Lecture 5 Skeletal and Muscular Systems 1 Skeletal and Muscular Systems 1. Skeletal System Bones Cartilage Ligaments & Tendons Joints 2. Muscles 2 1
Skeletal System 3 Functions of Skeleton Support of the body 2
Functions of Bones Protection of soft organs Functions of Bones Movement due to attached skeletal muscles 3
Functions of Bones Storage of minerals and fats Blood cell formation The Skeletal System Parts of the skeletal system Bones (skeleton) Joints Cartilages Tendons and Ligaments 4
Bones of the Human Body The adult skeleton has 206 bones At birth, humans have about 300 bones Fun Fact Dinosaurs have approximately the same number of bones as a human does 200 10 5
Fun Fact Dog has 321 Python has about 1800 11 Bones of the Human Body Two basic types of bone tissue Compact bone Homogeneous 6
Bones of the Human Body Two basic types of bone tissue Spongy bone Small needle-like pieces of bone Many open spaces 14 7
Bone Marrow Bone marrow is a semi-solid tissue which may be found within the spongy portions of bones. 15 Bone Marrow Bone Marrow Primary function is blood cell formation 16 8
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1. Long Bones 5 Types of Bones Femur can withstand up to 4 tons of pressure! 19 2. Short Bones 5 Types of Bones 20 10
3. Flat Bones 5 Types of Bones 21 5 Types of Bones 4. Sesamoid Bones - a small independent bones or bony nodules located in a tendon where it passes over an angular structure 22 11
5. Irregular Bones 5 Types of Bones 23 5 Types of Bones 24 12
Types of Bone Cells Osteocytes Mature bone cells Osteoblasts Types of Bone Cells Bone-forming cells 13
Osteoclasts Types of Bone Cells Bone-destroying cells Breaks down bone remodeling and release of calcium, phosphorus, etc. Bone is a dynamic tissue Bone remodeling is a process by both osteoblasts and osteoclasts 14
After you break a bone 29 Cartilage - a strong, flexible fibrous tissue 30 15
Cartilage - found throughout the body. 31 Tendons A flexible but inelastic cord of strong fibrous collagen tissue (proteins) attaching a muscle to a bone. 32 16
Ligaments A short band of tough, flexible fibrous connective tissue which connects two bones or cartilages or holds together a joint. 33 Joints of the Body Joint - The junction where two bones meet, also known as a bony articulation. 4 different types 34 17
Joints of the Body Movable joint, Ball and Socket joint 35 Joints of the Body Movable Joint, Hinge Joint 36 18
Joints of the Body Joint with Limited Movement 37 Immovable Joint Joints of the Body 38 19
The Skeletal System Divided into two divisions Axial skeleton- skull, spinal column Appendicular skeleton limbs and girdle Axial Skeleton Appendicular Skeleton 20
The Axial Skeleton Forms the longitudinal part of the body Divided into three parts Skull Vertebral Column Rib Cage Axial Skeleton -Skull 42 21
Skull Anatomy 43 Axial Skeleton Spinal Column 44 22
Axial Skeleton Rib Cage 45 The Axial Skeleton 23
Appendicular skeleton Includes the bones of limbs and bones that anchor them to the axial skeleton - pectoral girdle (clavicle, scapula) - upper limbs (arms) - pelvic girdle (sacrum, coccyx) - lower limbs (legs) Muscular System 48 24
The Muscular System Muscles are responsible for all movement of the body There are three basic types of muscle Skeletal Smooth Cardiac Did you know that? - more than 50% of body weight is muscle! - And muscle is made up of proteins and water 25
Info About Muscles Only body tissue able to contract create movement by flexing and extending joints Body energy converters (chemical energy to mechanical energy) 3 Types of Muscles 26
Skeletal Muscle Found in the Limbs Voluntary- subject to conscious control Produce movement, maintain posture, generate heat, stabilize joints Smooth Muscle Spindle shaped Involuntary- no conscious control Found mainly in the walls of hollow organs 27
Lines walls of viscera Smooth Muscle Found in longitudinal or circular arrangement Alternate contraction of circular & longitudinal muscle in the intestine leads to peristalsis Cardiac muscle Main muscle of heart Heart muscle cells behave as one unit Heart always contracts to it s full extent Contracts involuntarily and rhythmically 28