Nokea
Which structure of the respiratory system is involved in gas exchange?
- A. Trachea
- B. Bronchioles
- C. Alveoli
- D. Larynx
Correct Answer: C
Rationale: The alveoli are the primary site for gas exchange in the respiratory system. These tiny air sacs in the lungs are where oxygen is taken up into the bloodstream and carbon dioxide is released from the bloodstream into the lungs to be exhaled. The trachea (Choice A) is the windpipe that carries air to and from the lungs but is not directly involved in gas exchange. Bronchioles (Choice B) are smaller airway branches that lead to the alveoli but do not participate in gas exchange themselves. The larynx (Choice D) plays a role in producing sound and protecting the airway but is not primarily responsible for gas exchange.
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Which organ system is primarily responsible for integrating voluntary movements?
- A. Cardiovascular system
- B. Digestive system
- C. Respiratory system
- D. Nervous system
Correct Answer: D
Rationale: The correct answer is D: Nervous system. The nervous system is primarily responsible for integrating voluntary movements. This system includes the brain, spinal cord, and peripheral nerves that communicate signals throughout the body to control movement. The brain interprets sensory information, formulates decisions, and sends signals to the muscles to execute voluntary movements. The cardiovascular system is responsible for circulating blood, the digestive system for breaking down food and absorbing nutrients, and the respiratory system for gas exchange in the body. Choices A, B, and C are incorrect as they do not play a primary role in integrating voluntary movements.
Which part of the respiratory system is in the upper respiratory tract?
- A. Bronchioles
- B. Alveolar ducts
- C. Alveoli
- D. None of the above
Correct Answer: D
Rationale: The upper respiratory tract includes structures such as the nose, nasal cavity, pharynx, and larynx. These structures are responsible for filtering, warming, and humidifying the air. The lower respiratory tract comprises the trachea, bronchi, bronchioles, alveolar ducts, and alveoli. Bronchioles, alveolar ducts, and alveoli are all part of the lower respiratory system, involved in gas exchange. Therefore, the correct answer is 'None of the above' as none of the listed options are part of the upper respiratory tract.
How do the muscular and skeletal systems collaborate to facilitate movement?
- A. Muscles attached to tendons contract to bend the skeleton at the joints.
- B. The hard bones of the skeleton protect the voluntary muscles of the limbs.
- C. The cardiac muscles produce calcium that is needed for sturdy bones.
- D. Smooth muscles on internal organs leach excess minerals from the bones.
Correct Answer: A
Rationale: The muscular system and the skeletal system collaborate to facilitate movement. Muscles are connected to bones through tendons and contract to generate movement at the joints. When muscles contract, they exert force on the bones, resulting in actions like bending the arm or leg. This coordinated effort between muscles and bones is crucial for various activities such as walking, running, and grasping objects. Choices B, C, and D are incorrect because they do not accurately describe the interaction between the muscular and skeletal systems. The skeletal system's primary role is to provide structural support and protect internal organs, while cardiac muscles are responsible for heart function and not bone strength. Smooth muscles are found in internal organs and are not involved in leaching excess minerals from bones.
Why might certain young people be underweight?
- A. They are growing in height faster than they are gaining weight.
- B. They eat little protein and too much fat and sugar.
- C. They eat several meals a day and fail to exercise enough.
- D. They seldom eat a meal that contains foods from all food groups.
Correct Answer: A
Rationale: Certain young people might be underweight because they are growing in height faster than they are gaining weight. During periods of rapid growth, the body's energy requirements are primarily directed towards height growth rather than weight gain, resulting in some individuals being underweight despite consuming sufficient calories. Choice B is incorrect because the question focuses on reasons related to growth rather than diet composition. Choice C is incorrect as it suggests overeating rather than the specific growth-related issue of height surpassing weight gain. Choice D is incorrect as it addresses nutritional variety rather than the growth dynamics affecting weight.
Which type of muscles are involved in peristalsis?
- A. Smooth muscles
- B. Cardiac muscles
- C. Skeletal muscles
- D. Epaxial muscles
Correct Answer: A
Rationale: Peristalsis is a coordinated, wave-like muscular contraction that propels food and other materials through the digestive tract. Smooth muscles are responsible for this movement in the gastrointestinal tract, providing the involuntary contractions needed for peristalsis to occur. Skeletal muscles, cardiac muscles, and epaxial muscles are not directly involved in peristalsis. Cardiac muscles are found in the heart and are responsible for its contraction. Skeletal muscles are attached to bones and control voluntary movements. Epaxial muscles are located along the vertebral column and are involved in the movement and stabilization of the spine.