All Notes related to the chapter- Respiration and Circulation Human Respiratory system. Gases Exachange

1. Respiration and Circulation
RESPIRATION IN PLANTS AND ANIMALS
AKASH K. BAGADE
CSIR-NET, MH-SET and GATE
WELCOME – BIO- GEEK

2. RESPIRATION
To stay alive, animals must take in oxygen and release excess carbon dioxide.
➢ Most animal cells require a continuous supply of oxygen for cellular respiration.
➢ Brain cells may be damaged beyond repair if their oxygen supply is cut off for only a few
minutes.
➢ The exchange of gases between an organism and its environment is called respiration.
‘It is a biochemical process of oxidation of organic compounds in an orderly manner for the
liberation of chemical energy in the form of ATP’.
Equation-
For this, the process of gaseous exchange takes place between organism and the environment. The
site of gaseous exchange is called the respiratory surface.

3. Respiratory exchange is simple physical process.
Respiratory surfaces should have some features for efficient gaseous exchange.
1. It should have large surface area.
2. It should be thin, highly vascular and permeable to allow exchange of gases.
3. It should be moist.

4. GASEOUS EXCHANGE IN PLANTS
➢ The shape and structure of plants facilitate gaseous exchange by diffusion.
➢ A terrestrial flowering plants has many air spaces between the cells of stem, leaf and
leaves. These air spaces are continuous.
➢ Oxygen diffuses into the air spaces through stomata (i.e. pores on leaves and young
stems.) , carbon dioxide and water vapour diffuse out. In aerated soil, the oxygen
dissolves in the film of moisture of water around the root tissue and enters it by
diffusion.
➢ Woody flowering plants tree and shrubs have external impervious bark.
➢ Gaseous exchange occurs through small pores in the stem surface called lenticels.

5. RESPIRATION IN ANIMALS
➢ As compared to plants animals shows wide variety of respiratory surfaces or organs.
➢ Depending upon complexity of organization and surrounding medium, certain parts of
the body have become specialized into different types of respiratory organs.
Respiration
Aerobic
Direct
Indirect
Anaerobic

6. Air is a better respiratory medium than water

7. Protist, sponges and coelenterates-
1. Habitat- Aquatic
2. Respiratory surface/ organ in these animals is plasma membrane.

8. Flatworms like planaria.
Annelida- earthworm, nereis and leech
Amphibians- frog.
Habitat- aquatic and semi-aquatic
Respiratory surface and organ- plasma membrane, general body surface moist skin

9. Insects-
Habitat- Terrestrial
Respiratory surface/organ- Tracheal tubes and spiracles.
Arachnids- Spiders and scorpions-
Habitat- terrestrial
Respiratory surface/organ- Book lungs

10. Limnus - Arthorpoda
Habitat- Aquatic
Respiratory surface/ organ-Book gills
Amphibian-tadpoles of frog, salamander and newts
Habitat- Aquatic
Respiratory surface/ organ- External gills

11. Fish
Habitat- Aquatic
Respiratory surface/ organ-
Internal gills
Turtle
Habitat- Aquatic
Respiratory surface/ organ-
Cloaca

12. Reptiles, birds and mammals
Habitat- terrestrial
Respiratory surface/ organ- Lungs

13. HUMAN RESPIRATORY SYSTEM
➢ The respiratory system brings about inspiration, expiration and exchange of
gases in the lungs.
➢ The respiratory system can be divided into on upper respiratory system having
external nares, nasal cavities, internal nares, nasopharynx throat and associated
structures.
➢ The lower respiratory system refers larynx, trachea, bronchi , bronchioles and
lungs.

14. Nose
➢ The nose has a pair of slits like openings called external nares or nostrils for entry of the air into the nasal
cavity.
➢ The nasal cavity is divisible into right and left nasal chambers by a mesethemoid cartilage.
➢ Each nasal chamber is further divided into 3 regions.
1. Vestibule-
➢ It is the proximal of the nostrils.
➢ Skin has hair for filtering air and trapping dust and suspended particles in the inhaled air.
2. Respiratory Part-
➢ Called as conditioner.
➢ The middle thin walled highly vascular part for warming and moistening the inhaled air.
3. Olfactory or Sensory Chamber-
The uppermost part is lined by olfactory epithelium for detection of smell.

15. Pharynx
➢ It is divisible into three parts.
➢ The nasopharynx is the uppermost part from the nasal chamber it leads into oropharynx i.e.
common passage for food and air.
➢ Continues below as the laryngopharynx.
➢ Between the nasopharynx and oropharynx is the palate bone.
➢ The pharynx has a set of lymphoid organs called tonsils.

16. Larynx
➢ It is called voice box.
➢ It contains vocal cords for producing sound.
➢ The larynx extends from laryngopharynx and the hyoid bone to the
trachea.
➢ It is hollow, tubular structure.
➢ Its wall made up of cartilage plates held by membranes and muscles.
➢ Internally it is lined by a pair of folds of elastic vocal cords true vocal
cords
➢ Voice is produced by passage of air between the vocal cords and
modulations created by tongue, teeth, lips and nasal cavity.
➢ The larynx opens into the laryngopharynx through a slit like opening
called glottis.
➢ This opening of the trachea or wind pipe is guarded by a leaf like
called epiglottis.
➢ It prevents the entry of the food into trachea.

17. Trachea
➢ It is long tube – 10-12 cm in length.
➢ It runs through the neck in front of the esophagus and extends into and up to the
middle of the thoracic cavity.
➢ It is supported by C shaped 16-20 rings of cartilage which prevents the collapse
of trachea.
➢ Internally lined by ciliated, pseudostratified epithelium and mucus gland that
trap the unwanted particles preventing entry into the lungs.

18. Bronchi and Bronchioles
➢ The trachea divides into right and left primary bronchi as it reaches the middle of
the thoracic cavity.
➢ The bronchi are supported internally by ‘C’ shaped incomplete rings of cartilage.
➢ The primary bronchi divides to form secondary and tertiary bronchi which lead
into terminal bronchioles ending into alveoli.

19. Lungs
➢ These are the main respiratory organs of the human.
➢ One pair of spongy and elastic lungs are present in the thoracic cavity.
➢ Each lung is enclosed and protected by double pleural membrane, outer parietal and inner
visceral membrane.
➢ Between the two pleura is a pleural cavity filled with a lubricating fluid called pleural fluid.
➢ It is secreted by the membranes.
➢ The right lung is larger and divided into 3 lobes, while left lung is divided into 2 lobes.
➢ Each lobe of the lung has the terminal bronchioles ending in a bunch of air sacs, each with 10-
12 alveoli.

20. Alveoli
➢ These are thin walled lobulated structures, like a bunch of grapes.
➢ Each alveolus is surrounded by a network of capillaries of pulmonary arteries and veins.
➢ These have highly elastic wall made up of a single layer of squamous epithelium resting on
basement membrane of connective tissue.
➢ There are about 700 million alveoli in the lungs and they provide the surface area for exchange
of gases.

21. Diaphragm
➢ It is a muscular septum that separates the thoracic and abdominal cavity.
➢ It is dome shaped and on contraction it becomes flattened.

22. Mechanism of respiration.
Respiration is a physical process involving exchange of gases
between the atmosphere and the lungs and it results in the
formation of ATP.
It includes the following processes.
1.Breathing
2.External respiration
3.Internal respiration
4.Cellular respiration

23. 1. Breathing-
➢ It is a physical process by which gaseous exchange takes place between the
atmosphere and the lungs.
➢ It involves inspiration and expiration.
➢ Both these steps involved parts of the thoracic cage, the ribs, sternum and the
intercostal muscles and muscles of the diaphragm.

24. Inspiration-
➢ During inspiration the atmospheric air is taken in to the lungs.
➢ It is occurs due to the pressure gradient formed between the lungs and the atmosphere.
➢ It is an active process in which the diaphragm becomes flat and goes downward, the external
intercostal muscles contracts so the ribs and sternum move upward and outward.
➢ This leads to an increase in the thoracic volume and a decrease in pressure of thorax and the
lungs.
➢ The equalize the low pressure inside the lungs, air from atmosphere rushes into lungs.
➢ This is inspiration.

25. Expiration-
➢ During expiration, the thorax contracts causing air to be exhaled.
➢ The diaphragm relaxes and is pushed upwards.
➢ It is becomes dome shaped. The intercostal muscles also relax pulling the rib cage inward and
downward.
➢ This causes a decrease in thoracic volume and leads to increase in pressure on the thorax and
the lungs as compared to the atmospheric pressure.
➢ So air from the lungs rushes out this is expiration.
➢ One inspiration and one expiration is one breath.

26. External respiration/ exchange of gases at the alveolar level
➢ An alveolus consist of a layer of simple squamous
epithelium resting on basement membrane.
➢ It is surrounded by dense network of capillaries.
The capillary wall is also made up of simple
squamous epithelium resting on thin B.M.
➢ Both structure are similar and have thin membrane.
➢ Together they make up the respiratory membrane
through which gaseous exchange occurs i.e.
between the alveolar air and the blood.
➢ Diffusion takes place and depends on partial
pressure of gases.
➢ The partial pressure of CO2 of blood entering the
pulmonary capillaries is 45mmHg while partial
pressure of CO2 in alveolar air is 40mmHg.
➢ Due to this difference CO2 diffuses from the
capillaries into the alveolus.
➢ Partial pressure of O2 in pulmonary capillaries is
40mmHg while in alveolar air is 104mmHg.
➢ Due to this difference oxygen diffuses from alveoli
to the capillaries.

27. Lung/Pulmonary volume and lung/Pulmonary capacities
➢ While at rest, a healthy adult averages 12 breaths a minute, with each inhalation and exhalation moving about 500
mL of air into and out of the lungs.
➢ The volume of one breath is called the tidal volume (VT). The minute ventilation (MV )—the total volume of
air inhaled and exhaled each minute—is respiratory rate multiplied by tidal volume:
MV 12 breaths/min 500 mL/breath
6 liters/min
✓ The apparatus commonly used to measure the volume of air exchanged during breathing and the respiratory rate is
a spirometer (spiro- breathe; meter measuring device) or respirometer. The record is called a spirogram.

28. Image take from- Principles of Anatomy and Physiology By G. Tortora 12th edition

29. Internal respiration-
The two components of blood involved in transport of gases that is RBCs and plasma.
1. Transport of Oxygen-
➢ Oxygen does not dissolve easily in water, so 3 % Oxygen is transported in a dissolved state by
plasma and 97% Oxygen bound with hemoglobin present in RBC.
➢ Hemoglobin act as the respiratory carrier. It has high affinity for O2 and combines it to form
oxyhemoglobin. Oxygen and hemoglobin bind in an easily reversible reaction to form
oxyhaemoglobin:
➢ One molecule of Hb has 4 Fe++, each of which can pick up a molecule of oxygen.
Oxyhaemoglobin is transported from lungs to the tissue where is readily dissociate to release
O2

30. The degree of saturation of Hb with O2 depends on the O2 tension i.e. PO2.
❑100 percent saturation is rare.
❑Maximum saturation of 95 to 97 percent is at PO2 in alveoli is 100mmHg.
❑Degree of saturation decreases with drop in PO2. this begins the dissociation of HbO2.
❑At 30mmHg of PO2, only 50 percent saturation can be maintained.
❑The relationship between HbO2 saturation and oxygen tension PO2 is called oxygen
dissociation curve.
❑The Oxygen dissociation curve is a sigmoid curve and it shifts towards the right due to
increased in H+ concentration, increase in PCO2 and rise in temp. and rise in DPG, 2,3
diphosphoglycerate. It lowers the affinity of hemoglobin for oxygen.
Bohr effect- shift of oxyhemoglobin dissociation curve due to
change in partial pressure of CO2 in blood.
Haldane effect- Oxyhemoglobin function as an acid. It decreases
PH of blood. Due to increase in H+ ions, HCO3- changes in H2O
and CO2

34. Transport of Carbon dioxide

37. Regulation of respiration

42. Transportation in living organism
➢ All living organism show and important property of exchange if material with their surrounding as well as
between various part of the body.
➢ Organism take up oxygen and nutrients from the surrounding, these are circulated within body for various
metabolic activities.
➢ The waste generated within are given out into surrounding.
➢ Transportation in organism and animas occurs by diffusion and by active transport between the cells, when
surface area if the body is large and the distance between body parts is extremely small.
➢ Cyclosis- the streaming of movement od the cytoplasm. Ex. Paramecium, Amoeba root hair cells and WBCs.
➢ It is transportation within cells or intracellular transportation.
➢ In sponges and coelenterates the surrounding water is circulated through body cavity.
➢ In flatworms there is parenchymal circulation.
➢ In round worms there are no blood vessels and body fluid is moved around viscera by contraction of body wall
and muscles. This is extracellular transport.

43. CIRCULATION IN ANIMALS
In higher animals the circulation is carried out by special fluids blood and lymph.
Blood Vascular System-
Higher animals from Annelida to Chordata have special circulation fluid, the blood which is
pumped to the tissues by the heart through the blood vessels.
Types of Blood vascular system-
1. Open Circulation-
✓ Blood is circulated through the body cavities.
✓ Visceral organs are lie in the blood filled body cavity.
✓ Exchange of material takes place directly between blood and cells or tissue of the body.
✓ Blood flows with low pressure.
✓ Does not contain respiratory pigment.

44. Closed circulation-
✓ Blood is circulated all over the body through a network of blood vessels.
✓ In this blood flows within the vessels and does not come in contact with cell of
tissue.
✓ Exchange o material between blood and body tissue through and intermediate
fluid called lymph.
✓ Blood flows with high pressure.
✓ It contain respiratory pigment.
Closed circulation divide into two types-
1. Sigle circulation
2. Double circulation.

45. Single Circulation Double Circulation

46. CIRCULATORY SYSTEM IN HUMAN
The human circulatory system is composed of blood vascular system and lymphatic system.
1.BLOOD VASCULAR SYSTEM-
In human beings it consist of blood heart and blood vessels.
It is responsible for various functions like
Transport
Homeostasis
Protection

47. BLOOD AND BLOOD COMPOSITION
BLOOD
➢ Specialized connective tissue consisting fluid matrix.
➢ It is mesoderm in origin.
➢ An average adult has about 4-6 lit. of blood.
➢ Study of blood is called hematology.
➢ It is red in coloured.
➢ It is slightly alkaline, salty and viscous fluid.
➢ It is heavier than water.

48. COMPOSITION OF
BLOOD
Plasma
Formed
Elements
Blood cells
Erythrocytes Leucocytes
Granulocytes
Neutrophils
Basophils
Eosinophils
Agranulocytes
Monocytes Lymphocytes
B-lymphocytes T- lymphocytes
Blood
Platelets

49. PLASMA
Plasma is the straw colored , viscous fluid forming matrix of the blood.
It is slightly alkaline is nature.
Composition of plasma-
1. water- 90-92% of plasma is water.
2. Proteins- They constitute about 6-8 % of it. Fibrinogen, globulins and
albumins are the major plasma proteins.
a. fibrinogen- important clotting factor produced by liver.
b. Globulins- primarily involved in defense mechanism. They are
grouped as alpha, beta and gamma globulins.
c. Albumins- help in osmotic balance. They maintain osmotic
pressure. So helps in maintaining blood volume and pressure.
3. Minerals- plasma contains small amount of minerals like Na+, Ca++,
Mg++, HCO3-, Cl- etc.
4. glucose, amino acids, lipids etc. Dissolved gases. These substances
enter and leave the plasma at regular intervals. hormones, enzymes,
vitamins, cholesterol anticoagulants wastes etc. are also present in the
plasma.

50. Erythrocytes Red Blood cells
✓ It is most abundant of all cells in blood.
✓ A healthy adult man on an average has 5.1-5.8 million of RBCs mm-3 of blood and female- 4.3-5.2 million
mm-3
✓ Shape and structure- Mammals- biconcave and without nucleus. Camel and llama are oval and are
nucleated.
✓ The process of formation of RBCs is called erythropoiesis.
✓ RBCs are produced from hemocytoblast/reticulocytes.
✓ The erythropoietic organ of the foetus- liver and spleen and in the adult it is mainly in the bone marrow.
✓ Vitamin B12, folic acid and heme protein are required for RBCs for production.
✓ The old and worn out RBCs are destroyed in Spleen. i.e. graveyard of RBCs.
✓ Polycythemia-
✓ Erythrocytopenia-
✓ The hormone erythropoietin produced by the kidney and stimulates the bone morrow for erythropoiesis.
✓ RBC contain an enzyme Carbonic anhydrous.
Function of RBC-
✓ 1. Responsible for the transport of respiratory gases O2 and CO2.
✓ 2. Maintaining pH and viscosity of blood.
❑ The haemocrit is the ratio of the volume of RBCs to total blood volume of blood.
❑ It is different for men and women.

51. White blood cells/ leucocytes
Leucocytes are colorless, nucleated and amoeboid
cells larger than RBCs.
Due to their amoeboid movement they can move out
the capillary wall by a process called diapedesis.
A normal adult has on an average 5000-11000 WBCs
per mm3 of blood.
Decrease in number of WBC called leucopenia.
Increase in WBC number called leukocytosis.
Uncontrolled increase in number of WBCs is a type of
blood cancer called leukemia.
Leucocytes are mainly concerned with defense
mechanism i.e. protection.
Types of WBCs-
These are colorless, irregular nucleated cells that show
polymorphism. They classified into two main types.
Leucocytes
Granulocytes
Neutrophil
s
Basophils
Eosinophils
Agranulocytes
Monocy
tes
Lymphocytes
B-
lymphocytes
T-
lymphocytes

52. Granulocytes-
WBCs with granular cytoplasm.
Also called as polymorpho nuclear leucocytes.
They have lobulated nuclei in different shapes.
Granulocytes are formed from myeloid stem cells and once formed do not divide.
Granulocytes constitute about 72 percent of total WBCs.
Granules are actually secretary vesicles which contain various secretion, enzymes etc.
Depending upon staining property of the granules these are classified into 3 types as neutrophils,
basophils and acidophils.

54. Thrombocytes/ Platelets-
Thrombocytes are cellular fragments formed from large cells called megakaryocytes.
These are produced in bone marrow.
They are very small oval shaped cell fragments without nucleus.
Normal count of thrombocytes in human blood is about 2.5-4.5 lakh/ mm3 of blood.
If number of platelets decrease than normal condition is called thrombocytopenia.
This condition causes internal bleeding.
Platelets secrete platelet factors which are essential in blood clotting.
They also seal the ruptured blood vessels by formation of platelet plug/ thrombus.
They secrete serotonin a local vasoconstrictor.

55. BLOOD CLOTTING
Blood flows from cut or wound but after some time it stops automatically , it is called clotting of
blood.
Bleeding time- 1-3 min.
Clotting time- 2-8 min.
Some time clots formed are also formed in intact blood vessels which are of 2 types.
1. THROMBUS CLOT-
✓ Static clot which grow bigger and bigger and ultimately block the blood vessels.
✓ If this clot is formed in the coronary vessels then it is called coronary thrombus which can
cause heart attack.
✓ If found in brain then called cephalic thrombus causes paralysis.
2. AMBOLUS CLOT-
✓ Moving clots which flow with blood and ultimately dissolve in blood.
✓ More harmful due to its moving nature.

56. CLOTTING MECHANISM
ENZYME CASCADE THEORY
This theory is proposed by Macfarlane and Co-worker.
According to this theory there are 3 steps.
1. Releasing of Thromboplastin
Injured tissue, synthesize exothromboplastin and platelets synthesize endothromoplastin.
Both this thromboplastin react with plasma protein in the presence of Ca++ ions to form
Prothrombinase enzyme i.e. Thrombokinase.
This enzyme inactivate heparin.
2. Conversion of prothrombin into thrombin.
Prothrombinase enzyme convert inactive prothrombin into active thrombin in the presence of
Ca++ ion.
3. Conversion of fibrinogen into fibrin.
Fibrinogen is the soluble protein of plasma. Thrombin protein polymerize monomer of fibrinogen
to form insoluble fibrous protein fibrin.

58. STRUCTURE OF HUMAN HEART