Unit III: Bones

Identify the four normal curves of the body

Cervical, thoracic, lumbar, sacral

Identify curves

Pelvis brim : Pelvimetry Be able to discern make and female using several traits, width, heart shaped, 90 degree angle of pubis bones



Bone Healing: know the three steps




Fractures: know the types







Be able to label all bones of the skull, vertebral column, ribs and sternum. Know their functions.  You should be able to do this off of pictures from your book, coloring book, lab and unknown sources as well as the actual bones.


The functions and locations of fontanels


You do not need to Be able to discern the different types of vertebrae.


Discuss the roles of hormones in regulating bone growth and bone remodeling.


Be able to explain how a fetus and infant’s skeleton develops.


Be able to describe the disorders of the axial skeleton: cleft palate, deviated septum, spina bifida, abnormal vertebral curves, herniated disc and the difference between rickets and osteoporosis


Know the structural classification of joints

Know the functional classification of joints

synovial: know the parts of this type of joint and their function (KNEE)

synovial cavity: (diarthrosis); articular capsule ; synovial membrane; synovial fluid: accessory ligaments; menisci: bursae:


You do not need to know the types of specific synovial joints. Ex. Pivot, hinge…

Know the movements:

Movements at Synovial joints:

  1. angular
    1. flexion: decrease in angle between articulating bones
    2. extension: increase, often used to restore to anatomical position
    3. hinge, pivot, condyloid, saddle, ball and socket: flexion and extension
    4. hyperextension: put your head back
    5. abduction: move a bone away form the midline
    6. adduction: movement towards the midline
    7. condyloid, saddle, ball and socket: adduction and abduction
    8. circumduction: movement of a distal end in a circle (ball and socket)
  2. rotation: revolves around its own axis, shake your head no, ball and socket and pivot
  3. special: occur only at certain joints
    1. elevation: closing mouth and shrugging shoulders
    2. depression: opening mouth, reverse shrugged shoulders
    3. protraction: thrust your jaw out and clavicles
    4. retraction: protraction reversed
    5. inversion: movement of soles medially so they face each other
    6. eversion: move soles laterally face opposite
    7. dorsiflexion: stand on heels
    8. plantarflexion: stand on toes
    9. supination: palm is forward and upward (anatomical position)
    10. pronation: palm is backward and downward


Describe the functions of Bone and the Skeletal System:

  1. Support: soft tissues and muscles can attach
  2. Protection
  3. Movement
  4. Storage for minerals (Ca and P)
  5. Hematopoiesis in red bone marrow (pelvis, ribs, sternum, vertebrae, skull, epiphyses)
  6. Energy: yellow bone marrow (adipose cells with few blood cells: stores triglycerides)


Describe the Types of Bones:

Should be able to classify on shape and location

  1. long : curved shaft with heads at both ends(femur, tibia, fibula, humerus, ulna, radius, phalanges)
    1. both compact and spongy bone
  2. short: cube shaped, equal width and length, mostly spongy bone (carpals/wrist and ankle bones)
  3. flat: thin, give lots of protection, extensive areas for muscle attachment (cranial, sternum, ribs, scapulae)
    1. thin, curved, compact layer with spongy bone in between
  4. irregular: vertebrae and some facial bones, hip
  5. sesamoid: develop in certain tendons where there is considerable friction, tension, physical stress (palms, soles, vary) patella Function: protect tendons from excessive wear and tear, change direction of pull on a tendon therefore increasing efficiency of joint movement
  6. sutural bones are in joints in the cranium


Histology: Connective Tissue

What is meant by Calcification: a process of mineral salts (primarily: hydroxyapatie- a salt complex of Ca and P and Ca-Carbonate)salts deposit in the framework of collagen fibers and hardens



Describe the bone matrix: Sparsely distributed cells secrete matrix forming the intercellular materials

            Bone matrix:   mineral salts (inorganic) = hardness                Review: matrix vs cells

                                    Collagen fibers( organic) = strength


Describe the 4 types of cells in bone tissue:

            1. osteogenic cells: undergo cell division and become osteoblasts

2. osteoblasts: cells that form bone but cannot regenerate, located on the surface and secrete collagen and build bone tissue eventually trapping themselves in matrix and become osteocytes

3. osteocytes: mature bone cells, main bone cells and maintainmetabolism and exchange with blood, no regeneration

            Lacunae: cavities where osteocytes reside (in circles called lamellae)

                        **CYTES: maintain tissue

4. osteoclasts: megacell formed from 50 + monocytes with extremely powerful lysozyme that destroy bone matrix = resorption

Be able to label cells, Compact Bone: few spaces, external layer and bulk

  • Protection, support, resist stress by body’s weight
  • Concentric ring structure
  • Volkmans canals (perforating canals) blood vessels, lymph vessels and nerves penetrate transversely through bone width (blood vessels and nerves connect with others in meullary cavity, periosteum and Haversian canals)
  • Haversian canals: lengthwise
  • Concentric lamellae: rings of hard calcified matrix
  • Lacunae: small spaces between concentric rings which hold osteocytes
  • Canaliculi: tiny canals spreading from lacunae allowing projections of osteocytes to meet canals allowing for nutrient and waste exchange
  • Osteon (haversian system) a central canal with surrounding lamellae, lacunae, osteocytes and canaliculi






Describe bone formation in the fetus and the process of bone remodeling:

  1. Fetal skeleton is primarily composed of hyaline cartilage and fibrous CT
  2. This  cartilage “model” is covered with bone matrix by osteoblasts (secrete matrix)  and the cartilage is digested (begins 6th/7th week)


  1. Two methods of bone formation involve replacing CT with bone

intramembranous ossification : bone form on/in fibrous CT

a.      simpler method: used for flat bones of skull and mandible and sealing sutures after birth

b.      mesenchymal cells (tissue all CT comes from ) differentiate into osteogenic cells that beomce osteoblasts secreting matrix

c.      once trapped in their lacunae the osteocytes extend pm into canaliculi; salts are deposited and matrix hardens

d.      formation of trabeculae: as matrix forms it becomestrabeculae that fuse to form spongy bone; blood vessels grow in between trabeculae spaces and mesenchyme along newly formed bone; CT with blood vessels becomes red bone marrow

e.      development of periosteum: peripheral mesenchyme becomes periosteum, surface layersof spongy bone become compact bone

f.      much of the nre bone is reshaped into its adult size


2.      endochondral ossification: form bone within hyaline cartilage

a.      most bones made this way

b.      development of the cartilage model: bone site: mesenchymal cells form the shape of the future bone and develop into chondroblasts secreting cartilage matrix making a hyaline model.


  1. Long bone growth at epiphyseal plate is controlled by GH


Bone Remodeling in life is due to

  1. Ca+ in the blood
    1. Ca+ low: parathyroid glands release PTH which activates osteoclasts which destroy bone releasing Ca+ back into the bloodstream
    2. Ca+ high (hypercalcemia) Ca should be deposited into bone
  2. pull of gravity and muscles
    1. muscles attach to “bulky” bone and osteoblasts lay down new matrix and get trapped = osteocytes
    2. ie. Gymnasts, equestrians
    3. physical therapy


Bone Repair:

  1. Hematoma forms
  2. fibrocartillage callus : grow new capillaries into clotted blood= granulation tissue
    1. dispose of dead tissue by phagocytes
    2. CT forms a mass = fibrocartilage callus

                                                     i.     Cartilage matrix

                                                   ii.     Bony matrix

                                                  iii.     Collagen fibers

    1. splint closes the gap


  1. bony callus: spongy bone replaces fibrocartilage callus


Bone Markings:

depressions or cavities (indentations)

                                                    a.     foramen: a hole for blood vessels, nerves and ligaments

1.      ex. Formen magnum

    1. meatus: a tubelike channel in a bone

                                                    a.     ex. External auditory meatus of the temporal bone

    1. fossa: a shallow depression in/ on a bone

                                                    a.     ex. Mandibular fossa on temporal bone

Processes that form joints:

a. condyle : knuckle like , large rounded prominence

                                                                                                                 i.     ex. Condyle

b. head: a rounded prominence that forms a joint on the neck of a bone

                  ex. Head of the femur

c. facet: smooth, flat articulated surface

ex. Facet on vertebrae

Attachment processes

            a. tuberosity: a large rounded projection with a rough surface

ex. deltoid tuberosity of humerus

            b. spinous process or spine: sharp, slender projection

                        ex. Spinous process on vertebrae

            c. trochanter: large blunt projection only on femur (greater trochanter)

            d. crest: a prominent border or ridge (iliac crest of pelvis)



Long Bone Anatomy:

  • Proximal epiphysis: articular cartilage (a thin layer of hyaline cartilage reducing friction and absorbs shock) epiphyseal line
    • Epiphyses: thin layer of compact bone with spongy bone inside
  • Metaphysis: spongy bone (while growing has a epiphyseal plate: a layer of hyaline cartilage)
  • Diaphysis: shaft long and comact bone (out to in)
    • Periosteum: tough white fibrous membrane (CT) covers
    •  wherever there is not cartilage, growth and attachment for ligaments and tendons) compact bone,
    • Sharpey’s fibers connect and secure the periosteum
    • medullary cavity (yellow bone marrow)
    • endosteum: the lining of the cavity bone forming cells
  • Metaphysis
  • Distal epiphysis: articular cartilage

** Adults: red bone marrow in flat bones and epihyses


Paranasal sinuses are lined with what type of tissue that would secrete mucus and moisten air as it is inhaled?

simple columnar ciliated epithelial tissue  


The main hormone that regulates the Ca2+ balance between bone and blood is

parathyroid hormone


If an individual has hypercalcemia, meaning they have high levels of calcium in their blood, one would expect to see _______________ in their blood as well.

high levels of calcitonin


Place the following steps of endochondral ossification in the correct order:

1. hyaline  cartilage remains on the articular surfaces and the epiphyseal plates

2. Chondroblasts produce a growing hyaline cartilage model surrounded by perichondrium

3. Osteoblasts in the perchondrium produce compact bone

4. Secondary ossification centers form

5. Primary ossification center and medullary cavity form



Rickets is due to primarily a lack of



Floppy bones that are rubbery can form severe deformities like bow legedness are caused by



The formation of porous bones due to osteoclastic activity can be caused by

decreased estrogen and decreased calcium in the blood    


Name an opening for nerve passage?



Name a bone classified as a flat bone



What forms a lining for the medullary cavity?



Functions of the skeletal system do not include

Vitamin D production


Sites of hematopoiesis include

red marrow cavitites of spongy marrow, cavities in bones of infants, the spongy area between flat bones    


Name the cells that function in bone remodeling.

Osteoblasts and Osteoclasts                          


Which is characteristic of normal children's bones?

a.            the presence of epiphyseal lines      c.            The presence of a bony callus.        

b.            A medullary cavity filled with red bone marrow.


Describe what the osteon/haversian system exhibits: (the components)

a central haversian canal carrying a blood vessel; canaliculi that connect lacunae to the haversian canal; concentric lamellae of matrix; osteocytes in lacunae


Which of the following statements regarding the male pelvis is NOT true:

a.            the bones are heavier and rougher   c.            the male pubic arch is wider than a female           

b.            the male pelvis is narrow and deep  d.            the cavity of the pelvis is small


Since at birth the bones of the cranium have not completed their ossification, there are membranous portions between them called:



In the aged, osteoblastic activity is ____ osteoclastic activity.

less than


Where is compact bone located? Think long bone anatomy



What type of arthiritis is an autoimmune disorder?

Rheumatoid arthritis


Match the following joint types to the following questions

a.            Synarthroses        c.            Diarthroses         

b.            Amphiarthroses

c             exhibit a joint cavity


a             sutures  

c             Bones are connected by collagen fibers       

b             Types include intervertebral joints 

c             all are freely movable       

b             slightly moveable              

b             Bones connected by a disk of cartilage                        

a             immovable


f              E the  mandible bone? T/F

t              F the Mandible bone? T/F 

t              C is the lacrimal bone. T/F              

f              A is the parietal bone T/F 

t              D is the nasal bone. T/F    

t              B is the parietal bone. T/F


f              D is the lambdoidal suture. T/F       

t              G is the occipital bone. T/F             

t              B is the sphenoid bone. T/F             

t              T is the ethmoid bone. T/F

f              M is the styloid process. T/F          

t              S is the zygomatic process. T/F


f              Letter C is the manubrium. T/F       

t              E attaches to costal cartilage T/F    

t              Clavicle attaches to D. T/F



t              C is the glenoid fossa. T/F

t              B is the acromion process. T/F.      

f              D is showing the posterior view. T/F


f              E is the olcranon process. T/F        

t              AD is the trochlea T/F      

t              Bone G is the humerus. T/F             

t              AB  is the coronoid fossa. T/F


f              D is the distal phalanx.  T/F             

t              A are collectively known as carpals. T/F       

f              This view is anterior. T/F


f              B is the acetubular fossa. T/F.         

t              A is the ilium T/F              

t              C is the ischium. T/F


Firgure 1                                                                          Figure 2

t              Fig. 1. B is the greater trochanter. T/F          

f              Fig 1. D are the epicondyltes. T/F  

t              Fig 1. E is the intercondyloid fossa. T/F       

t              Fig 2. AD is near the tibial tuberosity. T/F   

f              Figure 2, AB is on the Lateral side. T/F        

t              Figure 2, AB is part of the ankle. T/F


t              A is the calcaneous. T/F    

f              AD  is the middle pphalanges. T/F  

f              This is the left foot. T/F



Figure 1                                Figure 2                                    Figure 3










b             Figure 1 is what type of joint?        

a             Figure 2 is what ype of joint?          

c             Figure 3 is what type of joint?        

a             Which type is slightly moveable?   

c             Which type is a common location for arthritis to develop?


The location where two bones meet is called an articulation: T/F



A reduction is the process of putting a dislocated bone back into place. T/F


Bursae are small pockets of synovial fluid that form to reduce friction and act as a shock absorbers where ligaments and tendons ? T/F


What is the cause of gout?

 the accummulation of uric acid in the blood forming sodium urate crystals and embedding into soft tissue


An immovable joint is a(n)



A slightly movable joint is a(n)

a.         synarthrosis       d.         gomphosis        

b.         diarthrosis         e.         synostosis        

c.         amphiarthrosis


A freely movable joint is a(n)



A suture would be an example of a(n)

a.         synarthrosis     d.         diarthrosis        

b.         syndesmoses     e.         amphiarthrosis  

c.         symphysis


A synovial joint would be an  example of a(n)



Which of the following is not a function of the synovial fluid?

a.         shock absorption                                                  d.       provide nutrients           

b.         increase osmotic pressure within a joint           e.         protect articular cartilage

c.         lubrication


Decreasing the angle between the bones is termed



A movement towards the midline of the body is termed



A twisting motion of the foot that runs the sole inward is termed (facing medially)



The opposite movement of pronation is



The movements known as dorsiflexion and plantar flexion involve moving the



The knee joint is reinforced by

a.         cruciate ligaments                                    d.       tibial (medial) collateral ligaments           

b.         fibular (lateral) collateral ligaments           e.         all of the above           

c.         patellar ligaments


Articular cartilage and bursae would most likely be found in which of the following?

a.         gomphosis         c.         pubic symphysis           

b.         suture                d.        the knee


The joints between the vertebrae and the joint between the hip bones are examples of which joint type?




A stretched or torn muscle is called a



Due to the avascular structure of connective tissue, a ________ is much more serious than a _________ due to the slow healing process and the loss of some effectiveness.

sprain, strain     


Aging joints demostrate all of the following characteristics EXCEPT:

a.         decrease in synovial fluid            d.         genetics

b.         articular cartilage thickens       e.         wear and tear   

c.         ligaments shorten and lose flexibility


__________ arthritis is the result of an antibacterial infection and treated with antibiotics.



A degenerative disorder of the articular cartilage  of the larger joints causing exposed bone to grow spurs and leads to painful crunching noises when joint is used.



This type of arthritis is treated through weight management, avoiding foods such as liver, kidney’s sardines, and alcohol due to the high nucleic acid content.





A body has been found at a crime scene where the lividity disappears when the coroner applies pressure to the skin. The coroner correctly times the death within the last 2 hours. T/F


When the rate is high enough and the muscle fiber cannot relax at all between stimuli  the twitches fuse into one smooth sustained contraction called  



Although, the autonomic nervous system does run to the heart it is not responsible for

maintaining regular rhytmic beats


Cardaic muscle has which characteristic to enable the organ to beat in synchrony?

            gap junctions


The structure of the heart demands a long refractory period which ensures

the heart cannot go into tetanus


An athlete can increase endurance by

loading creatine phosphate and loading glycogen  


In order to grow larger muscles, meaning grow more muscle cells, an individual can

take a myostatin inhibitor


Atrophy is the partial or complete wasting away of a part of the body.



Amyotrophic lateral scleros, otherwise known as Lou Gehrig’s disease, involves 

motor neuron degeneration as the cause of loss of muscle function


Myasthenia gravis is an auto-immune where antibodies are made to attack        

acetlycholine receptors


Match the following terms to their application in determining the time of death for a corpse.

a.         Algor Mortis      c.         Livor Mortis     

b.         Rigor Mortis


c          discoloration of the skin occurs when red blood cells begin to break and spilling their contents including hemoglobin which turns purple when outside of RBC. Purple color is visible on skin where blood pools       

b          temporary stiffnes         

a          a body loses about 1 degree of body heat per hour


The primary function of the skeletal muscle is

a.         movement of body extremities and locomotion           c.production of heat      

b.         movement of contents through the viscera


When the neurotransmitter is released and attaches to the receptors on the sarcolemma, __________ rushes into the cell causing, ____ which subsequently leads to the contraction process.

Na+, depolarization       


The mechanical force of the contraction is generated by:

sliding of the thin filaments past the thick


The ions that are released inside the muscle cell during action potential are



Characteristics of isometric contractions

shortening; increased muscle tension throughout; use in resistance training


The dense layer of collagen fibers that surround an entire skeletal muscle is the



Nerves and blood vessels that service the muscle fibers are located in the connective tissues of the perimysium


The delicate connective tissue that surrounds the skeletal muscle fibers and ties adjacent muscle fibers together is the



The bundle of collagen fibers at the end of a skeletal muscle that attaches the muscle to the bone is called a(n)



Skeletal muscle fibers differ from “typical cells”in that these muscle fibers

have many nuclei


List the advantages of having many nuclei in a skeletal muscle fiber :

the ability to contract; the ability to produce large amounts of the enzymes and structural proteins needed for contraction ; the ability to produce more ATP with little oxygen; the ability to repair the fiber after an injury


The cell membrane of skeletal muscle is called the



The cytoplasm of a skeletal muscle fiber is called the



The command to contract is distributed throughout a muscle fiber by the

transverse tubules


The membranous network of channels within a muscle fiber is the

sarcoplasmic reticulum


The functional unit of a skeletal muscle is the



The sarcoplasmic reticulum stores

calcium ions


Cross bridges are located on

myosin molecules


At rest, active sites on the actin are blocked by

tropomyosin molecules


At rest, the tropomyosin molecule is held in place by

troponin molecules


The ______________ contains vessicles filled with acetylcholine.

synaptic knob


The space between the neuron and the muscle is the

synaptic cleft


Active sites on actin become available for binding when

calcium binds to troponin


In response to action potentials arriving from the transverse tubules, the sarcoplasmic reiculum releases

calcium ions


The type of contraction represented by a single stimulus contraction relaxation sequence is

a twitch


Calcium ions are released from the sarcoplasmic reticulum during the ______ phase of contraction.



The smooth but steady increase in muscle tension produced by increasing the number of active motor units is called:



The type of contraction in which the muscle fibers produce increased tension, but do not shorten is called



A resting muscle generates most of its ATP by

aerobic respiration


Creatine phosphate

acts as an energy reserve in muscle tissue


When energy reserves in a muscle are exhausted or lactic acid levels increase

fatigue occurs


Describe Fast fibers

do not have high resistance to fatigue; contract quickly; do not have a high concentration of myoglobin; do not have many mitochondria


The type of muscle fiber that is best adapted for endurance is the

slow fiber


Activities that require anaerobic endurance

a.         require maximal contraction of muscles for short periods of time       

c.         usually do not cause an individual to develop an oxygen debt        

b.         do not use ATP very quickly     

d.         do not rely on the energy reserves of creatine phosphate


During activities requiring aerobic endurance

a.         glycogen and glycolysis are the primary sources of reserve energy 

d.         fatigue occurs in a few minutes  

b.         oxygen debts are common      

c.         most of the muscle’s energy is produced in mitochondria


Which of the following is not a characteristic of smooth muscle?

Nerves that innervate smooth muscle are under voluntary control.


Identify the  characteristic of cardiac muscle?

Striated; contain sarcomeres; cannot be tetanized; Nerves that innervate cardiac muscle are under involuntary control; are uninucleate


The more moveable end of a muscle is the



A muscle that assists the muscle that is primarily responsible for a given action is a(n)



Fast muscle fibers can develop a larger number of mitochondria in response to

repeated, exhaustive stimulation


Because skeletal muscle contractions demand large quantities of ATP, skeletal muscles have

a rich vascular supply


How would blocking the activity of acetylcholinerase affect skeletal muscle? (acetylcholinerase is an enzyme that degrades acetylcholine.

It would cause spastic paralysis (muscles are contracted and unable to relax)


Which of the following hormones regulate(s) calcium and phosphate ion concentrations?

both calcitonin and parathyroid hormone


Which hormone stimulates growth of muscle tissue and increased muscle mass?



In which of the following would the ratio of motor nuerons to muscle fibers be the greatest?

a.         large muscles of the upper arms  c.         muscles that control the eye    

b.         postural muscles of the back       d.         leg muscles


Which of the following scenarios would produce the most tension?

a.         a muscle with 20 motor units most active         b. a  muscle with 10 motor units active



Which of the following activities would employ isometric contractions?

a.         flexing the forearm         c.         maintaining an upright posture


Increased oxygen consumption would accompany

increased heat production; increased muscle activity; increased conversion of lactic acid to glucose; increased aerobic respiration by muscle cells


A person whose genetic makeup makes them a better marathon runner than a sprinter probably has more ________ in their leg muscles.

slow fibers


The term used to describe a number of inherited diseases characterized by progressive muscular weakness and deterioration.

muscular dystrophies


Rigor mortis occurs at death due to a lack of