Skin and Mucous Membranes🤧 Flashcards
What is the function of skin?
-Protection
-Thermoregulation
-Water regulation
-Sensation
-Absorption
-Storage and Synthesis
What are the the three layers of the skin?
-Epidermis
-Dermis
-Subcutaneous layer
Name 3 associated structures of the skin
-Nails
-Sweat Glands
-Sebaceous Glands
-Hair Follicles
Describe the structure of the Epidermis
-Stratified squamous epithelium
Layered
Flat, scale-like cells
Basic tissue type
-No blood vessels
-4-5 layers
Name the 5 layers of the epidermis
-Stratum Corneum
-Stratum Lucidum
-Stratum Granulosum
-Stratum Spinosum
-Stratum Bassle
Describe the Stratum Lucidum Layer of the Epidermis
-Only present in thick skin
-Waxy, clear, no nucleus
Describe the Stratum Corneum Layer of the Epidermis
-Corneated Layer
-What is seen in microscope
Describe the Stratum Granulosum Layer of the Epidermis
-Granular Layer of epidermis
-Blue dots, flat, nucleus becomes smaller
Describe the Stratum Spinosum Layer of the Epidermis
-Spinous Layer
-Main Bulk
-Epithelial Cells are attached by desmosomes (proteins)
-When tissue is prepared for sectioning, cells shrink and desmosomes stand out (look prickly)
Describe the Stratum Basale Layer of the Epidermis
-Basal/ Germinal Layer
-Attach to lower surface with hemidesmosomes
-1 layer of cells present
-Cuboidal/ Columnar Cells
-Cells divide and produce new cells that move up the epithelium
What are the 4 cells of the epidermis?
-Keratinocytes
-Langerhan Cells
-Morkel Cells
-Melanocytes
Keratinocytes?
Make up 95% of epidermal cells
Langerhans Cells?
Antigen- Presenting (produce antigens)
Merkel Cells?
Function as sensory receptors
Melanocytes?
Produce Melanin
What determines whether skin is thick or thin?
Stratum Lucidum
-Not physical Thickness
Describe thick skin and thin skin and their differences
Thick Skin
-Stratum Lucidum Present
-Thicker Stratum Corner
-Found on Palms of Hands and Soles of Feet
Thin Skin
-No Stratum Lucidum
-All Strata are are thinner
-Covers rest of body
Describe the dermis:
Lies under skin, strong, flexible dense connective tissue layer rich in collagen and elastic fibres
What does the dermis contain?
Fibroblasts
Macrophages
A few adipocytes
Nerve endings
Blood vessels
Glands
Smooth muscle (some areas)
Lymphatics
Hair follicles
What are the two layers of the dermis
-Papillary Layer
-Reticular Layer
Describe the Papillary layer of the dermis
-Projects into intervals between epidermal ridges.
-Richly supplied with capillaries and nerve endings.
Describe the reticular layer of the dermis
Made up of dense connective tissue and fiber components
What are two types of skin carcinoma?
Squamous cell carcinoma
Basal cell carcinoma
Explain how skin cancer occurs?
Keratinocytes in the epidermis grow out of
control to form a tumour.
Can occur on any part of your body
How does skin cancer appear?
as a scaly or crusty area of skin, with
a red and inflamed base
Risk factors and prevention measures for malignant melanoma?
Risk Factors- UV radiation, moles (collection of melanocytes), fairskin with freckles, sunburn, family history
Prevention- avoid over-exposure to sun, look for growing/ changing moles
What are mucous membranes?
Specialized epithelial lining which produces a lubricating fluid containing the sticky protein mucin
What is the function of mucin?
traps microbes and dirt particles and protects any body structure which is continuous with the external environment e.g. eyes, mouth, intestine
Generally speaking, mucous membranes in the body have functions that can be divided up into three groups.
What are these functions and give examples of organs where mucous membranes would perform these functions?
Protective
Oral cavity, nasal cavity, oesophagus
Secretory
Stomach
Absorptive
Entire small intestinal
Sensation
What is the basic structure of mucous membranes?
Layers;
-Made of Epithelium
-Lamina Propria
Describe the lamina propria layer of mucous membranes
The supportive areolar (loose fibrous connective tissue) layer found immediately beneath the mucosal epithelium and its basement membrane
What are the cells of the lamina proper mucosae?
Fibroblasts
Immune cells
Virtually lacking adipocytes
What is found in the extracellular matrix of lamina propria?
-Collagen
-Elastin fibres
The epithelium and lamina propria
mucosae together constitute what?
mucosa
What is the Trachea composed of?
Composed of a ciliated, pseudostratified epithelium and an elastic, fiber-rich lamina propria
What is the small intestine composed of?
-Simple Columnar Epithelium
-Brush-like Vesicles
-Contains goblet cells
-Lamina Propria
What are the functions of the oral mucosa
-Protection – barrier to micro-organism
-Sensation – receptors that respond to touch, taste, pain etc
-Secretion – maintains a moist surface ; salivary glands
-Permeability and absorption. A feature utilized in drug delivery.
What is the main function of the oral mucosa?
Protection- as the oral cavity contains a vast number of various pathogens and is also exposed to daily sources of trauma, whether acids, chemicals, food and smoke
Why are the elderly more prone to developing oral cancer than younger age groups?
As a person gets older the oral mucosa becomes thinner and this barrier function is diminished.
What does the oral mucousa consist of?
-Stratified Squamous Epithelium
-Lamina Propria
Give an example of a condition that affects both skin and mucous membranes?
Lichen Planus burning sensation in cheek and tongue
Describe Cystic Fibrosis
-An inherited disorder of ion transport
-Abnormal viscous secretions
-Affects epithelial lining of the respiratory, gastrointestinal and reproductive tracts
0Salivary glands may also be affected
