McKenzie Health Science 20 NAME:_________________

Lesson 3.1 and 3.2 Body Membranes & the Integumentary System

Objectives:1. Identify the different types of body membranes and explain their functions.2. Explain the purposes of serous fluid and synovial fluid.3. Explain how the skin continually regenerates.4. Describe the processes by which the skin helps to regulate body temperature.5. Explain the different protective functions of the skin.6. Identify the different glands and sensory receptors present in skin and describe their functions.

Saskatchewan Outcome:“I can analyze the anatomy and physiology of a healthy human”

Saskatchewan Indicators:“I can describe the anatomy (structure) and physiology (function) of the integumentary systems”

Before this lesson, try to answer the following questions:

1. Do membranes secret some type of fluid?

ANSWER:____________________________________________________________________

2. What is the common name for the integumentary system? ANSWER:____________________________________________________________________

3. What causes the difference in skin colour, and what causes tanning?

ANSWER:____________________________________________________________________

4. What causes people to have straight, wavy or curly hair?

ANSWER:____________________________________________________________________

Key Terms: Cutaneous membrane Epithelial membranes Membranes Mucous membranes Pericardium Peritoneum Pleura Serous fluid Serous membranes Synovial fluid Synovial membrane Dermis Epidermal dendritic cells Epidermis Hypodermis Integumentary system Keratin Keratinocytes Melanin Melanocytes Merkel cells Papillary layer Reticular layer Sebaceous glands Sebum Stratum basale Stratum corneum Stratum granulosum Stratum lucidum Stratum spinosum Sudoriferous glands

References: Notes & handouts, Textbook Pages: 82 – 91, Study Guide Pages: 25 – 27

McKenzie Health Science 20 NAME:_________________

Lesson 3.1 Body Membranes

Body membranes surround and help protect the body’s surfaces Cavities that open to the outside world Internal cavities Capsules

Body Membrane Types

1. Epithelial Membranes Provide a lining or covering for the internal and external surfaces of the body Include a sheet of epithelial cells and an underlying layer of connective tissue.

a. Mucous Membranes Line the body cavities that open to the outside world Examples: mouth, nose, lungs, digestive tract, bladder are lined with mucous membranes Layer of epithelium on top of loose connective tissue (lamina propria) Moist, often secrete mucus to protect membranes and aid in transporting substances

b. Serous Membranes Line the body cavities that are closed to the outside world Examples: pleura encloses the lungs and peritoneum lines abdominal cavity Layer of simple squamous (flattened) epithelium on a thin layer of loose connective tissue Outer lining = parietal layer, inner lining = visceral layer Secrete serous fluid (thin, clear) to lubricate between the layers and reduce friction

McKenzie Health Science 20 NAME:_________________

c. Cutaneous Membranes SKIN! Keratinizing, stratified (layered) squamous epithelium over dense, fibrous connective tissue Contains sweat glands, but dry when not sweating

2. Connective Tissue Membranes Synovial membrane = only membrane composed only of connective tissue Line the capsules that surround synovial joints Line tendon sheaths Bursae = small connective tissue sacs that cushion tendons and ligaments that surround joints Secrete synovial fluid to provide cushioning and reduce friction and wear on moving structures

McKenzie Health Science 20 NAME:_________________

Lesson 3.2: The Integumentary System (SKIN)Integumentary = Latin word “integumentum”, meaning “covering”

Function1. Protection

a. Tough keratin protects against mechanical and chemical damageb. Melanocytes produce melanin to protect against UV ray damage tanc. Acidic sweat protects against bacterial infection

2. Water barriera. Keratin and oils reduce water loss through evaporation and form a barrier against water

infusion3. Temperature Regulation

a. Capillaries dilate to dissipate heat and constrict to conserve heatb. Sweat evaporation provides a cooling effect

4. Vitamin D productiona. Sunlight converts modified cholesterol molecules to vitamin D

5. Waste eliminationa. Urea and uric acids are eliminated in sweat

6. Sensory receptiona. Receptor cells transmit nerve signals to the brain with information on the environment

Anatomy Two layers – epidermis (outer) and dermis (underlying) Hypodermis (fat storage repository) is underneath dermis = not part of skin Interesting fact: a blister is produces when a burn or friction causes the epidermis and dermis to

separate forms a fluid filled pocket

McKenzie Health Science 20 NAME:_________________

Epidermis

Outer layer Five layers of tissue No blood supply, stratum basale (innermost layer) absorbs nutrients from dermis Stratum basale constantly produces new skin cells. As cells develop, they are pushed toward the

surface and away from nutrients. The stratum corneum (outermost layer) consists of dead cells and is constantly shedding

Epidermis cells are keratinocytes = produce keratin Stratum basale contains melanocytes produce Melanin (pigment = skin tone) Sunlight causes melanocytes to produce more melanin

o these cells are eventually pushed out to the surface – tan) Albinism: inability to produce melanin Epidermal dendritic cells = respond to presence of foreign bacteria or viruses

o Initiate immune system response Merkel cells = touch receptors

o Relay information about touch to the brain

Epidermis:

McKenzie Health Science 20 NAME:_________________

Dermis “True Skin”

Dense, fibrous connective tissue containing collagen and elastic fibers Collagen fibers

o provide toughnesso bind with water molecules to keep inner skin moisto Collagen injections => provide more youthful appearance, but also toughen the skin

Elastin fiberso Provide youthful appearanceo Prevents wrinkles and sagging of skin

As we age, the number of collagen and elastin fibers decrease wrinkles and sagging Blood supply: dilate and constrict to dissipate or retain body heat Sensory receptors for touch, vibration, pain and temperature send nerve signals to brain Phagocytes (WBC) present ingest foreign material, including bacteria and dead cells Outer layer = papillary layer

o provides nutrients to epidermiso receives sensory information

Inner layer = reticular layero Contains collagen and elastin fiberso Contains blood and lymphatic (immune) vessels, sweat glands, oil glands, involuntary

muscles, hair follicles and nerve endings

Dermis:

Hypodermis Includes fibrous connective tissue and adipose (fatty) tissue Contains lipocytes (fat) cells

o Paddingo Insulation against heat losso Source of energy

Hypodermis:

McKenzie Health Science 20 NAME:_________________

Appendages of the Skin

1. Sudoriferous (sweat) Glands (shouldn’t that be Odoriferous?!?)

o Eccrine glands = major sweat glands Cover most of the body and open directly to the skin Sweat

clear, acidic fluid, 99% water, waste (urea, uric acid, salts, vitamin C)

o Apocrine glands = begin to function at puberty located in the genital and armpit area larger than eccrine glands secrete milky fluid into hair glands

sweat fatty acids protein

Sweat

2. Sebaceous Glandso Everywhere except palms and soleso Secrete sebum into a hair follicle

Sebum keeps skin and hair soft Sebum contains bacteria killing chemicals Very active during puberty = oily teenager skin

Sebum

3. Hairo Hair follicle is bulb shapes structures within the dermis that produce hairo As hair cells are produced they’re pushed up toward the scalp filled with keratin dieo Hair = nonliving material composed mainly of proteino Melanocytes within the hair follicle produce pigment (gene-determined) = hair colour

As you age, melanocytes produce less pigment = gray hairo Shape of follicle (gene-determined) = hair type

Round = straight hair, Oval = curly or wavy, Flat = curlyo “goose bumps” = tiny muscles that contract when stimulated pulls hair upright

Hair

4. Nailso Nail bed – underneath stratum basale (epidermis) Produces nailso Growth like hair as nail cells are produced they’re pushes out, become keratinized and die

Nails

McKenzie Health Science 20 NAME:_________________

McKenzie Health Science 20 NAME:_________________

Complete the Lesson1. In the Lab, #9, p. 842. In the Lab, #11, p. 913. Examine your skin cells under the microscope. Draw what you see below

Magnification: _______ X

Additional work (homework)1. Complete p. 33, 35, 37, 38 from the study guide (handout)2. Read p. 82 – 91 in your textbook3. Complete the “Check Your Understanding” Questions, p. 84, 86, 894. Correct your “Before this lesson” answers5. Complete #1 – 6, p. 84, Complete #1 – 7, p. 91