Download Anatomy and Physiology Day 2.pptm

Anatomy and Physiology
11/11/2013
Time Line
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11/4 Introductions/Rules/Integumentary pre-test
11/11 Integumentary System (pg14-31)
11/18 Integumentary System(pg14-31)
12/2 Nervous System (1-13)
12/9 Nervous System (1-13)
12/16 Immune System (32-45)
1/6 Immune System(32-45)
1/14 Wright State Invitational
Directional Terms
Hair
Hair Follicle
• Shaft
– Visible portion of
the hair
– Dead
– Shape determines
look and texture of
the hair
Wavy
Kinky
Strait
Hair Follicle
• Shaft
– Visible portion of
the hair
– Dead
– Shape determines
look and texture of
the hair
Wavy
Kinky
Strait
Hair Follicle
• Shaft
– Visible portion of
the hair
– Dead
– Shape determines
look and texture of
the hair
Wavy
Kinky
Strait
Hair Root
• Penetrates into dermis
• Composed of 3 layers
– Medulla
• Inner most layer
• Contains pigments and air
(provides color)
– Cortex
• Middle layer
• Pigmented in dark hair
• Air bubbles in gray and white
hair
– Cuticle
• Outer most layer
• Heavily keratinized cells that
lay like shingles on a roof
Hair Root
• Penetrates into dermis
• Composed of 3 layers
– Medulla
• Inner most layer
• Contains pigments and air
(provides color)
– Cortex
• Middle layer
• Pigmented in dark hair
• Air bubbles in gray and white
hair
– Cuticle
• Outer most layer
• Heavily keratinized cells that
lay like shingles on a roof
Base of the Hair Follicle
• Composed of
– The Bulb
• Contains the papilla
that provides blood
and nutrition to the
hair follicle.
– The Matrix
• Site of active growth
that is responsible
for the growth of the
hair.
Base of the Hair Follicle
• Composed of
– The Bulb
• Contains the papilla
that provides blood
and nutrition to the
hair follicle.
– The Matrix
• Site of active growth
that is responsible
for the growth of the
hair.
Base of the Hair Follicle
• Composed of
– The Bulb
• Contains the papilla
that provides blood
and nutrition to the
hair follicle.
– The Matrix
• Site of active growth
that is responsible
for the growth of the
hair.
Arrector pilli
• Smooth muscle
– Attached to the
dermis and the side
of the hair follicle.
– When muscle
contracts hair is
pulled from a
slanted to an up
right position.
• “Goose bumps”
Hair root plexus
• Dendrites of
neurons which are
sensitive to touch
• Makes the hair in to
a functional sensor
for touch.
Hair
• About 5 million on the
average human
• 100,000 or so on you
head
• Hair is everywhere
– Some exceptions
• No hair on palms or soles
of feet
• No hair on sides of digits
• Excluded from the lip
• Excludes from some
regions of the external
genitals.
Hair Growth Cycle
• Three phases
• Anagen
– Growth phase
• Catagen
– Transitional Phase
• Telogen
– Resting phase
http://www.youtube.com/watch?v=aWK6qJFv
WoM
Hair Functions
• Protects scalp from
sunlight and injuries to
the head
• Eyelashes and eyebrows
help keep debris out of
the eye
• Hair in nostrils also keep
debris from entering the
sinus
• Help in sensing light
touch (root hair plexus)
Hair Color
• Due to melanin in keratinized cells
• Melanocytes in matrix of the bulb
synthesize melanin that passes into
the cortex and medulla
• True melanin makes hair very dark
• Other varieties contain elements
like iron and sulfur which can make
the hair appear red or blonde,
respectively.
• Grey hair is caused by a decline in
the production of melanin
• When air bubbles accumulate in the
medullary shaft the hair appears to
be white in color.