Deck 4: Principles of Neural and Hormonal Communication

Question 1

Short-wave lengths of light within the visible spectrum are sensed as violet or blue.

Answer 1

True

Question 2

ACh is the neurotransmitter released to signal skeletal muscles.

Answer 2

True

Question 3

Light rays passing through a concave lens undergo convergence.

Answer 3

False

Question 4

Contraction of the radial muscle of the iris produces a dilation of the iris.

Question 5

The image on the retina is upside down and backward due to bending of light rays.

Question 6

Exposure to very loud noises can result in partial conductive deafness.

Question 7

A convex lens converges light rays or brings them closer together.

Question 8

Any stimulus can excite any excitable tissue.

Question 9

The term cataract refers to the condition in which the lens becomes stiff and loses its elasticity.

Question 10

The olfactory mucosa contains enzymes that remove odoriferous molecules so that the sensation of smell doesn't linger after the source of the odour is removed.

Question 11

Most innervated blood vessels receive only sympathetic nerve fibres.

Question 12

Muscarinic receptors are found on the effector cells innervated by the sympathetic division.

Question 13

The circular muscle of the iris contracts in response to dim light.

Question 14

Pain may be elicited by thermal or chemical stimuli.

Question 15

The terminals of both autonomic nerve fibres and motor neurons end in a single, enlarged knoblike structure that releases neurotransmitter.

Question 16

The sclera is the most internal layer of the eye.

Question 17

When an individual sees pure red, only the red cones are stimulated.

Question 18

Cones are more abundant than rods throughout the entire retina.

Question 19

Descending analgesic pathways are believed to suppress transmission in the pain pathways as they enter the spinal cord by blocking the release of substance P.

Question 20

Unmyelinated C fibres send impulses for slow pain pathways.

Question 21

Night blindness is due to a deficiency of vitamin

Question 22

The parasympathetic nervous system inhibits the rate of heartbeat.

Question 23

Accommodation permits near vision.

Question 24

The cortical gustatory area is located adjacent to the "tongue" region of the somatosensory cortex.

Question 25

The sympathetic nervous system is always excitatory to the organs it innervates.

Question 26

In response to high-frequency sounds, the segment of the basilar membrane closer to the oval window vibrates maximally.

Question 27

Sympathetic stimulation of the gallbladder relaxes the activity of this organ.

Question 28

Diplopia is another name for double vision.

Question 29

Rods produce vision in shades of grey.

Question 30

Most innervated blood vessels receive sympathetic and parasympathetic fibres.

Question 31

Sympathetic postganglionic fibres are longer than parasympathetic postganglionic fibres.

Question 32

In hyperopia the far source is focused on the retina with accommodation, and the near source is focused behind the retina.

Question 33

The sympathetic postganglionic fibres that innervate the sweat glands secrete acetylcholine rather than norepinephrine.

Question 34

Autonomic activity can be influenced by conscious neural activity.

Question 35

Phasic receptors are rapidly adapting receptors.

Question 36

The utricle detects changes in head position away from horizontally and vertically directed linear acceleration and deceleration.

Question 37

Receptors can respond only to electrical stimulation.

Question 38

The curvature of the lens must be adjusted to enable the eye to focus both near and far sources on the retina.

Question 39

Action potentials are initiated at the motor end-plate region of skeletal muscle fibres.

Question 40

The helicotrema is located beyond the tip of the cochlear duct.

Question 41

The incus is a structure of the middle ear.

Question 42

Binding of ACh with receptor sites on the motor end plate opens chemical messenger-gated cation channels in the motor end plate, bringing about depolarization of the motor end plate.

Question 43

Colour blindness may be caused by vitamin A deficiency.

Question 44

In the retina, photoreceptor cells do not synapse with bipolar cells.

Question 45

The greatest density of rods is found in the fovea of the macula lutea.

Question 46

Receptor potentials can be graded, with a stronger stimulus resulting in a larger receptor potential.

Question 47

Each region of the auditory cortex becomes excited only in response to a specific tone detected by a selected portion of the basilar membrane.

Question 48

The vestibular nuclei provide output important in maintaining balance and posture.

Question 49

The term adequate stimulus refers to the intensity of a stimulus developing above a threshold value.

Question 50

Prostaglandins suppress the sensitivity of nociceptors.

Question 51

Activation of a sensory pathway at any point gives rise to the same sensation that would be produced by stimulation of the receptors in the body part itself.

Question 52

Each cone contains three different photopigments for selectively responding to red, blue, or green wavelengths of light.

Question 53

Action potentials are transmitted on a one-to-one basis at both a neuromuscular junction and a synapse.

Question 54

Binocular vision enhances depth perception.

Question 55

The ossicular system transmits the vibrations of the tympanic membrane to the oval window, the movement of which sets up pressure waves in the cochlear fluid.

Question 56

Sour taste is caused by the hydrogen ions from acids.

Question 57

The Pacinian corpuscle is sensitive mainly to temperature changes.

Question 58

The parasympathetic nervous system dominates in fight-or-flight situations.

Question 59

The brain contains naturally occurring morphine-like substances.

Question 60

The autonomic nervous system is part of the somatic nervous system.

Question 61

The inner ear is involved only with hearing.

Question 62

Dual innervation of organs by both branches of the autonomic nervous system allows a fine degree of control over these organs.

Question 63

Parasympathetic activation of sweat glands occurs to help reduce body temperatures.

Question 64

Nociceptors are naked (free) nerve endings.

Question 65

Through lateral inhibition, a more intensely activated receptor pathway halts transmission of impulses in surrounding, less intensely stimulated pathways.

Question 66

Photoreceptors, bipolar cells, and ganglion cells all display action potentials.

Question 67

Osmoreceptors are sensitive to changing solute concentrations.

Question 68

Nicotinic and muscarinic receptors are the two kinds of adrenergic receptors.

Question 69

Axons from retinal ganglion cells form the optic nerve.

Question 70

By blocking the effect of acetylcholine at muscarinic but not nicotinic receptors, atropine is able to block parasympathetic effects while not influencing sympathetic activity at all.

Question 71

Unlike the visual pathways, auditory signals from each ear are transmitted to both hemispheres.

Question 72

A receptor cell initially develops a generator potential by the influx of potassium.

Question 73

Sympathetic preganglionic fibres originate in the thoracic and lumbar segments of the spinal cord.

Question 74

Receptors transduce one form of energy into electrical energy.

Question 75

Acetylcholinesterase is stored in secretory vesicles in the motor end plate of the muscle fibre.

Question 76

The fovea is the point on the retina where the optic nerve leaves.

Question 77

Light must pass through several layers of retinal cells before reaching rods and cones.

Question 78

Normal breathing patterns directly bring odoriferous molecules into contact with the olfactory mucosa.

Question 79

The external eye muscles contract to change the shape of the lens.

Question 80

The axons controlling skeletal muscles are large and myelinated.