1. Respiration and Circulation
Biology 155
Russo-Neustadt

3. Respiration and Circulation are coupled processes in most animals
The systems function together to exchange gases with the environment and transport them to the tissues

4. Types of Respiratory Exchange “Organs”:
The Body Surface –
Requires no respiratory system
Animal must be small or thin
Must have low oxygen /energy requirements
Diffusion alone accounts for gas exchange
Oxygen
Carbon Dioxide

5. Animals who use their body surface for respiratory exchange include
Sponges
Jellyfish
Flatworms (previous slide)
Sea stars

6. Muscles in oral cavity serve as pump for one-way water flow, due to density of water
B. Gills –
Evaginations from the body surface
(In mouth to oral cavity over gills and out slit)
2. Used by aquatic animals
Gill arch

7. Animals who use gills for respiratory exchange include
Marine worms
Clams and mussels
Lobsters and shrimp
Vertebrate fishes (previous slide)

8. C. “Lungs” Used by terrestrial animals
Invaginations from the body surface to decrease water loss
Two major types –
True lungs – used by snails and slugs, vertebrates from amphibians to mammals
Tracheal system of insects

9. a. True lungs – localized exchange surface where oxygen is loaded into the bloodstream
Carbon dioxide
oxygen
Trachea with cartilaginous rings
alveolus
bronchus
lung
Bronchial tree

10. Ventilation uses tidal flow of air due to density

11. b. Trachea = system of air filled tubes that branches throughout body
Tracheole delivers oxygen to individual cells
Note unique uncoupling between respiratory and circulatory systems

12. D. All Respiratory Systems have the Following Things in Common –
Large surface area to maximize gas exchange
Thin exchange surfaces to maximize the rate of gas exchange

13. D. All Respiratory Systems have the Following Things in Common – continued
Gills and true lungs are also –
Ventilated = use muscle pumps to keep oxygen rich medium in contact with the exchange surface
Perfused = use muscle pumps to move blood through the vessels at the exchange surface to keep oxygen depleted blood in contact with the exchange surface
Together these processes ensure a large concentration gradient for oxygen diffusion

15. II. Circulation: A. Components-
1. The cardiovascular system = heart + blood vessels
Function = Circulates the blood to and from the tissues

17. 8 Superior vena cava Capillaries of head, chest, and arms Pulmonary
artery
Pulmonary
artery
Capillaries
of right lung 9
Aorta
Capillaries
of left lung 2 7 2 3 3 5 4 10 4
Pulmonary
vein
Pulmonary
vein 6 1
Right atrium
Left atrium 9
Figure 23.3A Blood flow through the double circulation of the human cardiovascular system.
Right ventricle
Left ventricle
Inferior
vena cava
Aorta
Capillaries of
abdominal region
and legs 8

18. Right atrium To lung To lung Left atrium From lung From lung Semilunar
valve
Semilunar
valve
Atrioventricular
(AV) valve
Atrioventricular
(AV) valve
Figure 23.3B Blood flow through the human heart.
Right
ventricle
Left
ventricle

21. 2. The lymphatic system = lymph vessels + lymph nodes
Functions –
immune defense
returns some fluid from the tissues

22. Return of excess fluid from the tissues via the immune system

23. B. Functions of the Circulatory System
Transport – oxygen, carbon dioxide, nutrients, wastes and hormones in blood
Blood clotting – to seal breaks in vessels, uses platelets and clotting proteins
Protection – internal defense using the white blood cells and the lymphatic system

24. C. Types of Circulatory Systems
None –
Only used by small animals and/or those with low rates of oxygen use
Circulation occurs due to simple diffusion through the body tissues

25. Examples of Animals That Lack a Circulatory System
sponges (not shown)
jellyfish
flatworms
sea stars

26. Blood leaves vessels, loses pressure, thus low flow, low oxygen demand system2.
Few vessels
(Pump)
(Tissue sinuses)
Few vessels 3.
large vessels (arteries, arterioles)
Blood stays in vessels, thus high pressure, high flow system for high oxygen demand
(pump)
Capillaries in tissues for exchange
large vessels (veins)

27. Examples of Animals with an Open Circulatory System
clams
Crayfish, shrimp, lobsters (not shown)
insects as exception to low oxygen use rule (remember the tracheal system)

28. Examples of Animals with a Closed Circulatory System
vertebrates from fish to mammals

29. D. The Vertebrate Circulatory System -
Blood consists of–
Plasma = fluid with dissolved substances (examples – nutrients, hormones and most carbon dioxide)
Cells and cell fragments –
White blood cells – defense
Red blood cells – oxygen transport
Platelets – blood clotting

32. 2. Vertebrate hearts and circulatory patterns -
Note that the evolution of the four-chambered heart of the mammals and birds allows blood to be returned to the heart after exchanging gases at the lungs and to be pumped a second time before traveling to the tissues, needed for high oxygen demand associated with high body temperatures

33. (Pressure declines)
CO2 O2 O2
CO2
Pulmonary vein
Right atrium
arteries
aorta
Pulmonary artery
aorta
Atrium = receiving chamber
Ventricle = pump
Right ventricle
Left atrium
Vena cava
Vena cava
CO2 O2
CO2 O2
Two-chambered heart with blood pumped once; lower pressure, lower flow system
Mammals and
And thus blood is pumped twice for a higher pressure, higher flow system

35. 23.4 The heart contracts and relaxes rhythmically
During diastole, blood flows
From veins
Into heart chambers
During systole, blood flows
From atria
Into ventricles
For the BLAST Animation Cardiac Cycle Overview, go to Animation and Video Files.
Student Misconceptions and Concerns
1. Students often expect that the blood flowing through the heart supplies the heart muscle. The need for coronary arteries and veins is not clear to them. (The thickness of the walls of the heart does not permit efficient diffusion, and furthermore, the oxygen content of the blood in the right atrium and ventricle is very low.)
2. One function of the circulatory system that is rarely discussed is the transport of heat. Blood vessels near the surface of the body expand when we are overheated, releasing some of this excess to the environment. Conversely, during periods of exposure to cold, blood is shunted away from the skin to conserve heat.
Teaching Tips
1. Students often benefit from brief, concrete demonstrations of abstract ideas. When discussing the cardiac cycle, take the time to have students quickly take their own pulse as they are seated in class to help them relate the lecture topic to their own anatomy. This very short activity will provide a small break in the lecture routine and refocus the attention of those students whose minds may have begun to wander.
2. Having students take their own pulses also provides an opportunity to stimulate further curiosity. You may want to assign students to measure and record the variation in their pulse rates during the day's different activities, perhaps before and after drinking coffee, or prior to and during exercise.
Copyright © 2009 Pearson Education, Inc.

36. Semilunar valves closed Heart is relaxed. AV valves are open. 0.4 sec1
Heart is
relaxed.
AV valves
are open.
0.4 sec
Figure 23.4 A cardiac cycle in a human with a heart rate of about 72 beats a minute.
Diastole

37. Atria contract. Semilunar valves closed Heart is relaxed. 0.1 sec2
Atria
contract.
Semilunar
valves
closed 1
Heart is
relaxed.
0.1 sec
Systole
AV valves
are open.
0.4 sec
Figure 23.4 A cardiac cycle in a human with a heart rate of about 72 beats a minute.
Diastole

38. Atria contract. Semilunar valves closed Heart is relaxed. 0.1 sec2
Atria
contract.
Semilunar
valves
closed 1
Heart is
relaxed.
0.1 sec
Systole
AV valves
are open.
0.3 sec 3
Ventricles
contract.
0.4 sec
Figure 23.4 A cardiac cycle in a human with a heart rate of about 72 beats a minute.
Diastole
Semilunar
valves
are open.
AV valves
closed

39. 3. Generation of the heart beat – note that all cardiac cells are autorhythmic and contract on their own
Pacemaker (fastest rate of contraction) =
Electrical signals = action potentials pass due to intercalated discs
(Holds signal before passing to ventricles, connective tissue between atria and ventricles prevents immediate passage of signal