Answer:
The correct answer is D.
Explanation:
Papillary muscles, attached via chordae tendineae, help to close the valves and prevent regurgitation.
Pectinate muscles are parallel ridges in the walls of the atrium of the heart, mainly in right atrium. They can stretch during adverse loading conditions, to <em>help the right atrium to dilate without much wall stres</em>s.
Infectious diseases are transmitted from person to person by direct or indirect contact. Certain types of viruses, bacteria, parasites, and fungi can all cause infectious disease. Malaria, measles, and respiratory illnesses are examples of infectious diseases.
Answer: red blood cells
Explanation:
Hemoglobin, iron-containing protein in the blood of many animals—in the red blood cells (erythrocytes) of vertebrates—that transports oxygen to the tissues
Answer: B- chemicals (changing pH)
Explanation:
Chemoreceptors in the bodies and archs that are sensitive to changes in carbon dioxide, oxygen, and pH.
