Tissues!

Body Organization Cell – Tissue – Organ – Organ System - Body Tissues: Many similar cells that perform a specific function Tissue Types 1. Connective – Blood, Bone, Cartilage, Ligaments, & Tendons 2. Nervous – Tissue that transmits and receives messages or impulses (brain, spinal cord) 3. Epithelial – Skin 4. Muscle

Ligaments – join bones to other bones Skeletal System The skeletal system consists of 206 bones. At birth humans have 270 bones but many bones fuse together during growth. Ligaments – join bones to other bones Cartilage - soft portion on the tips of all bones and in the nose and ears (doesn’t contain calcium)  Skeletal System Functions 1. support 2. protection 3. produces blood cells

Spongy bone – the soft inner portion of the bone Bones have two parts: Spongy bone – the soft inner portion of the bone - yellow marrow that stores fat - red marrow where red & white blood cells are manufactured Compact Bone – the hard outer portion of the bone - contains Haversian canals which contain blood vessels Why would there need to be blood vessels in bones? Osteocytes (bone cells) – need oxygen and food for energy

Development of Bones In the second month of development bone starts to form where before the embryo had only a cartilage skeleton Ossification – is the process of cartilage turning into bone Epiphyseal plate is a layer of cartilage found at the end of each bone where growth takes place. Cells in this area undergo mitosis Divisions of these cells cause the cartilage to grow and the bones to lengthen as the bone cells ossify  Growth stops when these cells stop dividing Bones continue to grow in width throughout life growth in length stops at 25 if not sooner.

Four major types of joints: The place where bones meet is a joint Joints can be movable and immovable Where are immovable joints? Four major types of joints: 1. Hinge – elbow, knee, and ankle 2. Pivot – neck 3. Ball-and-socket – hip and shoulder 4. Gliding – carpal and tarsal bones Cartilage and synovial fluid (the WD-40 of your body) keep joints moving smoothly

Skeletal System problems Sprain – A stretch or tear of a ligament Arthritis – when joints become swollen or painful Rheumatoid arthritis – cartilage becomes swollen. Eventually it is replaced by bone, which fuses and prevents movement

Osteoarthritis – when cartilage wears away and bones rub together

Osteoporosis – a person loses bone density (usually begins around 40) More common in women because they lose their ability to absorb Calcium efficiently when they have children THANK YOU MOM!!

The body has more than 600 muscles (35-45% of body weight) The Muscle System The body has more than 600 muscles (35-45% of body weight)   Functions of Muscle System 1. Movement – main function 2. Digestion, Breathing, Heart Beating etc 3. Protection of internal organs 4. Sitting & Standing

Muscles only pull a bone Muscles CANNOT push a bone   Muscles only pull a bone Muscles CANNOT push a bone This is why muscles act in pairs One muscle to extend One muscle to bend

3. Cardiac Muscle – heart muscle   Muscle Types 1. Skeletal Muscles – move bones attached directly to bones or by a tendon   2. Smooth Muscle – found in internal organs (digestive tract, arteries, respiratory system) 3. Cardiac Muscle – heart muscle Smooth and Cardiac are both involuntary What does involuntary mean?

How Muscles Contract: 1. A nerve impulse transmitted to the muscle cell by a nerve. 2. The nerve releases Calcium into the cytoplasm of the muscle cell 3. Calcium attaches to molecules located in the cytoplasm called actin (protein) 4. ATP connects to myosin (protein) What does ATP do? 5. Using the energy from the ATP the myosin (protein) pulls the actin & the muscle contracts 6. When the message from the brain ends the Calcium leaves and the muscle relaxes

Exercise With aerobic exercise, chest muscles can be strengthened so that more air enters the body. This type of exercise helps your cardiovascular endurance. Why would this help? Resistance (anaerobic) exercise like weight lifting increases muscle size and strength but it does not increase the amount of oxygen that enters the body.  Anabolic steroids increase the size and strength of your muscles, synthetic chemicals (that resemble testosterone) trick your muscles into growing larger. They also cause many irreversible side effects including cancer, heart disease, and altered sexual development.

Muscle Problems   Shin Splints – inflammation of the tendons on the inside front of the lower leg, muscle strain , overuse injury  Muscle Cramps – occurs when a muscle cannot relax   Muscular Dystrophy – muscle tissue degenerates and is replaced by fatty tissue

The Skin is the human body's largest organ Integumentary System Covers the body Made up of the skin, hair, nails, & a variety of glands The Skin is the human body's largest organ The most important function is protection.

Controls the body through hormones Endocrine System Controls the body through hormones Example The hormone melatonin, which secreted by a gland in the brain called the pineal gland, is secreted at night when light is absent or dim. Melatonin is what makes us feel tired