Structure of the integument showing layers of skin and associated structures.

Let's go through each of the exercises in your image and solve them step by step.

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Exercise 6.5: The Scalp—Hair Follicles and Sebaceous Glands

9. Arrector pili muscles are small muscles that attach to the shaft of a hair.
✔ False

- Explanation: Arrector pili muscles are smooth muscles that attach to the hair follicle, not the hair shaft itself. When they contract, they pull on the follicle, causing the hair to stand upright (goosebumps) and helping to trap heat.

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10. ________ glands produce a thick, oily sweat that has pheromone-like properties.
✔ Apocrine

- Explanation: Apocrine glands are located in areas like the axillae (armpits), groin, and around the nipples. They secrete a viscous, milky fluid that is initially odorless but can develop a characteristic smell when broken down by bacteria. This secretion may have pheromone-like properties.

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Exercise 6.6: Axillary Skin—Apocrine Sweat Glands

11. Apocrine sweat glands open to hair follicles and secrete an oily substance whose function is to lubricate the hair follicle.
✘ False

- Explanation: While apocrine glands do open into hair follicles, their secretions are not primarily for lubrication. Instead, they are involved in thermoregulation and possibly communication via pheromones. Lubrication of the hair follicle is mainly the role of sebaceous glands.

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12. Apocrine sweat glands open to hair follicles, whereas merocrine (eccrine) sweat glands open to the surface of the skin.
✔ True

- Explanation:
- Apocrine glands release their secretions into hair follicles.
- Merocrine (eccrine) glands release sweat directly onto the skin surface via ducts. These are responsible for thermoregulation and are found all over the body.

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Exercise 6.7: Structure of a Nail

Match Column A with Column B:

| Column A | Column B |
|---------|----------|
| 1. skin underneath the free border of the nail | e. lunula |
| 2. main portion of the nail | b. body |
| 3. portion of the nail that lies beneath the eponychium | d. hyponychium |
| 4. white curved area at the base of the nail | a. body |
| 5. fold of skin at the root of the nail | c. hidden border |

Wait — let’s correct this carefully based on anatomy:

- 1. Skin underneath the free border of the nail → d. hyponychium
- The hyponychium is the thickened layer of epidermis under the free edge of the nail plate.

- 2. Main portion of the nail → b. body
- The body (or nail bed) is the visible part of the nail.

- 3. Portion of the nail that lies beneath the eponychium → c. hidden border
- The eponychium is the skin at the base of the nail (cuticle). The "hidden border" refers to the nail matrix beneath it.

- 4. White curved area at the base of the nail → e. lunula
- The lunula is the pale, half-moon-shaped area at the base of the nail.

- 5. Fold of skin at the root of the nail → a. eponychium
- The eponychium is the skin fold at the nail root (often called the cuticle).

✔ Correct Matching:
1. d. hyponychium
2. b. body
3. c. hidden border
4. e. lunula
5. a. eponychium

> ✔ Final Answer:
> 1. d
> 2. b
> 3. c
> 4. e
> 5. a

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Exercise 6.8: Observing Classroom Models of Integument

14. Label the following diagram of the integument.

You've already labeled several parts correctly. Let's verify and complete the labeling.

From the diagram (based on standard histology):

- 1. Epidermis → ✔ Correct
- 2. Dermis → ✔ Correct
- 3. Subcutaneous layer → ✔ Correct
- 4. Papillary layer → ✔ Correct (part of dermis)
- 5. Reticular layer → ✔ Correct (deeper part of dermis)

Now, label the rest:

- Hair shaft → Already labeled ✔
- Sebaceous gland → Already labeled ✔
- Sweat pore → Already labeled ✔
- Hair follicle → Should be labeled near the hair shaft and bulb
- Dermal papilla → Small projections from dermis into epidermis; often labeled
- Arrector pili muscle → Connects to hair follicle
- Blood vessels → In dermis and subcutaneous layer
- Nerve endings → Sensory receptors
- Lunula → At base of nail
- Nail bed → Underneath nail plate
- Eponychium → Cuticle at nail root
- Hyponychium → Under free edge of nail

But since you're asked to label the diagram, and only some labels are missing or unclear:

Let’s identify what might need correction:

- You have "Vessels" written — should be "Blood vessels" or "Capillaries"
- "Arrector pili" — yes, it connects to hair follicle
- "Sebaceous gland" — correct
- "Sweat gland" — probably refers to eccrine sweat gland
- "Sweat pore" — opening of sweat duct on skin surface
- "Hair shaft" — correct
- "Hair follicle" — correct
- "Dermal papilla" — small finger-like projection into epidermis
- "Papillary layer" — upper layer of dermis
- "Reticular layer" — deeper dermis
- "Subcutaneous layer" — fatty layer below dermis

✔ All major structures seem correctly identified.

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✔ Final Answers Summary:

#### Exercise 6.5
9. False
10. Apocrine

#### Exercise 6.6
11. False
12. True

#### Exercise 6.7
1. d. hyponychium
2. b. body
3. c. hidden border
4. e. lunula
5. a. eponychium

#### Exercise 6.8
Diagram labels are mostly correct. Ensure:
- Hair follicle is labeled
- Arrector pili is connected to follicle
- Sebaceous gland opens into follicle
- Sweat gland duct leads to sweat pore
- Dermal papilla is labeled (if not)
- Epidermis, dermis, subcutaneous layer are clearly labeled

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If you'd like, I can help draw or describe how to properly annotate the diagram. Let me know!