Week 6 — A&P Lab / Scientific Inquiry · "Read the Skin"

Course: Anatomy & Physiology I (BIOL 2301 + BIOL 2101) · Silver Oak University (fictional sample) · Prof. Navarro
Objective: Objective 3 — identify the layers and structures of the integumentary system and relate each to its function · SLO A (relate structure to function) · SLO B (use anatomical/physiological terminology correctly)
Worth 50 points · Labs group = 15% of the grade · Lab 6
Format: a guided exploration of a free virtual anatomy atlas (no download, nothing to buy) — you'll identify the skin's layers and structures, describe what each one does, and then catch the AI's mistakes when it labels a skin diagram.

This is the course's signature weekly component. Every instructional week has one A&P lab. This week's uses a free virtual anatomy atlas (the InnerBody integumentary guide); earlier weeks used the atlas for body regions and a virtual microscope for tissues, and later weeks add PhET physiology simulations and a few simple at-home measurements. 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 that the skin is an organ — a layered structure that acts as a barrier and a thermostat. A clinician reads the skin constantly: how deep is this burn? why is this wound bleeding? is this layer where the problem is? Today you'll read a real skin model — identify its layers and structures on a free virtual atlas and say exactly what each one does, the way a precise chart entry would.

The scientific habit this builds: observation → precise identification → relating each structure to its function. In A&P, naming a structure is only half the job — the other half is saying what it does and why its design makes that possible.

Background (optional, ~5 min): OpenStax A&P §5.1, "Layers of the Skin" — keep it open as your answer key for the layers, the strata order, and melanin vs. keratin: 🔗 https://openstax.org/books/anatomy-and-physiology-2e/pages/5-1-layers-of-the-skin

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Part 2 — Your Scientific Question & Hypothesis

Anatomy labs still start like any inquiry — with a question and a prediction you'll test against evidence (here, the atlas).

The question: Can you identify the skin's layers and structures and correctly pair each one to its function — well enough to catch a confident error when an AI describes the same skin?

Before you start, write your hypothesis / prediction:

I predict that for the structures below, I can name the correct layer and the correct function — and that when I ask an AI to describe the skin, it will make at least ______ labeling or structure→function error(s) I can catch (for example, claiming the epidermis has blood vessels).

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

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Part 3 — Materials & Procedure

You need (all free, in a browser):
- The InnerBody Integumentary System guide (free, no download): 🔗 https://www.innerbody.com/anatomy/integumentary
- Optional second reference: OpenStax §5.1 (linked above).
- An approved chatbot (Gemini, Claude, or ChatGPT) for Part 6.

Procedure:
1. Open the InnerBody integumentary guide and read/scan the sections on the epidermis, dermis, hypodermis, the glands, and the physiology (keratinization, temperature homeostasis).
2. For each structure in the Part 4 table, find it and record: (a) the layer it belongs to (epidermis / dermis / hypodermis / "accessory structure"), and (b) one correct function in your own words.
3. For the two ★ rows, also note whether the structure is vascular or avascular (does it contain blood vessels?).
4. Keep OpenStax §5.1 open and check each of your own answers against it before moving on.

No specific atlas access? Any free virtual anatomy atlas or 3D viewer with a skin section works (e.g., GetBodySmart: https://www.getbodysmart.com/). The skill — identify the structure and relate it to its function — is identical.

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

Structure	Layer it belongs to	One correct function	(★ rows) Vascular or avascular?
Epidermis	______ (it IS a layer)	______	★ ______
Stratum basale	______	The stratum basale ______ (what is made here?)	—
Stratum corneum	______	The stratum corneum ______	—
Dermis	______ (it IS a layer)	______	★ ______
Melanocyte (makes melanin)	______	Melanin ______	—
Sebaceous gland	______	Sebum ______	—
Eccrine sweat gland	______	Sweat ______	—
Hypodermis	______	______ (and: is it part of the skin proper?)	—

Use only standard terms. Layers: epidermis, dermis, hypodermis. Remember the strata order deep→superficial: basale → spinosum → granulosum → (lucidum) → corneum.

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Part 5 — Identify the Reasoning

Answer in a sentence each:
1. The epidermis is avascular. Explain how its cells get nutrients, and use that to explain why a very shallow scrape (removing only the stratum corneum) doesn't bleed. (This is the structure→function habit.)
2. New cells are made in the stratum basale and end up as the stratum corneum. Describe what happens to a single keratinocyte as it travels from the deepest layer to the surface — and why it ends up dead.
3. Pick one way the skin helps with thermoregulation (sweating, vasodilation, vasoconstriction, or goosebumps via the arrector pili) and explain it as part of a negative-feedback loop (what change is it opposing?).

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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 clinician who checks its chart.

1. Paste this to the chatbot: "Describe the layers of the skin and label the main structures. Tell me whether the epidermis has blood vessels, list the epidermal layers from deepest to most superficial, and say what melanin and keratin each do."
2. Check everything it says against the atlas and OpenStax §5.1:
   - Did it correctly say the epidermis is avascular (no blood vessels)? Chatbots frequently claim the epidermis is "rich in blood vessels" — it is not. The vessels are in the dermis.
   - Did it list the strata in the right order, deep→superficial: basale → spinosum → granulosum → (lucidum) → corneum? Watch for a scrambled order.
   - Did it keep melanin as the pigment/UV shield and keratin as the toughness/waterproofing protein? Watch for these getting swapped.
   - Did it correctly place the glands (sebaceous and sweat glands in the dermis) and treat the hypodermis as not part of the skin proper?
3. Write 2–3 sentences reporting what the AI got right and at least one labeling or structure→function error you caught and corrected (with the correct idea). If it happened to get everything right, say how you verified each label against the atlas — that's the skill.

The habit all term: the tool drafts, you judge. A chatbot will confidently say "the epidermis is full of blood vessels" or scramble the layer order — 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 table, your Part 5 answers, and your Part 6 AI-critique paragraph. Due Sunday, Oct 11, 11:59 p.m. (50 points).

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Instructor answer key — REMOVE BEFORE PUBLISHING TO STUDENTS

Every layer, structure, and function below is verified against standard anatomy (OpenStax A&P 2e §5.1–5.2; InnerBody integumentary).

Part 4 — verified answer table:

Structure	Layer	Correct function	Vascular/avascular (★)
Epidermis	the outer layer (keratinized stratified squamous epithelium)	barrier — protects against microbes, abrasion, water loss, UV	avascular (no blood vessels; fed by diffusion from the dermis)
Stratum basale	epidermis (deepest stratum)	makes new keratinocytes (stem cells divide here); also holds melanocytes	—
Stratum corneum	epidermis (most superficial stratum)	tough barrier of dead, keratin-filled cells; resists abrasion/water loss; flakes off	—
Dermis	the layer beneath the epidermis (connective tissue)	houses blood vessels, nerves, glands, follicles; gives strength (collagen) and stretch (elastin)	vascular (contains the skin's blood vessels)
Melanocyte	epidermis (stratum basale)	makes melanin, which absorbs UV and gives skin/hair color	—
Sebaceous gland	dermis (accessory structure)	makes sebum (oil) that lubricates/waterproofs skin and hair	—
Eccrine sweat gland	dermis (accessory structure)	makes watery sweat for thermoregulation (evaporative cooling)	—
Hypodermis	below the skin (subcutaneous)	adipose insulation/cushioning; anchors skin — NOT part of the skin proper	—

• Part 5: (1) The epidermis is avascular, so its cells get nutrients by diffusion from the blood vessels in the dermis below; the stratum corneum is dead, avascular cells, so removing only that surface layer reaches no blood vessels — no bleeding until the cut reaches the dermis. (2) A keratinocyte is born in the stratum basale, is pushed upward as new cells form beneath it, accumulates keratin along the way, and dies in the upper layers because it has moved too far from the dermal blood supply (the epidermis is avascular) — ending as a flat, dead, keratin-filled cell in the stratum corneum that eventually flakes off. (3) Example (sweating): when body temperature rises above the set point (~37 °C), eccrine sweat glands release sweat that evaporates and carries heat away; this opposes the temperature rise, returning it toward the set point — a negative-feedback loop (receptor in skin/hypothalamus → control center hypothalamus → effector sweat glands). Vasodilation, vasoconstriction, and goosebumps (arrector pili) are equally acceptable, each framed as opposing a temperature change.
• Part 6 (AI-critique): full credit for a specific catch — most commonly the AI claiming the epidermis is rich in / full of blood vessels (it's avascular), a scrambled strata order, or melanin and keratin swapped. Full credit also if the student verified each label against the atlas and OpenStax.

Grading rubric — 50 points

Criterion	Full	Partial	None
Hypothesis / prediction — a clear prediction about both the structures and the AI's reliability (6)	6	3–4	0–2
Structure table (Part 4) — layers + functions correct; both ★ vascular/avascular calls right (epidermis avascular, dermis vascular) (18)	18	9–15	0–7
Reasoning (Part 5) — avascular/diffusion logic, the basale→corneum journey, and a sound thermoregulation-as-negative-feedback point (14)	14	7–11	0–5
AI-critique (Part 6) — names a specific labeling/structure→function error caught and corrected with the right idea (8)	8	4–6	0–3
Anatomical language — uses standard terms correctly throughout (4)	4	2	0–1

Quality gate (self-checked): every layer, structure, and function in the key is verified against standard anatomy (OpenStax A&P 2e §5.1–5.2; InnerBody integumentary) — the epidermis as keratinized stratified squamous and avascular; the strata deep→superficial basale → spinosum → granulosum → (lucidum) → corneum; new cells made in the basale; the dermis as vascular connective tissue holding the glands; melanin as pigment/UV shield vs. keratin as toughness; the hypodermis below the skin proper; and thermoregulation (sweating + vasodilation/vasoconstriction) as negative feedback. No structure is mislabeled; every structure→function pairing is correct. Anatomy-accuracy gate: PASS. (No arithmetic in Week 6's lab, so the quantitative gate does not apply this week; the quantitative pockets are the Week 2 pH and Week 3 osmolarity labs and the Week 12 membrane-potential overview.)

Provenance: lab resource verified live 2026-06-27 (InnerBody integumentary; OpenStax §5.1). Links only — no license or open-textbook claim is made.