lecture 3 Flashcards
skin function (3)
- protection
- thermoregulation
(water exchange) - sensation
Structure of skin cells (3)
Epidermis
Dermis
Subdermal adipose tissue (hypodermis)
3 components of the epidermis
basal cells
keratinocytes/squames
melanocytes
nails and hair are derived from –
protein keratin, same protein found in skin
basal cells are
labile cells: constantly regenerating!!!
In the basal cell layer, keratinocytes arise, they slowly…
work their way up to the surface of our skin over a few weeks, cells gradually dehydrate and flatten
–> now they are squames cells!!!
They are kind of waterproof
Hyperhydrosis
=excess sweat
-Sympathetic nervous system overactivity
-leads to chafing, irritation, blisters, calluses
Blisters
-don’t open or pop it
-keep area dry
Calluses or corns
Shear or pressure on an area, skin thickens
Ingrown nail
Nail grows into nail bed, can open up skin, prone to infection
FUNGAL INFECTIONS
Caused by warmth, darkness, moisture, contamination
“tinea”
Tinea corporis
= on body (ringworm)
Tinea capitis
= scalp (rash and alopecia)
Tinea cruris
=groin
Tinea pedis
=feet
Tinea ungulum
= nails and nail beds
BACTERIAL INFECTIONS
Caused by direct and indirect contact
3 different categories:
Staphylococcus
Streptococcus
Bacillus
Treated with oral or topical antibiotics
Pes cavus
high arch
Pes planus
flat foot
Ground reaction forces (graph)
Heel strike= dramatic increase in force
Midstance= medial arch is collapsing; force is decreased because we are absorbing the force
When we are running, we are impacting the ground much more than when we are walking
Sprinter: bigger “spike in forces”
Distance runner: more stable ground rxn forces
Keystone bones=
support for arches of foot
2 main ligaments in the foot act like staple supports:
- Plantar calcaneonavicular ligament
- Long plantar ligament
(they hold adjacent ligaments in our foot together)
Windlass mechanism:
- Looks at movement of the medial longitudinal arch and how it is essential for BOTH shock absorption/dissipation of forces through the foot and stiff for propulsion
- Dosiflexed, tension through the plantar fascia (PF), arch is tight “locked”, medial arch is high, bones of the foot are locked in a lever, tension to be able to push off!
Contusion= bone bruise
bone bruise
Lis franc sprain is a
stretch of the bones between cuboid, cuneiform and metatarsals
Turf toe=
stretching of ligament at first metatarsophalangeal (MTP) joint
common bones fractured in the foot and their injury mechanism
metatarsals, phalanges= crush injury
metatarsals, calcaneus= overuse injury (stress fracture)
