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86 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Integumentary system consists of 6 items |
Skin Hair Nails Sensory receptors Exocrine glands Dermal blood vessels |
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The average adult has how much skin? |
Surface area of 1.2 sq meters (4 sq feet) & 2.2 sq meters 7 sq feet Skin weighs about 4-5kg 10lb or 7% of body weight Thickness 1.5-4.0 mm |
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Skin has 2 regions |
Top epidermis Bottom dermis |
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Epidermis is made of |
Stratified kerantized squamous epithelium. It is avascular, it's thickness is between .01 &1.0mm |
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What are the 4 cells found in the epidermis? |
Keratinocytes Melanocytes Merkel cells Langerhans cells |
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Keratinocytes |
Are most abundant, make a protein called keratin. Keratin is waxy & waterproof. It gives the epidermis it's protective properties |
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What is the deepest layer of the epidermis? |
Stratum basale. |
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What is the deepest layer of the epidermis? |
Stratum basale. |
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Keratinocytes undergo mitosis in |
The stratum basale |
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The superficial layer of the epidermis is the |
Stratum corneum |
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Keratinocytes die on their journey from the stratum basale to the stratum corneum. The journey takes between |
25-45 days. The stratum corneum is composed of dead keratinocytes. |
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Dead keratinocytes have thickened plasma membranes are filled with keratin |
Every month or so we acquire a completely new epidermis. |
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A callus is the result of |
Persistent friction which causes accelerated keratinocyte production |
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Melanocytes make a dark pigment called melanin |
Keratinocytes pick up melanin & use it to shield their nuclei from UV radiation I.e. Suntan |
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Langerhans cells |
Arise in bone marrows& migrate to the epidermis Are phagocytes & ingest foreign substances that penetrate the epithelium, they take it to the lymph nodes to help activate the immune system. |
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Merkel cells AKA Merkel disc |
Encapsulated nerve ending found in the epidermis. Merkel disc consists of a Merkel cell that surrounds the end of a sensory neuron. Light touch is sufficient to deform the Merkel disc. When disc is deformed it causes the sensory neuron to generate and conduct a nerve impulse |
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What are the 5 layers of the epidermis? |
Stratum basale"basement" Strtum spinosum Stratum granulosum Stratum lucidum Stratum corneum "outer most" |
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Stratum basale consists of |
A single layer of cells which under go continuous mitosis.mitosis gives rise to the youngest keratinocytes which replaces worn off cells |
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Stratum corneum |
Is the superficial layer of the epidermis, it is about 20-30 cell layers thick.accounts for 75% thickness of the entire epidermis . Is composed of dead keratinocytes. |
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What are the 2 layers of the dermis? |
Superficial layer--Papillary layer Deep layer--reticular layer |
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The papillary layer iS made of what tissue? |
Loose Areolar connective tissue. |
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The papillary layer iS made of what tissue? |
Loose Areolar connective tissue. |
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What percentage of dermal thickness does the papillary layer form? |
20% it is nipple like |
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The papillary layer is highly vascular. Vessels in the dermis |
nourish the cells avAscular epidermis |
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Name the 3 cells found in the papillary layer |
Fibroblasts Mast cells WBC white blood cells |
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Dense fibrous irregular connective tissue makes up the |
Reticular layer |
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Reticular layer forms what percentage of dermal thickness |
80% |
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The reticular layer is highly |
Vascular |
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What are the main cells found in the reticular layer of the dermis? |
Fibroblasts |
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Hair follicles are located in the deep _________ layer of the dermis |
Reticular |
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Hair follicles are located in the deep _________ layer of the dermis |
Reticular |
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What is at the base of each hIr follicle? |
A hAir root |
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Hair follicles are located in the deep _________ layer of the dermis |
Reticular |
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What is at the base of each hIr follicle? |
A hAir root |
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A hair root is composed of cells that undergo continual |
Mitosis |
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Hair follicles are located in the deep _________ layer of the dermis |
Reticular |
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What is at the base of each hIr follicle? |
A hAir root |
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A hair root is composed of cells that undergo continual |
Mitosis |
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New keratinozed hair cell acquire color from melanin they die and are fused into |
A hAir shaft. Hair grows about 8-10mm each month |
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Arrector pili muscle AKA Pilomotor muscle |
Smooth involuntary muscle GOOSEBUMPS when contracted |
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Arrector pili muscle AKA Pilomotor muscle |
Smooth involuntary muscle GOOSEBUMPS when contracted |
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Hair follicle receptors are sensory nerve endings |
When bent it stimulates tag sensory nerve endings warms of light touch or insects on the skin |
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Nails are scale like modification of |
The epidermis. They cover the dorsal surface of distal fingers & toes . |
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Nail bed is composed of deep layers of the epidermis |
Blood vessels in the dermis that give nails their pink color |
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Lunula is the proximal white crescent portion it covers the |
Nail root cells produced become keratinized & fuse into the nail. The body of the nail the slides distal over the nail bed
Nails about 3mm each month |
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Nail bed is composed of deep layers of the epidermis |
Blood vessels in the dermis that give nails their pink color |
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Lunula is the proximal white crescent portion it covers the |
Nail root cells produced become keratinized & fuse into the nail. The body of the nail the slides distal over the nail bed
Nails about 3mm each month |
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Cutaneous senses aka general senses these includ |
Touch Pain Heat Cold Pressure |
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Merkel discs & free nerve endings are sensory receptors housed in the epidermis |
Merkel discs are encapsulated nerve endings sensitive to light touch
Free nerve endings un-encapsulated are sensitive to pain heat & cold |
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Merkel discs & free nerve endings are sensory receptors housed in the epidermis |
Merkel discs are encapsulated nerve endings sensitive to light touch
Free nerve endings un-encapsulated are sensitive to pain heat & cold |
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What are the 4 receptors in the dermis? |
Free nerve endings Meissners corpuscles Pancinian corpuscles Hair follicle receptors |
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Merkel discs & free nerve endings are sensory receptors housed in the epidermis |
Merkel discs are encapsulated nerve endings sensitive to light touch
Free nerve endings un-encapsulated are sensitive to pain heat & cold |
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What are the 4 receptors in the dermis? |
Free nerve endings Meissners corpuscles Pancinian corpuscles Hair follicle receptors |
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Meissners corpuscles |
Provide discriminative touch Know what you are touching |
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Merkel discs & free nerve endings are sensory receptors housed in the epidermis |
Merkel discs are encapsulated nerve endings sensitive to light touch
Free nerve endings un-encapsulated are sensitive to pain heat & cold |
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What are the 4 receptors in the dermis? |
Free nerve endings Meissners corpuscles Pancinian corpuscles Hair follicle receptors |
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Meissners corpuscles |
Provide discriminative touch Know what you are touching |
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Pancinian corpuscles are sensitive to |
Deeper pressure & bumps |
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Exocrine glands are formed
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from glandular epithelium they are formed by invaginations of the superficial dermis into deeper dermis |
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What are the 4 exocrine glands of the skin? |
Sweat glands aka sudoriferous glands Oil glands Ceruminous glands Mammary glands |
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Sweat gland facts |
The skin had about 3 million sweat glands
Sweat glands are found almost everywhere
There are no sweat glands on nipples & external genitalia |
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What are the 2 types of sweat glands? |
Apocrine & eccrine Apocrine Located in armpit & genitals |
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What are the 2 types of sweat glands? |
Apocrine & eccrine Apocrine Located in armpit & genitals |
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Apocrine sweat gland facts |
On average skin has 2k apocrine sweet glands They are found I. The armpit & genital areas Inactive until puberty Not invoked in thermal regulation Secretions into hair follicles via ductrs Apocrine secretions is similar to sweat Contains more proteins and substances Equate aprocine sweat glands w/sec scent glands in animals |
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Eccrine sweat glands facts |
Found all over the body Most numerous on pals feet &forehead Sweat is secreted via a coiled tube located in the dermis Have ducts that open into pores Pores are funnel shaped channels Pores open onto the surface of the skin
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Eccrine sweat glands facts |
Found all over the body Most numerous on palms feet &forehead Sweat is secreted via a coiled tube located in the dermis Have ducts that open into pores Pores are funnel shaped channels Pores open onto the surface of the skin
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Cells that line a sweat gland secrete sweat by |
Exocytosis |
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Sweat facts |
500 ml on normal day pH 4- 6 Made from water derived from blood plasma Contains salts Na sodium & Cl chloride Contains vitamin C. Anti bodies & trace metabolic wastes |
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Oil glands )sebaceous glands |
Found everywhere but palms & soles of feet Secrete into hair follicles via ducts May also secrete directly onto the surface of skin |
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Sebum is a lipid (oily) substance |
Oil glands secrete Inhibits growth of bacteria Softens & lubricates skin |
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Dermal blood vessels |
Contains about 5% of the body's blood volume |
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Dermal blood vessels |
Contains about 5% of the body's blood volume |
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Thermoregulatiom |
Smooth muscle in the walls of the arterioles dilate or constrict |
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Vasodilation |
Smooth muscle relaxes arterioles dilate Increases blood flow through dermal blood vessels Occurs in a warm environment Brings excess heat closer to the surface of the skin Heat in blood is radiated to the envoroment lowering body temp |
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Vasoconstriction |
Smooth muscle contracts Arterioles constrict Decreases blood flow through the dermal blood vessels Occurs in cold environment Maintains heat within the core of the body |
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Vasoconstriction |
Smooth muscle contracts Arterioles constrict Decreases blood flow through the dermal blood vessels Occurs in cold environment Maintains heat within the core of the body |
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Fight or flight is a vasoconstriction of dermal blood vessels blood is sent to |
Skeletal muscles heart & brain |
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Vasoconstriction |
Smooth muscle contracts Arterioles constrict Decreases blood flow through the dermal blood vessels Occurs in cold environment Maintains heat within the core of the body |
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Fight or flight is a vasoconstriction of dermal blood vessels blood is sent to |
Skeletal muscles heart & brain |
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Vitamin D production begins in |
The skin Modified molecules circulating in dermal blood vessels are converted to a vitamin d precursor when exposed to sunlight Vitamin d in necessary to absorb calcium from food |
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Vasoconstriction |
Smooth muscle contracts Arterioles constrict Decreases blood flow through the dermal blood vessels Occurs in cold environment Maintains heat within the core of the body |
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Fight or flight is a vasoconstriction of dermal blood vessels blood is sent to |
Skeletal muscles heart & brain |
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Vitamin D production begins in |
The skin Modified molecules circulating in dermal blood vessels are converted to a vitamin d precursor when exposed to sunlight Vitamin d in necessary to absorb calcium from food |
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Hypodermis AKA superficial fascia |
Located deep to the dermis of the skin Not truly part of the skin Composed of loose Areolar connective tissue Maybe composed of adipose connective tissue if fat cells are present. |
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Hypodermics functions |
Absorbs shock Insulates against heat loss Defense against infection viaWBC anchors the dermis loosely to deep fascia |
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Deep fascia is the dense |
Fibrous irregular connective tissue that covers skeletal muscles |
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