Lecture 5: Circulatory System

Circulatory system consists of what 3 components

Circulatory fluid (blood) 

Interconnecting tubes (blood vessels) 

Pump (heart)

in an open circulatory system, the heart pumps fluid through vessels into ______.

cavities around organs

compared to closed circulatory systems, open circulatory systems are higher/lower pressure and more/less energy is required

lower;less

in a closed circulatory system, blood vessels keep circulatory fluid (blood) separate from ____ .

interstitial fluid

list two advantages of a closed circulatory system

Higher pressure: efficient delivery of nutrients and O2 (high metabolism)

Blood flow to specific tissues can be controlled (when we get cold, muscles can contract to keep heat within)

What is blood and what is it made of

It is a connective tissue made of:

1. Fluid plasma 

2. Erthrocytes (red blood cells: repsonsible for transport of oxygen)

3. Leukocytes (white blood cells)

4. Platelets (fragments of cells that function in clotting)

where are red blood cells produced

Bone marrow 

Do red blood cells have a short life span, if yes, why? 

Yes. they lose nucleus and recycled by spleen to conserve iron

What controls red blood cell production

Erythropoietin, a hormones released by the kidney in response to insufficient oxygen (hypoxia) 

do arteries take blood away or to the heart

away

do veins take blood away or to the heart

to

what is the purpose of the pulmonary circuit

moves blood between heart and lungs for gas exchange. deoxygenated blood leaves heart and oxygenated blood returns.

list blood flow of pulmonary circuit

1. Right atrium *deoxygenated blood

2. Right ventricle

3. Pulmonary arteries 

4.  Lungs 

5. Pulmonary veins * oxygenated blood

what is the purpose of the systemic circuit

moves blood between heart and the rest of the body. 

list blood flow of systemic circuit

1. Left atrium

2. Left ventricle 

3. Aorta 

4. Body tissues 

5. Vena cava 

vertebrates (animals with a backbone) have atrioventricular valves. what do Atrioventricular (AV) valves do?

regulate blood flow between atrium and ventricle to prevent backflow 

Why are the walls of the left ventricles of mammalian hearts thicker and more muscular than the walls of right ventricles? 

Left ventricle has to generate enough force to pump blood throughout entire body, while right ventricle only need to pump blood a short distance to the lungs

define systole and a diastole

Systole - when ventricles contract (blood pumps out)

Diastole - when ventricles relax (blood fills heart)

What is a heartbeat? What is the lub and dub?

The sound of valves in the heart closing and opening

1. Lub

   1. Atrioventricular valves

   2. End of diastoles 

2. Dup 

   1. Pulmonary & aortic valves

   2. End of systole 

 What is blood pressure? 

Pressure of fluid against the walls of blood vessels. 

How does blood pressure differ between veins and arteries?

Blood pressure is high in arteries and low in veins. Lowest returning to the heart and highest leaving it. 

list the order blood travels from these structures:

arterioles, veins, venules, arteries

arteries, arterioles, venules, veins

Blood flows fast/slow when pressure is high. Blood flows fast/slow when pressure is low. 

fast;slow

describe Fish / Shark circulatory systems

1. Single sequential circuit 

2. 2 chambered heart

   1. Atrium receives blood 

   2. Ventricle sends blood to gills 

describe Amphibians circulatory systems 

1. Mixed Double circuit system (pulmonary and systemic)

2. 3 chambered heart

   1. R atrium–deox. blood from body

   2. L atrium– oxygenated blood

from lungs

3. Ventricle–blood from both atria;

sends to lungs and/or body

describe Crocodilians/bird/mammal circulatory systems 

1. Completely separate pulmonary and systemic circuits.

2. 4-chambered hearts