Anatomy of Skin and Fascia

1. Skin and Fascia
Dr Kamran khan
Kabir medical college
Peshawar Pakistan

2. Skin
– Considered the Largest organ of the body
– Covering entire External surface of the body.
– Surface area: 1.5 to 2 Sq.meters

3. Layers of Skin
– Epidermis
– Dermis

4. EPIDERMIS
– Superficial, Avascular Layer of stratified Squamous epithelium.
– Ectodermal in origin
– Gives rise to skin appendages.
– Divided into Five layers.

5. EPIDERMIS
– Stratum Corneum
– Stratum Lucidum
– Stratum Granulosum
– Stratum Spinosum
– Stratum Basale

6. EPIDERMIS
– Stratum Basale is Important
– Columnar cells
– Proliferates and cells move up to corneum.
– Lose nuclei and flatten.
– Wear and tear

7. EPIDERMIS
Some Specialized cells in Epidermis:
– Keratinocytes: Produce keratin for strength
– Melanocytes: Contribute to skin color
– Langerhans' cells: Part of immune system
– Merkel's cells: Detect light touch & pressure (Attached to nerve endings)

8. EPIDERMIS

9. DERMIS
– Deep, vascular Layer
– Mesodermal in origin
– Divided in Two Layers
 Superficial Papillary Layer
 Deep Reticular Layer

10. DERMIS
 Superficial Papillary Layer:
– Thin layer
– Loose connective tissue with Collagen and Elastic fibers.
– Conical projections -dermal papillae - fit into reciprocal
depressions on undersurface of epidermis.
– Strengthens connection between two layers.

11. DERMIS
– Dermal papillae
– Contains capillaries, Free nerve endings, Lymphatics.
– Increase Surface area.
– Provides blood supply to Epidermis and nerve endings for
sensations.

12. DERMIS

13. DERMIS
 Deep Reticular Layer:
– Thick layer
– Organized layers of Collagen and Elastin.
– Arranged in Parallel lines called “Langer lines”.
– In old age, loses its elasticity. Skin becomes Wrinkled. Damages
easily.
– Contains Blood vessels, Nerves, Hair follicles.

14. DERMIS

15. Skin Colour
– Determined by
1-Pigments:
– Melanin: Brown colour
– Carotene: Yellow to orange colour
– Albinism: Deficiency or absence of pigment
2- Oxyhemoglobin- Red colour
3-Deoxyhemoglobin- Purple
4- Thickness of stratum corneum- Transparency

18. Skin Appendages
– Nails
– Hairs
– Sweat Glands
– Sebaceous Glands

19. NAILS
– Hardened Keratin plates on
dorsal surface of tips of fingers
and toes.
– Parts:
– Root
– Body
– Free border
Lunule
Eponychium(Cuticle)

21. Applied Anatomy of Nails
– Clubbing (Hypertrophy of nail bed): TOF, CCF, Bronchioectasis etc.
– Pale and White: Anemia
– Brittle and spoon shaped (Koilonychia): Iron deficiency anemia

22. HAIR
– Derived from invagination of
Germinative layer of epidermis into
dermis
– Distributed all over body except
palms, soles, umbilicus etc
– Parts:
– Root : Surrounded by Hair follicle
– Shaft
– Shaft parts: inside to out
– Medulla
– Cortex
– Cuticle

23. HAIR
– Arrector Pili:
– Muscle that attaches undersurface
of Hair follicle to dermis
– Erection of hair(Thermoregulation),
Squeezes out sebum

24. Applied Anatomy of Hairs
– Malnutrition: Thin, Dry
– Hypothyroidism: Coarse and dry
– Hirsutism: PCOS

25. Sweat Gland
– Eccrine:
– Abundant and distributed all over
body,
– Thin watery secretion
– Body: Coiled part
– Duct: Traverses through epidermis
and dermis
– Opens onto surface of skin
– Apocrine:
– Axilla, Eyelids, External genitalia,
Perianal region
– Thick secretion
– Specialized in External auditory
meatus
– Distal ends of hair follicles.
– No response to temperature change.

26. Function:
Helps in regulating body temperature
Excreting body salts.

27. Sebaceous Gland
– Over Dermis except palm and sole.
– Oily secretion under Hormonal control.
– Function:
– Lubricates skin and hair
– Prevents from desiccation, sun damage
– Bactericidal

28. Applied Anatomy of Sebaceous gland
– Sebaceous Cyst
– Ichthyosis: Abnormally dry skin
– Seborrhea: Excessive oiliness
– Acne Vulgaris

29. Functions of Skin
 Protection: sun damage, mechanical, Wound healing.
 Sensation: Pain, Touch, Temperature.
 Temperature regulation: Sweat, Hair, Fat
 Vitamin D production
 Excretion: Salts
 Absorption: Oily substances.
 Secretion: Sweat and Sebum
 Reparative: Wound and Cuts healed.

30. Fascia
– Divided into:
– Superficial Fascia
– Deep Fascia

31. Superficial Fascia
– Also called Subcutaneous tissue or Hypodermis
– General coating of the body beneath skin, made from loose areolar tissue and
Fat.
– Fat is abundant in Gluteal region, Breast, Anterior abdominal wall, Thighs.
– Females: Abundant. In Superficial fascia of lower abdomen and upper thighs.
– Men: Abdominal cavity.

32. Superficial Fascia
– More distinct in lower abdominal wall. Divides into Camper (fatty) and scarpa’s
fascia(Fibrous layer.)
– Dense in palms, soles, scalp.
– Thin on dorsal aspect of hand, feet, sides of neck.
Encloses muscle in some regions :
– Neck: Platysma
– Scrotum: Dartos muscle (Thermoregulation)
– Sub areolar muscle of the nipple

34. Function
– Facilitates movement of skin
– Conserves Body heat
– Serves as soft medium for passage of vessels and nerves to skin.

35. Deep Fascia
– Fibrous sheet that covers body beneath superficial fascia.
– Inelastic and Tough. Devoid of fat.
– Well defined in Thigh as Fascia lata (Iliotibial tract)
– Thin Over rectus sheath and abdomen.
– Absent over face.

36. Modifications of Deep Fascia
– Modified in certain parts of the body.
1-Extensions
– Intermuscular septa: Divides limb into compartments.
– Fibroareolar sheaths for muscles and nerves
– Epimysium, perimysium, endomysium
– Epineurium, Epineurium, Endoneurium

37. Compartment Syndrome

38. Deep Fascia
2-Retinaculum
– Thickenings of deep Fascia around certain joints like Ankle and Wrist.
– Carpal tunnel syndrome.
3-Bursae and Tendon sheath
– Fluid filled sacs
– When tendons cross over a joint
– Prevents wear and tear
4-Capsule and Synovial membrane
– Encircles joint and tendons.

40. Deep Fascia
Deep cervical fascia in neck is divided into:
Investing layer
Pretracheal layer
Prevertebral layer
Carotid sheath

41. Functions
 Keeps underlying structures in position
 Provides surface for muscle attachments.
 Helps in venous and lymphatic return
 Retinacula acts as pulley and prevents loss of power.