Chapter 6 Worksheet

piloerector muscle = arrector muscle

top to bottom: - stratum corneum - stratum lucidum - stratum granulosum - stratum spinosum - stratum basale - dermis

- The INTEGUMENTARY system's major contribution is that it acts as a barrier between the environment and the body - The initial step in the synthesis of the hormone known as calcitriol demonstrates the interaction of multiple organ systems, as in this example, where the ENDOCRINE system requires proper functioning of the integumentary system - Facial expressions require the integration of the MUSCULAR system in order to pull on skin attachments and create movements - An example of NERVOUS system interactions with the skin is the large number of sensory receptors that function to provide communication between the environment and body - By serving as a blood reservoir, the skin can support the function of the CIRCULATORY system by diverting blood to or from internal organs as necessary

- Skin contains the protein keratin and cellular junctions called desmosomes that confer a mechanical strength to the epidermis, which RESISTS MECHANICAL TRAUMAS, such as punctures and abrasions - As a result of impermeable cellular junctions and water-proofing lipids, the epidermis functions in CREATING A BARRIER TO SOME FLUIDS - The skin assists endocrine function by playing a role in VITAMIN-D SYNTHESIS, which is needed for calcium homeostasis

- Because it houses many nerve endings and sensory organs, the skin is vitally involved with SENSATION - Through vasodilation in times of excessive heat, and vasoconstriction during times of cold, the blood flow to the dermis aids the body through THERMOREGULATION - Skeletal muscle attachments to facial structures produce a wide variety of expressions and PRODUCE NONVERBAL COMMUNICATION with other individuals

1. The STRATUM CORNEUM is made up of multiple layers of dead keratinocytes that regularly exfoliate 2. The next layer is the STRATUM LUCIDUM, which is present only on the soles of the feet, hands, fingers and toes 3. The STRATUM GRANULOSUM is named for the presence of dark staining keratohyalin granules, which bind the cytoskeletal keratin filaments together 4. Towards the apical surface, in the STRATUM SPINOSUM, the keratinocytes cease cell division, while at the deeper regions, they can still undergo mitosis 5. Comprised of viable, cuboidal and columnar cells, the STRATUM BASEALE contains the keratinocyte stem cells that replenish the exfoliated cells at the surface

- Fingerprints are caused by FRICTION RIDGES - When you make a fist, your finger joints move at FLEXION CREASES in the skin on the anterior surface of the hand, where the skin is bound to deeper tissues - FRECKLES are flat, melanized patches that vary with heredity and sun exposure - MOLES are elevated patches of melanized skin. - A reddish birthmark made of benign tumors of capillaries is called a(n) HEMANGIOMA

superficial to deep: - hair shaft - hair root - hair matrix - hair bulb - dermal papilla

Scalp Hair: - makes up for a lack of insulation in the cranium - protects from the most direct rays of sunlight Vibrissa: - protects the ear from foreign particles - shields the eyes from windblown debris Beard, Pubic, & Axillary Hair: - signals sexual maturity - transmits pheromones

- To transmit sexual scents - To maintain the temperature of the head - To protect the skin from drying out - To express nonverbal communication

Sebaceous: - secretes sebum - usually opens up into a hair follicle - coats the scalp hair with oil - blockage and infection can cause pimples Ceruminous: - secretes earwax - coats guard hairs to improve their performance - simple, coiled, tubular glands - waterproofs the ear canal

- Sebaceous glands are a form of sudoriferous gland - Sebaceous glands secrete an oily substance called sebum - Sebaceous glands are found at the base of eyelash hairs - Sebaceous glands are responsible for the oil that coats the hair on your scalp

basal cell carcinoma: - most common type - seldom spreads to other tissues - arises from keratinocytes in the deepest layer of the epidermis squamous cell carcinoma: - arises from superficial cells of the epidermis - raised, reddened, scaly appearance - can spread from the keratinocytes to the lymph nodes melanoma: - if metastasized, the deadliest skin cancer - arises from the cells that protect from UV light - least common type - caused by mutations commonly found in moles

- MELANOMA arises from pigment-producing MELANOCYTES and is the deadliest form of skin cancer if it spreads - SQUAMOUS CELL CARCINOMA arises from the KERATINOCYTES of the stratum spinosum and sometimes spreads to the lymph nodes - BASAL CELL CARCINOMA arises from the deepest layer of the skin's EPIDERMIS and rarely metastasizes

first degree: - seldom leave scars - cause redness, slight edema, and pain - may heal in a few days second degree: - part of the dermis is involved - severe sunburns and many scalds third degree: - all of the dermis is effected - skin grafts may be required - sometimes muscles and bones are destroyed

- Fluid replacement and infection control are the most critical aspects of emergency care for severe burns - In order to avoid nourishing an infection, the patient should decrease caloric intake - Exfoliation, the removal of the eschar, must be stopped to save the skin - A patient may lose up to 75% of the blood plasma within hours - Skin grafts are often required for third degree burns

superficial to deep: - stratum corneum - stratum lucidum - stratum granulosum - stratum spinosum - stratum basale

epidermis: - composed of 4-5 layers - is avascular - composed of keratinocytes - most superficial layer dermis: - composed of 2 layers - contains hair follicles - contains sweat glands hypodermis: - also known as subcutaneous - composed of loose areolar and adipose tissue

superficial to deep: - epidermis - dermis - hypodermis - fascia lata (deep fascia) - muscle

1. The NAIL MATRIX contains mitotic cells 2. The NAIL ROOT is deep to the eponychium 3. The NAIL BODY contains layers of compacted, highly keratinized epithelial cells 4. The FREE EDGE OF THE NAIL is the part of the nail that can overhang the tip of the finger.

- The statrum BASALE is a single layer of columnar or high cuboidal cells resting on a basement membrane - The stratum SPINOSUM is composed of many layers of keratinocytes that are firmly attached to each other by desmosomes. This layer also contains dendritic cells - The stratum GRANULOSUM is composed of 3-5 layers of flattened keratinocytes containing dark staining keratohyalin granules - The stratum LUCIDUM is a translucent layer composed of 3-5 layers of keratinocytes without nuclei or organelles - The stratum CORNEUM is composed of up to 30 layers of cornified, dead cells

superficial to deep: - cuticle - cortex - medulla

dermis

- Undifferentiated cells that divide and give rise to keratinocytes: Stem cells - Epidermal cells that produce keratin: Keratinocytes - Cells that produce the dark pigments that act as a UV shield: Melanocytes - Sensory receptors for touch: Tactile cells - Immune cells that guard against pathogens that penetrate into the skin: Dendritic cells

1. Stratum corneum 2. Stratum lucidum 3. Stratum granulosum 4. Stratum spinosum 5. Stratum basale

- Stem cells divide, and new keratinocytes are produced: Stratum basale - Mitosis ceases. Keratinocytes are pushed upward as new cells are added below them: Stratum spinosum - Keratin filaments are bound together to form waterproof bundles. Keratinocytes die: Stratum granulosum - Dead keratinocytes exfoliate from the skin surface: Stratum corneum

- In darker skin, the melanocytes produce more melanin - In darker skin, the melanin granules are more tightly clumped - In darker skin, the melanin breaks down more slowly

The subcutaneous tissue is highly vascular

- Sweat: Sudoriferous glands - Oily secretions: Sebaceous glands - Earwax: Ceruminous glands - Milk: Mammary glands

- Only the epidermis is involved. There is redness, edema, and pain: First degree - The epidermis and part of the dermis is involved. There are usually blisters: Second degree - The epidermis, entire dermis, and often some deeper tissues are involved. This type of burn often requires a skin graft: Third degree