Lecture 22: The PNS- Sensation

Question 1

Transduction Pathway

Answer 1

Energy, sensory receptor, signal to brain

Question 2

Types of energy: Transduction Pathway

Answer 2

Chemical, mechanical, thermal, light

Question 3

Types of Sensory Receptors: Transduction Pathway

Answer 3

Simple, Complex, Special Sensory

Question 4

Cognition

Answer 4

When the signal reaches the cerebrum (most go through the thalamus)

Question 5

Mechanoreceptors

Answer 5

Detect mechanical deformation which stretches the membrane to open ion channels

Question 6

Baroreceptors

Answer 6

Senses pressure

Question 7

Proprioceptors

Answer 7

Senses body position (joints/muscles)

Question 8

Thermoreceptors

Answer 8

Change in temperature which alters the permeability of the membrane

Cold receptors respond if temperature < body temperature

Warm receptors respond if temperature > body temperature to 45C

> 45C: Nociceptors

Question 9

Photoreceptors

Answer 9

Electromagnetic radiation that changes the membrane characteristics

Question 10

Chemoreceptors

Answer 10

Application of chemical ligands which also opens ion channels

(Taste, smell, CO2, O2, H+)

Question 11

Subconscious

Answer 11

Processed in spinal cord or brain stem

Question 12

Special Senses

Answer 12

Vision, hearing, taste, smell, equilibrium

Question 13

Somatic Senses

Answer 13

Touch, temperature, pain, itch, proprioception

Question 14

Somatic Stimuli

Answer 14

Muscle length + tension, proprioception

Question 15

Visceral Stimuli

Answer 15

Blood pressure, distension of GI tract, blood glucose concentration, internal body temperature, osmolarity of body fluids, lung inflation, pH of CSF, pH + oxygen content of blood

Question 16

Where do equilibrium pathways primarily project to?

Answer 16

The cerebellum

Question 17

Where do most sensory pathways go through?

Answer 17

The thalamus

Question 18

Receptive Fields

Answer 18

Area monitored by a single receptive cell

Question 19

What increases receptive field size?

Answer 19

Convergence of primary neurons onto secondary neurons increase receptive field size

Question 20

Where are smaller receptive fields located?

Answer 20

More sensitive areas

Question 21

Labeled Line

Answer 21

1:1 association of a receptor to a sensation

Question 22

Larger receptive fields

Answer 22

More difficult to localize stimulus

Question 23

Lateral Inhibition

Answer 23

Enhances contrast and makes a stimulus easier to perceive

Question 24

Intensity

Answer 24

Frequency of action potentials

More frequent action potentials= longer and stronger

Question 25

Duration

Answer 25

When action potentials are firing

Question 26

Tonic Receptors

Answer 26

Slowly adapting receptors that respond for the duration of a stimulus

Question 27

Phasic Receptors

Answer 27

Rapidly adapt to a constant stimulus and turn off