1. C37: The Skeleton and muscles Mr. E Murphy

5. Objectives  Functions of the skeleton  Structure of human skeleton  Parts of the axial skeleton  Parts of the appendicular skeleton  Bones: types, growth and development  Joints  Musculoskeletal disorder  Muscles

6.  Support  Shape  Protection  Movement  Manufacture of blood components Functions of the skeleton

7. Skeleton Structure 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

8. Regions of the spine 1 2 3 4 5

9. Structure of the human skeleton  213 bones in the human skeleton  Divided into the axial and the appendicular skeleton

10. Parts of the axial skeleton Skull Skull consists of 22 bones Most are fused together except for the jaw Spine Made of 33 bones called vertebrate Top 24 vertebrate are held together by ligaments They are separated by discs of cartilage Last 9 are fused together and there are no discs between them No movement between them

11. TS of Vertebra

12. Activity  Complete diagram of the spine fig 45.2 p365  TS of vertebra into your notes copy fig 45.4 p365

13. Parts of the axial skeleton  Consists of the sternum (breastbone) and 12 pairs of ribs  All ribs are attached to the vertebra of the spine  Top 7 ribs are attached to the breastbone at the front (True ribs)  Next 3 ribs (8, 9 and 10) are attached to each other at the front of the chest by cartilage (false ribs)  Bottom two ribs (floating ribs) only attached to the spine Rib cage

14. Parts of the appendicular skeleton  Collarbone (clavicle) and the shoulder blade (scapula)  Forms a connection with the vertebral column and with the arms Pectoral girdle

15. Parts of the appendicular skeleton  Composed of two halves joined at the front by a band of flexible cartilage  Each half consists of 3 fused bones  Pelvic girdle is fused to the spine  Hip bones attach to the sacrum is called the pelvis  Pelvic girdle consists of the hip bones, the sacrum and the legs Pelvic girdle

16. Parts of the appendicular skeleton  Arms and legs have a similar design pattern  Each limb ends in 5 digits  Pentadactyl limb  The phlanges are the individual bones of the fingers and toes  Opposable thumbs Limbs The thumb can be pushed against all the other four digits

17. Parts of the appendicular skeleton  Long bones are enclosed by a membrane called the periosteum  Membrane contains blood vessels and nerves  Long shaft of the bone is the diaphysis, head of the bone is the epiphysis Structure of long bone Replacement of cartilage by bone in early life is called ossification

18. Parts of the appendicular skeleton  The collagen fibres are embedded in a matrix of calcium and phosphorous salts  Lacks in blood vessels and nerves  Transport occurs through diffusion  Cartilage is slower to heal than bone Cartilage Cartilage contains a firm but flexible fibrous protein called collagen Cartilage also found in the pinna of the ear, the nose, trachea and discs in between the trachea. Cartilage covers the end of bones, protects them and allows movement without friction

19. Types of Bone  Made in bone cells, a mixture of 70% inorganic salts and 30% protein  Blood vessels supply bones with nutrients  Nerve fibres run through the bone Compact bone Spongy bone Bone marrow Compact bone Calcium salts give bones their strength Protein gives bone its flexibility Location: Compact bone is mostly found in the diaphysis of a bone Also located as a layer around the end of bone

20. Types of Bone  Like compact bone but contains numerous hollows  Spaces in spongy bone are filled with red bone marrow that produces blood cells  Location: Mainly at the end (epiphyses) of bones Spongy bone Bone marrow  Soft fatty substance found in the medullary cavity and within spongy bone  Red marrow makes blood components

21. Bone growth  Begins around 8 weeks into development in the uterus  Bone forming cells called osteoblasts produce the protein collagen  Hard compound forms around the collagen fibres  Osteoblasts become trapped in this hard compound and become dormant bone cells The increase in the length of a bone is due to a growth plate made of cartilage

22. Bone development  Throughout life bone is dissolved and replaced  Catabolic cells digest bone cells depositing calcium into the bloodstream  Osteoblasts form new bone to replace the bone that is destroyed Bone material is removed from the interior of the medullary cavity and extra bone is deposited on the outside of the bone Osteoporosis is the loss of protein (collagen) material from the bone. Causes bone to become brittle and easily broken

23. Joints  Immovable E.g. Skull and pelvic girdle  Slightly movable E.g. Joints between vertebrae in the upper spinal column A joint is two or more bones meet Joints are classified according to the degree of movement they allow

24. Joints  Freely movable (synovial) E.g. Ball and socket joints (shoulder and hip) Hinge joints (elbow and knee) Ends of the bones are covered with cartilage Bones are separated by a cavity Held in place by ligaments Joint is enclosed in a synovial membrane Membrane secretes synovial fluid which lubricates the joint and reduces friction

25. Homework 16/12  Complete diagram p 371 diagram 45.10, typical synovial joint

26. Joints Ligaments Strong, fibrous, slightly elastic tissues Connect bone to bone Tendons Strong, flexible, inelastic fibres that connect muscle to bone Composed of collagen and contain some blood vessels

27. Musculoskeletal Disorder Arthritis Cause Arthritis is a skeletal disorder resulting from inflammation (swelling) of joint Most common arthritis is osteoarthritis Caused by the cartilage in synovial joints wearing down The underlying bones enlarge and more synovial fluid forms Joint becomes sore and stiff

28. Musculoskeletal Disorder  Rheumatoid arthritis is the most severe form of joint inflammation  Caused by the body’s immune system turning on itself Arthritis Cause Prevention Reduce damage to joints Wear proper footwear when running, avoid running on hard ground Treatment No cure for either form or arthritis Treatments include rest, exercises, weight loss and possibly surgery to replace the joint

29. Muscles  Concerned with body movements  Can contract quickly, but tires very easily  Under voluntary or conscious control Three types of muscle Skeletal e.g. body movements Smooth e.g. involuntary muscle Cardiac e.g. heart Skeletal muscle

30. Muscles  Involuntary muscle  Found in the digestive system, blood vessels, bladder and uterus  Contracts slowly, slow to tire  Involuntary or unconscious control Smooth muscle Cardiac muscle Found in the heart Involuntary

31. Muscles  Muscles can only pull (by contracting)  They cant push Antagonistic Pairs Muscles are connected to bones by tendons. When the muscle contracts, the tendons pull on the bone, causing it to move Forearm Biceps contract to pull the lower arm up The triceps contracts to straighten the arm

32. Muscles A pair of muscles that have opposite effects to each other is called an antagonistic pair Biceps are called flexors Triceps is called an extensor Generally flexors are stronger than extensors

33. Key Words  Endoskeleton  Exoskeleton  Axial and appendicular skeleton  Bone growth  Osteoblasts  Joints  Musculoskeletal disorder  Arthritis  Muscles

34. Homework 14/12  Q 4 2009 exam papers  Diagram of the internal and external structure of a long bone p368

35. Corrections Q4 2009

36. Homework 15/12  Q 15 a 2008  Q 15 a 2006

37. Exam Questions 2010 Q15 c

38. Exam Questions 2008 Q15 c

39. Exam Questions 2007 Q14 b

40. Exam Questions 2006 Q15 b

41. Exam Questions 2005 Q15 b

42. Solutions 1. skeleton, muscular, nervous 2. A) support, protection, movement and shape b) framework, inner organs muscles can move skeleton, features 3. A) skull, ribs, spine and sternum b) arms, legs, pectoral girdle and pelvic girdle

43. Solutions 4. A-neural spine, b_ transverse process, c- neural canal, d- centrum b) Muscular attachment c) Spinal chord d) Contact with next vertebrae 5. a) true- attached breast bone, false – attached to each other, floating- only to the spine

44. Solutions 5. b) pectoral-collar bone and shoulder blade pelvic- spine and hip c) compact- hard and strong, bone cells in salt and protein, spongy- hollow spaces containing bone marrow d) ligament- bone to bone, tendon – muscle to bone e) red- makes blood cells yellow- does not

45. Solutions 6. a) bones in the spine b) cervical-7, thoracic-12, lumbar- 5, sacrum- 5, coccyx-4 (33 in total) c) Inter vertebral disc d) Prevents friction (offers lubrication) 7. a) A- scapula, B- humerus, C- radius, D-carpel b) Ball and socket, hinge d) Radius and scapula e) Closes the joint