ANATOMY
UNIT 4: REVIEW
FLASHCARDS
Which structures are included in
the skeletal system?
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Bones
Cartilage
Fibrous Membranes
Joints
What occurs during
Intramembranous Ossification?
• Fibrous membrane forms on the outside of
the cartilage.
• Ossification centers form between the
fibrous membrane and cartilage.
• Osteoid is secreted from the oss. Centers.
• Clavicles and skull formed.
What occurs during
Endochondral Ossification?
• Ossification centers form within the cartilage.
• Osteoid secreted from oss. Centers
• Bone collar formed just under fibrous membrane
(est. during Intra.Oss.).
• Spongy bone forms on innermost region,
outerlayers of osteocytes lament to form
compact bone.
• Osteoclasts devour innermost spongy bone to
form medullary cavity.
• All other bones formed.
What occurs during Postnatal
Growth?
• Lengthening of bones
• Widening of bones
• Hormone regulation
What is the axial region of the
skeleton?
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Very center
Skull
Vertebra
Ribs
Pelvis
What is the appendicular region
of the skeleton?
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Off center
Shoulders
Hips
Limbs
What are some examples of flat
bones?
• Skull / Cranial Bones
• Sternum
What are some examples of
short bones?
• Wrist
• Ankle
What are some examples of
Irregular Bones?
• Vertebrae
• Hip
• Pelvic
What are some examples of
Long bones?
• Limbs
• Phalanges
What is the function of a flat
bone?
• Protection
• Like a plate of armor
What is the function of a short
bone?
• Allow for increased mobility
What is the function of an
Irregular Bone?
• Allow for attachment sites for ligaments
• Connect Joints / Increase # of Joints
What is the function of Long
Bones?
• Structure & Support
• Weight Bearing
What is the function of the
skeletal system?
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Support
Protection
Movement
Mineral & Hormone Storage
Blood Cell Formation (in the marrow)
What is compact bone?
• The outermost layer of bone
• Dense + Solid
What is spongy bone?
• The innermost bone
• Hole-y / Porous
• Little spines of bone = Trabeculae
What do you call the ends of a
Long Bone?
• Epiphyses
What do you call the shaft /
center of a long bone?
• Diaphysis
What is the Epiphyseal Line?
• Remnant of Epiphyseal Plate
• Where cartilage used to grow/divide to
allow for pubescent growth
• Found in the Epiphysis
What is the Periosteum?
• Outermost fibrous membrane
• Surrounds compact bone
What is the Endosteum?
• The innermost fibrous membrane
• Surrounds spongy bone
What causes bone injury?
• Increased weight
• Unusual twisting
• Unusual Rotation
What is a greenstick fracture?
• Partial break of the bone
• Common in kids
What is a depressed fracture?
• Bone is sunken in
• Typical in skull
What is a compressed fracture?
• Bone is crushed into a million little pieces
• Common in porous bones
What is a spiral fracture?
• Ragged break
• Break on the diagonal
• Caused by unusual twisting
What is a comminuted fracture?
• Bone breaks into 3 or more pieces
What is an epiphyseal fracture?
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Break @ Epiphyseal Plate
Common in kids
Common in areas where cartilage is FRESH
OR
Common in areas where cartilage is breaking
down
What are the events in bone
repair? (In Order)
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Hematoma Formation
Fibrocartilaginous Callus Formation
Bony Callus Formation
Final Repair
What would happen if your bones
skipped Fibrocartilagionous Callus
Formation during bone repair?
• Blood and Dead Bone Cells would remain
at the fracture site.
• Bone would not begin repair.
• Collagen fibers would not be secreted to
connect bone fragments.
What are the regions of the
vertebral column?
[Superior]
• Cervical
• Thoracic
• Lumbar
• Sacral
[Inferior]
What is the purpose of a joint?
• Allow for circular movement
• Allow for angular movement
• Increase mobility / Decrease rigidity
Where can you find a Condyloid
Joint?
• Wrist
• Knuckles
Where can you find a Plane
Joint?
• Intercarpal
• Intertarsal
• Vertebrae
Where can you find a Saddle
Joint?
• Thumbs
• Metacarpals
Where can you find a Ball &
Socket Joint?
• Shoulders
• Hips
What is skeletal muscle?
• On top of bones
• Voluntary movement
• Overall Body mobility
What is cardiac muscle?
• Heart muscle
• Involuntary movement
• Heartbeat & Blood pumping
What is smooth muscle?
• Digestive, Excretive, Respiratory Organs
• Involuntary movement
• Squeezing
What is the function of the
muscular system?
• Overall body movement
• Maintain bipedal posture
• Generate heat during contraction
What are the structures within
skeletal muscle?
[Microscopic]
• Myofilament (Actin & Myosin)
• Sarcomere
• Myofibril (Organelle)
• Muscle Fiber (cell)
• Fascicle (bundles w/in whole muscle)
• Muscle
[Macroscopic]
What is a sarcomere?
• The contractile unit/portion within the
myofibril
What are the 2 myofilaments?
• Actin
• Myosin
What are “other words” for actin
and myosin?
• Thick Filament = Actin
• Thin Filament = Myosin
What is a myofibril?
• The unique muscle cell organelle which
contains contractile elements.
What must occur PRIOR to the
opening of the Na/K channels
(during a muscle contraction)?
• Binding of ACh (acetylcholine) to the
muscle at the neuromuscular junction.
What must occur for a muscle to
relax / set up for the next
contraction?
• Calcium must be returned to the
sarcoplasmic reticulum.
• Troponin-Tropomyosin must recover actin
• Myosin must release actin
• ATP reloads onto myosin
What “slides” during a muscle
contraction?
• Actin & Myosin
• The Myofilaments
• Hence…. Sliding Filament Theory 
What occurs during a muscle
contraction (list out the events)?
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Depolarization of sarcolemma
Generation of action potential across muscle
Release of Ca ions from sarcoplasmic reticulum
Binding of Ca to troponin-tropomyosin-actin structure
Conformation change of troponin-tropomyosin structure
Actin exposed
Attachment of myosin head to actin
Myosin uses energy in ATP
Actin & Myosin Slide towards center of sarcomere
Ca ions back to sarcoplasmic reticulum
Tropomyosion recovers actin, relaxation
Which bones are in your arms?
• Bicep Area = Humerus
• Forearm Area = Radius + Ulna
Which bones are in your legs?
• Thigh Area = Femur
• Shin Area = Tibia & Fibula
Which bones are in your jaws?
• Upper = Maxilla
• Lower = Mandible
Which bones make up your
Thoracic Region?
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Ribs…
Which connect to the vertebra in back….
BUT connect to the sternum in the front…

Which bones are included in
your pelvic girdle?
• Iliac crest
• Pubis
• Ischial spine
What is the ONE thing that would
screw up mummification?!
• BACTERIA!!!
How can you tell if someone
suffered from arthritis?
• Lack of cartilage in between joints
• Bones sitting on top of each other
• Possibly smaller bones (due to wearing
down / friction)