Lab 3

Question 1

fill in the blank

Answer 1

Question 2

label the cranial nerves

Answer 2

Question 3

how important is the sense of smell to the sense of taste?

Answer 3

The sense of smell is closely linked to the sense of taste, as the olfactory nerve (Cranial Nerve I) detects odors that significantly enhance flavor perception. Without the olfactory input, the facial (VII), glossopharyngeal (IX), and vagus (X) nerves, which transmit taste signals, provide only basic sensations like sweet, salty, sour, bitter, and umami, making flavors less complex and enjoyable.

Question 4

where are visual signals initiated

Answer 4

retina

Question 5

what do drops that dilate the pupil do?

Answer 5

they allow more of the retina and vitreous humor to be viewed

Question 6

what is presbyopia

Answer 6

Presbyopia is an age-related condition in which the eye gradually loses its ability to focus on nearby objects. It occurs due to the hardening and loss of elasticity of the lens, making it difficult for the eye to adjust its focus for close-up vision, a process called accommodation.

Question 7

what are the four muscles controlling eye movement innervated by the oculomotor nerve

Answer 7

inferior rectus, medial rectus, superior rectus and levator palpebrae

Question 8

what causes constriction of the pupil

Answer 8

papillary sphincter

Question 9

what controls the lens thickness and distance accommodation

Answer 9

ciliary muscles

Question 10

what is astigmatism

Answer 10

refers to a mismatch in the curvature of the surface of the cornea and/or lens

Question 11

what are the visual cells for the perception of colour

Answer 11

cones

Question 12

what are the 3 colors that cones observe

Answer 12

red, green, and blue

Question 13

identify the 2nd, 3rd and 4th cranial nerves

Answer 13

Question 14

what does failing the H test mean

Answer 14

dysfunction of the extrinsic eye muscles or the trochlear nerve

Question 15

list the 3 rootlets of the trigeminal nerve

Answer 15

ophthalmic (eye and above)
maxillary (upper jaw)
mandibular (lower jaw)

Question 16

differentiate the eye movements controlled by the trochlear nerve and the abducens nerve

Answer 16

trochlear: movement of eye inferiorly and laterally
abducens: abduction of the lateral rectus

Question 17

what happens if there is damage to the vestibulocochlear nerve

Answer 17

sensorineural hearing loss

Question 18

glossopharyngeal nerve function

Answer 18

innervates the pharyngeal muscles, salivary glands and conducts signals from the pressure receptors in the carotid artery. also provides sensory innervation for taste -in the rear third of the tongue

Question 19

vagus nerve function

Answer 19

parasympathetic innervation of the heart and smooth muscles of the abdominal organs. also provides sensory innervation for the auditory canal linking nausea to water dripped into the ear.

Question 20

accessory nerve function

Answer 20

innervates the sternocleidomastoid muscle and the trapezoid muscle

Question 21

hypoglossal nerve

Answer 21

innervates muscles of the tongue

Question 22

during a dissection of a cows eyes, u notice that the cornea is cloudy. why

Answer 22

The cornea appears cloudy in a dissected cow’s eye because it has lost its transparency due to the lack of hydration and blood supply after death. In living animals, the cornea remains clear through a precise balance of hydration, maintained by the aqueous humor and active ion pumps, which cease functioning after death, leading to cloudiness.

Question 23

once the incision in the cows eye has been made, what fluid leaks out and what is its function

Answer 23

Question 24

fill in the blanks

Answer 24

Question 25

what is the gelatinous component found in the eye

Answer 25

vitreous humor

Question 26

what is the eye component that helps with night vision in animals

Answer 26

tapetum lucidum

Question 27

what is the purpose of the tapetum lucidum?

Answer 27

The tapetum lucidum is a reflective layer found in the eyes of many animals, including cows, located behind the retina. Its purpose is to enhance vision in low-light conditions by reflecting light back through the retina, giving the photoreceptor cells a second chance to detect the light. This is why animals with a tapetum lucidum often have eyes that “glow” in the dark.

Question 28

why is the optic disk referred to as the blind spot

Answer 28

The optic disk is referred to as the blind spot because it is the area on the retina where the optic nerve exits the eye and lacks photoreceptor cells (rods and cones). As a result, it cannot detect light, creating a small gap in the visual field.

Question 29

what are the 5 components of a reflex

Answer 29

Question 30

differentiate somatic and autonomic reflexes

Answer 30

Question 31

what is the difference between these two types of reflex arcs

Answer 31

Question 32

what is a myotic reflex

Answer 32

Question 33

Answer 33