Chapter 7 Note Outline: Skeletal System
Part 1 Objectives: Structure, Growth and Development
• 1) List the active tissues in a bone.
• 2) Describe the general structure of a bone, and list the functions of its parts.
• 3) Distinguish between intramembranous and endochondral bones, and explain how such bones develop and grow.
• 4)Discuss the major functions of bones.
Introduction
• Bones are very active tissues
• Each bone is made up of several types of tissues and so is an ______.
• Bone functions:
• ______body and provides shape.
• ______internal organs.
• ______and anchorage of ______.
• ______storage. (calcium and phosphorus)
• ______(blood formation)
Bone Structure
• Bones differ in size and shape, yet are similar in several ways.
Classification of Bones
Bones are classified according to following shapes:
• ______– Forearm and thigh bones
• ______– bones of the wrists and ankles
• ______– ribs, scapulae and some skull bones
• ______– Vetebrae and some facial bones
• ______(small and nodular)- kneecap
Structure and Formation of Bone
• Osteocytes – mature bone ______; makes up bone
• Bone = ______% organic material and ______% inorganic mineral salts and water.
• Organic
• ______(fibrous material) - flexibility
• Jellylike material between collagen fibers
• Inorganic
• Mineral salts (magnesium phosphate, calcium carbonate, calcium fluoride, etc)
• Gives bones ______and durability, brittle
Parts of a Long Bone
• Expanded ends of bones that form joints with adjacent bones are called ______.
• Articular cartilages (______cartilage) cover the epiphyses.
• The shaft of the bone is the______.
• A tough layer of vascular connective tissue, called the ______, covers the bone and is continuous with ligaments and tendons.
• A bone's shape makes possible its function; bony processes or grooves indicate ______of ______for muscles.
• Compact bone makes up the wall of the diaphysis; the epiphyses are filled with spongy bone to reduce the ______of the skeleton.
• The diaphysis contains a hollow medullary cavity that is lined with ______and filled with______.
Terminology
• Osteoblasts: Bone cells that ______new bone tissue
• Osteoclasts: Bone cells that secrete enzymes that ______bone from the medullary canal
• Medullary Canal – marrow cavity of the bone
• Central Canals (Haversian) – branch into compact bone and carry ______for nourishment (go up and down)
• Perforating Canals (Volkman’s) – transverse bone tissue (______)
Microscopic Structure
• Bone cells (osteocytes) are located within ______that lie in concentric circles around central canals.
• Osteocytes pass nutrients and gasses in the matrix through ______.
• Intercellular material consists of ______
• In compact bone, osteocytes and intercellular material are organized into ______that are cemented together.
• Central canals contain blood vessels and nerve fibers, and extend ______through bone.
• Central canals are interconnected by transverse ______canals.
• Unlike compact bone, the osteocytes and intercellular material in spongy bone are not arranged around central canals.
Storage of Inorganic Salts
• The inorganic matrix of bone stores inorganic mineral salts in the form of ______that is important in many metabolic processes.
• Calcium in bone is a reservoir for body calcium; when blood levels are low, osteoclasts release calcium from bone.
• Bones can also accumulate harmful elements, such as ______
Blood Cell Formation
• Blood cells begin to form through hematopoieses in the yolk sac; they are later manufactured in bone ______.
• Two kinds of marrow occupy the ______cavities of bone.
• ______marrow functions in the formation of red blood cells, white blood cells, and platelets, and is found in the spongy bone of the skull, ribs, sternum, clavicles, vertebrae, and pelvis.
• ______marrow, occupying the cavities of most bones, stores ______.
Bone Formation
• Embryonic skeleton – initially collagenous protein fibers secreted by osteoblasts
• Osteoblasts – ______
• Later, hyaline cartilage is deposited between fibers
• ______– mineral matter begins to replace previously formed cartilage created bone (at _____ weeks)
• Fontanel – ______on baby’s head (bones not complete)
• Ossification continues through childhood
Bone Development and Growth
• Bones form by replacing ______tissues in the fetus.
• Intramembranous bones – form within ______layers
• Endochondral bones – replace ______of cartilage
Intramembranous Bones
• The flat bones of the ______form as intramembranous bones that develop from layers of connective tissue.
• Osteoblasts deposit bony tissue around ______
• Once osteoblasts deposit bone that is located in lacunae, they are called osteocytes.
• Cells of the membranous connective tissue that lie outside the developing bone give rise to the ______.
Endochondral Bones
• Most of the bones of the skeleton fall into this category.
• They first develop as ______cartilage models and are then replaced with bone.
• Cartilage is broken down in the diaphysis and progressively replaced with bone while the periosteum develops on the outside.
• Cartilage tissue is invaded by blood vessels and ______that first form spongy bone at the primary ossification center in the diaphysis.
• Osteoblasts beneath the periosteum lay down compact bone outside the spongy bone.
• Secondary ossification centers appear later in the epiphyses.
• A band of hyaline cartilage, the epiphyseal plate, forms between the two ossification centers.
• Layers of cartilage cells undergoing ______make up the epiphyseal plate.
• Osteoclasts ______the calcified matrix and are replaced with bone-building osteoblasts that ______bone in place of calcified cartilage.
• Bone growth in length
• Bones ossify from center of diaphysis towards epiphyseal extremities.
• Growth zone – where ossification occurs; doesn’t interfere with articulation between 2 bones
• Length of diaphysis continues until all epiphyseal cartilage (______plate) is ossified.
• New bone growth can occur in a broken bone at any time
• Bone cells near site of ______become active
Homeostasis of Bone Tissue
• Osteoclasts tear down and osteoblasts build bone throughout the lifespan with the processes of resorption and deposition, with an average of _____% to _____% of bone calcium exchanged annually.
Part 2 Objectives: Bones!
• 5) Distinguish between the axial and appendicular skeletons and name the major parts of each
• 6) Locate and identify the bones and the major features of the bones that compose the skull, vertebral column, thoracic cage, pectoral girdle, upper limb, pelvic girdle, and lower limb.
Skeletal Organization
• ______bones in the human body
• Axial Skeleton – located on the body’s ______
• Skull, vertebrae, ribs & sternum
• Appendicular Skeleton – associated with the ______of the body
• Pectoral girdle (clavicle, scapula), arms, wrists and hands
• Pelvic girdle (pelvis), legs ankles and feet
• Joints
The Skull
• The skull is made up of ______bones, including 8 cranial bones, 13 facial bones, and the mandible.
• You will need to know 11 bones and 4 important sutures in the skull
• The cranium encloses and protects the brain, provides attachments for muscles, and contains air-filled sinuses that reduce its weight.
• Look at your Bones Study guide for Bones to Know!
Sutures
• Joints between skull bones
• Coronal, Sagittal, Lamboidal, Squamosal
Vertebral Column
• The vertebral column is what makes up the “______”
• Supports the head, provides attachment for ribs, and encloses spinal cord
Cervical Vertebrae
• Seven vertebrae located in the ______area
• Atlas – ______– first cervical vertebra
• Articulates with ______bone in skull
• Permits us to nod up and down (______)
• Axis – ______– second cervical vertebra
• Forms pivot for atlas to______
• Permits us to turn our heads (______)
• Spinous process of 3rd – 6th vertebrae are ______
• Divided at one end into 2 equal parts (2______)
Thoracic Vertebrae
• Twelve thoracic vertebrae are located in the ______area
• Have ______spinous processes
• Have facets for articulation with ______
Lumbar Vertebrae
• Five lumbar vertebrae are located in the ______
• Have large______that bear most of the body’s weight
• Have prominent transverse processes
• Short, thick spinous process
Sacrum and Coccyx
• Sacrum
• Wedge shaped, composed of ______fused vertebrae
• Forms posterior pelvic girdle
• Articulation points for hips
• Coccyx
• “______”
• Small and triangular, composed of ______fused vertebrae
Thorax
• Helps protect the ______region of body
• Ribs( ______) – 3 kinds of ribs
• True – ______(7 pairs)
• Articulate with vertebrae and sternum
• False – ______(3 pairs)
• Articulate with vertebrae and costal cartilage that attaches to true ribs
• Floating (2 pairs)
• Articulates with vertebrae but not attached to costal cartilage or sternum
• Sternum- 3 parts
• ______– upper region
• Body – midportion
• Xiphoid process – inferior end of sternum - ______
Appendicular Skeleton
• ______bones
• Composed of the
• Upper Extremities
• Pectoral girdle (clavicle, scapula), arms, wrists and hands
• Lower Extremities
• Pelvic girdle (pelvis), legs ankles and feet
Pectoral Girdle
• AKA the shoulder – permit ______of muscles assisting in arm movement
• 2 clavicles and 2 scapulae
Arms
• Composed of
• 2 humerus – 2nd largest bone in body
• 2 radius – ______side of lower arm, can rotate around ulna
• 2 ulna – larger than radius, limited movement, proximal end =______process
Wrists and Hands
• ______bones per hand
• Wrists – ______
• 8 small bones in 2 rows held together by______
• Hands composed of 2 parts
• 5 ______
• 14 ______
• Fingers have 3 parts, distal, middle, proximal
• Thumb has 2 parts, proximal and distal
Pelvic Girdle
• Pelvis ______soft organs of lower abdominal area
• Found on either side of midline of body
• Composed of 3 bones – ilium, ischium and pubis
• Fuse with ______to form bowl-shaped structure
• Form joint in front – ______
• Form joint in back with sacrum – ______
• Female pelvis is wider, lighter and smoother
Legs
• Femur – ______bone
• Lightest and strongest
• Tibia – ______bone
• largest in lower leg, medial
• Fibula – lateral bone of leg
• Patella - ______
• Seismoid bone, surrounded by bursae
Ankles and Feet
• Ankles – ______
• 7 bones – Calcaneus, talus, navicular, cuboid, and 3 cuneiform bones
• Feet
• 5 ______bones
• Form 2 distinct arches, longitudinal and transverse
• Strong ligaments and tendons
• Toes – ______
• Big toe – 2 phalanges, proximal and distal
• 4 toes – 3 phalanges, proximal, middle and distal
Part 3 Objectives: Joints and Disorders
• 7) Classify joints according to the type of tissue binding the bones together, describe their characteristics and name an example of each.
• 8) List 6 types of synovial joints and describe the actions of each.
• 9) Explain how skeletal muscles produce movement at joints and identify several types of joint movements.
• 10) Identify several bone and joint disorders.
Joints- Intro
• Joints (______) are the functional junctions between bones.
• Joints enable a wide variety of body movements.
• Joints can be classified according to the degree of movement possible and can be immovable, slightly movable, or freely movable.
• Joints can also be classified according to the type of ______that binds them together.
Fibrous Joints
• Fibrous joints are held close together by dense connective tissue and are ______(sutures of skull) or only ______movable (joint between the distal tibia and fibula).
Cartilaginous Joints
• ______cartilage or disks of ______unite the bones in cartilaginous joints.
• Intervertebral disks between vertebrae help absorb shock and are ______
• Other examples of cartilaginous joints include the symphysis pubis and the first rib with the sternum.
Synovial joints
• ______
• Most of the joints in our body
• Consists of three main parts
• ______cartilage
• ______(joint capsule)- lubricated sacs to reduce friction between tendons and bones
• ______capusule – lined by synovial membrane that secretes watery fluid into synovial cavity
• ______
6 Types of Synovial Joints
Type of Joint / Ball and Socket / Hinge / Pivot / Gliding / Saddle / Condyloid (ellipsoidal)Movement
Found in…
Disorders of Bones and Joints
• Fractures – ______in bone
• Most common traumatic injury to bone
• Types of Fractures - basics
• Partial (fracture) - incomplete break of bone, e.g. a greenstick fracture or a hairline fracture.
• Complete (fracture) - complete break resulting in bone being separated into 2 or more pieces.
• Closed or "Simple" (fracture) - fractured bone(s) do not break through the skin.
• Open or "Compound" (fracture) - at least some part of fractured bone(s) protrude through the skin.
Other Injuries
• Dislocation- Bone displaced from proper position in joint
• Sprain- Sudden or unusual motion, ligaments torn but joint not dislocated
• Strain- Overstretching or tearing muscle
Diseases of Bones and Joints
• Arthritis – ______of one or more joints
• Rheumatoid arthritis – chronic, ______disease that causes inflammation in joints, thickening of synovial membrane and fusion of joints
• Muscles will atrophy (______) and cartilage will degenerate
• Gout – joint disorder that causes acute inflammation commonly affecting the ______
• Body’s reaction to accumulation of ______crystals in affected joint
• Rickets – caused by lack of vitamin _____, bones become ______due to lack of calcification
• Can be prevented by sufficient Ca, vitamin D and sunlight.
• Slipped (herniated) disc
• Cartilage between vertebrae ruptures or protrudes out of place, placing pressure on spinal cord