Body Membranes

• ​Epithelial

  • ​mucous membranes

    • ​body cavities that open outside the body

      • nose, mouth, digestive

  • ​serous

    • ​line body cavities

      • Heart, lungs, abdominal cavity

  • ​Cutaneous

    • ​the skin

​Serous Membranes

• Peritoneum

  • ​abdominal cavity

• ​Pleura

  • ​lungs

• Pericardium ​

​Connective Tissue Membrane

• ​Synovial

  • ​encapsulates a synovial joint

  • ​tendon sheath

    • ​a thin layer of fibrous tissue that surrounds a tendon

  • ​synovial fluid

    • ​thick fluid that lubricates the joints

​Integumentary Function

• ​Protection from

  • ​Abrasions

  • ​Chemical damage

  • ​Dehydration

  • ​UV damage

• ​Temperature regulation

​Protection

• ​Keratinocytes

  • ​build fibrous proteins that form a protective layer against mechanical stress

  • ​prevent water loss

• Melanocytes​

  • Prevent damage from UV radiations ​

​Temperature Regulation and Waste Removal

• ​Capillaries

  • ​contract to conserve body heat

  • ​dilate to release heat

• ​Exocrine glands

  • ​release sweat to cause evaporative cooling

  • ​sweating rids the body of Urea and Uric acids

Sensory and ​Other Awesome Skin Stuff

• ​Receptor cells

  • ​pressure

  • ​temperature

  • ​pain

  • ​touch

• ​Cholesterol conversion

  • ​sunlight converts modified cholesterol into Vitamin D

​Skin Anatomy

• ​Epidermis

• ​Dermis

• ​Hypodermis

​Epidermis Layers

• ​

​Epidermal Layers

• ​Stratum Basal

  • ​mitosis of a single layer cuboidal keratin producing stem cells

• ​Stratum Spinosum

  • ​stratified keratinocytes

    • bound by tight junctions and desmosomes​

​Epidermal Layers

• ​Stratum Granulosum

  • ​Keratohyalin granules

    • ​crosslinking keratin filaments

    • ​coarse surface

• ​Stratum Lucidum

  • ​thick skin only

  • ​densely packed keratinocytes and clear protein eleidin

​Epidermal Layers

• ​Stratum corneum

  • ​up to 30 layer of dead keratinized cells

  • ​durable surface protection from

    • ​abrasions

    • ​water loss

Epidermal Cells​

• ​Keratinocytes

  • ​produce keratin forming layers of the epidermis

• ​Epidermal dendritic cells

  • Langerhans cells

    • ​infection prevention

• ​Merkel Cells

  • ​touch receptors

​Dermis

• Dense fibrous connective tissue​

• ​Papillary

  • ​Areolar loose CTP

  • ​Finger prints

• ​Reticular Layer

  • ​Irregular dense CTP

  • ​deepest layer of the skin

​Hypodermis

• ​Fibrous connect tissue

  • ​adipose

• ​Larger blood vessels

• ​Macrophages

  • ​Large white blood cells