The Integumentary System

Dermal macrophages

"Second line of defense". Attack bacteria and viruses that have penetrated the epidermis. This and Langerhan's cells help activate the body's immune system.

Excretion/absorption

(Two words) Elimination of nitrogen-containing wastes (ammonia, urea, uric acid), sodium chloride, and water. Also regulates water loss.

Blood reservoir

A function of the skin provided by the extensive network of blood vessels in the dermis; preferential shunting of blood to needed areas.

Human defensin

A secretion that is a natural antibiotic.

Photosensitivity

A skin reaction that is caused by exposure to sunlight, antibiotics, and antihistamines. Can cause cellular damage.

Hypodermis, connective, adipose, insulation, cold

Also called the subcutaneous tissue. It attaches the skin to underlying organs and tissues. It is not part of the skin. It contains _________ tissue and _______ tissues (subcutaneous fat) for ____________. Infants and elderly have less of this than adults and are therefore more sensitive to _____.

Brusing, clotted, vitamin C, hemophilia

An appearance of the skin also known as hematoma. Escaped blood has __________ hematomas, deficiency in ___________ ____ , or ____________.

Bronzing

An appearance of the skin due to Addison's disease, adrenal cortex not producing hormones, etc.

Leathery skin, elastin fibers, immune, cancer

An appearance of the skin due to overexposure, clumping of elastin fibers, depressed _________ system. Can alter DNA to cause skin _______.

Pallor

An appearance of the skin that shows paleness due to emotional state, anemia, low blood pressure, etc.

Cyanotic, breathing, hemoglobin

An appearance of the skin where someone who has stopped ____________ and the skin appears bluish because the ____________ is depleted of oxygen.

Melanin

Chemical pigment that prevents UV damage.

70%, strength, elasticity

Collagen fibers make up ____ of the dermis and give structural toughness and ________. Elastin fibers are loosely arranged in all directions and give _________ to the skin.

Hair root plexus

Cutaneous sensory receptor that detects sensations from movement of hairs. They are dendrites of neurons which are sensitive to touch.

Hair follicle receptors

Cutaneous sensory receptors that detect movement across the surface of the skin.

Bare nerve endings

Cutaneous sensory receptors that detect painful stimuli (chemicals, heat, cold)

Constrict

Dermal blood vessels _____ to retain heat.

Melanocytes, keratinocytes

Difference in skin color is due to the amount of pigment that ____________ produce and disperse to _____________.

Oxygen, carbon dioxide, steroids, fat-soluble vitamins

Examples of lipid-soluble substances that can penetrate the skin.

Poison ivy and poison oak

Examples of oleoresins that can penetrate the skin.

Acetone, dry cleaning fluid, paint thinner

Examples of organic solvents that can penetrate the skin.

Lead, mercury, nickel

Examples of salts of heavy metals that can penetrate the skin.

Reticular layer, collagen/elastic fibers, strength, elasticity, sebaceous, sudoriferous

This layer is the deeper portion of the dermis. It consists of dense irregular connective tissue containing _______/________. Provides skin with ________ and _________. Contains hair follicles, nerves, __________ glands and _____________ glands.

Papillary layer, elastic fiber, dermal papillae, epidermal ridges

This layer is the superficial portion of the dermis. It consists of areolar connective tissue containing _______ ________. Surface area is increased due to projections called _________ __________. ________ _________ conform to the dermal papillae.

Stratum basale, germinatum, deepest, cuboidal, columnar

This layer of the epidermis is also referred to as stratum _______________ because it is where new cells are formed. It is the ______est layer of the epidermis and is a single row of __________ or ___________ keratinocytes.

Low

This of pH, and also sebum, slows bacterial growth on skin surface.

Integumentary system

This organ system consists of the skin, hair, nails, the subcutaneous tissue below the skin, and assorted glands.

Pliable, durable

Two characteristics that seemingly contradict each other of the integument.

Increases, increased, tan, eumelanin, pheomelanin, cancer

UV light __________ enzymatic activity in the melanosomes and leads to ___________ melanin production. A ____ is achieved because the amount of melanin has increased as well as the darkness of the melanin. (___________ provides protection from UV exposure while _____________ tends to break down with too much UV exposure.) The melanin provides protection from the UV radiation but prolonged exposure may cause skin _________.

Rickets

Vitamin D deficiency causes this.

Epidermis and dermis

What layers is the integument composed of?

Dilate, sweat

When body temperature rises and is hotter than the external environment the blood vessels in the dermal area _____ and the _____ glands are stimulated into activity.

Constrict, away

When it is cold outside, the dermal blood vessels _______ and pull the blood _______ from the skin and keeps it close to the body core to protect crucial internal organs.

Calcium, phosphate, bloodstream

When the body is deficient in vitamin D, it is unable to properly regulate ________ and __________ levels. If the blood levels of these become low, the other body hormones may stimulate release of the two things from the bones to the _____________.

Pink/red, oxygen, capillaries

White skin appears _____/______ depending on amount and _________ content of blood moving in the __________ of the dermis.

Melanocytes, melanin, skin color, UV

8% of epidermal cells are this. It produces _________. It contributes to ____ ______ and absorbs ____ light.

Keratinocytes, fibrous

90% of epidermal cells are this. Contains keratin, which is a _______ protein. The cells protect and waterproof the skin.

Vitamin D, intestines, liver, kidneys

A fat-soluble vitamin that may be absorbed from the _______ or may be produced by the skin when it is exposed to UV light (sunlight). It is converted to its active form by the body in 2 steps: first in the _____ and completed in the _______.

Jaundice, bilirubin, liver disease, red blood, liver, intestine, stool

An appearance of the skin where there is buildup of __________ (yellow pigment) in the blood, giving a yellowish appearance of eyes and skin indicating _________ _____________. The yellow pigment is produced when ____ ________ cells get old and are broken down by the body. Normally it is processed in the _______ and then is deposited in the __________ so it can come out in the ________.

Erythema, capillaries

An appearance of the skin where there is engorgement of cappilaries in the dermis indicating skin injury, infection, heat exposure, inflammation, allergies, emotional state, hypertension, etc. Red appearance of the skin.

Chemical conversion

Another metabolic function of the integumentary system dealing with chemicals.

Physical barriers

Barriers due to the skin's physical characteristics such as the continuity of the skin, hardness of keratinized cells, and waterproofing properties of the glycolipids.

Keratin

Fibrous structural proteins that helps waterproof the skin the protects from abrasions and bacteria.

Blood vessels, nerves, glands, hair follicles

Four things that are embedded in the dermis.

Melanin

Freckles and liver spots are caused by the accumulation of ____________ in patches.

2 meters

How long is the integument?

Hormone, intestine, calcium, phosphate

In its active form, vitamin D acts as a _______ to regulate calcium absorption from the ___________ and to regulate levels of _______ and __________ in the bones.

Hairless

Is thick skin hairy or hairless?

Hairy

Is thin skin hairy or hairless?

Stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, stratum basale

Layers of the epidermis, from outermost to deepest.

Merkel discs/cells, light

Least numerous of the epidermal cells and founs in the deepest layer of the epidermis (stratum basale). Along with tactile discs, they function in sensation of ______ touch.

Melanin, tyrosine, tyrosinase, melanosome

Melanocytes synthesize _________ from an amino acid called ________ along with an enzyme called __________. All this occurs in the _____________ which is an organelle in the melanocyte.

Cutaneous membrane

Membrane also known as skin.

Glycolipids

Membrane components composed of lipids that are covalently bonded to monosaccharides or polysaccharides. Prevent diffusion of water and water-soluble substances between cells

Synovial membranes

Membranes that form the inner lining of joint cavities and secrete a thick fluid called synovial fluid.

Serous membranes

Membranes that line body cavities that have no opening to the outside. They secrete a watery fluid called serous fluid that lubricates surfaces.

Mucous membranes

Membranes that line cavities and tubes that open to the outside.

Vitamin D, calcium

Metabolic function of skin: synthesizes _________ ___ to increase _______ absorption in the body.

Cathelicidins

Proteins that prevent Strep A infection in wounded skin.

1.5 to 6.0 mm

Range of thickness of integument in general.

1-2 mm, 0.5 mm

Range of thickness of thin skin, and thin skin in eyelids.

Pascinian receptors

Receptors that lie in deeper dermis/hypodermis and detect deep pressure contacts.

Friction ridges

Skin markings on fingertips characteristic of primates (fingerprints). They allow us to manipulate objects more easily.

Meissner's corpuscles, light

Skin receptors enclosed in a capsule of connective tissue. They react to _____ touch and are located in the skin of your palms, soles, lips, eyelids, external genitals and nipples. Particularly sensitive.

Lipid-soluble substances, oleoresins, organic solvents, salts of heavy metals, and topical medications

Substances that are able to penetrate the skin.

Melanin, carotene

The epidermis appears translucent when there is little __________ or __________.

Protects against injury and infection, regulates body temperature, sensory perception, regulates water loss, synthesizes chemicals

The five basic functions of the integumentary system.

Keratinocytes, melanocytes, Langerhans cells, Merkel cells

The four types of cells in the epidermis.

Stratum basale, keratinization, keratin, apoptosis, 4, increases

The growth of the epidermis: newly formed cells in the _________ ___________ undergo ________________ as they are pushed to the surface. They accumulate more _________ during the process. Then they undergo _________. Eventually they slough off and are replaced. This process takes about __ weeks. Rate of cell division in the first layer __________ during injury.

Heaviest, 16%

The integument is the _______est organ; what is its percentage of the mass of a body?

Integument

The largest organ that covers the entire body.

Stratum spinosum, 8-10, division, cytoskeleton, strength, flexibility

The layer of epidermis above the stratum basale. #-# layers of keratinocytes. Some cells retain their ability for cell _________. Cells have spinelike projections (bundles of filaments of the __________) and they tightly join cells to each other. The layer provides _________ and __________ to the skin.

Stratum granulosum, 3-5, apoptosis, transition, lamellar granules, lipid, water

The layer of epidermis above the stratum spinosum. #-# layers of flattened keratinocytes undergoing _______. Organelles disintegrate and become non-living cells. The layer marks the transition between active deeper strata (metabolically) and the dead cells of the upper strata. Contains _________ __________. Secretes ____-rich secretion that acts as a _______ sealant.

Stratum lucidum, 3-5, intermediate filaments, plasma

The layer of epidermis present only in thick skin. It is #-# layers of clear, flat, dead keratinocytes, with dense packed __________ ___________. Thick ________ membranes.

Same

The number of melanocytes are about the ______ in all races.

Stratum corneum, 25-30, barrier

The outermost layer of the epidermis composed of #-# layers of dead flat keratinocytes. It sheds continuously and is replaced by cells from the deeper strata. It serves as a water, microbe, and injury _________.

Hemoglobin

The oxygen-carrying pigment in red blood cells.

Melanin, eumelanin, pheomelanin

The pigment that is located mostly in the epidermis. There are two types of this: ________ which is brownish black and ___________ which is reddish yellow.

Keratinization

The process and replacement of cell contents with new protein, occurring as cells move to the skin surface over 2-4 weeks.

Dermis

The second deepest part of the skin. It is composed mainly of connective tissues (collagen and elastic fibers).

Sweat

The skin produces copious amounts of this to dissipate heat.

Melanin, carotene, hemoglobin

The three pigments responsible for skin color.

Papillary layer and reticular layer

The two layers of the dermis are...

Carotene, A, vision, corneum, fatty

The yellow-orange pigment. Precursor for vitamin __ which is used to make pigments needed for _________. Found in stratum ___________ and _______ areas of dermis and hypodermis layer.

Langerhans cells, red, immune, UV

These cells, a small portion of epidermal cells, arise from ___ bone marrow and migrate to the epidermis. They participate in _________ responses. They are easily damaged by _____ light.

Langerhans' cells

These cells, in epidermis, present antigens to lymphocytes. The arise from red bone marrow and migrate to the epidermis. They are a small portion of epidermal cells and participate in immune responses. They are easily damaged by UV light.

Merkel cells, deepest, tactile discs, touch

These cells, the least numerous of the epidermal cells, are found in the _______est layer of the epidermis. Along with ______ _______, they function in sensation of ______.

Skin secretions and acid mantle

These two things are chemical barriers that retard bacteria growth and/or kill them.

6 mm

Thick skin can be up to __ ___ thick.

Palms of hands and soles of feet

Thick skin covers...

Thick, stratum lucidum

Thick skin has a _______ epidermis and a distinct ______ ___________.

Dermal papillae

Thick skin has epidermal ridges, which are present due to well-developed, numerous ________ ___________.

Sebaceous, sweat, sense receptors

Thick skin lacks ___________ glands. It has more ________ glands, and _________ _____________ are also more densely packed.

Membranes

Thin sheet-like structures that protect parts of the body.

Palms of hands and soles of feet

Thin skin covers all parts of the body except....

Thin, stratum lucidum

Thin skin has ______ epidermis and lacks ________ ___________ (layer of epidermis)

Sebaceous, sweat, sensory receptors

Thin skin has more ___________ glands, fewer _____ glands and fewer ________ ____________ than thick skin.

Dermal papillae

Thin skin lacks these bumpy-looking parts of the dermis.

Continuity

This characteristic of the skin prevents bacterial invasion.

Albinism, melanin, tyrsinase, initiates

This is an inherited trait dealing with skin appearance where a person cannot produce __________. They have melanocytes but are unable to make _________ (the enzyme which _________ melanin production).