CHAPTER 5A The Skeletal System

“Skeleton” means “dried up body” in Greek.

Skeletal System = bones of the skeleton, joints, cartilages, and ligaments.

Skeleton is divided into two sections:

Axial skeleton = bones of longitudinal axisAppendicular skeleton = bones of limbs and girdles

Axial SkeletonAppendicular Skeleton

CHAPTER 5A The Skeletal System

Functions of Bones

1.Support (internal framework)2.Protection (of organs)3.Movement (with skeletal muscles)4.Storage (fat, minerals – especially calcium and phosphorus)

Calcium comes and goes from bones continually as it is needed in the blood.

5.Blood Cell Formation (hematopoiesis) occurs in bone marrow

CHAPTER 5A The Skeletal System

Classification of Bones

1.Compact Bone = dense, smooth, homogeneous

2.Spongy Bone = made of small needlelike pieces of bone and open spaces

CHAPTER 5A The Skeletal System

Classification of Bones

1.Long BonesLonger than wideHead at each endMostly compact boneLimb bones

CHAPTER 5A The Skeletal System

Classification of Bones

1.Short BonesCube-shapedSpongy boneEx. Wrist and ankle

CHAPTER 5A The Skeletal System

Classification of Bones

1.Flat BonesThin, flattened, usually curved.Two thin layers of compact bone sandwiching spongy bone.Ex. Skull, ribs, and sternum.

CHAPTER 5A The Skeletal System

Classification of Bones

1.Irregular BonesDon’t fit into other categories.Ex. Vertebrae, hip bones.

CHAPTER 5A The Skeletal System

Structure of a Long Bone Gross Anatomy (See TXT pg 114 Fig 5.2)

Diaphysis = shaftPeriosteum = covers shaftSharpy’s Fibers = hold periosteum to bone

Epiphyses = ends of boneArticular cartilage = covers epiphysesEpiphyseal line = only in adults

Epiphyseal plate = growth portion in youth

CHAPTER 5A The Skeletal System

Structure of a Long Bone Gross Anatomy (See TXT pg 114 Fig 5.2)

Red Marrow Infants: forms blood cells Adults: only in spongy bone

of flat bones.

Yellow Marrow Adults only.

CHAPTER 5A The Skeletal System

Structure of a Long Bone Gross Anatomy (See TXT pg 115 Table 5.1)

Bone Markings Categories:

Projections (Processes) Grows out from bone surface.

Depressions (Cavities) Indentations into the bone.

CHAPTER 5A The Skeletal System Microscopic Anatomy

(See TXT pg 116 Fig 5.3)

Mature bone cells

Cavities in matrix

Circles of lacunae

Lamellae surround it

Central canal + matrix rings

Canals connect all tissues

Communication pathway

CHAPTER 5A The Skeletal System Bone Growth

(See TXT pg 117 Fig 5.4)

Bone Growthhttp://highered.mcgraw-hill.com/sites/0072507470/student_view0/chapter6/animation__bone_growth_in_width.html

Skeletal System Interactivehttp://player.discoveryeducation.com/index.cfm?guidAssetId=B7D2D569-417F-454B-8490-4681832950A5&blnFromSearch=1&productcode=US

For this slide, you will receive a handout that accompanies the skeletal system interactive video. Vocabulary will be included in the handout.

CHAPTER 5A The Skeletal System Fractures

(See TXT pg 119 Table 5.2)

Types of Bone Fractureshttp://video.about.com/orthopedics/Fractures-2.htm

CHAPTER 5A The Skeletal System Fractures

More Fractures online…

Click-on Fracture Animations http://www.argosymedical.com/Skeletal/index.html

CHAPTER 5A The Skeletal System Fractures

Reduction = repair of fractures.

Emergency procedures for broken bones http://www.argosymedical.com/Skeletal/samples/animations/Broken%20Bone/index.html

CHAPTER 5A The Skeletal System Fractures

CHAPTER 5A The Skeletal System / Bones

(See TXT pg 120 Fig 5.5)

Stages of Healing:

1.Hematoma2.Soft Callus3.Bony Callus4.Remodeling

CHAPTER 5A The Skeletal System / Bones

(See TXT pg 121 Fig 5.6)

Axial Skeleton:

SkullVertebral columnBony thorax

CHAPTER 5A The Skeletal System / Bones

(See TXT pg 122 Fig 5.7)

Laterial View of the Skull

The SKULL

CHAPTER 5A The Skeletal System / Bones

Ancient man following skull surgery.

This weird looking skull is the famous Starchild Skull that was found in 1930. The Starchild Skull was discovered in a mine tunnel about 100 miles southwest of Chihuahua, Mexico along with several other normal skeletons.

100,000-year-old skull was found in a cave in Qafzeh, Israel,

Other Lateral Views

of Skull

CHAPTER 5A The Skeletal System / Bones

Anterior View of the Skull

CHAPTER 5A The Skeletal System / Bones

8-13 yr old boy

More Anterior

Views of Skulls

CHAPTER 5A The Skeletal System / BonesSinus = air filled cavity

Process = projection

Foramen = hole or opening

Suture = immovable fibrous joints between bones

Condyle = rounded projection at the end of a bone that articulates with another bone

Paranasal Sinuses

CHAPTER 5A The Skeletal System / Bones

Hyoid Bone

Not part of skull.Only bone that does not interact directly with another bone.Suspended and anchored by ligaments.Moveable base for tongue.Attachment point for swallowing.Aids in speech.

CHAPTER 5A The Skeletal System / Bones

Fetal Skull

Face is small compared to cranium.

Skull overall is large for the body.

Cranial bones connected by fontanels which harden post partem.

http://ect.downstate.edu/courseware/haonline/quiz/practice/u5/quiztop5.htm

CHAPTER 5A The Skeletal System / Bones

Vertebral Column

Also called spine.

Before birth = 33 vertebraeAfter birth = 24 vertebrae

CHAPTER 5A The Skeletal System / Bones

Vertebral Column

Separated into 5 major sections:

Cervical (neck)Thoracic (mid back)Lumbar (lower back)Sacrum (top of tail)Coccyx (tail bone)

Scoliosis Animationhttp://www.spine-health.com/video/scoliosis-video-what-scoliosis

CHAPTER 5A The Skeletal System / Bones

Vertebral Column

Intervertebral discs = separate vertebrae

90% water

Dries as ages.

Herniated discs results from drying and weakening of ligaments holding discs in place.Herniated disc animationhttp://www.spine-health.com/video/lumbar-herniated-disc-video

CHAPTER 5A The Skeletal System / Bones

Vertebral Column

S-shaped structure

Provides flexibility and prevents shock to the brain

Primary curvaturesformed at birthThoracic and Sacral

Secondary curvaturescervical – when baby begins raising headlumbar – when baby begin walking

CHAPTER 5A The Skeletal System / Bones

Thoracic Vertebra

Body

Pedicle

Superior Articular Process

Transverse Process

Lamina

Spinous Process

Vertebral Arch

Vertebral Foramen

Weight bearing

CHAPTER 5A The Skeletal System / Bones

Cervical Vertebra1st Vertebra: Atlas Has no body Holds occipital condyles of skull Allows nodding = “yes”

2nd Vertebra: Axis Acts as pivot for rotation of skull Allows side-to-side motion = “no” Dens: Pivot point

CHAPTER 5A The Skeletal System / Bones

Thoracic Vertebra

Supports ribs.

CHAPTER 5A The Skeletal System / Bones

Lumbar Vertebra

Block-like body.

Most of stress on spine occurs in lumbar region.

CHAPTER 5A The Skeletal System / Bones

Sacrum

Formed by fusion of 5 vertebrae.

Alae = articulates with hip bones.

Formed by fusion of 3 vertebrae.

“Tailbone”

Coccyx

CHAPTER 5A The Skeletal System / Bones

Bony Thorax

Ribs:

True Ribs: 1st 7 ribs Attach to sternum.

False Ribs: Last 5 ribs Attach indirectly to sternum or not attached at all. Last 2 false ribs are “floating ribs” – unattached.

CHAPTER 5A The Skeletal System / Bones

Bony Thorax

Sternum:

Manubrium ProcessBodyXiphoid process easily broken during CPR

CHAPTER 5A The Skeletal System / Bones

TEST TIME!

CH 5 AXIAL SKELETON