Unit 4-integumentary system - Dorchester School District Two

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INTEGUMENTARY SYSTEM

Unit 4 WARM-UP #1

Describe the 4 types of tissues found in your body.

OBJECTIVES:

Compare the general structures and functions of cutaneous, mucous, serous, and synovial membranes.

BODY MEMBRANES

Function:Cover body surfacesLine body cavitiesForm protective sheets around organs

Classified by tissue types

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CLASSIFICATION OF BODY MEMBRANES

Epithelial membranesCutaneous membranesMucous membranesSerous membranes

Connective tissue membranesSynovial membranes

CUTANEOUS MEMBRANE

Cutaneous membrane = skin Dry membrane

Outermost protective boundary

Epithelial (epidermis) on top of connective (dermis).

Superficial epidermis is composed of keratinized stratified squamous epithelium

Underlying dermis is mostly dense connective tissue

We will discuss this in much greater detail later in this unit.

MUCOUS MEMBRANES

Epithelial sheet on top of connective tissue.

Lines all body cavities that open to outside Include hollow organs of many systems

Functions: Absorption, secretion, lubrication, protection.

SEROUS MEMBRANES

Simple Squamous epithelium on top of areolar connective tissue

Lines body cavities that are closed to the exterior of the body

Serous membranes occur in pairs separated by serous fluid

Visceral layer covers the outside of the organ

Parietal layer lines a portion of the wall of ventral body cavity

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THINK OF A SEROUS MEMBRANE LIKE… SPECIFIC SEROUS MEMBRANES

Peritoneum Abdominal cavity

Pleura Around the lungs

Pericardium Around the heart

SYNOVIAL MEMBRANE

Connective tissue onlyNO epithelial tissue.Lines joint cavitiesSecretes a lubricating fluid (synovial fluid)

DO YOU UNDERSTAND?

1. List the two main categories of body membranes.

2. What kind of membrane is open to the exterior?

3. What type of membrane covers the exterior of the body?

4. What type of membrane do you find in the joint?

5. What membrane lines the inside of the lungs?

6. If synovial fluid were not present, what would happen to the joints in the body?

EpithelialConnective

Mucous

CutaneousSynovial

mucous

Stiff, hard to move, no lubrication for easy movement

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OBJECTIVES:

Identify structures and functions of the integumentary system and epidermal derivatives.

INTEGUMENTARY SYSTEM

INCLUDES:

1. Skin (cutaneous membrane)

2. Skin derivativesSweat glandsOil glandsHairNails

FUNCTIONS:

1. Protects deeper tissues from:a. Mechanical damage: bumps and cuts (keratin)b. Chemical damage: acids and bases (keratin)c. Bacterial damage (sweat and oil)d. Ultraviolet radiation: damaging effects of sunlight

(melanocytes)e. Thermal damage: heat or cold (capillaries and sweat)f. Desiccation: drying out (keratin and oil)

2. Aids in body heat loss or heat retention (Controlled by the nervous system)

3. Aids in excretion (sweating waste)4. Synthesizes Vitamin D

• Modified cholesterol molecules in skin are converted to vitamin D

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EPIDERMIS Avascular Keratinocytes (make keratin, waterproofing, and

barrier) 5 layers (strata)

1. Stratum corneum: outermost layer2. Stratum lucidum: layer is found only where the skin is hairless

and thick (on palms of hands or soles of feet)3. Stratum granulosum4. Stratum spinosum5. Stratum basale: deepest layer; only layer where the cells

receive nourishment; cells are constantly dividing, produces melanin

*Carry Loves Growing Sweet Basil (on hands and feet)*Carry Grows Sweet Basil (on rest of body)

Stratum corneum. Cells are dead;represented only by flat membranoussacs filled with keratin. Glycolipids inextracellular space.

Stratum granulosum. Cells areflattened, organelles are deteriorating;cytoplasm full of granules.

Stratum spinosum. Cells contain thickbundles of intermediate filamentsmade of pre-keratin.

Stratum basale. Cells are activelydividing cells; some newlyformed cells become part of the moresuperficial layers.

DermisSensorynerveending

Melanocytes

Figure 4.4

NORMAL SKIN COLOR DETERMINANTS

Controlled by three main pigments:1. Melanin

Yellow, brown, or black pigmentsProduced in the stratum basale by melanocytes. Protection from sunlight

2. CaroteneOrange-yellow pigment

3. HemoglobinRed coloring from blood cells (blushing)Oxygen content determines the extent of red coloring

ALTERATIONS IN SKIN COLOR

Redness (erythema)—due to embarrassment, inflammation, hypertension, fever, or allergy

Pallor (blanching)—due to emotional stress such as fear, anemia, low blood pressure, impaired blood flow to an area

Jaundice (yellowing)—liver disorder, excess bile pigments in blood

Bruises—hematomas

Cyanosis- skin appears blue (poorly oxygenated blood) Heart failure or respiratory problems

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DERMISUnder the epidermis

DENSE Fibers (connective tissue)Elastic (keep skin looking young, no wrinkles)Collagen (toughness)

Contains:Glands (Sweat and oil) Blood vesselsSensory receptors (touch, pain, temperature)Hair follicles

Figure 4.5

1. Papillary layer• Superior surface-dermal

papillae, contains capillaries (nutrients)

• Fingerprints• Friction and gripping

2. Reticular layer –fibers have irregular arrangement

• App. 80% of thickness of skin and contains: Blood vessels, Sweat and oil glands, receptors

DERMIS-TWO LAYERS HYPODERMIS

Subcutaneous tissue

Not technically part of the skin, but anchors skin to underlying organs or muscles (connective tissue) Mostly contains adipose tissue

Function: Insulation, shock absorption

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DO YOU UNDERSTAND?

1. Name a function of the skin.

2. What are the 5 layers of the epidermis?

3. Describe what causes variation in skin color.

4. The epidermis is avascular. Describe how those cells get nutrients in order to divide.

5. What layer of skin causes fingerprints?

Protect deeper tissues, aid in maintaining body temp, aid in excretion, synthesize vitamin D

(1) Stratum corneum (2) Stratum lucidum (3) Stratum granulosum (4) Stratum spinosum (5) Stratum basale

Amount of melanin produced by melanocytes.

Bottom layer (stratum basale) is next to blood flow, which is where the cells get enough nutrients to divide.

Dermis

ACTIVE CLOSURE

With your partner, organize the words in the Ziploc bag. Be ready to justify your reasoning.

WARM-UP # 2 OBJECTIVES:

Identify structures and functions of the integumentary system and epidermal derivatives.

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SKIN APPENDAGES

Glands

Hair

Muscle

Nails

GLANDS

Cutaneous glands are all exocrine glandsSebaceous glands (oil)- Typically activated at

puberty.oil glands usually associated with hair folliclessecret an oily substance called Sebum a mixture of fats, cholesterol, protein and inorganic salts

helps prevent desiccation of skin and hair inhibits growth of certain bacteria

GLANDS

Sudoriferous glands (sweat)1. Eccrine glands: produce sweat

A. Most numerous; found all over the body (as many as 3000 per square inch on palms)

B. Clear acidic fluid, mostly water with a little waste like uric acid and salts. C. Acidity inhibits growth of bacteria

2. Apocrine glands: located in the axillary and genital regionsA. Larger and activate at pubertyB. Associated with hairC. Fluid is milky and consist of sweat, fatty acids, and proteins.

Ceruminous glands- modified sweat gland located in the ear.

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HAIR (PILI)

primary function is protectionguards the scalp from injury and sunlighteyebrows - eyelashes protect the eyeears and nostrils keep out foreign objects

helps regulate body temperature

touch receptors associated with hair follicles

COMPONENTS OF HAIR

Shaft = portion of hair above the surface of the skin (visible)

Root = portion of hair below the skin Hair Follicle = cells that surround the root

Bulb = onion shaped structure at the base of each hair follicle papilla = indentation of bulb where blood vessels, nerves, etc. enter and exit

Matrix = area of cell division and hair growth

HAIR STRUCTURESHairshaft

Hair root

Hair bulbin follicle

(a)

Smooth muscle Attaches hair to the

dermis Moves hair when

contracted Pulls hairs upright

when cold or frightened Goose bumps

ARRECTOR PILI MUSCLE

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NAILS

scale-like modification of the epidermis

Mostly nonliving material

Transparent and colorless Look pink because of blood supply in underlying dermis

Exception: white crescent region at proximal end called lunula Nail Matrix

Mitosis

Responsible for nail growth

DO YOU UNDERSTAND?

1. Name 3 appendages of the skin.

2. Compare Eccrine and apocrine glands.

3. What are the anatomy terms for sweat glands and oil glands?

4. Where are ceruminous glands located?

5. What is a nail?

6. Describe the arrector pili muscles.

OBJECTIVES:

Summarize disorders of the skin and body membranes.

SKIN CANCER

Cancer—abnormal cell mass

Skin cancer is the most common type of cancer, mostly benign.

Most often caused by sun exposure.

3 types 1. Basel cell

2. Squamous cell

3. Malignant Melanoma

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BASAL CELL CARCINOMAS

Most skin cancers

tumors that arise from the basal layer

slow growing

Typically over 40 and fair skin

SQUAMOUS CELL CARCINOMAS

tumors that arise from the squamous cells

vary in the ability to metastasize

Starts from skin lesions

Most often seen in fair skinned men

MALIGNANT MELANOMAS

least common type of skin cancer (3%)

arise from melanocytes of the stratum basal

leading cause of skin cancer deaths

spreads through the lymph and blood

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DO YOU UNDERSTAND?

What are the 3 types of skin cancer?

Which one if the most common?

Which one is the most deadly?

How is possible skin cancer assessed?

ACTIVE CLOSURE

Describe skin cancer in a way that a third grader would understand. Be ready to share your ideas.

WARM-UP #3

In the summer months, exposure to extreme temperatures can be life threatening, but specialized glands close to the surface of the skin help to keep the body cool. What are these specialized glands and how do they help to regulate body temperature?

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ACTIVE CLOSURE

Write down what questions that you still have about skin homeostatic imbalances.

WARM-UP #4

Describe 3 skin appendages and their functions.

Then take a few minutes to look over your unit 4 stems.

TEST DAY!

Make sure that your notebook packet is in the correct order and stapled together. IS YOUR NAME ON IT? DID YOU FILL OUT THE TABLE OF CONTENTS?

You may have 10 minutes to look over your packet.

After the 10 minutes, then place your notebook on the front demo table and pick up a zip grade sheet.

Phones and electronic devices are off and placed in book bags.

Bags are at the front of the room. DO NOT BLOCK WALKWAY!