Lecture 1: Skin Flashcards
Integumentary
= Skin and accesory structures
Functions of the skin and accesory structures:
PETMVLD
Protection ( underlying tissues and organs from abrasions, fluid loss, chemicals etc
Excretes salts, water, and organic wastes using glands
Temperature regulation by insulation or evaporative cooling as required
Produces melanin: protects underlying tissues against UV
Synthesize Vitamin D3 (steroid) converted to calcitriol: a
hormone important for normal calcium metabolism
Lipid storage in adipocytes, some in the dermis and mostly in adipose tissue in the hypodermis
Detect touch, temperature, pain, and pressure stimuli and
from abrasions, fluid loss, chemicals etc
Skin consists of 3 primary layers;
- Epidermis (Cutaneous)
• Stratified barrier
• Mostly keratinocytes
• No blood circulation (avascular) - Dermis (Cutaneous)
• Protein fibres for strength
• Vascular (nourishes epidermis) - Hypodermis (Subcutuaneous)
• Adipose tissue
Types of Epithelia
Simple (1 layer) or stratified (many layers)
- squamous (flat)
- cuboidal
- Columnar (tall)
Stratum corneum (spiky layer)
• Dead, dried-out hard cells
without nuclei
Stratum granulosum (granular
layer)
Contain granules that promote
dehydration of the cell, crosslinking
of keratin fibre
• Waxy material is secreted into the
intercellular spaces
Stratum spinosum (spinous,
or prickly cell layer)
• Intercellular bridges
called desmosomes link the cells
together.
• The cells become increasingly
flattened as they move upward.
•Contains dendritic (immune) cells.
Stratum basale (basal layer)
• Columnar (tall) regenerative cells.
• As the basal cell divides, a daughter
cell migrates upwards to replenish
the layer above.
What are Desmosomes?
anchors adjacent/neighboring cells in epidermis
What do hemidesmosomes do?
anchors stratum basale to the dermis
Name layers of thin skin:
4 Layers: Come Get Some Burgers
- Stratum corneum
- Stratum granulosum
- Stratum spinosum
- Stratum basale
Name the layers of thick skin:
5 Layers: Come Lets Get Some Burgers
- Stratum corneum
- Stratum Lucidum
- Stratum granulosum
- Stratum spinosum
- Stratum basale
What and where is the Dermis?
- Situated below the epidermis &
anchors via hemidesmosomes - Not shed
- Two Layers
What is the Papillary Layer?
- One layer of the dermis (above reticular layer)
- Consists of highly vascularised
tissues (for nourishment).
What is the Reticular Layer?
- A layer of the dermis(below papillary layer)
- ‘Mesh-like’ structure ofcollagen and elastin fibres (for strength)
