BIOL 203 - Lab Practical #3

effect of neurotransmitters on frog heart rate

-acetylcholine: will decrease frog's heart rate -epinephrine: will increase heart rate -atropine: will increase heart rate -pilocarpine: will decrease heart rate

autonomic neuropathy

-alteration to normal gastrointestinal function -erectile dysfunction -loss of ability to urinate -dizziness or fainting -blurry vision -dry skin

peripheral neuropathy

-loss of sensation in feet -difficulty walking -weakness in arm muscles

order of structures that an odor passes through

1) naris 2) nasal vestibule 3) olfactory epithelium 4) olfactory bulb 5) olfactory tract

three tunic layers of the eye

1) the fibrous tunic is the avascular, superficial coat of the eyeball. it consists of the anterior cornea and posterior sclera 2) the vascular tunic is the middle layer of the eyeball that contains three parts: iris, choroid, and ciliary body 3) the nervous tunic (retina) is the inner coat that lines the posterior eyeball with its visual receptors to receive light

why is Q10 a useful concept?

Q10 allows us to determine which bodily processes are energy dependent or passive. From the data, we can see that the bodily processes in this frog heart are passive

describe the mechanisms by which epinephrine affects heart rate

epinephrine increases heart rate by binding to both alpha and beta adrenoceptors

retina

innermost layer of the eye that has retinal cells

vitreous body

internal gelatinous substance that fills the eye

which muscle is affected when it feels harder to keep your eyes open?

levator palpebrae superioris

how does light reach the retina?

light must first pass through the cornea. it goes through the anterior chamber and through the pupil that is surrounded by the iris. from the iris, light travels into the posterior chamber and on to the lens. the lens reflects the light through the vitreous chamber and onto the retina at the back of the eye

optic disc

location where retinal axons exit the eye as the optic nerve

hearing and equilibrium have

mechanoreceptors

myopia

nearsightedness; distant objects appear blurry because incoming light is focused in front of the retina, rather than on the retina

which part of the visual pathway would be damaged for a person to experience peripheral vision loss?

optic chiasm

lens

oval located behind the iris

what functions as both endocrine and exocrine gland?

pancreas -alpha cells: glucagon -beta cells: insulin

fungiform papillae

perception of taste; are mushroom-shaped structures located on the sides and tip of the tongue; look like red or pink spots (10)

circumvallate papillae

perception of taste; circumvallate papillae are large, flat-topped structures that are encircled by a depression. they lie just anterior to the terminal sulcus of the tongue

foliate papillae

perception of taste; small lateral folds on the posterior sides of the tongue

filiform papillae

perception of touch; are long and thin structures that cover most of the tongue

iris

structure that controls pupil size

what produces saliva?

submandibular gland and sublingual gland

epinephrine mimics the effects of which branch of the autonomic nervous system?

sympathetic nervous system

what is Q10?

the Q10 is the ratio (or rate of change) of a chemical or biological system at two temperatures that are 10°C (18°F) apart. Passive processes in the body (for example, diffusion) have Q10 ratios of ~1.3, whereas active processes in the body (for example, metabolism) have Q10 ratios of ~2.3; also called temperature coefficient

describe the delay between the QRS complex and ventricular contraction

the frog heart is behaving rhythmically. There is a noticeable delay between atrial and ventricular contractions. This delay occurs by the AV node, which prevents both the atria and ventricles from contracting at the same time.

how do the latencies and amplitudes in the skin of the hand and the foot compare? explain any differences in the latencies

the latency of the foot is longer, which is to be expected because the nerve impulse must travel a greater distance. the amplitudes are bigger for the hand. this is likely because of how many sweat glands are controlled by the autonomic nervous system

which nerve is responsible for detecting the saltiness and texture of a potato chip on your tongue?

the lingual nerve detects sensory information on the anterior 2/3 of the tongue. the chorda tympani detects taste. the glossopharyngeal nerve detects sensory information and taste on the back 1/3 of the tongue

choroid

the pigmented vascular layer of the eyeball between the retina and the sclera

describe the volunteer's skin potential response after the startle, gasp, and thump stimuli. how can you explain these findings?

the sweat glands are only supplied by the sympathetic nervous system. stressful stimuli activate the SNS and stimulate sweating. gasping also activates the SNS by stimulating stretch receptors in the lung. thumping is also stressful stimuli, but would be less stressful than being startled

pinna (auricle)

the visible part of the ear on each side of the head; collects sound waves

stapes

transfer the force of vibrations from the incus to the oval window; smallest of the ossicles, shaped like a stirrup

incus

transfer the force of vibrations from the malleus to the stapes; small, anvil-shaped bone that contacts the malleus and the stapes

cochlea

transfers auditory information from the inner ear to the brain; shell-shaped bony structure that connects to the oval window of the middle ear

oval window

transfers the force of vibrations from the middle ear to the inner ear; membrane covered opening that leads into the inner ear that connects the stapes to the cochlea

malleus

transfers the force of vibrations from the tympanic membrane to the incus; small, hammer-shaped bone that contacts the tympanic membrane and the incus

balance

vestibule and ampulla

how does temperature affect frog heart rate?

warm temperature increases heart rate and cold temperatures decrease heart rate

sclera

white outermost part of the eyeball

compare the effect of acetylcholine on cardiac muscle with its effect on skeletal muscle. can you explain the mechanistic basis for the difference?

acetylcholine decreases the heart rate in cardiac muscle, which means that there are fewer contractions per minute. acetylcholine in skeletal muscle actually activates the muscles, leading to more contractions. the difference is that acetylcholine is released by the parasympathetic nervous system in cardiac muscle (rest and digest).

describe the mechanisms by which acetylcholine affects heart rate

acetylcholine slows heart rate by binding to M2 receptors

describe the mechanisms by which atropine followed by acetylcholine affects heart rate

atropine followed by acetylcholine has little effect on heart rate. Atropine has inhibitory effects that prevent acetylcholine from slowing the heart rate

tapetum lucidum

blue layer that also reflects; cow ONLY

terminal sulcus

divides the tongue in two; v-shaped groove towards the back of the tongue

external auditory meatus

canal for sound to travel from the auricle to the tympanic membrane

taste and smell have

chemoreceptors; taste requires breakdown beforehand

sound

cochlea, saccule, utricle

vestibule

communicates with the cochlea and semicircular canals; oval chamber that holds the utricle and saccule of the vestibular system; communicates with the cochlea anteriorly but semicircular canals posteriorly

tympanic membrane

converts incoming sound waves to mechanical vibrations

why should you abrade the skin and clean with alcohol wipes before attaching electrodes?

decreases the electrical resistance of the outer layer of the skin and ensures good electrical contact

utricle and saccule

detect linear positional changes and acceleration

semicircular canals

detect rotational position and acceleration

role of microvilli in taste

detect the different tastes (bitter, sweet, sour, etc) from within the tastebud

what papillae does not have taste buds?

filiform

nasal vestibule

has hairs to trap particles; located in the very front of the nose

what is the effect of acetylcholine and atropine on frog heart rate?

has no effect; acetylcholine decreases heart rate and atropine increases heart rate; no net effect

pupil

hole or space within iris

superior, middle, inferior nasal conchae

increase the surface area of the nasal cavity to warm and humidify inspired air more effectively

how can you explain the change in potential across the hand and foot that follows peripheral nerve stimulation?

peripheral nerve stimulation activates the sympathetic nervous system, and this leads to increased sweat production. there is a difference in potential between the palm of the hand and back of the hand and top of foot versus sole of foot because the palm and sole contains sweat glands that are controlled by the autonomic nervous system

vision has

photoreceptors

superior, middle, inferior meatus

produce turbulence that moistens and warms the air as it enters the lungs

semicircular canals function

provides information of balance to the brain; three that are at right angles to each other; posterior and superior to the vestibule

cornea

refracts light into the eye

you may observe a change in the skin potential even before the stimulus is delivered. how can you explain this?

result of anticipation of the stimulus