Chapter 50: Sensory and Motor Mechanisms

Question 1

Mechanoreceptor

Answer 1

a type of sensory receptor which relays extracellular stimulus to intracellular signal transduction through mechanically gated ion channels (i.e. touch, pressure, stretching, sound waves, and motion)

Question 2

Hearing process is called…

Answer 2

Auditory transduction

Question 3

Oval window

Answer 3

membrane-covered opening from the middle ear to the cochlea of the inner ear

Question 4

Round window

Answer 4

a membrane covering the entrance to the cochlea in the inner ear

Question 5

hair cells

Answer 5

sensory cells with hair like projections that detect motion

Question 6

Cochlea

Answer 6

the spiral cavity of the inner ear containing the organ of Corti, which produces nerve impulses in response to sound vibrations; diameter is not the same throughout

Question 7

Equillibrium

Answer 7

(type of mechanoreceptor) pertains to the condition of achieving balanced thereby resulting in a stable system

Question 8

statocyst

Answer 8

a small organ of balance and orientation in some aquatic invertebrates, consisting of a sensory vesicle or cell containing statoliths

Question 9

Semicircular canals

Answer 9

three tiny, fluid-filled tubes in your inner ear that help you keep your balance; perceive rotational movement

Question 10

utricle and saccule

Answer 10

perceive linear acceleration

Question 11

Mammalian middle ear converts…

Answer 11

Air pressure waves to fluid pressure waves

Question 12

What causes dizziness?

Answer 12

Moving fluid in the semicircular canals encounters a stationary cupula

Question 13

Electromagnetic receptor example

Answer 13

photoreceptors

Question 14

photoreceptors

Answer 14

sensory cells that contain light-absorbing pigment molecules

Question 15

rods

Answer 15

grayscale detection, night vision, located at edges of retina, shared ganglia

Question 16

cones

Answer 16

different colors, fine detail, less numerous than rods, individual ganglia

Question 17

Light reaction

Answer 17

Light alters retinal from cis to trans isomer closing Na+ channels

Question 18

Glutamate

Answer 18

the neurotransmitter of the neurons of the vertical pathways through the retina

Question 19

Amacrine cells

Answer 19

Interneurons in the retina

Question 20

Chemoreceptors

Answer 20

receptors that sense solute concentration (ex: smell and taste)

Question 21

Smell process

Answer 21

1. Odorants bind with chemoreceptor on membranes of olfactory cilia
2. Cyclic AMP opens channels permeable to Na & Ca

Question 22

Taste buds

Answer 22

Epithelial cells - not neural cells

Question 23

Taste process

Answer 23

Chemical dissolved in saliva will bind with certain receptors

Question 24

Number of smell receptors vs number of taste receptors

Answer 24

400 vs 5

Question 25

Connection between taste and smell

Answer 25

Independent systems that work together to communicate to the brain; about 75% of taste comes through our nose

Question 26

Thermoreceptors

Answer 26

Receptors beneath epidermis where protein next to ion channel responds to temperature change; expansion of protein causes ion channel to close; exist in large quantities

Question 27

Muscle structure

Answer 27

Neurons connect 1 to many fibers

Question 28

Muscle fibers are made up of…

Answer 28

Myofibrils

Question 29

Myofibrils are made up of…

Answer 29

Sarcomeres

Question 30

Sarcomere

Answer 30

The contractile unit; thick filaments of myosin and thin units of actin

Question 31

Process of muscle contraction

Answer 31

1. Neurotransmitter starts action potential at muscle fiber
2. Action potential travels down T tubules
3. Myosin binds to sites on actin filaments
4. Myosin heads bind to actin, then bend during “power stroke”
5. Myosin releases from actin

Question 32

Cycle of muscle contraction continues as long as what is present?

Answer 32

Calcium

Question 33

Visual information is integrated where?

Answer 33

the retina and the visual cortex

Question 34

Calcium’s role in muscle contraction

Answer 34

bind with troponin, changing its shape so that the myosin binding sites on actin are exposed