introduction to musculoskeletal system 2012

7/27/2019 Introduction to Musculoskeletal System 2012

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Introduction of bones and cartilage. (of the limb)

Vignette

Subpokok bahasan:

Fungsi tulang

Struktur tulang - Bone Structure

Proses pembentukan tulang dan perkembangannya

Fetal skeleton

Axial skeleton

a. Tulang penyusun axial skeleton

b.

Ciri-ciri axial skeleton

Cartilago

Function of the Bone

Support - framework that supports body and cradles its soft organs

Protection - for delicate organs, heart, lungs, brain

Movement - bones act as levers for muscles

Mineral storage - calcium & phosphate

hematopoiesis - blood cell formation

Struktur tulang

Facts

There are 206 bones in the adult human body.

The largest bones in the adult human body is the femur.

There are about 300 bones in a newborn baby but they grow together to make 206 when an adult.

The Facts About Bones.


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One function of spongy bone is to produce red blood cells.

The smooth, flexible layer of tissue covering the ends of bones is called cartilage.

The hard, strong layer of bone is called compact bone.

Minerals make bones strong.

The human skeleton has 206 bones of various sizes and shapes.

Bone Structure

Bone enclosed in periosteum, which is continuous

with tendons and ligaments

blood vessels in periosteum

Epiphysis- ends

spongy bone contains red marrow

compact bone, articular cartilage

Diaphysis- middle

compact bone

medullary cavity- contains yellow marrow (fat)

lined with endosteum (squamous epithelium)

Compact bone

osteocytes within lacunae

arranged in concentric circles called lamellae

This surround a central canal; complex is called

Haversian system

Canaliculiconnect osteocytesto central canaland


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to each other


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Prenatal development

skeleton is mostly cartilaginous

Cartilage cells and then osteoblasts start to

deposit minerals

Cartilaginous disk (epiphyseal disk) remains

in epiphysis

Cells eventually stop dividing


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Bone Development

Initial skeleton of cartilage in infants

Replaced with bone by osteoblasts

More than 300 bones at birthfuse to 206

Always growing and breaking down

Osteoblastsform new bone cells

Osteoclastsbreak bone cells down

Osteocytesmature bone cells


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Adults continually break down and build up bone

Osteoclasts remove damaged cells and release

calcium into blood

Osteoblasts remove calcium from blood and build

new matrix. They become trapped

osteoclasts

Broken Bones

Fracture is a break of the bone

Simple or Complex fracture

Regrowth of bone:

Spongy bone forms in first few days

Blood vessels regrow and spongy bone hardens

Full healing takes 1-2 months

Fracture repair

Hematoma- blood clot in space between edges of break

Fibrocartilage callus- begins tissue repair

Bony callus- osteoblasts produce trabeculae (structural support) of spongy bone and replace fibrocartilage


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Remodeling- osteoblasts build new compact bone, osteoclasts build new medullary cavity

Types of Bones

Long Bones- metacarples, metatarsals, phelangies, humerus, ulna, radius, tibia, fibula

Short Bones- carpals, tarsals

Flat Bones- rib, scapula, skull, sternum

Irregular Bones- vertebrae, some facial bones

Sesamoid- patella

Axial Skeleton


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The skull

8 sutured bones in cranium

Facial bones: 13 sutured bones, 1 mandible

Cranium

encases brain

attachments for muscles

sinuses


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Cranium

The bones of the cranium are:

I frontal bone

2 parietal bones

2 temporal bones

I occipital bone

1 sphenoid bone

1 ethmoid bone.


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The cranial vault or calvaria forms the superior, lateral, and posterior aspects of skull

The cranial base forming the inferior aspect of skull


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Cranial Base

Cranial base forms the skulls inferior aspect

Three prominent ridges divide the base into fossae

The brain rests on these cranial fossae completely enclosed by the cranial vault

The brain occupies the cranial cavity


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Vertebral column

7 cervial vertebrae

12 thoracic

5 lumbar

1 sacrum (5 fused

1 coccyx (4 fused)

Vertebrae vary in size and morphology


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Thoracic cage

ribs

thoracic vertebrae

sternum

costal cartilages

True ribs are directly attached to the sternum

(first seven pairs)

Three false ribs are joined to the 7th rib

Two pairs of floating ribs


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Aging and bones

both bone and cartilage tend to deteriorate

cartilage: chondrocytes die, cartilage

becomes calcified

osteoporosis; bone is broken down faster

than it can be built

bones get weak and brittle; tend to fracture

easily

Risk factors for osteoporosis

Inadequate calcium

Little weight-bearing exercise

Drinking alcohol, smoking

Being female: decreased estrogen secretion

after menopause

Small frame

Caucasian or Asian ethnicity

Skeleton and other systems

Skin makes vitamin D which enhances calcium

absorption

Skeleton stores calcium for muscle contraction,

nervous stimulation, blood clot formation


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Red marrow- site of blood cell formation

Calcium levels regulated by

parathyroid hormone and calcitonin

kidneys (can help provide vitamin D)

digestive system (can release calcium

into blood

Growth hormone regulates skeletal growth

stimulates cell division in epiphyseal disks

in long bones

Growth stops when epiphyseal disks are

converted to bone

When excess growth hormone is produced in

In adulthood- acromegaly. Bones cant grow

but soft tissue can


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introduction to musculoskeletal system 2012

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