Nokea
To which system do the retinas belong?
- A. skeletal system
- B. nervous system
- C. lymphatic system
- D. circulatory system
Correct Answer: B
Rationale: The retinas belong to the nervous system. The retina is a layer of tissue at the back of the eye responsible for detecting light and sending visual information to the brain through the optic nerve. This process is essential for vision, which is controlled by the nervous system. Choices A, C, and D are incorrect because the retinas have no association with the skeletal, lymphatic, or circulatory systems.
You may also like to solve these questions
The sebaceous glands are part of which system?
- A. Endocrine system
- B. Digestive system
- C. Respiratory system
- D. Integumentary system
Correct Answer: D
Rationale: The sebaceous glands are a component of the integumentary system, which includes the skin, hair, nails, and associated structures. Sebaceous glands are typically found throughout the skin and are responsible for producing an oily substance called sebum, which helps keep the skin and hair lubricated and moisturized. The endocrine system (Choice A) consists of glands that produce hormones, the digestive system (Choice B) is responsible for processing food, and the respiratory system (Choice C) is involved in breathing and gas exchange.
Which of the following is true about skeletal muscle?
- A. Skeletal muscle makes up 40% of the body's weight.
- B. Skeletal muscle attaches to bones by tendons.
- C. Muscle contraction is not involved in temperature regulation.
- D. Skeletal muscles contract only when in use.
Correct Answer: B
Rationale: The correct statement is that skeletal muscle attaches to bones through tendons, enabling movement. Tendons connect muscles to bones and allow the force generated by muscle contraction to be transmitted to the bones, facilitating voluntary movements. Choice A is incorrect because skeletal muscle typically makes up around 40-50% of an individual's body weight, not a fixed 40%. Choice C is incorrect as muscle contraction plays a vital role in temperature regulation by generating heat. Choice D is incorrect as skeletal muscles may have constant low-level contractions even at rest, known as muscle tone.
Which hormone is produced by the pineal gland?
- A. Corticosteroid
- B. Oxytocin
- C. Prolactin
- D. Melatonin
Correct Answer: D
Rationale: Melatonin is the hormone produced by the pineal gland. It plays a crucial role in regulating the sleep-wake cycle and is instrumental in maintaining the body's circadian rhythm. Melatonin production is triggered by darkness and inhibited by light, aiding in signaling the body when it is time to sleep. Corticosteroid, oxytocin, and prolactin are hormones produced by other glands in the body and are not associated with the pineal gland. Therefore, they are incorrect choices for this question.
Which mineral is considered an antioxidant?
- A. Selenium
- B. Calcium
- C. Sulfur
- D. Iron
Correct Answer: A
Rationale: Selenium is the correct answer. It is considered an antioxidant mineral that plays a crucial role in protecting cells from damage caused by free radicals. Selenium is an essential component of the body's antioxidant defense system, promoting overall health and well-being. Calcium (Choice B), Sulfur (Choice C), and Iron (Choice D) are not typically classified as antioxidant minerals. While these minerals have other important functions in the body, they do not primarily act as antioxidants like selenium.
Which organ system is primarily responsible for maintaining temperature control?
- A. The skeletal system
- B. The digestive system
- C. The nervous system
- D. The integumentary system
Correct Answer: D
Rationale: The integumentary system, which includes the skin, hair, and nails, is primarily responsible for maintaining temperature control in the body. The skin helps regulate body temperature through processes like sweating to cool down and shivering to generate heat. Additionally, blood vessels in the skin can dilate or constrict to control the amount of heat lost or retained by the body. This system plays a crucial role in maintaining homeostasis and keeping the body at a stable temperature. The skeletal system (Choice A) provides structural support and protection to the body but is not directly involved in temperature regulation. The digestive system (Choice B) is responsible for breaking down food and absorbing nutrients, not for regulating body temperature. The nervous system (Choice C) controls body functions through electrical impulses but is not the primary system responsible for temperature control.