Answer:
The heart is a cone-shaped muscular organ located within the THORAX
. Its apex rests on the DIAPHRAGM , and its base is at the level
of the SECOND rib. The coronary artenes that nourish the
myocardium arise from the AORTA. The coronary sinus empties
into the RIGHT ATRIUM . Relative to the roles of the heart chambers, the
ATRIA are receiving chambers, whereas the VENTRICLES are
discharging chambers. The membrane that lines the heart and
also forms the valve ſaps is called the ENDOCARDIUM , The outermost
layer of the heart is called the EPICARDIUM . The fluid that fills the
pericardial sac acts to decrease FRICTION during heart activity.
The heart muscle, or myocardium, is composed of a special-
ized type of muscle tissue called CARDIAC MUSCLE
Explanation:
Answer:
Below.
Explanation:
Air pollutants.
Allergies.
Chronic sinusitis.
Lack of pertussis immunization.
Malnutrition (particularly in children)
Exposure to chemicals, fumes, and dust.
Smoke inhalation.
Nucleus is the most important factor of a cell
