??? What causes a black eye? How many bones are in the human body? Blood vessels burst causing blood to pool in that area. How many bones are in the human body? 206 What is the human body’s largest organ? Skin

Introduction to Body Structure Chapter 37 Introduction to Body Structure

Section 37.1 Body Organization

4 Levels of Structural Organization Organ Systems Organs Tissues Cells Tissue Group of similar cells that perform a common function Building blocks of the human body

4 Kinds of Tissues 1. Epithelial 2. Nervous 3. Connective 4. Muscle Lines most body surfaces Protects other tissues from dehydration and physical damage 2. Nervous Consists of nerve cells and supporting cells Carries info. throughout the body 3. Connective Supports, protects and insulates Includes fat, cartilage, bone, tendons and blood 4. Muscle Enables movement of body structures

3 Types of Muscle Tissue 1. Skeletal 2. Smooth 3. Cardiac Voluntary Moves bones in the trunk and limbs 2. Smooth Involuntary Line the walls of blood vessels and some organs 3. Cardiac Found in the heart Pump blood throughout the body

Stem Cells Give rise to all types of cells Can form any type of body tissue Can divide indefinitely in embryos Can possibly repair damaged tissues Produce blood cells in bone marrow Adult stem cells only divide ~100 times

Organ Systems A group of organs that work together to carry out a major activities or processes Table 1 p. 848 Circulatory Digestive Endocrine Excretory Immune Integumentary Muscular Nervous Reproductive Respiratory Skeletal

Body Cavities Fluid-filled spaces that house and protect major internal organs 5 Types 1. Cranial Brain 2. Spinal Spinal cord 3. Thoracic Heart and lungs 4. Abdominal Digestive organs 5. Pelvic Reproductive organs

Endothermy Organisms that maintain a constant internal temperature Critical to homeostasis Negative feedback system Output of a system acts to oppose changes to the input of a system

Answer the Following ?’s List the 4 levels of structural organization within the body. Describe the 4 types of body tissues. List the body’s major organ systems and describe their function. Describe how endothermy helps maintain homeostasis.

??? What part of your skeletal system do you think is the most important? Why?

Section 37.2 Skeletal System

The Skeleton Allows us to stand and perform everyday activities (along with our muscles) Axial Skeleton Bones of the skull, spine, ribs and sternum 80 Appendicular Skeleton Bones of the arms, legs, pelvis and shoulder 126

Axial Skeleton 29 bones in the skull 26 vertebrae 12 pairs of ribs 8 form the cranium 14 are facial bones 6 middle ear bones 1 supports your tongue 26 vertebrae 12 pairs of ribs 1 sternum

Appendicular Skeleton Forms limbs (arms & legs) Shoulders Arms Hips Legs Shoulder blades Collar bones Pelvic bones

Structure of Bone Compact bone Spongy bone Bone Marrow Periosteum Dense tissue, provides support Spongy bone Loose structure of connective tissue Bone Marrow Soft tissue inside the bone Red Production of blood cells Yellow Consists of fat Periosteum Hard, outer layer

Growth of Bones Haversian Canals Osteocytes Hallow channels in compact bone where new bone cells are added in layers Osteocytes Maintain the mineral content of bone Blood vessels that run through haversian canals provide nutrients to osteocytes

Osteoporosis Occurs when bone tissue is lost, and becomes less dense Porous bone

Joints Where 2 bones meet Cartilage cushions joints Held together by ligaments Prevent bones from moving too far in one direction

3 Main Types of Joints Immovable Slightly Movable Freely Movable Little or no movement Cranial bones Slightly Movable Limited movement Vertebrae Freely Movable Movement allowed Knee

Movable Joints Ball-and-socket Pivot Hinge Gliding Saddle Shoulders and hips Pivot Rotation Turning of head Hinge Bending and straightening Elbows, knuckles, knees Gliding Sliding Wrists and ankles Saddle Rotation, bending and straightening Base of thumbs

Disorders of Joints Rheumatoid arthritis Osteoarthritis Inflammation of freely movable joints Cells of immune system attack tissues around joints Osteoarthritis Degeneration of cartilage Bones rub together

Section 37.3 Muscular System

Muscles and Movement Everyday activities require muscles. Walking Running Brushing your teeth Eating Writing notes

Movement of the Skeleton Tendons Connect muscles to bones Origin Bone that stays stationary during muscle contraction Insertion Bone that moves when muscle contracts

Movement of the Skeleton Flexor Muscle that causes a joint to bend Extensor Muscle that causes a joint to straighten

Muscle Structure Actin and Myosin Myofibrils Sarcomere Protein filaments of connective tissue that holds muscle cells together and provide elasticity. Myofibrils Muscle fibers that have a cylindrical structure Sarcomere Area between the Z lines of myofibrils Myofibrils and sacromeres are made up of actin and myosin

Muscle Contraction Step 1 Step 2 Step 3 Sarcomere is relaxed, myosin and actin partially overlap each other Step 2 Nerve cells povide signal Actin and myosin overlap more Sarcomere becomes shorter Step 3 Sarcomere is fully contracted Actin and myosin fully overlap each other

Aerobic and Anaerobic Energy Pathways Aerobic respiration requires ATP to power muscle contractions Glycolysis (an anaerobic process) supplies ATP during intense activity When aerobic and anaerobic pathways cant keep up we use glycogen and fat as energy sources

Exercise and Fitness Why does exercise become easier after prolonged training? More oxygen supplied to muscles More ATP available for contractions Reduces muscle fatigue Why is stretching necessary? Over-stretched muscles can tear How do muscles increase in size? Muscle break apart and repairing makes them bigger

Section 37.3 Questions Describe the action of muscles moving in pairs in the body. Describe the different parts of the muscle and how they play a role in muscle contraction. How is energy supplied to the muscles for contraction?

Muscle and Bone Research Part II Use the supplies on the side counter to complete a detailed drawing of your muscle and your bone. Try to be as detailed as you can. Muscle fibers Structure of bones Once your drawings are complete attach them to the right side of the cardboard cutout or the piece of butcher paper that represents the back of the skeleton.

??? List 5 things you did so far today that required the use of your muscular system. List any other organ system on p. 848 that your body has used, and the activity that required that system to function. Your skin has many functions. How is it helped/protected you today? List as many as you can.

Section 37.4 Skin, Hair, and Nails

Skin 15% of total body weight Largest organ of your body Hair and nails form here Protection from dehydration 2 main layers: Epidermis Dermis

Skin Epidermis Keratin Melanin Outermost layer of the skin Keratin A protein that makes skin tough and waterproof Melanin Cells that give skin its color Skin cells aren’t repaired, they are replaced

Skin Dermis Temperature Regulation Functional layer of skin that is beneath the epidermis Contains hair follicles, nerve cells, blood vessels, other skin cells Nerve cells in dermis give us the sense of touch Temperature Regulation Blood vessels flowing near the surface release heat from the body Sweat glands also releases heat

Skin Subcutaneous tissue Layer of connective tissue, mostly fat, found underneath the dermis Provides insulation and stores energy

Hair and Nails Protrude from the epidermis Hair sheds because it is no longer growing The white area near the base of your nail is where new nail cells are made Nails grow throughout your entire life

Skin Disorders Acne Skin Cancer Oil glands in the dermis secrete sebum Sebum clogs pores causing the oil to build up Skin Cancer Can be caused by over-exposure to UV rays Carcinomas More treatable Melanomas Grow quickly less treatable

Chapter 37 Wrap-Up ? Describe how the organization of the different structures in your body allow you to complete the everyday activities you enjoy, and how they help you function in a stable manner. Organ systems, Organs, Tissue, Cells Bones, Muscle, Skin Answer this question on a piece of notebook paper in no less than 5 sentences.