1. Cardio – heart Pulmonary - lungs
Cardiopulmonary
Cardio – heart
Pulmonary - lungs

2. O2 CO2 Respiratory medium (air of water) Respiratory surface
Organismal level
Cellular level
Circulatory system
Cellular respiration
ATP
Energy-rich molecules from food
Respiratory surface
Respiratory medium (air of water) O2
CO2

3. Types of Respiration 1. Direct with Environment: - small organisms
- gas exchange through epidermis
EX: platyhelminthes, sponges, cnidarians
annelids: partial - assisted by a circulatory system

4. 2. Gills:
Evaginated Structure: extensions of the body
- large surface area for gas exchange
- CO2 diffuses out of blood vessels into water
- O2 diffuses out of water into blood vessels
EX: Aquatic Organisms
echinoderms
annelids
mollusks
crustaceans
amphibian larvae
fish (exception: lungfish)
- Fish: blood flow is counter current
- flows in opposite direction of water for better gas exchange -
- protected by operculum

6. Countercurrent exchange
Figure 42.21
Gill arch
Water flow
Operculum
Gill arch
Blood vessel
Gill filaments
Oxygen-poor blood
Oxygen-rich blood
Water flow over lamellae showing % O2
Blood flow through capillaries in lamellae showing % O2
Lamella
100%
40%
70%
15%
90%
60%
30% 5% O2

7. 3. Trachea:
chitin lined tube permeate insect bodies diffusion at tracheal endings (tracheole) - branch to individual cells – enter through spiracles

8. Tracheae
Air sacs
Spiracle
(a) The respiratory system of an insect consists of branched internal tubes that deliver air directly to body cells. Rings of chitin reinforce the largest tubes, called tracheae, keeping them from collapsing. Enlarged portions of tracheae form air sacs near organs that require a large supply of oxygen. Air enters the tracheae through openings called spiracles on the insect’s body surface and passes into smaller tubes called tracheoles. The tracheoles are closed and contain fluid (blue-gray). When the animal is active and is using more O2, most of the fluid is withdrawn into the body. This increases the surface area of air in contact with cells.

9. Figure 42.22b 2.5 µm Body cell Air sac Tracheole Trachea Body wall Air
Tracheoles
Mitochondria
Myofibrils
Body wall
(b) This micrograph shows cross sections of tracheoles in a tiny piece of insect flight muscle (TEM). Each of the numerous mitochondria in the muscle cells lies within about 5 µm of a tracheole.
Figure 42.22b
2.5 µm
Air

10. 4. Lungs:
Invaginated structures: cavity within the body of the organism
- diffusion of CO2 and O2 across thin, moist membranes
- isolated to one area in the body
- gas exchange for the cells must be carried out by the circulatory system
Amphibians: small lungs:
may rely on diffusion of gases across the skin (pulmonary cutaneous)
Reptiles
Birds
Mammals
Spiders: Book Lungs - stacks of inflated membranes enclosed by a sac
Terrestrial Snails

11. Gas Exchange in Humans 1. Mouth/Nose/Nasal Cavity, Pharynx, Larynx:
air entrance
Epiglottis open - allows air into trachea
Larynx:
Voice Box - air passing over vocal chords causes vibration

12. 2. Trachea: Wind Pipe - in front of esophagus
Cartilage rings - reinforcement
3. Bronchi:
Trachea splits into bronchi
Each bronchus splits further into more bronchioles

15. 4. Alveolus: air sac
- located at the end of bronchioles
- enveloped by capillaries for gas exchange
5. Diffusion of Gases
Inhale: lots of oxygen - diffuses across membrane into blood - fixed by hemoglobin - binds to the iron at the center of the hemoglobin subunit (heme)
- four heme groups per hemoglobin - cooperativity
- oxygen binds less well in acid environments (control mechanism)
Blood has lots of CO2 - diffuses out of RBC into alveoli

16. Heme group
Iron atom
O2 loaded
in lungs
O2 unloaded
In tissues
Polypeptide chain O2

17. Circulation: RBC move throughout body and O2 diffuses with concentration gradient to cells via the interstitial fluid
- CO2 diffuses opposite direction

18. 7. CO2 combines with water in RBC to form Carbonic Acid
ENZYME: Carbonic Anhydrase
CO2 + H2O  H2CO3  HCO3- + H+
Carbonic acid dissociates releasing H+ forming bicarbonate making the deoxygenated blood acidic (control mechanism)
- under normal conditions, H+ are absorbed by amino acids in plasma (buffer)
- under stressful conditions, too much CO2 can make the blood acidic stimulating the heart to beat faster and respiration rate to increase
- Bicarbonate diffuses into plasma from RBC
- Lungs: Bicarbonate diffuses into RBC and converted back to CO2
- diffusion across alveoli occurs

19. Figure 42.30
Tissue cell
CO2
Interstitial fluid
CO2 produced
CO2 transport from tissues
Blood plasma within capillary
Capillary wall
H2O
Red blood cell Hb
Carbonic acid
H2CO3
HCO3– H+ +
Bicarbonate
Hemoglobin picks up CO2 and H+
Hemoglobin releases CO2 and H+
CO2 transport to lungs
Alveolar space in lung 2 1 3 4 5 6 7 8 9 10 11
To lungs
Carbon dioxide produced by body tissues diffuses into the interstitial fluid and the plasma.
Over 90% of the CO2 diffuses into red blood cells, leaving only 7% in the plasma as dissolved CO2.
Some CO2 is picked up and transported by hemoglobin.
However, most CO2 reacts with water in red blood cells, forming carbonic acid (H2CO3), a reaction catalyzed by carbonic anhydrase contained. Within red blood cells.
Carbonic acid dissociates into a biocarbonate ion (HCO3–) and a hydrogen ion (H+).
Hemoglobin binds most of the H+ from H2CO3 preventing the H+ from acidifying the blood and thus preventing the Bohr shift.
CO2 diffuses into the alveolar space, from which it is expelled during exhalation. The reduction of CO2 concentration in the plasma drives the breakdown of H2CO3
Into CO2 and water in the red blood cells (see step 9), a reversal of the reaction that occurs in the tissues (see step 4).
Most of the HCO3– diffuse into the plasma where it is carried in the bloodstream to the lungs.
In the HCO3– diffuse from the plasma red blood cells, combining with H+ released from hemoglobin and forming H2CO3.
Carbonic acid is converted back into CO2 and water.
CO2 formed from H2CO3 is unloaded from hemoglobin and diffuses into the interstitial fluid.

20. RESPIRATION CONTROL 1. Bulk Flow: moving air in and out of lungs
Negative Pressure: mammals, birds and reptiles
- generated by diaphragm (muscle separating the pulmonary and abdominal cavities) and intercostal muscles (muscles between ribs)
- diaphragm contracts and moves downward
Result: decreases the pressure in lungs (more volume)
- air rushes in
- diaphragm relaxes and moves up - air expelled

21. Figure 42.24 Air inhaled Air exhaled
INHALATION Diaphragm contracts (moves down)
EXHALATION Diaphragm relaxes (moves up)
Diaphragm
Lung
Rib cage expands as rib muscles contract
Rib cage gets smaller as rib muscles relax
Figure 42.24

22. Birds: Air sacs: addition to lungs - allows lungs to always be inflated whether exhaling or inhaling - air flow through lungs in one direction – always oxygen rich

23. Figure 42.25 Air Anterior air sacs Trachea Lungs Posterior air sacs
INHALATION Air sacs fill
EXHALATION Air sacs empty; lungs fill
Anterior air sacs
Trachea
Lungs
Posterior air sacs
Air
1 mm
Air tubes (parabronchi) in lung
Figure 42.25

24. Positive Pressure: amphibians
- pushes air down windpipe and inflates lungs

25. 2. Breathing Rate:
Balance of pH
- chemoreceptors in carotid artery and medulla oblongata monitor pH
- when pH drops (excess CO2) a signal is sent to the breathing control center (medulla oblongata) in the brain which signals the diaphragm to contract more often – CO2 out/O2 in/pH rises

26. Figure 42.26 Cerebrospinal fluid The medulla’s control center 1
Pons
Breathing control centers
Medulla oblongata
Diaphragm
Carotid arteries
Aorta
Cerebrospinal fluid
Rib muscles
In a person at rest, these nerve impulses result in about 10 to 14 inhalations per minute. Between inhalations, the muscles relax and the person exhales.
The medulla’s control center
also helps regulate blood CO2 level.
Sensors in the medulla detect changes
in the pH (reflecting CO2 concentration)
of the blood and cerebrospinal fluid
bathing the surface of the brain.
Nerve impulses relay changes in CO2 and O2 concentrations. Other sensors in the walls of the aorta and carotid arteries in the neck detect changes in blood pH and send nerve impulses to the medulla. In response, the medulla’s breathing control center alters the rate and depth of breathing, increasing both to dispose of excess CO2 or decreasing both if CO2 levels are depressed.
The control center in the
medulla sets the basic rhythm, and a control center in the pons moderates it, smoothing out the transitions between
inhalations and exhalations. 1
Nerve impulses trigger muscle contraction. Nerves from a breathing control center in the medulla oblongata of the brain send impulses to the diaphragm and rib muscles, stimulating them to contract and causing inhalation. 2
The sensors in the aorta and carotid arteries also detect changes in O2 levels in the blood and signal the medulla to increase the breathing rate when levels become very low. 6 5

27. Circulatory System Function: distribute nutrients and oxygen
transport waste products for removal
immune system

28. Types:
Open: blood vessels move blood into open cavity = hemocoel
- tissues and organs bathed in hemolymph
- gathered in ostia and moved to heart
EX: insects, mollusks (except cephalopods), arthropods
Closed: blood remains in vessels
- nutrients diffuse out of vessels to interstitial fluid
EX: annelids, cephalopods, chordates

29. (a) An open circulatory system
Heart
Hemolymph in sinuses surrounding ograns
Anterior vessel
Tubular heart
Lateral vessels
Ostia
(a) An open circulatory system

30. (b) A closed circulatory system
Interstitial fluid
Heart
Small branch vessels in each organ
Dorsal vessel (main heart)
Ventral vessels
Auxiliary hearts
(b) A closed circulatory system

31. Structures of Closed Circulatory Systems Vessels: Arteries Veins
move blood away from heart blood to heart
thick layer of smooth muscle thin layer of smooth muscle
Branch into arterioles Formed from converging venules

32. Artery
Vein
100 µm
Arteriole
Venule
Connective tissue
Smooth muscle
Endothelium
Valve
Basement membrane
Capillary

33. Capillaries: smallest blood vessels - transfer of nutrients and waste
Heart: Pumping mechanism: cardiac muscle tissue
Compartments:
Atria/Auricles: receive blood from veins pump blood to ventricles
Ventricles: typically larger chamber with thicker wall - pump blood into arteries

34. Generalized Schemes of Circulation:
Two Chambered Heart: FISH
- 1 atrium, 1 ventricle
- single circuit of blood flow
Ventricle to arteries to gills
to body to veins to atria

35. REPTILES (EXCEPT BIRDS) Pulmocutaneous circuit
FISHES
AMPHIBIANS
REPTILES (EXCEPT BIRDS)
MAMMALS AND BIRDS
Systemic capillaries
Lung capillaries
Lung and skin capillaries
Gill capillaries
Right
Left
Systemic circuit
Pulmocutaneous circuit
Pulmonary circuit
Systemic circulation
Vein
Atrium (A)
Heart: ventricle (V)
Artery
Gill circulation A V
Systemic aorta
Right systemic aorta
Figure 42.4

36. Three Chambered Heart: Amphibians and Reptiles (except crocadilians(4))
- 2 atria, 1 ventricle - lack septum or just a partial septum (wall separating the ventricle into two parts)
- mixing of oxygen poor and oxygen rich blood
- decreases rate of metabolism
- two circuits of blood flow
Pulmonarycutaneous: lung and skin
Systemic: body

37. REPTILES (EXCEPT BIRDS) Pulmocutaneous circuit
FISHES
AMPHIBIANS
REPTILES (EXCEPT BIRDS)
MAMMALS AND BIRDS
Systemic capillaries
Lung capillaries
Lung and skin capillaries
Gill capillaries
Right
Left
Systemic circuit
Pulmocutaneous circuit
Pulmonary circuit
Systemic circulation
Vein
Atrium (A)
Heart: ventricle (V)
Artery
Gill circulation A V
Systemic aorta
Right systemic aorta
Figure 42.4

38. Four Chambered Heart: mammals and birds
- 2 atria, 2 ventricles – complete septum dividing the ventricles
- no mixing of O2 rich and O2 poor blood –
higher metabolism
- Double circulation – pulmonary and systemic

39. REPTILES (EXCEPT BIRDS) Pulmocutaneous circuit
FISHES
AMPHIBIANS
REPTILES (EXCEPT BIRDS)
MAMMALS AND BIRDS
Systemic capillaries
Lung capillaries
Lung and skin capillaries
Gill capillaries
Right
Left
Systemic circuit
Pulmocutaneous circuit
Pulmonary circuit
Systemic circulation
Vein
Atrium (A)
Heart: ventricle (V)
Artery
Gill circulation A V
Systemic aorta
Right systemic aorta
Figure 42.4

40. Figure 42.5 Anterior head and forelimbs artery of right lung
Pulmonary
vein
Right atrium
Right ventricle
Posterior
vena cava
Capillaries of
abdominal organs
and hind limbs
Aorta
Left ventricle
Left atrium
artery
Capillaries
of left lung
head and
forelimbs
Anterior
of right lung
Figure 42.5 1 10 11 5 4 6 2 9 3 7 8

41. Human Circulatory Systems
Parts/Pathway:
1. Vena Cava- largest veins: Superior (anterior) - head and forelimbs and Inferior (posterior) - torso and legs
2. Right Atrium (RA)- receives blood from vena cavas
3. Atrioventricular Valve (AV valve): tricuspid valve
- passes blood to RV - separates the right chambers
- prevents backflow of blood from RV so blood only moves forward

42. Aorta
Pulmonary veins
Semilunar valve
Atrioventricular valve
Left ventricle
Right ventricle
Anterior vena cava
Pulmonary artery
Posterior vena cava
Right atrium
Left atrium

43. 4. Right Ventricle (RV)- thicker wall- pumps blood to Pulmonary Artery
5. Pulmonary Semi-lunar Valve: gateway to pulmonary artery - prevents blood from flowing into the RV
6. Pulmonary Artery: carries blood to lungs for oxygen - NOTE: blood is leaving the heart through an artery but is O2 Poor
- in lungs the arteries branch into arterioles and then into a capillary net around the alveoli allowing for gas exchange

44. Aorta
Pulmonary veins
Semilunar valve
Atrioventricular valve
Left ventricle
Right ventricle
Anterior vena cava
Pulmonary artery
Posterior vena cava
Right atrium
Left atrium

45. 7. Pulmonary Veins: from lungs to LA - carries O2 rich blood
8. Left Atrium (LA): receives O2 rich blood and pumps it into the LV
9. Left Atrioventricular Valve - aka mitral valve or bicuspid valve
- prevents backflow from LV

46. Aorta
Pulmonary veins
Semilunar valve
Atrioventricular valve
Left ventricle
Right ventricle
Anterior vena cava
Pulmonary artery
Posterior vena cava
Right atrium
Left atrium

47. 10. Left Ventricle (LV) : pumps blood into Aorta 11
10. Left Ventricle (LV) : pumps blood into Aorta 11. Left Semilunar Valve : prevents blood from flowing back into LV
12. Aorta: main artery - branches
- sends blood to body systems
13. Arteries:
- branch into arterioles and then into capillaries
14. Capillaries/Capillary Nets:
- gas and nutrient exchange
15. Venules and veins: capillaries merging into larger vessels like streams into rivers

48. Figure 42.5 Anterior head and forelimbs artery of right lung
Pulmonary
vein
Right atrium
Right ventricle
Posterior
vena cava
Capillaries of
abdominal organs
and hind limbs
Aorta
Left ventricle
Left atrium
artery
Capillaries
of left lung
head and
forelimbs
Anterior
of right lung
Figure 42.5 1 10 11 5 4 6 2 9 3 7 8

49. Heart Cycle
Control: Nodal Tissues- clusters of nervous and muscle tissue
- send signals to the cardiac wall to contract
Sinoatrial node: pacemaker - upper wall of right atrium
- stimulates the contraction of both atria
- blood flows into ventricles
- sends a signal to AV node
Atrioventricular Node: stimulates contraction of ventricles
- sends impulse to nerves called the bundle branches and the Purkinje fibers
“Heart-beat” = closing of the valves
“lub” - blood against AV valves
“dub” - blood against semilunar valves

50. Figure 42.7 Semilunar valves closed AV valves open AV valves closed
Semilunar valves open
Atrial and ventricular diastole 1
Atrial systole; ventricular diastole 2
Ventricular systole; atrial diastole 3
0.1 sec
0.3 sec
0.4 sec

51. Pacemaker generates wave of signals to contract. Signals pass
Figure 42.8
SA node (pacemaker)
AV node
Bundle branches
Heart apex
Purkinje fibers 2
Signals are delayed
at AV node. 1
Pacemaker generates wave of signals to contract. 3
Signals pass
to heart apex. 4
Signals spread
Throughout ventricles.
ECG

52. THE HEART
In 1 year, the average human heart circulates from 770,000 to 1.6 million gallons of blood through the body. This is enough fluid to fill 200 tank cars, each with a capacity of 8,000 gallons
Beating Heart/Heart Surgery
Replacing Body Parts

53. Blood Pressure: 120/80
Systole: blood being forced into the arteries
- larger pressure because of the stronger contraction of the ventricles
Diastole: relaxing of the ventricles
Sphygmomanometer

54. Figure 42.12 Artery Rubber cuff inflated with air Artery closed 120
Pressure in cuff above 120
Pressure in cuff below 120
Pressure in cuff below 70
Sounds audible in stethoscope
Sounds stop
Blood pressure
reading: 120/70
A typical blood pressure reading for a 20-year-old is 120/70. The units for these numbers are mm of mercury (Hg); a blood pressure of 120 is a force that can support a column of mercury 120 mm high. 1
A sphygmomanometer, an inflatable cuff attached to a pressure gauge, measures blood pressure in an artery. The cuff is wrapped around the upper arm and inflated until the pressure closes the artery, so that no blood flows past the cuff. When this occurs, the pressure exerted by the cuff exceeds the pressure in the artery. 2
A stethoscope is used to listen for sounds of blood flow below the cuff. If the artery is closed, there is no pulse below the cuff. The cuff is gradually deflated until blood begins to flow into the forearm, and sounds from blood pulsing into the artery below the cuff can be heard with the stethoscope. This occurs when the blood pressure is greater than the pressure exerted by the cuff. The pressure at this point is the systolic pressure. 3
The cuff is loosened further until the blood flows freely through the artery and the sounds below the cuff disappear. The pressure at this point is the diastolic pressure remaining in the artery when the heart is relaxed. 4 70

55. Increased blood pressure:
- higher amounts of water in the blood due to increased solute content
- sugar or salt
- decreased diameter of blood vessels – atherosclerosis and arteriosclerosis

56. Atherosclerosis/Arteriosclerosis
Figure 42.18a, b
(a) Normal artery
(b) Partly clogged artery
50 µm
250 µm
Smooth muscle
Connective tissue
Endothelium
Plaque

57. Pressure is highest at ventricular contraction
- initial movement is due to hydrostatic pressure
- as blood flows, pressure reduces - at capillaries, blood pressure is zero
- movement of blood in veins is based on the squeezing of skeletal muscle - includes the rhythmic expansion of the thoracic cavity
- squeezing moves the blood through the vein and valves prevent backflow -

58. Direction of blood flow in vein (toward heart)
Valve (open)
Skeletal muscle
Valve (closed)

59. Capillary Exchange:
- nutrient rich blood from arteries enters capillaries
- water, food and gases leave blood to cells
- metabolic wastes enter blood and nearly all of the fluid that left the capillary
- remaining fluid enters the lymphatic system

60. Arterial end of capillary
At the arterial end of a
capillary, blood pressure is
greater than osmotic pressure,
and fluid flows out of the
capillary into the interstitial fluid.
Capillary
Red
blood
cell
15 m
Tissue cell
INTERSTITIAL FLUID
Net fluid
movement out
movement in
Direction of
blood flow
Blood pressure
Osmotic pressure
Inward flow
Outward flow
Pressure
Arterial end of capillary
Venule end
At the venule end of a capillary, blood pressure is less than osmotic pressure, and fluid flows from the interstitial fluid into the capillary.

61. Lymphatic System:
- tiny vessels in capillary net that gather lost fluid to prevent accumulation in the tissues - fluid forms the lymph
- emptied back into the circulatory system in the RA
- lymph is filtered by lymph nodes
- clusters of connective tissue filled with WBC’s
- multiply during an infection - swollen “glands”

62. Blood Clotting
Platelet plug
Collagen fibers
Platelet releases chemicals that make nearby platelets sticky
Clotting factors from: Platelets Damaged cells Plasma (factors include calcium, vitamin K)
Prothrombin
Thrombin
Fibrinogen
Fibrin
5 µm
Fibrin clot
Red blood cell
The clotting process begins when the endothelium of a vessel is damaged, exposing connective tissue in the vessel wall to blood. Platelets
adhere to collagen fibers in
the connective tissue and release a substance that
makes nearby platelets sticky. 1
The platelets form a plug that provides
emergency protection
against blood loss. 2
This seal is reinforced by a clot of fibrin when vessel damage is severe. Fibrin is formed via a multistep process: Clotting factors released from the clumped platelets or damaged cells mix with clotting factors in the plasma, forming an activation cascade that conboobverts a plasma protein called prothrombin to its active form, thrombin. Thrombin itself is an enzyme that catalyzes the final step of the clotting process, the conversion of fibrinogen to fibrin. The threads of fibrin become interwoven into a patch (see colorized SEM). 3
Figure 42.17