2 DIVISIONS of Human Skeleton
1. AXIAL SKELETON
and
2. APPENDICULAR SKELETON
Bones of the AXIS
Bones of the:
- Skull,
- Spine
- Chest
- Hyoid Bone
AXIAL SKELETON
How Many Bones?
80 Bones
APPENDICULAR - EXTREMITIES
- UPPER EXTREMITIES
Shoulder - Pectoral - Girdles - Arms - Wrists & Hands
- LOWER EXTREMITIES
Hip - Pelvic - Girdles - Legs - Ankles & Feet
SKULL - CRANIAL CAVITY
HOW MANY BONES ?
8
BONES IN THE MIDDLE OF EAR
HOW MANY ?
6 BONES - 3 IN EACH EAR
FONTANELLES
-
SOFT SPOT ON BABY’S HEAD.
-
-
6 FONTANELS, or areas where Ossification is incomplete at birth.
-
- The fontanels EVENTUALLY FUSE before a BABY IS 2-3 YEARS old.
What Are The Different
FONTANELLE'S &. FUNCTIONS
ANTERIOR FONTANELLE: LAST TO FUSE
- Frontal. - Sagittal. - and - Coronal Sutures
Occipital Fontanelle:
- Lambdoid - and - Sagittal Sutures
Sphenoidal Fontanelles:
- Squamous - and - Coronal Sutures
Mastoid Fontanelles:
- Squamous - and - Lambdoid Sutures
SINUSES
- Sinuses are Spaces or Cavities within some of the cranial bones.
4 Pairs of SINUSES
referred to: Paranasal Sinuses
- FRONTAL,
- MAXILLARY
- SPHENOID
- ETHMOID BONES
FRONTAL CRANIAL BONE: Contains
FRONTAL SINUSES
Occipital Bone
Forms the Posterior and Inferior Surfaces of the Cranium.
1. OCCIPITAL CONDYLES:
- Articulate with Neck
2. FORAMEN MAGNUM:
- Connects Cranial and Spinal Cavities
TEMPORAL BONE
-
Part of Lateral Walls of Cranium and Zygomatic Arches
-
-
Articulate with Mandible
-
-
Surround and Protects Inner Ear
SPHENOID
-
Unites Cranial and Facial Bones
- Contains SPHENOIDAL SINUSES
Ethmoid Bone
Roof of the Nasal Cavity
Palatine Bones
Form the Posterior Portion of the Hard Palate.
THE MAXILLAE
-
Form Upper Jaw and Hard Palate
- Contain MAXILLARY SINUSES (largest sinuses)
VERTEBRAL COLUMN
- Protects the Spinal Cord
-
-
26 Bones: Supports the Head and Body
-
-
24 Vertebrae: the SACRUM, and the COCCYX
VERTEBRAL COLUMN
Consists Of ?
The Vertebral Column consists of a series of Separate Bones, or Vertebrae, Connected in such a way that they form a Fexible Curved Rod.
VERTEBRAE SMALL BONE
SPINOUS PROCESS (or spine), its TWO TRANSVERSE PROCESSES, and the Hole In Its Center, VVcalled the VERTEBRAL FORAMEN.
2 CURVES of the VERTEBRAL
THORACIC and SACRAL CURVES
• Are called Primary Curves
• Or Accommodation Curves (accommodate internal organs)
LUMBAR and CERVICAL CURVES
- Are called Secondary Curves (appear after birth)
-
- Also called Compensation Curves
SPINAL CURVATURE:
CONVEX CURE: KYPHITIC
-
Primary Curve of spine is C in Babies.
- Gradually Secondary Curves develop in the Cervical and Lumbar regions; Growing Stops.
Kyphotic Curve - Thoracic Dpine: Balance and Shock Absorption
SCOLIOSIS
Defined as a Spinal Curvature
COMMON PARTS OF THE SPINAL CORD
- BODY
- ARCH
Cervical Vertebrae LOCATION:
( C1 – C7 )
Thoracic Vertebrae LOCATION:
( T1 – T12 )
Thoracic vertebrae LOCATION:
( T1 – T12 )
Lumbar vertebrae LOCATION:
( L1 – L5 )
How many RIBS DO WE HAVE?
12 RIBS
TRUE & FALSE RIBS
1-7 RIBS are TRUE Ribs
8-12 are FALSE.
STERNUM: 3 Parts of the Sternum
- MANUBRIUM
-
- STERNAL BODY
-
-
XIPHOID process
APPENDICULAR SKELETON
Allows us to Move and Manipulate Objects
Includes ALL Bones besides Axial Skeleton
• The LIMBS
• The supportive GIRDLES
PECTORAL - GIRDLE
Connects the Arms to the body
- TWO CLAVICLES
- TWO SCAPULAE
CLAVICLES
ALSO CALLED THE: Collarbones
SCAPULAE
Also called Shoulder Blades
HUMERUS
- Also called the Arm:
-
- is the Long Bone of the Arm and the 2nd Longest Bone in the body.
-
- Attached at the Concave GLENOID CAVITY of the scapula at its Proximal End
WRIST – HAND BONES: Name and Count
8 Bones: CARPAL or Wrist bones,
5 Bones: METACARPAL bones Palm of the Hand.
14 Bones: PHALANGESOR FINGER BONES (3 in all fingers, 2 in the thumb)
27 BONES In All
METACARPAL BONES
The 5 Long Bones of the Hand.
PHALANGES of the Hands: HOW MANY BONES
14 Total Finger Bones – Pollex.
BONES OF THE PELVIC GIRDLE
-
ILIUM - ISCHIUM - PUBIS:
-
-
Hip, or Pelvic Girdle, connects the legs to the Trunk.
-
-
Pelvic Girdle as a whole consists of 2 Large Coxal Bones (= pelvic bones).
-
- Bones Grow Together to become one bone in an adult
BONES OF THE LOWER LIMBS
-- Femur (Thigh)
– Patella (Kneecap)
– Tibia and fibula (Leg)
– Tarsals (Ankle)
– Metatarsals (Foot)
– Phalanges (Toes)
THE PATELLA
– Also called the Kneecap
- BASE attaches Quadriceps Femoris.
– APEX attaches Patellar Ligament.
THE TIBIA
Also called the Shinbone.
THE FIBULA
Attaches Muscles of Feet and Toes.
Foot bones comparable to the Metacarpals and Carpals of the Hand have Slightly Different Names. They are called METATARSALS and TARSALS in the foot..
-- The Largest Tarsal Bone is the CALCANEUS, or Heel Bone.
PHALANGES OF THE FOOT – PHALANGES
• 14 Bones TOTAL of the Toe Bones – Hallux:
• Big Toe or Great Toe, 2 Phalanges ( distal, proxima l)
– Other four toes:
• 3 Phalanges (distal, medial, proximal)
HematoPoiesis - ( RED Marrow )
BLOOD CELL PRODUCTION
-
Process of Blood Cell Formation.
- PROTECTION - Hard, Bony “Boxes” Protect Delicate Structures enclosed within them.
- LEVERAGE (force of motion) - As muscles contract and shorten, they Pull on Bones and thereby move them.
4 Major Types of Bones
According to Overall Structure
-
Humerus ------ Arm bone - Long
-
-
Carpals ----- Wrist bone - Short
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Frontal ------ Skull bone - Flat
-
-
Vertebrae - Spinal bones - Irregular
Diaphysis
-
Shaft — a Hollow Tube Made of Hard, Compact Bone.... Permits Easy Movement.
Medullary Cavity
-
HOLLOW Area inside the Diaphysis of a bone….
- Contains “SOFT yellow BONE MARROW”, an Inactive, Fatty Form of Marrow found in the Adult Skeleton
Epiphyses
-
Wide Part at Each End — Red Bone Marrow Fills in Small Spaces in the Spongy Bone composing the Epiphyses
Articular Cartilage
-
Thin Layer of Cartilage Covering Each Epiphysis.
- Functions like a Small Rubber Cushion over the ends of bones where they Form a Joint
Periosteum
Strong Fibrous Membrane covering long bone everywhere except at joint surfaces.
Endosteum
Thin Membrane that Lines the Medullary Cavity
SPONGY BONE
-
COMPACT BONE appears Solid to the Naked Eye.
- Porous Bone in the End of the Long Bone is called SPONGY BONE or CANCELLOUS BONE.
COMPACT & SPONGY BONE
Circular and Tube like OSTEON is composed of Calcified Matrix Arranged in Multiple Layers that Resemble the Rings of an Onion.
CARTILAGE
Cartilage is Avascular and Bone is Abundantly Vascular.
- NOTE: Cartilage Cells, called chondrocytes
HYALINE CARTILAGE
-
Most common type of Cartilage the Body.....
2 TYPES OF CARTILAGE
-
ELASTIC CARTILAGE: Gives Form to the External Ear, the Epiglottis
- FIBROCARTILAGE: Fibrous cartilage — is Strong, Rigid.
- Characterized by Abundant Fibrous Elements within the Matrix...
Bone Contains - 3 Types of Cells
1. OsteoCytes
2. OsteoBlasts
3. OsteoClasts
ONLY 2% of Bone Mass.
OSTEOBLASTS
-
Immature Bone Cells that Secrete Matrix Compounds
-
- ( OsteoGenesis )
OSTEOCYTES
FUNCTIONS:
- Maintain Protein and Mineral Content of Matrix
- Help Repair Damaged Bone
- Do NOT Divide
OSTEOCLASTS
-
Bone-Dissolving Cells that Remove the Hard Calcium Salts in Bone Matrix.
STRUCTURE OF SPONGY BONE
-
Matrix Forms an Open Network of TRABECULAE
- Space between TRABECULAE is filled with RED BONE MARROW.
- HAS BLOOD VESSELS
- FORMS RED BLOOD CELLS ( or, HEMATOPOIESIS )
BONE DEVELOPMENT
-
Human Bones Grow Until about AGE 25
- Osteogenesis - Bone formation
- Ossification - The Process of Replacing Other Tissues with Bone.
2 TYPES OF BONE GROWTH
-
INTRAMEMBRANOUS: Bone Forms Directly within MesenChyme.
-
-
ENDOCHONDRAL: Involves Replacement of Cartilage with Bone.
INTRAMEMBRANOUS
INTRAMEMBRANOUS Ossification:
- Occurs within the Womb ( Begins 8th- 9th week ).
ENDOCHONDRAL
All Cartilage is Ossified Except the areas between the Diaphysis (shaft) and Epiphysis (end).