Term 1 Exam: Chapter 5 Integumentary System (from slides) Flashcards
What are the organs of the integumentary system?
The skin and its accessory structures including hair, nails, and glands as well as blood vessels, muscles and nerves
What are some common skin diseases?
Skin cancer Viral infections such as chicken pox or measles
What is another name for the skin?
Cutaneous Membrane
What are 6 functions of the Skin?
- Temp regulation 2. Blood reservoir 3. Protection from external environnment 4. Cutaneous sensations (touch, pressure, vibrations) nerve endings 5. Excretion: (urea and ammonia) and aborption (vit D) 6. Synthesis of Vitamin D
What is the structure of the skin?
Skin consists of two layers: 1. epidermis - Outer, thinner layer that consists of epithelial tissue 2. Dermis - Inner, thicker layer that consists of connective tissue
What is the subcutaneous layer (SubQ layer)?
Lies beneath the dermis Attaches the skin to the underlying tissues and organs
What forms the integument?
Skin and subQ layer
Label 1; 2; 3; 4
- Epidermis
- Dermis
- Subcutaneous layer
- Sebaceous (oil) gland
The Skin contains 4 principle types of cells what are they?
- Keratinocytes (~90%) 2. Melanocytes (~8%) 3. Langerhans cells (aka intraepidermal macrophage cells) 4. Merkel cells
What are keratinocytes?
skin cells that produce keratin and lamellar granules to provide a waterproof environment for skin
What are Melanocytes?
Produce melanin pigments that protect against UV
What are Langerhans Cells
Involved in immune response
What are Merkel Cells?
Skin cells that function in the sensation of touch along with the adjacent tactile (Merkel) discs
How many layers does thin skin have? What are they from deepest?
4 1. Stratum Basale 2. Stratum Spinosum 3. Stratum Granulosum 4. Stratum Corneum
How many layers does Thick Skin have? What are they (from deepest)?
5 1. Stratum Basale 2. Stratum Spinosum 3. Stratum granulosum 4. Stratum Lucidum ( only in fingertips, palms and soles) 5. Stratum Corneum
What are 6 features of the stratum basale?
- Deepest layer where continuous cell division occurs (produces all the other layers) 2. Where stem cells are located 3. Composed of a single row of cuboidal or columnar keratinocytes 4. Nuclei of keratinocytes are large with abundant ribosomes, a small golgi complex and few mitochondria 5. Presence of keratin intermediate filaments (aka tonofilaments) protects deeper layers from injury 6. Melanocytes and Merkel cells are found in this layer
What are 4 features of the Stratum Spinosum?
- 8-10 layers of keratinocytes from the stem cells 2. Cells are rounder and larger, but flatten at more superficial layers 3. Bundles of tonofilaments insert into desmosomes 4. Layer also contain projections from intraepidermal macrophages (langerhans cells) and melanocytes
What are four features of the Stratum Granulosum?
- 3-5 layers of flattened keratinocytes 2. Keratinocytes contain keratohyalin and lamellar granules 3. Keratohyalin converts keratin intermediate filaments into keratin 4. Lamellar granules release lipid-rich water repellent - prevents loss of body fluids and entry of foreign materials
What are three features of the Stratum Lucidum?
- Present only in THICK skin (fingertips, palms, soles) 2. 4-6 layers of clear, flat, dead keratinocytes with large amount of keratin and thickened plasma membrane 3. Keratin arranged parallel to skin surface - provides an additional level of toughness
What are three features of the Stratum Corneum?
- Surface layer 2. 23-50 rows of dead, flat keratinocytes called corneocytes or squames (scale) - continuously shed and replaced by cells from deeper strata 3. Constant friction to the skin cases formation of a callus (abnormal thickening of the corneum)
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What are two important characteristics of the Dermis?
- Composed of Connective Tissue 2. Contains Collagen and elastic fibres
What are the two layers of the Dermis?
- Papillary region 2. Reticular Region
What are 2 features of the Papillary region of the dermis?
- Most Superficial layer (represent 1/5 of thickness of dermis) 2. Consists of areolar connective tissue with thin collagen and elastic fibres
What does Dermal Papillae House?
- Capillary loops 2. Corpuscles of touch (meissners corpuscles) 3. Some with free nerve endings
What are three characteristics of the Reticular Region of the dermis?
- The deepest layer 2. Consists of dense irregular connective tissue: -collagen and elastic fibres -adipose cells -hair follicles -nerves -sebaceous (oil) glands -Sudoriferous (sweat) glands 3. Striae or stretch marks can appear if the skin is stretched too much
What three pigments are responsible for variations in skin color?
- Melanin 2. Carotene 3. Hemoglobin
What are five characteristics of Melanin?
- melanin is a yellow-red or brown-black pigment produced by melanocytes (mostly in epidermis where it absorbs UV radiation) 2. The amount of melanin causes skin colour to vary from pale yellow to red to tan to black 3. Melanocytes are more concentrated in the skin of penis, nipples, face, areolae and limbs 4. the number of melanocytes are bout the same in all people (difference is how much pigment the cells produce) 5. Freckles are accumulation of patches of melanin
What are two features of Carotene?
- Yellow-orange pigment 2. Found in the stratum corneum, dermis and the subcutaneous layer
What are two features of Hemoglobin?
- Red colour 2. Located in erythrocytes flowing through dermal capillaries
What are four features of the Subcutaneous Layer?
- Lowest part of the integument 2. Is not part of the skin but plays a role in its functions 3. SubQ attaches the skin to the underlying tissues and organs - consists primarily of loose connective tissue and lobules of fat; and contains larger blood vessels and nerves 4. Contains lamellated corpuscles (detect external pressure)
What is the difference between albinism and vitiligo?
Albinism: has melanocytes but dont produce melanin Vitiligo: Melanocytes have been killed off
What are four diagnostic clues we can get from skin colour?
- Cyanotic: skin turning blue = lack of O2 2. Jaundice: Buildup of yellow pigment bilirubin = may indicate liver disease 3. Erythema: redness due to vasodilation of capillaries = inflammation 4. Pallor: paleness = shock or anemia
What are three accessory structures of the skin?
- Hair 2. Nails 3. Sweat Glands
What are the functions of the accessory structures of the skin?
Protection (hair and nails) Temperature Regulation (sweat glands)
What is the anatomical name for Hair?
pili
What are the primary functions of hair?
- protection 2. Reduction of heat loss 3. Sensing light touch
What is hair composed of?
Dead, keratinized epidermal cells
What are the structural features of hair?
- shaft : projects above the surface of the skin - Root: Penetrates into the dermis - Hair follicle: surrounds the root - epithelial root sheath which in turn is surrounded by a dermal root sheath
What are the three types of hair?
- Lunago 2. Vellus hairs (peach fuzz) 3. Terminal hairs
What is lunago hair?
Non-pigmented hair -Normally develop during 5th month of fetal development and shed before birth
What are Vellus hairs?
New, short fine hair that replaces lunago over most of a childs body -at puberty vellus hair differentiate into terminal hairs at specific regions of the body
What is Terminal Hair?
develop at puberty with those on the head, eyebrows and eyelashes ~95% of male body hair is terminal while only ~35% is terminal on a female
What are two characteristics of Sebaceous (Oil) Glands
- Typically connected to hair follicles 2. Secrete an oily substance (sebum) which prevents dehydration of hair and skin and inhibits growth of certain bacteria
What are two features of Sudoriferous (sweat) glands?
- Produce sweat (perspiration) 2. Two types of sweat glands: -Eccrine sweat glands -apocrine sweat glands
What are 4 important notes about Eccrine Sweat Glands?
-Have an excretory duct that opens at a pore at the surface of the epidermis -More common than apocrine -Sweat from these glands helps cool the body and eliminates small amount of waste -Distributed throughout the skin of most parts of the body (except lips, nail bed, glans penis, clitoris, labia minora and eardrum)
What is sensible perspiration?
Sweat that is excreted in larger amounts and is seen as moisture on the skin
What is Insensible perspiration?
Sweat that evaporates from the skin before it is perceived as moisture
What are two important notes about apocrine sweat glands?
- Located mainly in the skin of the axilla (armpit), groin, areolae and bearded facial regions of adult males 2. Secretory ducts open into hair follicles and subjected to stimuli - emotional stress and sexual excitement -cold sweat
What are Ceruminous Glands?
Modified sweat glands, located in the ear canal
What is produced by Ceruminous Glands?
A waxy secretion: cerumen (earwax) -Prevents entry of foreign bodies into the ear canal
What are nails made up of?
Hard keratinized epithedermal cells located over the dorsal surfaces at the ends of fingers and toes
What are the structures of the nails?
Free edge (white tip) Transparent nail body (plate) Lunula (white half moon base) Nail root - embedded in a fold of the skin, not visible
What are three structures associated with the nail?
- Hyponychium (nail bed) 2. Eponychium (cuticle) 3. Nail matrix
Where is the Hyponychium located?
Under the free edge - attaches the nail to the fingertip
What is the function of the Eponychium?
Attaches the margin of the nail wall to the neighboring epidermis
What is the Nail Matrix?
Location of cell division for nail growth
What are four funtions of the nail?
- helping to grasp and manipulate objects 2. Providing protection against trauma to the ends of the digits 3. Scratching various parts of the body 4. Provide support and counter pressure to the palmar surface of the finger (enhances touch perception and manipulation)
What is the clinical definition of a burn? What is the formal cause on a molecular level? What is the result of a burn?
A burn is tissue damage caused by excessive heat, radioactivity, electricity or corrosive chemicals -denatures proteins in the skin cells -Damage results in loss of protection against microbial infection, dehydration and the regulation of body temperature
Label A, B, C, D, and E
A - Epidermis
B- Papillary Region
C- Dermis
D- Reticular Region
E- Epidermal Ridge
Label A through J
A- Nail Root
B- Eponychium
C- Lunula
D- Nail Bed
E- Nail Body
F- Free Edge
G- Hyponychium
H- Epidermis
I- Dermis
J- Nail Matrix
