The Human Body in Health and Illness 4

The Human Body in Health and Illness, 4 th edition Barbara Herlihy Chapter 8: Skeletal System

Lesson 8 -1 Objectives • • • List the functions of the skeletal system. Describe the structure of a long bone. Compare compact and spongy bone. Describe how bones grow. Describe the roles of osteoblasts and osteoclasts. Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 2

Skeletal System Overview • The skeletal system is composed of – Bones – Joints – Cartilage – Ligaments Axial skeleton in pink Appendicular skeleton in tan Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 3

Functions of the Skeletal System Supports body weight Supports and protects soft organs With muscles, enables body movement Stores important minerals, including calcium and phosphorus • Contains red bone marrow, which produces blood cells • • Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 4

Sizes and Shapes of Bones • Long-longer than wide – Femur, humerus, metacarpals, phalanges • Short-shaped like cubes – Carpals, tarsals • Flat-thin, flat, curved – Ribs, sternum, skull, scapula • Irregular-leftover category – Coxal bone, vertebrae, some bones of the skull Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 5

Two Types of Bone • Compact or hard • Spongy or soft Copyright ©

Two Types of Bone • Compact • Spongy(cancellous) – Osteon http: //www. youtube. co m/watch? v=ylman. EGj. Ru Y&feature=related – Shafts of long bones and outer surface of other bones – – Trabecular plates Swiss cheese Bone marrow http: //www. youtube. co m/watch? v=c 5 zc. Gv 8 Mv Mc Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 7

Parts of Long Bone • • Diaphysis Epiphyseal disc Medullary cavity Endosteum Periosteum Articular

Two Types of Ossification • Intramembranous ossification – Replacement of thin connective tissue membrane with bone – In flat bones • Endochondral ossification – Replacement of fetal cartilage skeleton with bone – In long, irregular, and short bones Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 9

Ossification in the Fetus • Intramembranous ossification – In flat bones of skull • Endochondral ossification – In all other bones Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 10

Bones Growing Taller • Occurs at the epiphyseal disc – Osteoblasts invade cartilage in disc. – They mature into osteocytes (bone). • Affected by hormones – Growth hormone – Estrogen – Testosterone Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 11

Bones Growing Wider • Sculptor (osteoclasts) hollows bone. • Builder (osteoblasts) deposits bone on outer surface. • Osteoclastic activity is called resorption. Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 12

Bone Markings: Projections • • Condyle: Large knob Epicondyle: Enlargement near a condyle Head: Enlarged, rounded end Facet: Small flattened surface Crest: Ridge Spine: Sharp projection Tuberosity: Knoblike projection Trochanter: Large tuberosity only on femur Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 13

Bone Markings: Depressions and Openings • Foramen: Opening, usually passage for nerves, blood vessels, ligaments • Fossa: Groove • Meatus: Tunnel or tubelike passageway • Sinus: Cavity or hollow space Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 14

Types of Fractures • Simple • Compound – Breaks through the skin • Greenstick – Incomplete break usually in children Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 15

Lesson 8 -2 Objectives • List the bones of the axial skeleton. • List the bones of the appendicular skeleton. • Label important landmarks for selected bones on the skeleton. Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 16

Bones of the Axial Skeleton • Skull: Cranium, facial, middle ear bones • Hyoid • Vertebral column • Thoracic cage: Ribs, sternum, thoracic vertebrae Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 17

Bones of the Skull • Cranial – Held together by sutures – Little movement • Facial – Mandible contains only movable joint • Middle ear bones Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 18

Special Markings • Temporal bone – External auditory meatus – Zygomatic process – Styloid process – Mastoid process • Occipital bone – Foramen magnum – Occipital condyles Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 19

Paranasal Sinuses • • • Frontal Ethmoidal Sphenoidal Maxillary Functions: – Lessen weight of skull – Alter or adapt the sound of the voice Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 20

Fetal Skull and Fontanels • Fontanels are soft spots – Not yet converted to bone – Covered with fibrous tissue – Allow for cranial growth – Compression of skull for Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. birth 21

Fontanels Continued • Observations – Bulging-possible brain swelling or excessive fluid within the brain – Sunken-dehydration Microcephalia: the skull fuses prematurely Hydrocephalus: excessive fluid within the brain of an infant • Suture: a joint between bones of the skull; no significant movement • Fontanels replaced by bone around 2 years of age. Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 22

Other bones • Hyoid bone • Ossicles – U-shaped – Located in the upper neck – Anchors tongue – Associated with swallowing – The three small bones in each ear Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 23

Vertebral Column • Functions – – Supports the head and thorax Forms an attachment for the pelvic girdle Encases and protects the spinal cord Provides flexibility for the body Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 24

Vertebral Column or Backbone • 26 vertebrae • 7 cervical – neck region – C 1 -C 7, C 7 -vertebra prominens • Sacrum – 5 sacral vertebrae fused together • Tail bone – coccyx • 12 thoracic – chest region • 5 lumbar – lower back region Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 25

Vertebral Column • Sections – Cervical – Thoracic – Lumbar – Sacrum and coccyx • Curves – Cervical-toward front – Thoracic-toward back – Lumbar-toward front – Sacral –toward back Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 26

Vertebrae • Atlas (C 1): Nods “yes” • Axis (C 2): Rotates “no” • Other vertebral parts – Vertebral foramen: opening for the spinal cord – Body – Lamina – Spinous process – Padded by intervertebral discs Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 27

Vertebral Column Concerns • Spina bifida – Failure of the lamina to fuse during fetal development – Spinal cord protrudes on the surface of the back – If compressed causes paralysis and loss of bladder and bowel control • Laminectomy – http: //www. youtube. com/watch? v=Ji. Vja. EIPn 0&feature=fvst • Spinal fusion – http: //www. youtube. com/watch? v=WID 1 p_UJZIM Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 28

Disorders of the Vertebral Column • Scoliosis: Lateral curve • Kyphosis: Hunchback • Lordosis:

Thoracic Cage • Sternum – Manubrium, body, xiphoid process • Ribs (12 pairs) – Seven pairs of true ribs: directly attached to sternum – Five pairs of false ribs, including two pairs of floating ribs • Thoracic vertebrae • Intercostal muscles Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 30

Landmarks of Thoracic Cage • Xiphoid process • Suprasternal notch: superior edge of manubrium • Sternomanubrial joint: manubrium&body • Costal angle • Costal margins: edges of the cartilage that form an angle as they converge near the xiphoid process Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 31

Bones of the Appendicular Skeleton • Pectoral girdle – Scapulae – Clavicles • Upper limbs • Pelvic girdle – Coxal bones • Lower limbs Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 32

Pectoral Girdle and Upper Limb • Pectoral girdle – Clavicle – Scapula Copyright ©

Pectoral Girdle Continued • The shoulder girdle supports the upper limbs and serves as a place of attachment for muscles. • Great flexibility • Clavicle articulates with the sternum and scapula – easily dislocated or broken – Also called the collarbone • Scapula – Glenoid cavity – where the head of the humerus fits – Acrimion process and coracoid process – places of attachment of ligaments and muscles Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 34

Upper Limbs • Humerus – Proximal fits in glenoid cavity of the scapula – Distal articulates with radius and ulna • Radius – Located on thumb side when palm of hand is facing forward • Ulna – – Longer than the radius Olecranon process – bony point of elbow When palm-up, ulna and radius parallel When palm-down, cross Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 35

Upper Limbs continued • Hand – Carpal bones – 8 – Metacarpal bones – 5 – Phalanges – 14 • Each digit has three • Thumb (pollex) has just two Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 36

Pelvic Girdle: Coxal Bones • Composed of two coxal bones • Functions – Weight bearing – Attachment for lower limbs – Protection of organs Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 37

Pelvis • Formed by the pelvic girdle, sacrum, and coccyx • Female pelvis is broader and shallower than the male • Coxal bone has three parts – Ilium • Connects in the back with the sacrum, forming the sacroiliac joint – Ischium – Pubis • Symphysis pubis – place where the two pubis join, disc of cartilage separates the two pubis – Acetabulum – the depression where three parts fused • Receives the head of the femur Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 38

Lower Limb • Thigh – Femur- longest and strongest bone • Leg bones – Patella – Tibia-shin bone, weight bearing – Fibula-smaller Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 39

Lower Limb: Ankle and Foot • Foot bones – Tarsals – Metatarsals – Phalanges • Hallux-great toe • Arches Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. – Form instep Read foot problems p. 131 40

Lesson 8 -3 Objectives • List the main types and functions of joints. •

Types of Joints • Immovable • Slightly movable • Freely movable Copyright © 2011,

Structure of Freely Movable Joints • Articular cartilage • Joint capsule – http: //www. hylarub. com/ understanding_joint_heal th. htm • • Synovial membrane Synovial fluid Cartilage Some joints also have – Bursae – Ligaments Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 43

Types of Freely Movable Joints • Hinge: Elbows, knees • Ball-and-socket: Shoulders, hips • Pivot: Atlas-axis joint • Saddle: Carpometacarpal • Gliding: Wrist • Condyloid: Knuckles • Table p. 132 Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 44

Joint Names: Articulating Bones • Tibiofemoral – Tibia and femur • Humeroulnar – Humerus and ulna • Metacarpophalangeal – Metacarpal bone and phalange • Glenohumeral – Glenoid cavity and humerus Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 45

Types of Joint Movement Flexion-extension Inversion-eversion Supination-pronation Abduction-adduction Dorsiflexion-plantar flexion • Hyperextension • Circumduction • • • Copyright © 2011, 2007 by Saunders, an imprint of Elsevier Inc. All rights reserved. 46