Week 15 — A&P Lab / Scientific Inquiry · "Test Your Own Senses"

Course: Anatomy & Physiology I (BIOL 2301 + BIOL 2101) · Silver Oak University (fictional sample) · Prof. Navarro
Objective: Objective 8 — the special senses; relate the structure of each sensory organ to its function · SLO A (relate structure to function) · SLO B (use sensory terminology correctly)
Worth 50 points · Labs group = 15% of the grade · Lab 15
Format: a set of simple at-home sensory demos (no equipment to buy) on your own eyes, ears, and nose, paired with a free virtual anatomy atlas for the structures — then you catch the AI's mistakes when it describes the senses.

This is the course's signature weekly component. Every instructional week has one A&P lab. This week's is hands-on with your own body: you'll map your blind spot, run a taste-without-smell test, and test sound localization, then confirm the structures on a free atlas. All lab resources are links to external sites — nothing to buy or download.

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Part 1 — The Big Picture

This week you learned how each sense organ captures a stimulus and converts it into nerve signals: the eye refracts and focuses light onto photoreceptors (rods and cones), the ear funnels sound through the ossicles to the cochlea (and senses balance in the semicircular canals), and the tongue and nose detect chemicals as chemoreceptors. Today you'll demonstrate three of these on yourself — your blind spot proves where the optic nerve leaves the retina, a taste-without-smell test proves that flavor is mostly smell, and a localization test shows how two ears place a sound — and then confirm the structures on a virtual atlas.

The scientific habit this builds: observation → measurement/manipulation → checking your result against the known anatomy. In A&P, your own senses are a free, always-available lab bench.

Background (optional, ~5 min): OpenStax A&P §14.1, "Sensory Perception" — keep it open as your answer key for receptor classes and how each sense works: 🔗 https://openstax.org/books/anatomy-and-physiology-2e/pages/14-1-sensory-perception

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Part 2 — Your Scientific Question & Hypothesis

Sensory labs start like any inquiry — with a question and a prediction you'll test against evidence (here, your own perception).

The question: Can you demonstrate, on your own body, that each sense organ has a specific structure tied to a specific function — a blind spot where the optic nerve exits, a flavor that depends on smell, and a localization that depends on two ears?

Before you start, write your hypothesis / prediction:

I predict that (a) I will have a blind spot in each eye where the optic nerve exits the retina; (b) when I block my sense of __, I will be far less able to identify a food by flavor; and (c) when I ask an AI to describe the eye and ear, it will make at least _ structure→function error(s) I can catch (for example, reversing and ___).

(There's no single "right" number — you're predicting how reliable your senses and the AI will be, then checking.)

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Part 3 — Materials & Procedure

You need (all free):
- Your own eyes, ears, and nose. A blank sheet of paper and a pen. A partner or a quiet room helps for the sound test.
- A few small food or scent items for the taste test (e.g., a piece of apple and a piece of potato/onion cut to the same shape; or two flavors of jellybean). (Skip anything you're allergic to.)
- The InnerBody atlas for the structures (free, no download): the eye page 🔗 https://www.innerbody.com/image/nerv09.html and the nervous-system / sense-organs overview 🔗 https://www.innerbody.com/image/nervov.html
- An approved chatbot (Gemini, Claude, or ChatGPT) for Part 6.

Procedure:
1. Blind-spot demo (vision). On the paper, draw a small + on the left and a small ● about 6–7 inches to its right. Hold the paper at arm's length. Close your left eye, stare at the + with your right eye, and slowly bring the paper toward your face. At one point the ● disappears — that's its image landing on your blind spot (where the optic nerve exits and there are no photoreceptors). Note roughly the distance at which it vanishes. Repeat with the other eye (close the right, stare at the ● with the left, watch the + vanish).
2. Taste-without-smell demo (flavor). Have a partner hand you the two same-shaped foods, or close your eyes and shuffle them. First, pinch your nose shut and chew one — try to identify it by taste alone. Then release your nose mid-chew and notice the flavor "switch on." Record how well you identified each food nose-pinched vs. nose-open.
3. Sound-localization demo (hearing & two ears). Sit in a quiet room with your eyes closed. Have a partner snap or tap from different positions (left, right, front, behind, above). Point to where you think each sound came from. Record which positions were easy and which were hard to locate.
4. Confirm the structures. Open the InnerBody eye and sense-organs pages and locate the structures in the Part 4 table; record each one's function, and check your answers against OpenStax §14.1.

No partner or food handy? Do the blind-spot demo (needs only paper) and the structure table; for the others, describe what you'd expect and confirm on the atlas. The skill — connect a structure to its function and verify it — is identical.

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Part 4 — Structure-Identification / Data Table (fill this in)

4a. Sense-organ structures (confirm on the atlas):

Structure	Sense organ	Its function	Receptor class
Cornea	Eye	______	(none — it's clear tissue)
Retina (rods & cones)	Eye	______	______
Stapes	Ear (middle)	______	—
Cochlea	Ear (inner)	______	______ (hair cells)
Semicircular canals	Ear (inner)	______	______ (hair cells)
Taste buds / olfactory receptors	Tongue / nose	______	______

Receptor classes to choose from: photoreceptor, mechanoreceptor, chemoreceptor.**

4b. Your demo results:

Demo	What you observed
Blind spot — right eye	The ● disappeared at about ______ inches
Blind spot — left eye	The + disappeared at about ______ inches
Taste test — nose pinched	Could / could not identify the food(s): ______
Taste test — nose open	Could / could not identify the food(s): ______
Sound localization	Easy positions: __ · Hard positions: ____

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Part 5 — Identify the Reasoning

Answer in a sentence each:
1. Your blind spot has no photoreceptors. What structure is located there, and why does that explain why the dot disappeared? (Tie the structure to the function.)
2. In the taste test, what changed between nose-pinched and nose-open? Use this to explain why flavor is mostly smell and what that means when you have a cold. Name the receptor class taste and smell share.
3. Pick one sense and explain how a structure's shape serves its function (e.g., why the fovea is cone-packed, why the cornea is clear and curved, or why the cochlea is coiled and fluid-filled). (This is the structure→function habit.)

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Part 6 — AI-Critique Moment (required — this is the BYOAI step)

Now bring in your approved chatbot (Gemini, Claude, or ChatGPT) and be the anatomist who checks its work.

1. Paste this to the chatbot: "Describe the special senses for me: which photoreceptors in the retina detect color and which work in dim light; list the three middle-ear ossicles in order from the eardrum; say which inner-ear structure does hearing and which does balance; and name the five basic tastes."
2. Check everything it says against the atlas and OpenStax §14.1:
   - Did it keep cones = color / bright light and rods = dim light / no color (not reversed)? Chatbots flip these constantly.
   - Did it list the ossicles as malleus → incus → stapes (not scrambled or reversed)?
   - Did it say the cochlea = hearing and the semicircular canals = balance (not swapped)?
   - Did it give the five basic tastes as sweet, sour, salty, bitter, umami (not "spicy" or "fatty")?
3. Write 2–3 sentences reporting what the AI got right and at least one structure→function error you caught and corrected (with the correct fact). If it happened to get everything right, say how you verified each claim against the atlas — that's the skill.

The habit all term: the tool drafts, you judge. A chatbot will confidently reverse rods and cones or misorder the ossicles — catching it is the point, and in the clinic it's not optional.

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Part 7 — What to Submit

Submit a single document (or text entry) with: your hypothesis/prediction, your completed Part 4 tables, your Part 5 answers, and your Part 6 AI-critique paragraph. Due Sunday, Dec 13, 11:59 p.m. (50 points).

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Instructor answer key — REMOVE BEFORE PUBLISHING TO STUDENTS

Every structure→function pairing below is verified against standard anatomy (OpenStax §14.1; InnerBody eye & nervous-system references). Rods = dim light/no color; cones = color/bright. Ossicles = malleus → incus → stapes. Cochlea = hearing; semicircular canals = balance. Taste & smell = chemoreceptors.

Part 4a — verified structure table:

Structure	Sense organ	Function	Receptor class
Cornea	Eye	Refracts (bends) most of the incoming light	none (clear tissue)
Retina (rods & cones)	Eye	Detects light — rods (dim light, no color), cones (color, bright light)	photoreceptor
Stapes	Ear (middle)	Last ossicle in the chain (malleus → incus → stapes); pushes the cochlear fluid	—
Cochlea	Ear (inner)	Hearing — hair cells turn fluid vibrations into nerve signals	mechanoreceptor (hair cells)
Semicircular canals	Ear (inner)	Equilibrium / balance — sense head movement	mechanoreceptor (hair cells)
Taste buds / olfactory receptors	Tongue / nose	Taste & smell — detect dissolved/airborne chemicals (flavor)	chemoreceptor

Part 4b — expected demo results: the blind spot typically appears with the paper ~10–14 inches from the face (varies by person and dot spacing — any distance at which the dot vanishes is correct). Taste test: students usually cannot reliably identify the food with the nose pinched (especially apple vs. potato/onion) and can once the nose is open — that's the key result. Sound localization: left/right are usually easy (the two ears get the sound at slightly different times/loudness); directly front, behind, or overhead are harder because both ears receive the sound nearly identically.

• Part 5: (1) The optic disc (where the optic nerve exits the retina) sits at the blind spot; it has no rods or cones, so when the dot's image lands there, there's nothing to detect it and it disappears — structure (no photoreceptors) explains function (no vision at that spot). (2) Pinching the nose removed the smell input; with the nose open, odor molecules reach the olfactory receptors and "flavor" returns — because flavor is mostly smell, which is exactly why food tastes bland during a cold. Taste and smell are both chemoreceptors. (3) Example: the fovea is packed with cones, so it gives the sharpest, most detailed color vision — which is why we aim images there; (also acceptable: the cornea is clear and curved to transmit and bend light; the cochlea is coiled and fluid-filled so vibrations can travel along its hair cells).
• Part 6 (AI-critique): full credit for a specific catch — most commonly the AI reversing rods and cones (claiming rods see color or cones work in dim light), scrambling the ossicle order, or swapping the cochlea and semicircular canals. Full credit also if the student verified each claim against the atlas and OpenStax.

Grading rubric — 50 points

Criterion	Full	Partial	None
Hypothesis / prediction — a clear prediction about the demos and the AI's reliability (6)	6	3–4	0–2
Structure table + demo data (Part 4) — structures→functions + receptor classes correct; demo results recorded (18)	18	9–15	0–7
Reasoning (Part 5) — blind-spot/optic-nerve logic, flavor = smell + chemoreceptors, and a sound structure→function point (14)	14	7–11	0–5
AI-critique (Part 6) — names a specific structure→function error caught and corrected (8)	8	4–6	0–3
Sensory terminology — uses standard terms correctly throughout (4)	4	2	0–1

Quality gate (self-checked): every structure→function pairing in the key is verified against standard anatomy (OpenStax §14.1; InnerBody eye & nervous-system references) — cornea refracts; retina holds photoreceptors with rods = dim light/no color and cones = color/bright; ossicle order malleus → incus → stapes; cochlea = hearing, semicircular canals = balance; taste & smell = chemoreceptors with five basic tastes including umami. No structure is mislabeled and no rod/cone or cochlea/canal pairing is reversed. Anatomy-accuracy gate: PASS. (No arithmetic in Week 15's lab — the blind-spot distance and demo outcomes are observed, not computed — so the quantitative gate does not apply this week.)