INTRODUCTION TO BODY STRUCTURE

BELL RINGER ACTIVITY: WHAT DO YOU THINK CAUSES A BLACK EYE. THEN READ THE REAL LIFE FEATURE IN THIS SECTION

AND COMPARE YOUR ANSWER TO THE ONE GIVEN THERE.

I. Levels of Structural Organization

A. Our Bodies are organized into 4 levels:Cells Tissues Organs Organ Systems

Tissues are a groups of cells that work

together to perform a particular function.

B. 4 Basic kinds of tissue:• 1. Epithelial

• 2. Nervous

• 3. Connective

• 4. Muscle

Epithelial• Lines most body surfaces

• Protects from dehydration

and physical damage

• Only a few cells thick

• Shape: Flat and Thin

• They are constantly being replaced.

• Cells contain very little cytoplasm.

Nervous• Carry information throughout the body.

Connective• Supports, protects and insulates the

body.

• Includes fat, cartilage, bone, tendons and blood.

• Cells in bone are densely packed while cells in blood are farther apart from each other.

Muscle Tissue• Enable the Movement of body structures by

Muscle Contraction• 3 kinds of muscle tissue: Skeletal,smooth and

cardiac

1. Skeletal Muscle is called VOLUNTARY muscle because you can Consciously control its contractions. This muscle moves BONES and LIMBS.

3 kinds of muscle tissue: Skeletal,smooth and cardiac con’t2. Smooth muscle is called

INVOLUNTARY muscle because you CANNOT CONSCIOUSLY control its slow, long lasting contractions. Some must be STIMULATED to CONTRACT, others CONTRACT spontaneously.

3 kinds of muscle tissue: Skeletal,smooth and cardiac con’t

• 3. Cardiac muscle is found in the HEART. The contractions of cardiac muscle pump BLOOD to all body tissues.

STEM CELLS

• ARE UNDIFFERENTIATED WHICH MEANS THAT THEY WILL GIVE RISE TO ALL OF THE OTHER TYPES OF CELLS. An embryonic stem cell can become ANY TYPE OF TISSUE IN THE BODY. The use of human embryonic stem cells is CONTROVERSIAL. WHY?

Organ Systems• Each system is made up of ORGANS that work

together to perform certain functions.• Look at your Body systems chart • Which system is made up of skin, hair and

nails?

Integumentary• What is the function of this system? protects against injury, infection and fluid

loss;helps regulate body temp• The pancreas is part of which 2 systems?

Digestive and endocrine

Body CavitiesThe major organs of the Body are protected by

4 large fluid-filled spaces called BODY CAVITIES.

What are the 4 body cavities?

CRANIAL,SPINAL,THORACIC,ABDOMINAL

• Cranial cavity protects THE BRAIN WITH SKULL

• Spinal cavity protects THE SPINAL CORD WITH THE VERTEBRAE

• Thoracic cavity protects THE HEART AND LUNGS WITH THE RIBS AND STERNUM

• Abdominal cavity protects THE DIGESTIVE ORGANS WITH THE PELVIS AND ABDOMINAL MUSCLES.

ENDOTHERMY• Humans are ENDOTHERMIC which means

that our bodies maintain a constant internal TEMPERATURE.

• A large amount of food you eat is devoted to MAINTAINING YOUR BODY TEMPERATURE.

• To maintain HOMEOSTASIS, the body’s organ systems must function smoothly TOGETHER.

• What does homeostasis mean?? Look it up if you don’t remember!!!!

• HOMEOSTASIS INCLUDES BODY TEMP REGULATION, ADJUSTING METABOLISM, DETECTING AND RESPONDING TO ENVIRONMENTAL STIMULI, AND MAINTAINING WATER AND MINERAL BALANCES

• Try to perform a few simple tasks without bending your fingers, such as picking up your pencil, turning a page, puttin on your jacket, tying your shoe.

• How important are joints?

Skeletal system

• The functions of the

skeleton include:

1. PROTECTION FOR INTERNAL ORGANS

2. ENABLES MOVEMENT (WORKS WITH MUSCULAR SYSTEM)

• The human skeleton is made up of 206 bones.

(80 form the AXIAL skeleton and 126 form the APPENDICULAR skeleton)

• The skull,spine, ribs and sternum are part of the AXIAL skeleton and the bones of the arms,legs, pelvis and shoulder are part of the APPENDICULAR

skullclaviclescapula

sternum

femurpatella

carpels

metacarpels

tarsels

metatarsels

radiusulna

vertebratehumerus

tibiafibula

Pelvic girdle

phalanges

phalanges

Structure of the Bone

Some cavities in spongy bone are filled with a soft tissue called BONE MARROW.

• Red Marrow- PRODUCTION OF ALL BLOOD CELLS AND PLATELETS

• Yellow Marrow- CONSISTS OF FAT WHICH STORES ENERGY

• Periosteum- TOUGH EXTERIOR THAT SURROUND AND PROTECTS BONES.

The periosteum contains many BLOOD VESSELS that supply NUTRIENTS to bones.

• In Early development, the skeleton is mostly made of CARTILAGE. During development, cartilage is replaced with BONE.

OSTEOPOROSIS• Is caused by severe BONE LOSS.

Osteoporosis means “POROUS BONES”. Bones affected by osteoporosis become brittle and are easily broken.

• How to prevent it?EAT A HEALTHY DIET RICH IN VITAMINS AND MINERALS AND EXERCISE.

Notes Ch 37 (con’t) Muscular System

Muscles and Movement Every time you MOVE you use your

MUSCLES.Movement of the Skeleton• Muscles can move body parts because they are

attached to the BONES OF THE SKELTON by TENDONS.

• One attachment of the muscle that remains stationary during a muscle contraction is the ORIGIN. The muscle pulls AGAINST the origin.

• The INSERTION is the bone that MOVES during the contraction.

• Movement occurs when A MUSCLE CONTRACTION PULLS THE MUSCLE’S INSERTION TOWARD ITS ORIGIN.

• Skeletal muscles are generally attached in opposing PAIRS. One muscle in a pair pulls a bone in one DIRECTION and the other muscle pulls the bone in the OPPOSITE DIRECTION.

• In the limbs (arms,legs, etc. ) each opposing pair of muscles includes a FLEXOR muscle and an EXTENSOR muscle.

• Answer the questions below:

MUSCLE CELLS• ARE ELASTIC

• CONTAIN ACTIN AND MYOSIN WHICH ENABLE MUSCLE TO CONTRACT

• HAVE THE ABILITY TO STRETCH OR EXPAND

• HAVE THE ABILITY TO RESPOND TO STIMULI (SUCH AS SIGNAL MOLECULES RELEASED BY NERVE CELLS)

• Muscle cells require a lot of ENERGY. The energy molecule that is used is ATP. ATP is also used to move CALCIUM ions into muscle cells. Without CALCIUM IONS and ATP, muscle cells could not contract.

Aerobic and Anaerobic Energy Pathways

• (aerobic= with oxygen; anaerobic= without oxygen) During strenuous workouts muscles can use only GLYCOGEN as an energy source. When ATP use EXCEEDS production, muscle fatigue and soreness may result.

HAVE YOU EVER BEEN TOLD

THAT YOUR EPIDERMIS IS

SHOWING?

WELL IT IS!!!!!!!!!!

INTEGUMENTARY SYSTEM-SKIN,HAIR AND NAILS

SKIN

• Largest organ of the body

• Protects the body from injury

• Provides the first line of defense against disease

• Helps regulate body temperature

• Prevents the body from drying out

The 2 primary layers of skin are the DERMIS and EPIDERMIS.

• EPIDERMISThe OUTERMOST layer of skin are the DERMIS and EPIDERMIS. It is made up of several layers of EPITHELIAL cells. The outside layer of cells are dead and are made up of the protein KERATIN. This protein makes the skin TOUGH and WATERPROOF.

Cells of the epidermis are shed about a MONTH after they reach the surface. The inner layer of the epidermis contains the pigment MELANIN which determines a person’s SKIN COLOR. Exposure to UV radiation INCREASES the production of melanin, giving some people a SUNTAN.

Dermis• The dermis is the

FUNCTIONAL layer of skin beneath the epidermis.

• The dermis contains:

NERVE CELLS, BLOOD VESSELS, HAIR FOLLICLES, AND SPECIALIZED SKIN CELLS and tiny MUSCLES. These tiny muscles cause you to get GOOSE BUMPS.

Hair follicle

Sebaceuos

gland

muscle

epidermis

Subcutaneous Tissue• It is located under the DERMIS and is

made mostly of FAT.

This layer acts as a

• SHOCK ABSORBER

• PROVIDES ADDITIONAL INSULATION

• STORES ENERGY

• ANCHORS SKIN TO ORGANS

Hair and Nails

• They come from the EPIDERMIS.

• Hair PROTECTS and INSULATES the body. Hair is mostly made from dead KERATIN-FILLED cells.

Nerve

epidermis

Dermis

muscle

Hair shaft

pore

Oil gland

Hairfollicle

Blood vessel

Sweat gland

Skin DisordersACNE• Involves the Skin’s OIL PRODUCING

GLANDS

• Oil glands release SEBUM. Acne is caused by excessive secretion of sebum which BLOCKS PORES WITH OIL, DIRT AND BACTERIA.The surrounding tissue becomes infected and the pores accumulate pus, producing PIMPLES

Skin Cancer• Can result form overexposure to UV

RADIATION.

• CARCINOMAS are the most common types of skin cancer.

• Malignant melanoma is a cancer caused by MUTATIONS in pigment-producing cells.

• Prevention of skin cancer includes: AVOID OVER-EXPOSURE TO SUN &WEAR SUNSCREEN