DECEMBER 7 T H , 2015

GET ANYTHING TOGETHER YOU WILL NEED FOR YOU PRESENTATION

Skeletal System

Presentations

Each group will have a maximum of 5 minutes to present about their person

JeremyEleanorMarissa

You are not required to but I would suggest taking some sort of notes while watching the other presentations

Skeletal System Intro 7.1

Constituents of BoneBone tissueCartilageDense Connective TissueBloodNervous Tissue

Skeletal System intro

Functions of BonesPoints of attachment for musclesProtect and support softer tissues

House blood producing cellsStore inorganic saltsForm passageways for blood vessels and nerves

Bone Structure 7.2

Classification of Bones Long Bones – long longitudinal axes and

expanded ends Ex: Femur, Humerus, Radius, Ulna, Tibia, Fibula

Short Bones – roughly equal length and width Ex: Carpals and Tarsals

Flat Bones – platelike with broad surfaces Ex: Scapula, Skull bones

Irregular Bones – variety of shapes, usually connected to several other bones Ex: Vertebrae, Facial Bones

Bone Structure 7.2

Classification of Bone Sesamoid Bone or Round Bones

Small nodular bones usually found embedded in tendons adjacent to joints

Ex: Patella

Support and Protection

Bones of the lower limbs, pelvis and backbones support majority of the body’s weight

In general bones provide protection for vital organs Skull – protect eyes, ears, brain Rib Cage – protect heart and lungs Pelvic Girdle – protect lower abdominal and

reproductive organs

Body Movement

Bones and Muscles work together as levers for body movement

Lever components Rigid bar or rod – Bone Fulcrum/Pivot – Joint Object moved against resistance – object

being moved Force to supply energy - Muscle

Blood Cell Formation

Hematopoiesis

process of blood cell formation

Begins in yolk sac outside human embryo

Later in life continues in the liver, spleen and bone marrow

Blood Cell Formation

Bone Marrow Located in medullary cavity of long bones, irregular spaces of

spongy bone and larger central canals of compact bone Mostly red marrow as an infant progressively being replaced by

yellow marrow in adulthood

RED MARROW Formation of red blood cells (erythrocytes) Formation of white blood cells (leukocytes) Formation of platelets

YELLOW MARROW Storage of fats Not active in blood cell production

Storage of Inorganic Salts

Calcium is stored in bone primarily through calcium salts like calcium phosphate Calcium plays role in muscle contraction, nerve

impulse conduction, blood clotting and other physiological processes

Magnesium, sodium, potassium and carbonate ions are also stored in bones

Harmful metallic elements such as lead, radium or strontium can also accumulate in bones if accidentally ingested

Storage of Inorganic Salts

Calcium Homeostasis Low blood calcium parathyroid hormone

release stimulate osteoclasts to breakdown bone release calcium into blood

High blood calcium inhibit osteoclast activity calcitonin from thyroid stimulates osteoblasts to form bone tissue storing excess calcium

Bone Fractures

Classified by cause of break Traumatic – fracture due to sustained trauma

Spontaneous – fracture in seemingly normal bone with no evidence of blunt force trauma

Pathologic – fracture through bone that has been weakened by underlying disease

Classified by… Simple – does not break through skin Compound - breaks through the skin

Bone Fractures

Classified by nature of break Greenstick – incomplete, occurs on

convex surface of bend in bone

Fissured – incomplete, longitudinal

Comminuted – complete, fragmented

Transverse – complete, right angle to axis of bone

Oblique – complete, angle other than right angle to axis of bone

Spiral – excess twisting of bone

Bone Fractures

What happens when a bone fractures Blood vessels rupture

Periosteum tears

Hematoma – blood clot forms

Vessels from surrounding tissues dilate to swell and inflame the tissues

Bone Fractures

Within days or weeks Developing blood vessels and large numbers of

osteoblasts originating in periosteum invade the hematoma

Osteoblasts rapidly divide in the regions close to new blood vessels building spongy bone

Fibroblasts produce masses of fibrocartilage Phagocytic cells begin to remove the blood clot

and any other dead or damaged cells in affected area

Osteoclasts appear and resorb bone fragments aiding in cleaning up debris

Bone Fractures

Weeks later… Fibrocartilage fills the gap between the

ends of the broken bone called a cartilaginous callus, it is replaced later by a bony callus

More bone is produced at the site than is necessary

Osteoclasts remove the extra to make the bone look very similar to the original

Skeletal Organization

Axial Skeleton Bony and cartilaginous parts that support

and protect the organs of the head, neck and trunk

Include Skull (22 bones) Hyoid Bone (1 bone) Vertebral Column (26 bones) Thoracic Cage (25 bones) Middle ear bones (6 bones)

Axial Skeleton

Skull Composed of cranium and facial bones Contains a total of 22 bones

Hyoid Bone Located in neck between lower jaw and

larynx Supports the tongue and is an attachment

for muscles that help move the tongue

Axial Skeleton

Vertebral Column Consists of vertebrae separated by cartilaginous

intervertebral discs At distal end vertebrae fuse to form the sacrum Several more fused vertebrae for the coccyx

Thoracic Cage Protects organs of thoracic cavity and upper

abdominal cavity Composed of 12 pairs of ribs Includes the sternum the attachment of ribs

anteriorly Vertebral column is the attachment of ribs posteriorly

Skeletal Organization

Appendicular Skeleton Consists of bones of the upper and lower

limbs and the bones that anchor the limbs to axial skeleton

Includes Pectoral Girdle (4 bones) Upper Limbs (60 bones) Pelvic Girdle (2 bones) Lower Limbs (60 bones)

Appendicular Skeleton

Pectoral Girdle Formed by the scapula and clavicle on each side

of the body Connects the bones of the upper limbs to axial

skeleton

Upper Limbs Consist of humerus, radius, ulna and hand Humerus, radius and ulna articulate at the elbow

joint Hand consists of 8 carpals, 5 metacarpals and 14

phalanges

Appendicular Skeleton

Pelvic Girdle Formed by two hip bones attached to each

other anteriorly and to the sacrum posteriorly

Connect bones of lower limbs to axial skeleton

With sacrum and coccyx form the pelvis

Lower limbs Consists of a femur, tibia, fibula, patella

and foot Foot contains 7 tarsals, 5 metatarsals, 14

phalanges

Section 7.6 Human Skull

Cranium (eight bones) Frontal Bone –

anterior portion of skull above the eyes Marked by

supraorbital foramen

Contains two frontal sinuses

Section 7.6

Cranium Parietal Bones –

located on each side of skull just behind frontal bone Form bulging sides

and roof of cranium Fused at midline

along Sagittal Suture

Meet frontal bone along the Coronal Suture

Section 7.6

Cranium continued… Occipital bone – forms

back of the skull and base of cranium Joins parietal bones

along lambdoid suture Contains large opening

called Foramen Magnum

Allows nerves from brain to travel to spinal cord

Occipital condyles articulate with first vertebra (atlas)

Section 7.6

Cranium continued… Temporal bones – form parts

of the sides and base of cranium Joins parietal bone along

squamous suture Contains external acoustic

meatus that leads into inner ear

Mandibular fossae articulate with mandible

Mastoid process – attachment for certain neck muscles

Styloid process – anchor muscles associated with tongue, pharynx

Zygomatic process – project anteriorly, forms prominence of cheek

Section 7.6

Cranium Continued… Sphenoid Bone –

forms base of cranium, sides of skull and floors and sides of the orbits Contains sella

turcica – an indent where the pituitary gland resides

Contains two sphenoidal sinuses

Section 7.6

Cranium continued… Ethmoid Bone –

located in front of sphenoid bone Two masses on sides of

nasal cavity connected by thin cribiform plates

Crista galli – attachment for membranes that enclose the brain

Perpendicular plate – forms most of the nasal septum

Middle Nasal Conchae Contain ethmoidal

sinuses