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87 Cards in this Set
- Front
- Back
functions of the skeletal system |
1. Support 2. Protection 3. Movement 4. Storage 5. Hematopoiesis |
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Bone types |
1. long bones 2. short bones 3. flat bones 4. irregular bones **sesamoid bones |
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Structure of long bones |
1. Diaphysis 2. Medullary cavity 3. Epiphysis 4. Articular cartilage 5. Periosteum 6. Endosteum |
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Diploe |
cancellous (spongy) bone layer of flat bones |
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outer layer of bone |
compact bone |
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trabeculae |
the beams that form the lattice of spongy bone |
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osteons (aka haversian systems) |
numerous structural units of bones |
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concentric lamella |
rings of calcified matrix that compose osteons |
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central canal (aka haversian canal) |
contains blood vessels and are surrounded by circular lamallae |
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transverse canals (aka Volkmann canals) |
connected to central canals |
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osteocytes |
bone cells |
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osteocytes lie between hard layers of lamallae in spaces called |
lacunae |
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canaliculi |
connect the lacunae with each other and the central canal |
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chondrocytes |
cartilage cells that are located in the lacunae |
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before birth, babies don't have bones, but instead have |
cartilage and fibrous structures shaped like bones |
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osteoblasts |
bone-forming cells |
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osteoclasts |
bone-reabsorbing cells |
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In athletes' bones, these are simulated to strengthen their bones |
osteoblasts |
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endochondral ossification |
formed in cartilage |
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epiphyseal plate |
cartilage between epiphyses and diaphysis that remains as long as growth continues. Turns into bone once growth stops |
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instramembraneous ossification |
some bones are formed by calcification of fibrous membranes |
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fontanels |
soft spots |
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axial skeleton |
skull, trunk, and spine bones |
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appendicular skeleton |
upper and lower extremity bones |
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skeleton is divided into two parts called |
axial and appendicular skeleton |
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Total bones in the body |
206 |
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Skull bones |
Cranium - 8 bones Face - 14 bones Middle ear - 6 bones |
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sinuses |
spaces and cavities within some cranial bones |
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paranasal sinuses |
have openings into the nose |
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sutures |
immovable joints (found in the skull) |
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hyoid bone |
anchor for tongue muscles and helps support the larynx |
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the flexible vertebral column consists of 24 bones called |
vertebrae |
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sacrum and coccyx |
inferior end of vertebral column |
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atlas |
first cervical vertebra, ring made up of an anterior arch and posterior arch |
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axis |
second cervical vertebra |
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articulation |
joint between two or more bones |
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synarthroses |
joints with no movement (sutures) |
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amphiarthroses |
joints with slight movement (symphysis pubis) |
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diarthroses |
joints with free movement |
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shoulder joint type |
ball and socket |
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elbow joint type |
hinge joint |
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does not characterize freely movable joints |
tendons |
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zygomatic |
facial bone |
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origin |
attachment to the more stationary none |
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insertion |
attachment to the more movable muscle |
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tendon sheaths |
enclose some tendons |
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myosin |
protein that forms thick myofilaments |
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actin |
protein that forms thin myofilaments |
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sarcomere |
contractile unit |
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sliding filament model |
explanation of how a skeletal muscle contracts |
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functions of a skeletal muscle |
1. Movement
2. Posture 3. Heat production 4, Fatigue |
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prime mover |
muscle mainly responsible for movement |
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synergist muscle |
helps in producing movement |
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antagonist muscle |
relaxes when the prime mover and synergist muscles contract (opposite) |
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tonic contraction |
muscle tone |
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maintains posture |
muscle tone |
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fatigue |
occurs when muscles don't have adequate rest |
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oxygen debt |
increased metabolism required to remove excess lactic acid |
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motor neuron |
stimulates muscle fibers |
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neuromuscular junction (NMJ) |
the point of contact between nerve ending and muscle fiber |
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acetylcholine |
type of neurotransmitter in each NMJ |
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threshold stimulus |
the minimal level of stimulation required to cause a fiber to contract |
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"All or None" |
muscles contract completely when subjected to a threshold stimulus |
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Types of skeletal muscle contraction |
1. Twitch 2. Tetanic 3. Isotonic 4. Isometric |
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tenanus contraction |
contractions "melt" together to produce a sustained contraction |
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concentric contraction |
muscle shortens |
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eccentric contraction |
muscle lengthens |
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isotonic contraction |
produces movement of a joint |
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isometric contraction |
muscle contracts and no movement results |
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disuse atrophy |
loss of muscle mass during prolonged inactivity |
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hypertrophy |
increase in muscle size due to exercise |
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flexion |
makes angle between two bones smaller |
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extension |
extends angle between two bones (opposite of flexion) |
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abduction |
away from midline |
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adduction |
toward midline |
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supination |
top of hand down |
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pronation |
palm of hand down |
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inversion |
big toe up |
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eversion |
pinky toe up |
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pectoralis major |
flexes arm |
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latissimus dorsi |
extends arm |
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deltoid |
abducts arm |
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biceps brachii |
flexes forearm, flexes elbow |
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triceps brachii |
extends forearm, known as boxer's muscle |
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quadriceps femoris group (extend lower leg) |
rectus femoris vastus muscles |
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orbicularis oris |
found in face |
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circumduction |
movement around a longitudinal axis |