/
Human Physiological Systems
Save to my account
Sign up
Human Physiological Systems
Human Physiological Systems
Study
1
Question
What are the five main functions of the skeletal system?
Page 1
Answer
Support, protection, movement, mineral and fat storage, blood cell production.
2
Question
What cells build bone tissue during remodeling?
Page 1
Answer
Osteoblasts.
3
Question
What condition results when bone breakdown outpaces building?
Page 1
Answer
Osteoporosis.
4
Question
How does exercise strengthen bone tissue?
Page 1
Answer
Through increased remodeling that favors osteoblast building over osteoclast breakdown.
5
Question
What is the key tradeoff in types of joints?
Page 1
Answer
Stability versus flexibility.
6
Question
Which muscle type is voluntary, striated, and multinucleated for movement?
Page 1
Answer
Skeletal muscle.
7
Question
What distinguishes cardiac muscle from other types?
Page 1
Answer
Involuntary, striated, branched, heart only.
8
Question
Where is smooth muscle primarily located?
Page 1
Answer
Internal organs and blood vessels.
9
Question
What initiates muscle contraction at the neuromuscular junction?
Page 1
Answer
Motor neuron releases acetylcholine (ACh).
10
Question
What does calcium binding to troponin cause in muscle contraction?
Page 1
Answer
Tropomyosin shifts, exposing myosin-binding sites on actin.
11
Question
How do myosin heads contribute to contraction powered by ATP?
Page 1
Answer
Bind actin, form cross-bridges, pull thin filaments inward.
12
Question
What is the final result of the sliding filament mechanism?
Page 1
Answer
Sarcomere shortens, muscle contracts.
13
Question
Why is ATP required for muscle relaxation?
Page 2
Answer
To detach myosin heads from actin.
14
Question
What is a sarcomere in muscle structure?
Page 2
Answer
The repeating functional unit that shortens during contraction.
15
Question
What is a motor unit?
Page 2
Answer
One neuron and all the muscle fibers it controls.
16
Question
How is muscle contraction force graded?
Page 2
Answer
Via summation, tetanus, and recruitment of motor units.
17
Question
What are the three energy pathways for muscles?
Page 2
Answer
Creatine phosphate (fastest, <5 sec), fermentation (anaerobic short-term), cellular respiration (aerobic efficient).
18
Question
What causes oxygen debt after exercise?
Page 2
Answer
Need to repay anaerobic energy use and clear lactate.
19
Question
How do fast-twitch fibers differ from slow-twitch fibers?
Page 2
Answer
Fast-twitch: explosive, anaerobic, quick fatigue, high force low endurance, few mitochondria light color. Slow-twitch: sustained aerobic fatigue-resistant, low force high endurance many mitochondria dark myoglobin.
20
Question
What causes weakness in myasthenia gravis?
Page 2
Answer
Immune destruction of ACh receptors prevents muscle signal reception.
21
Question
What is the molecular defect in Duchenne muscular dystrophy?
Page 2
Answer
Missing dystrophin allows Ca2+ leak, enzymes destroy fibers.
22
Question
What are the categories of sensory receptors?
Page 3
Answer
Photoreceptors (light), mechanoreceptors (force), chemoreceptors (chemicals), thermoreceptors (temperature), nociceptors (pain).
23
Question
How do rods differ from cones in vision?
Page 3
Answer
Rods for dim light black/white; cones for color/bright light.
24
Question
What is the path of light in the eye?
Page 3
Answer
Cornea and lens focus, pupil controls amount, retina detects.
25
Question
Trace the path of sound from ear to brain.
Page 3
Answer
Pinna → canal → tympanic membrane → ossicles (malleus, incus, stapes) → oval window → cochlea hair cells → auditory nerve → cortex.
26
Question
How does the cochlea distinguish pitch and volume?
Page 3
Answer
Pitch by vibrating region; volume by basilar membrane movement amount.
27
Question
What are the five basic taste categories?
Page 3
Answer
Sweet, sour, salty, bitter, umami.
28
Question
Why does food taste bland with a stuffy nose?
Page 3
Answer
80-90% of taste is smell; olfactory input missing.
29
Question
What characterizes an action potential in neurons?
Page 3
Answer
All-or-nothing electrical signal traveling down the axon.
30
Question
What is the role of the refractory period in neurons?
Page 3
Answer
Prevents backward firing, ensures one-way signal travel.