Fish Heart Structure and Function

The video explores the heart structures of various fish, starting with jawless fish like hagfish and lampreys, highlighting their primitive features. It then compares these with the more advanced heart structures of jawed fish, including sharks and bony fish, noting the presence of coronary vessels and valves. The video concludes with lungfish, which show evolutionary traits leading to tetrapods, such as partial atrial separation.

What is a primitive feature of hagfish related to their heart structure?

• A completely isolated pericardial cavity

• A four-chambered heart

• A connection between the pericardial and peritoneal cavities

• Presence of coronary blood vessels

What initiates the heartbeat in hagfish?

• Coronary blood vessels

• Autorhythmic fibers in the sinus venosus

• The atrium

• The ventricle

Which feature do lampreys share with higher vertebrates?

• A single heart chamber

• A connection between the pericardial and peritoneal cavities

• Lack of semilunar valves

• The development of a fourth heart chamber

What happens to the connection between the pericardial and peritoneal cavities in lampreys after development?

• It becomes a coronary vessel

• It becomes larger

• It remains open

• It closes

What is a characteristic of the heart in jawed fish?

• Presence of semilunar and atrioventricular valves

• Lack of coronary blood vessels

• A non-muscular heart structure

• A single atrium and ventricle

What is the function of the thicker wall in the ventricle of jawed fish?

• To connect to the peritoneal cavity

• To create blood pressure for circulation

• To separate oxygenated and deoxygenated blood

• To store blood

How is the heart of bony fish similar to that of sharks?

• Both have a single heart chamber

• Both lack atrioventricular valves

• Both have a similar flow of blood through the heart chambers

• Both have a non-muscular heart structure

In bony fish, where does blood enter after the sinus venosus?

• Into the single atrium

• Into the coronary vessels

• Into the pulmonary trunk

• Directly into the aorta

What is a precursor to the tetrapod condition found in lungfish?

• A single atrium

• Lack of pulmonary veins

• A completely isolated pericardial cavity

• A partial septum between the atria

How does the lungfish heart manage oxygenated and deoxygenated blood?

• By mixing them in a single chamber

• By using a partial septum to separate them

• By sending all blood to the lungs first

• By having no separation at all