Download Exam 2 Review KEY

BIOL 255 SI, Molly
Exam 2 Review KEY
10-3-16
1.) Give some functions of bone.
Support, protection, movement, mineral storage, blood cell production, storage of energy
2.) In a bone, there are osteoprogenitor cells, osteoblasts, osteocytes, and osteoclasts. How do all
these cells work together?
Osteoprogenitor cells are unspecialized and become osteoblasts. Osteoblasts form the bone
by secreting osteoid (matrix). Osteocytes are created from osteoblasts and work to maintain
the bone. Osteoclasts form from monocytes and work to resorb the old bone so the
osteoblasts can put new bone on top of it.
3.) Give an example of:
a. Long bones – humerus
b. Short bones – carpals
c. Flat bones – frontal bone
d. Irregular bones – vertebrae
e. Sesamoid bones – patella
4.) Describe each of the following parts of long bones (i.e. Where are they located? What are their
functions?)
Diaphysis – long part of the bone
Epiphyses – proximal and distal ends of bone/ spongy bone with red bone marrow for
hematopoiesis, site of attachment for tendons and ligaments
Metaphyses – located between diaphysis and epiphysis/ site of epiphyseal plate where long
bone growth occurs
Articular cartilage – thin layer of hyaline cartilage that covers epiphyses
Periosteum – fibrous covering of the rest of the bone/ site of bone growth, repair, and
nutrition
Medullary cavity – located in the diaphysis/ site of yellow marrow (fat and blood cells)
5.) What is the difference between intramembranous and endochondral ossification vs interstitial
and appositional growth?
intramembranous and endochondral ossification (hyaline cartilage model) are the steps in
creating new bone. Interstitial (length – from epiphyseal plate) and appositional (width)
growth are the constant remodeling and creating bone
6.) The cribiform plate of the Ethmoid bone allow passage of the olfactory nerves which involves
your sense of smell, while the crista galli which is a small ridge of bone that attaches to the dura
mater of the brain’s meninges and holds the brain in place. 2B 2
7.) The sella turcica of the sphenoid bone contains the hypophyseal fossa which encloses the
pituitary gland, while the optic canals of the sphenoid bone allows passage of the optic nerves
where some nerves cross in the optic or chiasmic groove. 2B3
8.) In the intervertebral disks, the annulus fibrosis encloses the gelatinous nucleus pulposis and
acts like a shock absorber.2B 5
9.) Articulations or joints are classified by how they function, Diarthroses are free moving,
Amphiarthroses are slightly moveable and synarthroses are unmovable. 2C 1
10.) Classify the Fibrous joints:
Structure
Function
Amount of movement
Gomphoses = Synarthroses = immobile
Sutures = Synarthroses = immobile
Syndesmoses = Amphiarthroses = slightly mobile
11.) Classify the Cartilaginous joints:
Structure
Function
Amount of movement
Synchondrosis = Synarthroses = immobile
Symphysis = Amphiarthroses= slightly mobile.
12.) Classify the Synovial joints:
Structure
Function
Amount of movement
Synovial = Diarthroses = freely moving.
13.) Movements at synovial joints are caused by muscle contraction. The origin of the muscle is
attached to less movable bone, which is usually located more medially while the insertion is
where it attaches to moveable bone is usually more lateral. 2C 3
14.) In angular movements, flexion decreases the angle and extension increases the angle between
two bones, while hyperextension is movement beyond the anatomical position and lateral
flexion is bending along the frontal plane.
15.) List the functions of muscle below.
Motion, stabilizing body position and joints, regulation of volume, thermogenesis
16.) Skeletal Muscle is striated, multinucleated, unbranched and under voluntary control. The
skeletal muscle cell can also be referred to as muscle fibers or myofibers. Its function is to
move bones and stabilize body positions and skeletal joints. 2D 1
17.) Cardiac Muscle is also striated, but is uninucleate, branched, and under involuntary control
which can also be referred to as autorhythmic. Its function is to pump the blood and regulate
volume. 2D 1
18.) Smooth muscle which can be found in blood vessels, stomach & intestines, is nonstriated,
involuntary and autorhythmic and under the control of the nervous system.
19.) Lay out the organization of a muscle, including the coverings of the appropriate layers.
Muscle (epimysium)  fascicle (perimysium)  Myofiber (endomysium)  myofibril 
myofilaments
**SARCOMERE ACTIVITY**
20.) Motor units consist of a motor neuron and all the myofibers (muscle fibers) that stimulates or
innervates it. 2D 4
21.) Each muscle is stimulated by a nerve, each muscle fiber is stimulated by a synaptic end bulb or
knob or motor end plate (which is the same thing) at the neuromuscular junction. 2D 2
**TALK ABOUT THE NEUROMUSCULAR JUNCTION**
22.) The fact that muscles are never totally relaxed and that there are always some motor units
contracted is referred to as muscle tone. 2D 5
23.) What are the three types of muscle fibers? Are they fast/slow, red/white, oxidative/glycolytic?
Intermediate, slow, red, oxidative
Fast, red, oxidative
Fast, white, glycolytic
24.) Differentiate among agonist, antagonist, and synergist. Provide an example.
An agonist is the muscle that produces the desired effect.
An antagonist is a muscle that does opposite of the agonist – is relaxed when the agonist is
contracted.
A synergist helps the agonist.
For example, when the biceps brachii is the agonist, it is contracted. The triceps brachii is
relaxed and therefore is the antagonist. The brachialis is the synergist because it is also
contracted, but not the prime mover of the forearm.
25.) What does it mean when a lever operates at a mechanical disadvantage?
It means the effort is closer to the fulcrum, and the load is far from the fulcrum.
26.) Label each of the following examples as first-class, second-class, or third-class levers. (No
repeats)
Found in the joints forming the ball of the foot when standing tip-toe, where the fulcrum is the
phalanges, the effort is the gastrocnemius, and the resistance is the weight of the body. Second
-class
Raising your head, where the fulcrum is the cervical vertebrae, the effort is the back neck
muscles, and the resistance is the weight of the front of the head. First-class
Lifting your arm, where the fulcrum is the synovial joint, the resistance is the distal part of the
arm and hand, and the effort is the insertion of the biceps brachii. Third-class