Unit 5 Integumentary Flashcards
Define membrane (integumentary)
a flat tissue covering or lining a body region
Define epithelial membrane
a membrane made mostly of epithelial tissue
usually also has connective tissues
may also include other tissues
Name the types of epithelial tissues
There are three.
Mucosa
Serous membrane
Cutaneous
Describe the location of mucosa
Lines cavities that opens to exterior
What connective tissues are present in mucosa?
areolar tissue
What tissues are present in mucosa?
There are two.
Epithelial
Areolar
Is mucosa moist or dry?
Moist
Describe the location of serous membrane.
Lines ventral body cavity.
Name the different serous membranes.
There are three.
Pleural
Peritoneum
Pericardium
Define mesothelium
The epithelial tissue of the serous membrane.
Describe the tissue of the mesothelium.
Simple squamous epithelial tissue.
Describe the structure serous membranes.
There are two layers.
Parietal
Visceral
What connective tissues are present in serous membranes?
Areolar
Is serous membrane moist or dry?
Moist
Describe the location of cutaneous membrane.
It is skin; it covers the body!
Name the tissues present in the cutaneous membrane.
There are three.
Keratinized stratified squamous epithelial
dense irregular connective
areolar connective
Is the cutaneous membrane moist or dry?
Dry.
Define the integumentary system.
The skin and its accessory organs.
Name the specialized branch of anatomy for the integumentary system.
Dermatology.
Four facts about the integumentary system.
Largest organ
Covers ~22 sq ft.
Weighs 10-11 lbs
Thickness varies between body regions
What are the functions of the integumentary system?
There are four. Protects internal body structures. Senses (detects) stimuli Vitamin D production Thermoregulation
What does the integumentary system protect against?
There are three.
Mechanical stress
Liquids & Chemicals
Microbes
What are the ways the integumentary helps with thermoregulation?
There are two.
Perspiration for cooling
Blood flow to reduce or increase heat loss
Name the layers of the integumentary system.
There are two.
Epidermis
Dermis
Describe the location of the epidermis.
Superficial
Describe the tissues of the epidermis.
keratinized stratified squamous epithelial tissue
Describe the blood supply of the epidermis.
Is avascular!
Describe the location of the dermis.
deep
Describe the tissues of the dermis.
dense irregular connective tissue
areolar connective tissue
Describe the blood supply of the epidermis.
Has blood supply (NOT avascular)!
What region is deeper to the dermis?
hypodermis
Describe the location of the hypodermis
The subcutaneous layer immediately deep of the dermis. (It is NOT part of the integumentary system).
Describe the tissues of the hypodermis.
There are two.
Adipose connective
Areolar connective
What are the functions of the hypodermis?
There are four. Stores fat. Absorbs shock. Insulates. Anchors skin.
Name the cell types found in epidermis.
There are five. Stem cell. Keratinocyte. Melanocyte. Dendritic (Langerhans) cell. Tactile (Merkle) cell.
Describe the function of stem cells in the epidermis.
Divides by mitosis creating two daughter cells.
One of the daughter cells differentiates into a keratinocyte.
Describe the type of stem cell of the epidermis.
Unipotent stem cell.
Describe the type of cell of the keratinocyte.
epithelial cells
Describe the functions of the keratinocyte.
There are four. Makes keratin. Releases water proofing lipid. Releases filaggrin. Produces envelope proteins for increased stress resilience.
What are the unique organelles of the keratinocyte?
There are two.
Membrane coating vesicles.
Keratohyalin granules.
Describe filaggrin.
A protein produced in keratinocytes that binds keratin fibers together for increased strength.
How much of the epidermis is composed of keratinocytes?
approx 90%
What type of cell is the melanocyte?
epithelial
What are the functions of melanocytes?
Makes melanin.
What is melanin.
A colored protein.
What are the possible colors of melanin?
There are three.
Black
Brown
Yellow
Describe how melanin accumulates.
Melanin is created in melanocytes.
Keratinocytes take up the melanin by phagocytosis.
Keratinocytes store the melanin.
What are the functions of melanin?
Absorb UV light.
How much of the epidermis is composed of melanocytes?
approx 8%
What type of cell is the dendritic (Langerhans) cell?
macrophage (a type of white blood cell)
What is the function of the dendritic (Langerhans) cell?
Active protection (against chemicals? and microbes?)
How much of the epidermis is dendritic (Langerhans) cells?
approx 2%
What type of cell is the tactile (Merkle) cell?
epithelial
What are the functions of the tactile (Merkle) cell?
as a touch receptor
Describe the structure of the tactile (Merkle) cell that allows it to communicate stimulus?
It is connected to a nerve cell in the dermis.
How much of the epidermis is made up of tactile (Merkle) cells?
less than 1%
Describe the growth of the epidermis.
The epidermis grows outwards.
New cells differentiate from stem cells in the deepest layer.
New cells push older cells superficially.
Oldest cells are shed from the top.
How long does it take for new cells to age and shed from the epidermis?
typically 30-40 days
Describe the location of thick skin.
High-friction areas such as palms, finger tips, soles
Describe the location of thin skin.
low-friction areas
Name the zones of the epidermis.
There are five. (superficial) Stratum corneum Stratum lucidum (thick ONLY) Stratum granulosum Stratum spinosum Stratum basale (deepest)
Which zone of the epidermis is only present in thick skin?
Stratum lucidum.
Location of stratum basale.
Deepest layer of the epidermis.
Number of cell layers of the stratum basale.
1 single layer
What cells are present in the stratum basale?
There are four. Keratinocytes Tactile Melanocytes Stem cells.
What are the features of the stratum basale?
There are six.
Desmosomes bind cells together.
Hemidesmosomes bind cells to the basement membrane.
Cells have many organelles.
Most metabolically active layer of the epidermis.
Mitotic rate increases when skin is injured.
Cells are columnar shaped.
What is the location of the stratum spinosum?
2nd deepest layer of the epidermis.
The stratum spinosum has how many layers of cells?
between 8 and 10
What are the types of cells in the stratum spinosum?
There are four. keratinocytes tactile melanocytes dendritic cells
What are the features of the stratum spinosum?
There are four.
Keratinocytes have many sides (“spikey keratinocytes”)
Keratinocytes change shape to become flattened cuboidal.
Contains both desmosomes and tight junctions.
Cells receive less nutrients.
Describe the location of the stratum granulosum.
3rd deepest layer of the epidermis
3rd/2nd most superficial layer
How many layers are there to the stratum granulosum?
between 3 and 5
What types of cells are present in the stratum granulosum?
There are two.
keratinocytes
dendritic cells
Describe the features of the stratum granulosum and the changes to the keratinocytes.
There are six. Very little nutrients. Keratinocytes begin to flatten. Keratinocytes release filaggrin. Envelope proteins deposited (beneath cell membrane). Vesicles release lipids (by exocytosis). Organelles degrade. Cells of the uppermost layer are no longer living, just bags of bundled keratin.
Describe the location of the stratum lucidum.
2nd most superficial layer of thick skin (not present in thin skin)
Number of layers to the stratum lucidum.
between 3 and 4
What cell types are in the stratum lucidum?
Only keratinocytes.
Describe the features of the stratum lucidum.
There are three.
Present only in thick skin.
Appear clear under the microscope.
Keratinocytes are now squamous.
Describe the location of the stratum corneum.
Most superficial layer of the epidermis.
How many layers in the stratum corneum?
approx 30
What cell types are in the stratum corneum?
only keratinocytes
What are the features of the stratum corneum?
There are four. This is the "largest" zone. Keratinocytes are squamous. Uppermost cells are shed. A callus is a thickening of this zone.
