Mammalian Transport System: Heart and Regulation

Play an AI-generated podcast conversation about this lesson

What is the main transport system in mammals?

Respiratory system

Nervous system

Digestive system

Circulatory system (correct)

What is the function of the heart?

To pump air to the lungs

To filter waste products from the blood

To regulate body temperature

To pump blood to all parts of the body (correct)

What is the duration of each cardiac cycle at an average heart rate of 72 beats/min?

1.0 sec

0.5 sec

1.2 sec

0.8 sec (correct)

Where is the heart located?

Thoracic cavity Signup and view all the answers

What is unique about cardiac muscle?

It is myogenic, contracting and relaxing automatically Signup and view all the answers

How many stages are in the cardiac cycle?

3 stages Signup and view all the answers

What is the approximate flow rate of lymph compared to blood?

100ml/hr to 5L/min Signup and view all the answers

What is the primary function of lymph nodes?

To produce lymphocytes Signup and view all the answers

What is the primary function of xylem in plants?

To transport water and minerals from roots to leaves Signup and view all the answers

What is the process by which water enters the root hair cell?

Osmosis Signup and view all the answers

What is the pathway through which water moves across spaces between cellulose fibers in the cell wall?

Apoplast pathway Signup and view all the answers

What is the process by which water is evaporated from the leaves of a plant?

Transpiration Signup and view all the answers

What is the primary function of the thoracic duct and the right lymphatic duct?

Return of lymphatic fluid to the blood Signup and view all the answers

What is the main component of tissue fluid that differs from plasma?

Protein content Signup and view all the answers

What is the primary mechanism of fluid entry into lymphatic capillaries?

Interstitial fluid pressing against endothelial cells Signup and view all the answers

What is the fate of excess fluid (~10%) in the interstitial spaces?

It is taken up by the lymphatic capillaries Signup and view all the answers

What is the function of lymphocytes in the lymphatic system?

To combat infections Signup and view all the answers

What is the characteristic of the walls of lymphatic capillaries?

One-cell thick Signup and view all the answers

Which pathway involves water movement through the vacuoles, cytoplasm, and cell wall?

Vacuolar pathway Signup and view all the answers

What is the primary function of the phloem in a plant?

To translocate organic solutes from the leaves to other parts of the plant Signup and view all the answers

Where does water finally leave the xylem and enter the cells of a plant?

In the leaves Signup and view all the answers

Through which structure do water and minerals move from one cell to another in the symplast pathway?

Plasmodesmata Signup and view all the answers

In which direction can organic solutes be transported in the phloem?

Both upwards and downwards Signup and view all the answers

What happens to most of the water that enters the spongy and palisade layers in the leaves?

It is lost in transpiration Signup and view all the answers

What occurs when the ventricles contract?

Blood is forced into the pulmonary arteries and the aorta. Signup and view all the answers

What is the function of the semi-lunar valves?

To prevent backflow of blood from the arteries to the ventricles. Signup and view all the answers

What is the role of the atrio-ventricular node?

To conduct electrical impulses to the bundle of His. Signup and view all the answers

What is the functional connection between the circulatory and lymphatic systems?

The lymphatic system is closely associated with the circulatory system. Signup and view all the answers

What is the result of the ventricular pressure increase during systole?

The atrio-ventricular valves close. Signup and view all the answers

What is the sound produced when the atrio-ventricular valves close?

Lub. Signup and view all the answers