Chapter 5 The Integumentary System HS Anatomy, Physiology and Chemistry

Functions of Skin Protects from injuries

Functions of Skin Protects from injuries Acts as barrier and regulates what enters/leaves body.

Functions of Skin Protects from injuries Acts as barrier and regulates what enters/leaves body. Regulates body temperature.

Functions of Skin Protects from injuries Acts as barrier and regulates what enters/leaves body. Regulates body temperature. Synthesizes and stores vitamins.

Functions of Skin Protects from injuries Acts as barrier and regulates what enters/leaves body. Regulates body temperature. Synthesizes and stores vitamins. Sensory functions

Chapter 6 The Skeletal System HS Anatomy, Physiology and Chemistry

Bone Formation and Growth The process of bone formation  Most of the skeleton of the fetus begins cartilage.  Gradually the cartilage is replaced by calcified bone matrix (endochondral ossification)  A few flat bones form by intramembranous ossification  A newborn’s skeleton has many bones that have not completely ossified.

Longitudinal Section of a Long Bone Structure of Long Bones

Bone Formation and Growth The process of bone growth  In long bones  Starts in the diaphysis (shaft)  Then, the center of the (epiphysises) bone ends Epiphyseal plate Epiphyseal line The process of “remodeling”  Osteoblasts form new bone  Osteoclasts resorb bone

Microscopic Structure of Bone

Chapter 7 The Muscular System HS Anatomy, Physiology and Chemistry

Effects of Exercise Regular, properly practiced exercise improves muscle tone and posture Results in more efficient heart and lung functioning Reduces fatigue Helps muscle tissue develop Helps maintain a healthy weight

Effects of Exercise Effects of exercise on skeletal muscles  Prolonged inactivity causes disuse, or atrophy  Regular exercise increases muscle size, called hypertrophy

Effects of Exercise Strength training: Exercise involving contractions of muscles against heavy resistance  Increases number of myofilaments in each muscle fiber  Total mass of the muscle increases  Does not increase the number of muscle fibers

Effects of Exercise Endurance training: Exercise that increases a muscle’s ability to sustain moderate exercise over long periods  Sometimes called aerobic training  Allows more efficient delivery of oxygen and nutrients to a muscle via increased blood flow  Increases the number of blood vessels in a muscle  Does not usually result in muscle hypertrophy

Question Why do breathing and heart rate remain elevated after exercise stops?

Answer Stored ATP is quickly depleted, and if oxygen supplies are not sufficient, muscle cells switch to energy conversion that does not require oxygen. However, this energy conversion produces lactic acid. The “oxygen debt” is paid when labored breathing and an increased heart rate are required to remove lactic acid and replace depleted energy reserves, even after exercise has ended.

Question Why would a “physically fit” person return to normal breathing and heart rate levels more quickly than an unfit person?

Answer Increased efficiency of the respiratory and circulatory systems An increase in the number of blood vessels in muscles More efficient delivery of oxygen and glucose to muscle fibers More oxygen is available = the less “oxygen debt” there will be in the muscles.