for CBSE class 12 /11 biology and NEET

1. CIRCULATORY SYSTEMS IN THE LIVING WORLD
( PART 1)
Smita Amit – M.sc (botany ) M.ed
28 years of Teaching experience as P.G.T biology in K.V and other leading
plus two schools , as well as Faculty for pre medical entrance preparation

2. Lesson outline
Introduction
a. What is the need
b. What does it do
c. Certain important points
Types
• Circulation in simple organisms (one / few cell thick )
• Transport in plants (in brief )
• Types of circulation / systems in complex animals
• Features in mammals
In man
• What does it consist of
• Explanation of different organs / organ systems
connected
• Physiology and working
• Diseases
CIRCULATORY SYSTEM

3. CIRCULATORY SYSTEM
NEED & FUNCTION :
 Body , as e result of metabolic activities( in tissues
and cells 24x7), needs to use and throw out
materials all the time
 Use-oxygen , nutrients
 Throw out -carbon dioxide , metabolic wastes
 For this a fluid is needed to transport
DEFINITION
 System (in animals) which transport materials like
nutrients, gases, hormones etc. to the various parts
of the body and remove waste materials from the
body cells is known as circulatory system. It
generally comprises channels in the form of vessels,
one or a few pumping organ/s known as hearts/s
and a fluid ,generally the blood.
 Note
 Body fluid (in animals )-Blood, lymph, tissue fluid,
urine, bile etc.
 Circulation of body fluids are of two types–A.
Intracellular -occurs inside the cell through cyclosis
 B. Extracellular circulation-- occurs outside the body
cell i.e. extracellular
1. Study of circulatory system is called
angiology.
2. Father of angiology is William Harvey

4. Circulation in simple organisms
Single celled or few cell thick plants like Algae , Bryophytes and animals like sponges ,
cnidarians , flatworms, nematodes, jelly fish , sea anemone and corals
They obtain nutrients and oxygen directly
across the cell surface through
1. Simple diffusion
2. Cytoplasmic streaming
Protista Porifera Cnidaria

5. Circulatory Systems in Larger and more complex plants and animals
Animals
Heart and blood vessels known as
arteries, veins, and capillaries
Plants
Consists of vessels called xylem and phloem that
run throughout the tissue.
*Bulk flow through a transport system is
the only method by which the entire body
needs are met

6. OPEN CIRCULATORY SYSTEM
Where fluid is circulated through an open body chamber
Found in Arthropods , molluscs etc

7. Closed circulatory system
Where fluid is circulated through blood vessels
Found in annelids, few molluscs and almost all vertebrates

8. BLOOD
BLOOD
BLOOD
BLOOD
1. Single Loop Circulation
2. Venous Heart
3. Two accessory chambers- sinus venosus, bulbous arteriosus.
4. Blood contains Haemoglobin
5. Lower blood pressure in capillaries.
2-CHAMBERED HEART : FISHES

9. Right
Atrium
Left
Atriumm
Ventricl
e
Body
Lung
s
Chambers of the heart
Atrium (superior chambers ) 2 in no- Receive
blood
a. Right – deoxygenated blood from body
b. Left – oxygenated blood from lungs and skin
Ventricle (inferior chamber )- Pump out blood
a. Deoxygenated to lungs
b. Mixed blood to body
c. Two circuits- (blood passes through heart
twice)
Pulmocutaneous circuit
i. Right atrium send deoxygenated blood to
ventricle and from there to lungs
ii. Left Atrium receives oxygenated blood
from lungs.
Systemic Circuit
i. Blood from ventricles (mixed) goes to
entire body
ii. Deoxygenated blood from entire body
goes to right atrium
Note
There is a ridge within the ventricle that diverts
oxygen-rich blood through the systemic
circulatory system and deoxygenated blood to
the pulmocutaneous circuit.
The advantage to this arrangement is that high
pressure in the vessels pushes blood to the
lungs and body
Incomplete double circulation
& 3 chambered heart in Amphibians

10. Right
atrium
Right side
ventricle
Pulmonary
artery
lungs
Pulmonary
vein
Left atrium
Left side
Ventricle
Body
SYSTEMIC CIRCUIT
PULMONARY CIRCUIT
1. Most reptiles also have a three-chambered heart similar to the amphibian heart that directs
blood to the pulmonary and systemic circuits.
2. The ventricle is divided more effectively by a partial septum, which results in less mixing of
oxygenated and deoxygenated blood
Reptiles -3 chambered heart-TURTLES , SNAKES, LIZARD

11. Right
atrium
ventricle
Pulmonary
artery
lungs
Pulmonary
vein
Left atrium
Ventricle
Body
SYSTEMIC CIRCUIT
PULMONARY CIRCUIT
1. They are the most “primitive” animals to exhibit a four-chambered heart.
2. In crocodilians the heart shunts blood from the lungs toward the stomach and other organs during long periods of
submergence, for instance, while the animal waits for prey or stays underwater waiting for prey to rot ( two main arteries
leave the same part of the heart: one takes blood to the lungs and the other provides an alternate route to the stomach
and other parts of the body)
3. Foramen of Panizza : A hole in the heart between the two ventricles.
CROCODILIANS & ALLIGATORS are special reptiles
4 chambered heart

12. BIRDS & MAMMALS
FOUR-CHAMBERED HEART
 The four-chambered heart, seen in birds
and mammals, allows complete separation
of oxygenated and deoxygenated blood.
 The left side i.e the left atrium and left
ventricle receive and send oxygenated
blood
 The right side i.e the right atrium and
right ventricle receive and send
deoxygenated blood.
 Complete separation is necessary to
support a fast metabolism found in
homeotherms.

13. 1. Why does the fish heart pump only deoxygenated blood?
2. Why is the closed circulatory system considered advantageous?
3. What is specific in the heart of crocodiles among reptilians?
4. Distinguish between open and closed circulatory systems.
5. Explain the relationship between the circulatory system and the metabolic demands an organisms
body. How does circulation enable metabolism in the body?
6. Which of the following has a closed-type circulatory system?
a) Cockroach
b) Fish
c) Mollusca
d) Scorpion
7. The study of the blood circulatory system is called
a) Angiology
b) Cardiology
c) Haematology
d) Osteology
8. Which of the following are NOT a component of the circulatory system?
a) Capillaries
b) Villi
c) Veins
d) Arteries
9. Which of the following has closed circulatory system
a)Arthropods
b) Molluscs
c) Platyhelminthes
d)Annelida
10. Single Circulation is found in fishes
a) True
b) False
Test your knowledge

14. THANK YOU
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