ATI TEAS 7
ATI TEAS 7 Version 1 Science Questions
Extract:
Question 1 of 5
What is the approximate threshold value for mammalian neurons?
Correct Answer: B
Rationale: The approximate threshold value for mammalian neurons is around -55 mV. At this membrane potential, the neuron becomes more excitable and is more likely to generate an action potential. If the membrane potential reaches this level or depolarizes beyond it, it triggers the opening of voltage-gated ion channels, leading to the initiation of an action potential. Values below this threshold are considered subthreshold and do not usually result in action potential generation. Understanding the threshold potential is crucial in assessing the excitability and firing properties of neurons, as it represents the critical point at which the neuron transitions from a resting state to an active state, enabling the transmission of electrical signals.
Extract:
Question 2 of 5
Which of the following physiological responses is caused by the release of anti-diuretic hormone?
Correct Answer: D
Rationale: The correct answer is D: Increase in water reabsorption in the collecting duct. Anti-diuretic hormone (ADH), also known as vasopressin, acts on the kidneys to increase water reabsorption in the collecting ducts, leading to the concentration of urine and conservation of water in the body. This hormone helps regulate water balance by decreasing urine output and increasing blood volume and pressure when needed.
Question 3 of 5
Which of the following vessels carries oxygenated blood?
Correct Answer: A
Rationale: The correct answer is A, the pulmonary vein. The pulmonary vein carries oxygenated blood from the lungs back to the heart. It is crucial to differentiate between the pulmonary vein, which carries oxygenated blood, and the pulmonary artery, which carries deoxygenated blood. This understanding is fundamental in comprehending the flow of oxygen-rich and oxygen-poor blood within the cardiovascular system.
Question 4 of 5
Which of the following organs is covered by the pleura, a connective tissue sheath?
Correct Answer: B
Rationale: The pleura is a protective membrane that covers the lungs. It consists of two layers: the visceral pleura (inner layer) and the parietal pleura (outer layer). The pleural space between these layers contains a small amount of fluid that helps reduce friction during breathing movements. The spleen, heart, and liver are not covered by the pleura. Therefore, the correct answer is the lungs.
Question 5 of 5
Which of the following substances is responsible for donating H+ ions to act as a buffer when blood pH rises?
Correct Answer: D
Rationale: Carbonic acid is a pivotal buffer in blood that plays a key role in maintaining pH balance. When blood pH rises, indicating increased alkalinity, carbonic acid releases hydrogen ions (H+) to counterbalance the excess base, thereby preventing significant changes in pH levels. This mechanism highlights the essential function of carbonic acid in regulating the acid-base equilibrium in the blood.