Cardiovascular and Nervous System

The autonomic nervous system (ANS) controls involuntary functions including heart rate and force (cardiac regulation) and digestive gland secretions (gastrointestinal regulation). The CNS processes information but the ANS executes these specific involuntary controls. Spinal and cranial nerves are pathways but don't regulate these functions autonomously.

The contractions of cardiac muscle fibres are described as myogenic since they are produced spontaneously without requiring stimulation from nerve cells. The heart of elephant is myogenic. 

Calcium ions (Ca++) are essential for the blood clotting cascade. Factor IV in the coagulation pathway is actually calcium ions, which are required cofactors for multiple steps in the clotting process.

Correct option is (1). 

A healthy adult human heart rate is 72 beats per minute on average, with the normal resting range being 60-100 bpm. The 70-80 range is the most typical for healthy adults at rest. Rates below 60 suggest bradycardia, while rates above 100 at rest indicate tachycardia. Athletes often have lower resting rates (50-60) due to cardiovascular conditioning.

The normal systolic pressure is about 120 mm Hg. 

Depolarization and repolarization are extremely rapid processes during an action potential, typically occurring within milliseconds. Depolarization involves the rapid influx of sodium ions, while repolarization involves the rapid efflux of potassium ions to restore the resting potential.

Depolarization and repolarization phases of an action potential occur very rapidly, typically taking only 1-5 milliseconds total. This speed allows neurons to transmit signals quickly over long distances, enabling rapid communication within the nervous system.

This is the correct answer. The chambers of a heart are separated by a partition called septum.

This is the correct answer choice as this statement is incorrect. The pulse rate of an adult while resting is 70 to 72 per minute.

Arterial elasticity normally dampens pressure fluctuations during cardiac cycle. When arteries become rigid (arteriosclerosis), they cannot expand during systole, causing systolic pressure to rise significantly. This explains isolated systolic hypertension in elderly patients. Diastolic pressure may actually decrease due to reduced arterial recoil.

Chordae tendineae are fibrous cords that connect the AV valve cusps to the papillary muscles in the ventricles. During ventricular contraction (systole), they prevent the tricuspid and bicuspid (mitral) valves from prolapsing into the atria by resisting the high pressure generated.

Bradycardia is defined as a heart rate of fewer than 60 beats per minute in adults. This can be normal in well-trained athletes during rest, but may indicate issues with the heart's electrical conduction system in other individuals. Options A and C incorrectly describe tachycardia (elevated heart rate), not bradycardia.

A cardiologist specializes in diagnosing and treating diseases of the heart and cardiovascular system. The prefix 'cardio-' comes from the Greek word for heart. Pulmonologists treat lungs, hepatologists treat liver, and neurologists treat brain conditions.

The human heart has four chambers: two atria (receiving chambers) and two ventricles (pumping chambers). The right side pumps blood to the lungs, and the left side pumps blood to the body. This four-chamber design is efficient for separating oxygenated and deoxygenated blood.