Question

1.The flat worm (Planeria) represents a key stage of evolution of the nervous system because...

a.The receptor cells, ganglion cells, and effector muscle cells are contained within the external epithelium

b.the muscle cells have become integrated into the skeletal system for movement

c.the inner layer of the mouth funnel of the Laminaria has the ganglion cell deep to the surface epithelium

d.the ganglia are localized outside of the esophagus altogether

2.Which of the following genes has evolved selectively for cold thermoreceptors?

A.MS

B.TRPM8

C.TRPV4

D.TRPA1

E.TRPV1

3. The olfactory mucosa as a chemoreceptor is unique in that

a. they have glomeruli like the kidney vasculature

b. the olfactory sac of Anguilla contains plates just like in humans

c. the olfactory bulb of the brain is directly integrated into the cellular layers

d.the sensory neuron dendrites, soma, and proximal axons are located within the epithelial lining

4. Which of the following cutaneous receptors depends on a sensory cell entirely integrated into the epidermis

a. Pacinian corpuscle

b.Ruffini ending

c.Meissner’s corpuscle

d.Merkel disk

5. Which of the following is a shared characteristic of both the Golgi tendon organ and annulospiral ending of the muscle spindle apparatus?

a.Spiralling around collagen or extrafusal muscle fibers brings about depolarization.

b.Muscle tension is indirectly transmitted as stretch to sensory receptors.

c.Free nerve endings detect the extracellular surface chemicals and convert the signal into sensory information.

d.External stretch, like the knee jerk reflex, can only stimulate the Golgi tendon organ.

6.Hair cells of the lateral line, ear, and electroreceptors...

a.are comprised of hair, rod, and cone cells.

b.are functioning like sustentacular cells to keep the sensory epithelium refreshed

c.are specialized epithelial cells that use cilia to move the cupula orienting toward sensory signals in the environment

d. are another example of modified epithelial cells that respond to stimuli by releasing a chemical transmitter.

7.A major distinction between Neuromasts and Electroreceptors is

a. the role played for orientation and movement.

b.the inclusion of hair cells even though they might have different receptor cell specializations.

c.innervation via the anterior lateral line nerve

d.the central termination in the lateral line lobe.

Answer 1

1. The correct answer is option (D).

d.the ganglia are localized outside of the esophagus altogether

The nervous system of the flatworms differs by the presence of nerve cords in them. They are connected by the ganglia located in the head region. It is also knoen as the ladder-like system as the nerves connect the nerve cords.

2. The correct answer is option (D).

TRPA1

The TRPA1 is involved in the cold sensation. it selectively mediates the cold sensation and mechanical hypersensitivity in some pathological condition. This ion channel is a sensor for environmental irritants and give rise to modalities such as pain cold.

3.The correct answer is option (C).

c. the olfactory bulb of the brain is directly integrated into the cellular layers