Nokea
What defines the systole phase in the cardiac cycle?
- A. Relaxation of the heart
- B. Contraction of the heart
- C. Diastole of the heart
- D. Pulse rate of the heart
Correct Answer: B
Rationale: The correct answer is B: Contraction of the heart. Systole is the phase of the cardiac cycle during which the heart muscle contracts, pumping blood out of the chambers. It is essential for maintaining circulation and delivering oxygen and nutrients to the body's tissues. Diastole (choice C) is the relaxation phase of the heart when the chambers fill with blood. Pulse rate (choice D) is the number of heartbeats per minute, not specifically related to the systole phase. Choice A, 'Relaxation of the heart,' is incorrect because systole refers to the contraction phase of the cardiac cycle, not relaxation.
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What is glucagon, where is it produced, and what is its function?
- A. Produced in the liver, releases glucose
- B. Produced in the pancreas, raises blood sugar
- C. Produced in the pancreas, lowers blood sugar
- D. Produced in the adrenal glands, regulates stress response
Correct Answer: B
Rationale: Glucagon is a hormone produced in the pancreas and functions to raise blood sugar levels. It does so by signaling the liver to release stored glucose into the bloodstream. Therefore, the correct answer is B, 'Produced in the pancreas, raises blood sugar.' Choices A, C, and D describe functions or locations of other hormones, not glucagon. Glucagon is specifically released by alpha cells in the pancreas, making option B the correct choice.
What is the normal (complete) flow of blood through the heart?
- A. Right atrium → lungs → left atrium → body
- B. Left atrium → left ventricle → body → right atrium
- C. Right atrium → right ventricle → lungs → left atrium → left ventricle → aorta → body
- D. Right ventricle → left ventricle → body
Correct Answer: C
Rationale: The correct flow of blood through the heart starts with the right atrium receiving deoxygenated blood from the body, followed by the right ventricle pumping blood to the lungs for oxygenation. Oxygenated blood then returns to the heart through the left atrium, then passes to the left ventricle which pumps it out to the body through the aorta. This flow ensures that blood is properly oxygenated before circulating through the body. Choice A is incorrect as the blood does not go directly from the left atrium to the body, skipping the left ventricle. Choice B is incorrect as it does not follow the correct flow sequence in the heart. Choice D is incorrect as it does not include the full pathway of blood through the heart.
How many mL of a 0 M stock solution of HCl should be added to water to create 250 mL of a 50 M solution of HCl?
- A. 31.25 mL
- B. 32 mL
- C. 30 mL
- D. 31.3 mL
Correct Answer: B
Rationale: To prepare 250 mL of a 50 M solution of HCl, the formula V1 x C1 = V2 x C2 is used, where V1 is the volume of the stock solution, C1 is the concentration of the stock solution, V2 is the final volume of the desired solution, and C2 is the final concentration of the desired solution. Given V1 x 0 M = 250 mL x 50 M, solving for V1 results in V1 = (250 mL x 50 M) / 0 M = 32 mL. Therefore, 32 mL of the 0 M stock solution of HCl needs to be added to water to create a 250 mL solution of 50 M HCl. Choices A, C, and D are incorrect because they do not represent the accurate volume required for the dilution calculation based on the given concentrations and volumes in the problem.
What are the two layers of the spinal cord?
- A. White matter and grey matter
- B. Epithelial and connective tissue
- C. Adipose and muscular tissue
- D. Dermis and hypodermis
Correct Answer: A
Rationale: The correct answer is A: White matter and grey matter. The spinal cord is composed of an exterior layer of white matter, which surrounds an interior core of grey matter. White matter consists mainly of myelinated axons, while grey matter contains cell bodies, dendrites, and unmyelinated axons. White matter is responsible for transmitting nerve signals up and down the spinal cord, while grey matter processes sensory information and initiates motor commands. The other choices (B, C, D) are incorrect as they do not represent the anatomical layers of the spinal cord. Epithelial and connective tissue, adipose and muscular tissue, dermis, and hypodermis are not the layers of the spinal cord but are found in other parts of the body such as skin and organs.
Which plane divides the body into left and right halves?
- A. Sagittal/Median Plane
- B. Frontal/Coronal Plane
- C. Transverse/Cross-Section Plane
- D. Horizontal Plane
Correct Answer: A
Rationale: The correct answer is A: Sagittal/Median Plane. This plane divides the body into left and right halves. The Frontal/Coronal Plane (choice B) divides the body into front and back, while the Transverse/Cross-Section Plane (choice C) divides it into top and bottom. The Horizontal Plane (choice D) divides the body into upper and lower portions. Understanding these planes is essential in anatomy as they help describe the orientation and relationships of body structures.