The 'P' wave in a standard ECG represents: MCQ with Answer and Explanation

The 'P' wave in a standard ECG represents:
A. Atrial repolarization
B. Ventricular repolarization
C. Ventricular depolarization
D. Atrial depolarization
Answer: Option D
Solution (By JKExamLibrary)
An Electrocardiogram (ECG or EKG) is a graphical record of the heart's electrical activity. The 'P' wave represents the depolarization of the atria, which leads to atrial contraction. The QRS complex represents ventricular depolarization, and the 'T' wave represents ventricular repolarization, which leads to ventricular relaxation.

Discuss this Question (0)

No comments yet. Be the first to start the discussion!

Practice More Biology Questions

Question #1
The scientist who first used the term 'antibiotic' was:
A. Paul Ehrlich
B. Alexander Fleming
C. Gerhard Domagk
D. Selman Waksman

Correct Answer: Option D


Explanation:
Selman Waksman coined the term 'antibiotic' in 1942 to describe chemical compounds produced by microorganisms that inhibit or kill other microbes. Fleming discovered penicillin, Ehrlich developed the concept of chemotherapy, Domagk discovered sulfa drugs.

This question belongs to: Science Biology
Question #2
In the endocrine system, the hormone 'Oxytocin' is synthesized in the hypothalamus but is stored and released by the:
A. Posterior pituitary (Neurohypophysis)
B. Adrenal medulla
C. Thyroid gland
D. Anterior pituitary

Correct Answer: Option A


Explanation:
Oxytocin (and ADH/vasopressin) are peptide hormones synthesized by the neurosecretory cells of the hypothalamus (supraoptic and paraventricular nuclei). They are transported down the axons of these neurons and stored in the nerve terminals of the posterior pituitary (neurohypophysis). Upon neural stimulation, they are released directly into the bloodstream from the posterior pituitary. The anterior pituitary synthesizes its own hormones.

This question belongs to: Science Biology
Question #3
The part of the brain that acts as a relay station for sensory information is the:
A. Hypothalamus
B. Thalamus
C. Cerebellum
D. Medulla

Correct Answer: Option B


Explanation:
The thalamus, a paired structure in the diencephalon, processes and relays sensory information (except olfaction) to the cerebral cortex. It also regulates consciousness and alertness. The cerebellum coordinates movement, hypothalamus maintains homeostasis, medulla controls vital reflexes.

This question belongs to: Science Biology