptive field is a circumscribed area of the skin surrounding the point of stimulation. The ______ the receptive field for a sense on the skin surface, the ______ the acuity.

Answer 41

Smaller Greater

Question 42

________: The smaller the receptive field is in a region, the greater its acuity or discriminative ability

Answer 42

Acuity

Question 43

_______: influences acuity

Answer 43

Lateral inhibition

Question 44

______enhances localization and contrast of stimuli

Answer 44

Lateral Inhibition

Question 45

A ___________ represents a map of brain areas dedicated to sensory processing for different anatomical divisions of the body. The primary sensory cortex is located in the __________, and handles signals coming from the thalamus.

Answer 45

sensory homunculus postcentral gyrus

Question 46

The rate of action potentials is proportional to _______intensity

Answer 46

Stimulus

Question 47

______ - a reduction in receptor potential despite sustained stimulation of the same magnitude •Here, it is a reduction in the number of action potentials in response to the continuous presence of a stimulus •Helps prevent sensory overload

Answer 47

Adaptation

Question 48

________: Stimulus above threshold gives rise to APs in a sensory neuron that projects to the CNS • Stimulus intensity and duration are coded in the pattern of APs reaching the _____

Answer 48

Receptor potential CNS

Question 49

Stimulus location and modality are coded according to which receptors are activated (RECEPTIVE FIELD ) and fine-tuned by _______ • Each sensory pathway projects to a specific region of the ________ dedicated to a particular receptive field. • For somatosensory system, it follows “________”

Answer 49

Lateral inhibition Cerebral cortex Labelled lines