1. Do Now: 12/11-12
Turn in your letters and take out your vocabulary list for Unit 4.
Study the scientific terms you are least familiar with first.
If you have flashcards or study aids you may silently use them now.
You have exactly 10 min

2. Pop Quiz: Take out a clean sheet of paper and title it Vocabulary Quiz: Unit 4
I will read each anatomical term three times. You must write the word (this is not a spelling test) and define it.
There will be 10 words selected from your reference list. You may number your page now

3. Review
I will grade your exit slips to avoid confusion on answers, please pass them forward now into two neat stacks.
We will review the quiz as a class.

4. Big Idea: Accessory Structures
Hair and nails are interesting adaptations in both humans and a wide range of animals. Understanding their physiology and the physiology of their accessory organs can lead to better personal hygiene techniques that more align with how these accessory organs work in our bodies.

5. Unit 4: Daily Objective
Locate and describe the function of hair, sebaceous glands, arrector pili, and nails
As always- you need to know the where, the what and the how of these features.

6. Explore
We will be moving back into the lab area for a brief lab activity to get us engaged with hair.
Listen carefully while explain the directions
Expectations:
EVERYONE will participate in the activity
The lab area will be respected, clean and safe
Hair will be pulled back
Volume level will stay at a 2 to allow all lab groups to work
We will attempt to look as excited as the students in this clip art.

7. Unit 4: Accessory Structures
Cell sink inward during development to form:
Hair
Oil and Sweat Glands
Nails

8. Hair Where is it? What is it?
Present on most skin surfaces except the palms, palmar surfaces of the digits, soles, and plantar surfaces of the digits.
Check for Knowledge:
What do the words palmar and plantar mean?
Hair consists of
a shaft above the surface
a root that penetrates the dermis and subcutaneous layer
the cuticle
a hair follicle

9. Anatomy of Hair Shaft- visible Root- below the surface
Follicle- surround root

11. Hair Grow it. Show it. Long as I can show it.
How does hair grow?
Hair grows in a very similar way to epidermal cells. A depression of epidermal cells called the hair follicle divide creating the hair root. The root gets nourishment from dermal blood vessels that connect to the hair root. As these cells get pushed upwards towards the surface, they are keratinized, die, and turn into the hair shaft.

12. Hair Growth in Detail Growth Cycle Growth Stage Resting Stage
Lasts for 2-6 Years
Produces Length
Resting Stage
Lasts for 3 months
Matrix cell are inactive, follicle will atrophie
Normal Hair Loss: hairs per day

13. I’m worth it. Hair color… what’s that about?
The color of your hair depends on the amount of melanin that the
hair follicle melanocytes produce
Dark hair contains true melanin
Blond and red hair contain melanin with iron and sulfur added
Graying hair is result of decline in melanin production
White hair has air bubbles in the shaft

14. Function of Hair
• Prevents heat loss • Decreases sunburn • Eyelashes help protect eyes • Touch receptors (hair root plexus) senses light touch

15. Arrector Pili Attached to each hair follicle
These muscles are positioned so that their contraction will lead to the hair shaft standing up.
This happens when people are scared or get cold (goose bumps).

16. Glands of the Skin Specialized exocrine glands found in dermis
Sebaceous (oil) glands
Sudiferous (sweat) glands
Ceruminous (wax) glands
Mammary (milk) glands

17. Sebaceous glands:
Produce the oil that keeps our hair and skin pliable (moveable) and waterproof.
The oil produced is called sebum.
Acne is a bacterial inflammation of these glands

18. Nail root is where hairs divide from
Nail root is where hairs divide from. As they move outwards, they keratinize with a very hard version of keratin.
The active growing region is called the lunula which is the lighter half-moon region of the nail. Nails slide forward over the nail bed. Nails exist to help protect the ends of our digits.
Nails
Lunula is white due to a thickened stratum basale

19. Think-Pair-Share: Adaptations
There are different adaptations of hairs and nails in humans and the animal world.
Why?
Examples: greasy hair, really long nails, claws, hooves, rhino horns, pangolin scales, and bison horns