skin color and geography qod: how would you describe the distribution of skin color around the...
Post on 12-Jan-2016
221 Views
Preview:
TRANSCRIPT
Skin Color and Geography
Skin Color and Geography
QOD: How would you describe the distribution of skin color around the world, based on what you know? Consider the skin color of indigenous populations, in other words, people who evolved where they currently live and haven’t migrated (voluntarily or otherwise) in the last 500 years. Why do you think skin color has the pattern it has?
QOD: How would you describe the distribution of skin color around the world, based on what you know? Consider the skin color of indigenous populations, in other words, people who evolved where they currently live and haven’t migrated (voluntarily or otherwise) in the last 500 years. Why do you think skin color has the pattern it has?
Solar radiation worldwide
Solar radiation worldwide
QuickTime™ and a decompressor
are needed to see this picture.
Which explains…Which explains…
…why these people evolved near the equator.
…why these people evolved near the equator.
QuickTime™ and a decompressor
are needed to see this picture.
QuickTime™ and a decompressor
are needed to see this picture.
QuickTime™ and a decompressor
are needed to see this picture.
QuickTime™ and a decompressor
are needed to see this picture.
And…And…
…why these people evolved in the north
…why these people evolved in the north
QuickTime™ and a decompressor
are needed to see this picture.
QuickTime™ and a decompressor
are needed to see this picture.
QuickTime™ and a decompressor
are needed to see this picture.
…but it doesn’t explain …but it doesn’t explain
…why these people evolved in the most northern latitudes in the world (the arctic circle)
…why these people evolved in the most northern latitudes in the world (the arctic circle)
QuickTime™ and a decompressor
are needed to see this picture.
QuickTime™ and a decompressor
are needed to see this picture.
QuickTime™ and a decompressor
are needed to see this picture.
Skin Color and Geography
Skin Color and Geography Humans, like all species, are subject
to the laws of evolution and natural selection
Evolutionary fitness depends on reproductive success
You have to live long enough to have babies to reproduce
Q: What is the reproductive advantage of having dark skin where UV light is more intense? What is the reproductive advantage of having light skin where UV light is less intense? What about the Inuits?
Humans, like all species, are subject to the laws of evolution and natural selection
Evolutionary fitness depends on reproductive success
You have to live long enough to have babies to reproduce
Q: What is the reproductive advantage of having dark skin where UV light is more intense? What is the reproductive advantage of having light skin where UV light is less intense? What about the Inuits?
Skin Color and Geography
Skin Color and Geography Each team gets a set of cards. Divide the
cards into 2 piles: 1) cards that give facts about advantages of darkly pigmented skin 2) cards that give facts about advantages of lightly pigmented skin
Make 2 columns in your I.N. (INPUT page) for each group or cards and record the information that belongs in each column
Once you have gathered and recorded all the information given, Write a 1 paragraph explanation (on binder paper, to be turned in) for the pigmentation of Northern Europeans, West Africans and the Inuit and other people of the Arctic circle.
Each team gets a set of cards. Divide the cards into 2 piles: 1) cards that give facts about advantages of darkly pigmented skin 2) cards that give facts about advantages of lightly pigmented skin
Make 2 columns in your I.N. (INPUT page) for each group or cards and record the information that belongs in each column
Once you have gathered and recorded all the information given, Write a 1 paragraph explanation (on binder paper, to be turned in) for the pigmentation of Northern Europeans, West Africans and the Inuit and other people of the Arctic circle.
Physiology: T 10.4Physiology: T 10.4
TCBVideo group: please send me an email explaining exactly which parts of the project you were responsible for. (this is separate from the weekly email assignment)
GOALS/AGENDAReview yesterday’s activity, write or complete paragraph explanation.
Structure & function of skin
TCBVideo group: please send me an email explaining exactly which parts of the project you were responsible for. (this is separate from the weekly email assignment)
GOALS/AGENDAReview yesterday’s activity, write or complete paragraph explanation.
Structure & function of skin
The integumentary system
The integumentary system
Includes skin, hair, nails and glands
FunctionsProtection (UV, injury, infection)Vitamin D productionTemperature regulationHolds in moistureSense organRemoves wastes
Includes skin, hair, nails and glands
FunctionsProtection (UV, injury, infection)Vitamin D productionTemperature regulationHolds in moistureSense organRemoves wastes
The skin has 2 layersThe skin has 2 layers Epidermis:
Outermost Origin of glands, hair follicles, glands
Mostly epithelial Growth and cell division at deepest part pushes cells outward
Outermost epidermis is dead, flattened cells which flake away
Many keratinocytes which make keratin for waterproofing
Melanocytes make melanin
Epidermis: Outermost Origin of glands, hair follicles, glands
Mostly epithelial Growth and cell division at deepest part pushes cells outward
Outermost epidermis is dead, flattened cells which flake away
Many keratinocytes which make keratin for waterproofing
Melanocytes make melanin
QuickTime™ and a decompressor
are needed to see this picture.
Skin colorSkin color Melanin provides basic lightness or darkness
Equal numbers of melanocytes, difference is in how much melanin they produce
Other pigments: carotene, hemoglobin
Melanin provides basic lightness or darkness
Equal numbers of melanocytes, difference is in how much melanin they produce
Other pigments: carotene, hemoglobin
QuickTime™ and a decompressor
are needed to see this picture.
The skin has 2 layersThe skin has 2 layers Dermis:
Deeper than epidermis
Connective tissue Tough and strong- collagen fibers
Flexible- elastin fibers
Can separate from epidermis, space fills with fluid…blister. Ouch.
Contains blood vessels and nerves
Dermis: Deeper than epidermis
Connective tissue Tough and strong- collagen fibers
Flexible- elastin fibers
Can separate from epidermis, space fills with fluid…blister. Ouch.
Contains blood vessels and nerves
QuickTime™ and a decompressor
are needed to see this picture.
Exocrine GlandsExocrine Glands Secrete substances that leave the body through ducts
Found w/in dermis but derived from epidermis (epithelial) Sebaceous gland: produces oil, found near hair follicles
Sweat gland: temperature regulation & chemical signals
Secrete substances that leave the body through ducts
Found w/in dermis but derived from epidermis (epithelial) Sebaceous gland: produces oil, found near hair follicles
Sweat gland: temperature regulation & chemical signals
QuickTime™ and a decompressor
are needed to see this picture.
SweatSweat
Made of: water, dissolved salts, wastes, other substances
2 types of sweatStimulated by temperatureStimulated by stress, pain, hormones
Made of: water, dissolved salts, wastes, other substances
2 types of sweatStimulated by temperatureStimulated by stress, pain, hormones
OilOil
Sebum Sebaceous glands found everywhere except palms of hands and soles of feet
Softens and lubricates skin and hair, helps kill bacteria and keep skin from cracking
Sebum Sebaceous glands found everywhere except palms of hands and soles of feet
Softens and lubricates skin and hair, helps kill bacteria and keep skin from cracking
Hair Hair
Keratinized cells Growth at the root Straight or curly depends on angle of follicle and shape of hair shaft
Keratinized cells Growth at the root Straight or curly depends on angle of follicle and shape of hair shaft
QuickTime™ and a decompressor
are needed to see this picture.
Below the SkinBelow the Skin Deeper than the dermis is the layer called the hypodermis
Technically not considered part of skin
Primarily adipose and connective tissue
Deeper than the dermis is the layer called the hypodermis
Technically not considered part of skin
Primarily adipose and connective tissue
QuickTime™ and a decompressor
are needed to see this picture.
Sweaty fingersSweaty fingers
What happens when you have to talk in front of a large group?
Sweaty palms? Find out what else makes you sweat.
NotebookTitlePurposeObservations (follow to do and notice)Interpreting your observations Qs
What happens when you have to talk in front of a large group?
Sweaty palms? Find out what else makes you sweat.
NotebookTitlePurposeObservations (follow to do and notice)Interpreting your observations Qs
Examining structure of skin
Examining structure of skin
View slides of scalp, draw in notebook Line up slide so that epidermis is visible at the edge
label epidermis, dermis, follicle, hair shaft, sebaceous gland, sweat gland, any other structures you can find
take your time- make these the best microscope drawings you’ve ever done. Use colored pencil, draw individual cells and tissue layers
Make sure labels point inside the field of view and clearly point to structures
Will be graded separately when notebooks are collected
View slides of scalp, draw in notebook Line up slide so that epidermis is visible at the edge
label epidermis, dermis, follicle, hair shaft, sebaceous gland, sweat gland, any other structures you can find
take your time- make these the best microscope drawings you’ve ever done. Use colored pencil, draw individual cells and tissue layers
Make sure labels point inside the field of view and clearly point to structures
Will be graded separately when notebooks are collected
Physiology: W 10.5Physiology: W 10.5
TCBHomework checkMovieAssessments
GOALS/AGENDASweaty fingersFinish skin presentation
TCBHomework checkMovieAssessments
GOALS/AGENDASweaty fingersFinish skin presentation
top related