The Integumentary System (Skin)

Human Body Systems
Links
The Incredible Human Machine Video      Skin Interactive   Skin - Know more! 
Integumentary System Jeopardy

The Integumentary System is the organ system that protects the body from damage, comprising the skin and its appendages (including hair, scales, feathers, hoofs, and nails).

Skin is 15% of your total body weight.

Functions

1. Protection
2. Sensory Response (nerve cells relay information to the brain)
3. Formation of Vitamin D (produced with ultraviolet light in epidermis)
4. Regulates body temperature (blood vessels in the skin can hold or release heat, sweat glands remove heat cooling the skin)
5. Gets rid of waste (sweat glands release water, salt, and other waste products)

Skin is the largest organ in the human body
   Layers

• Epidermis - outermost layer of the skin composed of squamous cells. This layer is characterized into two distinct types: thick skin and thin skin.
• Dermis - thickest layer of skin that lies beneath and supports the epidermis.
• Hypodermis (Subcutis) - innermost layer of the skin that helps to insulate the body and cushion internal organs.

The major cell of the epidermis is the keratinocyte, which produces keratin. Keratin is a fibrous protein that aids in protection. Keratin is also a water-proofing protein. Millions of dead keratinocytes rub off daily. The majority of the skin on the body is keratinized, meaning waterproofed. The only skin on the body that is non-keratinized is the lining of skin on the inside of the mouth.

The color of human skin depends on the amount of pigment melanin that the body produces. Small amounts of melanin result in light skin while large amounts result in dark skin.

Hair

¡Made from epidermis

¡Hair à mostly dead, keratin-filled cells

¡Each hair grows for several years

¡Hair color based on amount of melanin

§Blonde, red hair has less than brown, black

Nails

¡Made by specialized epidermal cells located in light, semicircular area at base of nail

¡Become filled with keratin as they get pushed forward

¡Continue to grow throughout life

Fun Facts about Skin

¡ A large amount of the dust in you home is actually dead skin

¡ Although polar bears have both white and transparent (see through) fur, their skin is actually black.

¡ Amphibians such as frogs have unique skin. Rather than drinking water, frogs actually soak it into their body through their skin. They also use their skin to absorb around half the air they need.

Summary

The Homunculus Man (How your brain represents skin)The most sensory rich areas of the body are the
hands, feet, and facial structures.

This is how the your body sensory mechanism is represented in the brain

 

Lesson Review 

1.      What are the 5 functions of the integumentary system? Answer in complete sentences

2.      What is the outer layer of the skin?

     a. Dermis

     b. Collagen

     c. Subcutaneous

     d. Epidermis

3.   Which of the following is NOT a part of the integumentary system?

     a. skin

     b. hair

     c. cartilage

     d. nails

4. What does the color of human skin depend on?

     a. genetics

     b. melanin

     c. sun exposure

     d. all of the above

5. How does sweat maintain homeostasis within the human body? Answer in 2 complete sentences

6. What is the majority of dust in your house made from? Answer in 1 complete sentence

Organization of Living Things

What does 'Organization of Living Things' mean?

We know it all starts with the cell. And for some species it ends with the cell. But for others, the cells come together to form tissues, tissues form organs, organs form organ systems, and organ systems combine to form an organism.

Levels of Organization

The living world can be organized into different levels. For example, many individual organisms can be organized into the following levels:

• Cell: Basic unit of structure and function of all living things.
• Tissue: Group of cells of the same kind. 
• Organ: Structure composed of one or more types of tissues. The tissues of an organ work together to perfume a specific function. Human organs include the brain, stomach, kidney, and liver. Plant organs include roots, stems, and leaves. 
• Organ system: Group of organs that work together to perform a certain function. Examples of organ systems in a human include the skeletal, nervous, and reproductive systems.
• Organism: Individual living thing that may be made up of one or more organ systems.
• 
                                                    Cells make up tissue
  Tissues makes up organs
  Organs make Organ Systems
  Organs Systems make
  Organisms
  

Types of TissueThere are four main types of tissue: muscle, epithelial, connective and nervous. 

Each is made of specialized cells that are grouped together according to structure and function. Muscle is found throughout the body and even includes organs such as the heart.

There are 3 types of Muscle Tissue

Lesson Review

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• 1. 
  The smallest living this is
  • A. 
    A cell
  • B. 
    A tissue
  • C. 
    An organ
  • D. 
    An organ system
  • E. 
    An organism
• 2. 
  Anything living is also called
  • A. 
    A tissue
  • B. 
    An organism
  • C. 
    An organ
  • D. 
    An organ system
  • E. 
    A cell
• 3. 
  A group of cells working together is
  • A. 
    An organism
  • B. 
    An organ system
  • C. 
    An organ
  • D. 
    A tissue
  • E. 
    A cell
• 4. 
  A group of tissues working together is
  • A. 
    A tissue
  • B. 
    A cell
  • C. 
    An organ
  • D. 
    An organ system
  • E. 
    An organism
• 5. 
  A group of organs working together is
  • A. 
    An organ system
  • B. 
    An organism
  • C. 
    An organ
  • D. 
    A cell
  • E. 
    A tissue

    
    

    6. Which of the following is NOT one of the four main types of tissues?

       a. basement
       b. epithelial
       c. connective
       d. muscle

    7. Which type of tissue is designed to stretch?
       a. stratified
       b. squamous
       c. transitional
       d. epthelial

    8. Tissues are groups of similar cells working together to:
       a. increase the size and mass of structures in the body
       b. perform common functions
       c. fight against diseases
       d. deliver messages

    9. Smooth muscle is found mainly in:
       a. the heart
       b. the stomach
       c. the brain
       d. the skeletal system

10. What does the X represent?