Vertebrate Heart Functions

Questions and Answers

What are the functions of the vertebrate circulatory system?

Transport oxygen from the lungs (gills if fish) to the tissue and transport carbon dioxide from the tissues to the lungs. 2. Distribute nutrients from the digestive system to body cells. 3. Transport wastes and toxins to the liver. 4. Distribute hormones from the glands and organs to the tissue. 5. Regulate body temperature. 6. Protect the body from bacteria and viruses.

What sends blood to the ventricles of the heart?

Atrial contractions

What do ventricular contractions do?

Send blood to all parts of the body

Name an animal that has a two chamber heart and describe how they circulate.

A fish has a two-chamber heart (one atrium and one ventricle). Blood is first pumped from the ventricles to pass through the gill capillaries where it picks up oxygen and gives off carbon dioxide, then it goes to the rest of the body. Signup and view all the answers

Name an animal that has a three chamber heart and how many of each chamber do they have?

Reptiles and amphibians have three-chamber hearts, with two atria and one ventricle. Signup and view all the answers

Besides mammals, what other animal has a four chamber heart?

Birds have four chamber hearts as well. Signup and view all the answers

Fish mix oxygenated and deoxygenated blood in circulation.

False Signup and view all the answers

Amphibians use lung capillaries in oxygenation.

True Signup and view all the answers

There is a large difference between the respiratory systems of birds and mammals.

False Signup and view all the answers

What is the name for the contraction and relaxation of the chambers?

Cardiac cycle Signup and view all the answers

When does one measure systolic blood pressure?

During ventricular contraction Signup and view all the answers

When does one measure diastolic blood pressure?

Between the contractions of the atria and ventricles Signup and view all the answers

Which valve allows the flow from the left atrium to the left ventricle?

Bicuspid/Mitral valve Signup and view all the answers

To which parts of the heart do semilunar valves allow blood to flow?

The pulmonary arteries and the aorta Signup and view all the answers

Where has the heart not evolved in its anatomy?

There is no valve separating the atria from the veins and vena cavas, causing slight backflow. Signup and view all the answers

What is a pacemaker, and what does the natural pacemaker do?

The pacemaker is a collection of muscle cells in the heart that coordinate and initiate the heart's contractions. Signup and view all the answers

What is the heart's primary pacemaker and where is it located?

The sinoatrial (SA) node, located in the upper wall of the right atrium. Signup and view all the answers

How are the cardiac muscle cells linked, and what does this allow to happen?

The muscle cells are linked by gap junctions, which allows electrical signals to pass freely and rapidly. Signup and view all the answers

Why must there be a delay between the SA and AV nodes?

This is in order to give the heart ample time for the blood to have flowed through the atria. Signup and view all the answers

What is fibrillation and how is it caused?

Fibrillation refers to the disorganized, weak contractions of the heart caused by the failure of the pacemaker due to disorders within the complex cardiac cycle. Signup and view all the answers

What does an electrocardiogram do?

An electrocardiogram measures the electrical activities that power the heart's contractions. Signup and view all the answers

Without hormones and impulses, what would the SA's natural heart rate be?

100 bpm Signup and view all the answers

What does epinephrine do?

It raises the heart rate when at higher concentrations. Signup and view all the answers

What do the valves of the heart do?

Prevent backflow of the blood. Signup and view all the answers

What is blood clotting caused by?

Platelets' and other components of the plasma's contact with an irregular surface. Signup and view all the answers

Study Notes

Functions of the Vertebrate Circulatory System

Transports oxygen from lungs (or gills in fish) to tissues and removes carbon dioxide from tissues to lungs.
Distributes nutrients from the digestive system to body cells for energy and growth.
Carries wastes and toxins to the liver for detoxification.
Distributes hormones from glands to target tissues, regulating various bodily functions.
Regulates body temperature through vasodilation and vasoconstriction.
Provides protection against pathogens through immune responses.

Blood Flow Mechanics

Atrial contractions propel blood into the ventricles.
Ventricular contractions send blood throughout the body's circulatory system.

Heart Structure in Different Animals

Fish possess a two-chambered heart (one atrium and one ventricle) with blood passing through gill capillaries for oxygenation.
Reptiles and amphibians have three-chambered hearts, consisting of two atria and one ventricle.
Birds also have a four-chambered heart similar to mammals, responsible for efficient separation of oxygenated and deoxygenated blood.

Blood Circulation Characteristics

Fish do not mix oxygenated and deoxygenated blood during circulation, ensuring efficient oxygen delivery.
Amphibians utilize lung capillaries for oxygenation, allowing for dual respiratory systems during growth stages.
Respiratory systems of birds and mammals show minimal differences, both optimized for high oxygen demands.

Cardiac Cycle and Blood Pressure

The cardiac cycle refers to the contraction and relaxation of the heart’s chambers.
Systolic blood pressure is measured during ventricular contraction, while diastolic blood pressure is measured between contractions.

Heart Valves and Blood Flow Regulation

The bicuspid (mitral) valve directs blood from the left atrium to the left ventricle.
Semilunar valves regulate blood flow to the pulmonary arteries and aorta, preventing backflow.
Lack of a valve between the atria and veins (vena cavas) can cause minor backflow of blood.

Pacemaker Functionality

The pacemaker is a group of muscle cells responsible for initiating and coordinating heart contractions.
The primary pacemaker, the sinoatrial (SA) node, is located in the upper wall of the right atrium, setting the rhythm for heartbeats.
Cardiac muscle cells are interconnected by gap junctions, enabling rapid transmission of electrical signals.

Heartbeat Control and Fibrillation

A delay between SA node impulses and atrioventricular (AV) node firing allows time for blood to flow adequately through the atria.
Fibrillation describes disorganized heart contractions, often resulting from pacemaker dysfunction.

Diagnostic and Hormonal Dynamics

Electrocardiograms (ECGs) measure electrical activity that drives heart contractions, essential for diagnosing cardiac issues.
The SA node generates a natural heart rate of 100 beats per minute without external influences.
Epinephrine (adrenaline) can increase heart rate at elevated levels, highlighting the influence of hormones on cardiac function.

Importance of Heart Valves and Blood Clotting

Heart valves are crucial for preventing backflow of blood, ensuring efficient circulation.
Blood clotting occurs when platelets and plasma components interact with an irregular surface, initiating a cascade that seals wounds.

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Description

Explore the essential functions of the vertebrate circulatory system with this flashcard quiz. This quiz covers the transport of oxygen, nutrients, and waste, as well as the role of hormones and body temperature regulation. Perfect for students studying zoology or biology.