I AM HEMANT GARG MAM,THIS IS MY PRESENTATION

2. 1. What is a circulatory system?
2. Characteristics of our circulatory system
3. The heart
4. The blood vessels
5. The blood
6. Health problems in the circulatory system

3.  Circulatory system =
◦ A type of transport system, transporting
substances around the body via the blood
 Transport system =
◦ Transports substances around the body
◦ Can be via blood or lymph

4. A. Why do we need a circulatory system?
B. What are circulatory systems like?
C. How is our circulatory system special?

5. ◦ Cells in multicellular organisms are organized into
systems
 E.g. Digestive system
 Cells  Tissues  Organs  Systems
◦ A transport system is needed to carry substances
from 1 part of the body to another

6. ◦ Our circulatory system consists of
1. The heart
2. Arteries
3. Arterioles
4. Blood capillaries
5. Venule
6. Veins

7. ◦ Pulmonary circulation
 Blood from heart to lungs and back
 Pulmonary arteries: Heart  lungs
 Pulmonary veins: Lungs  heart,
oxygenated blood
◦ Systemic circulation
 Blood from heart to rest of body
 Arteries: Heart  rest of body
(except lungs), oxygenated blood
 Veins: Body  Heart, deoxygenated blood
Lungs
Round
the
body
LR

8. A. Structure and Function of the heart
B. The Path blood takes through the heart
C. The Cardiac Cycle
D. Blood Pressure

9. ◦ Size: About the same as a clenched fist
◦ Shape: Roughly conical
◦ Location: Behind the chest bone
Between the two lungs
 Inside pericardium (double
membrane with fluid in between)
Function: helps to reduce friction
when heart is beating

10. ◦ Blood passes from
the atria to ventricles
via the valves
 Flaps of tissue
 Function: Prevent
backflow of blood
 So that blood flow is
unidirectional

11. ◦ There are 4 stages
 Corresponding to steps in the path
of blood through the heart
 Occurs in left and right sides
simultaneously
 Stage 1: (Step 1 / 7)
 Stage 2: (Steps 2 and 3 / 8 and 9)
 Stage 3: (Step 4 / 10)
 Stage 4: (Step 5 and 6 / 11 and 12)
◦ Stage 4 returns the heart to Stage 1

12. ◦ It is the force that blood exerts on the walls of
blood vessels
◦ Unit: millimetres (mm) of mercury
 mmHg
◦ Instrument: sphygmomanometer

13. 1. Within the body
a) Varies in different parts of the body
 In the circulatory system,
 Where is blood pressure highest?
 Where is blood pressure lowest?
b) Varies at different stages in the cardiac cycle
 In the arteries,
 When is blood pressure highest?

14.  Function
◦ To transport blood
around the body
 Structure of arteries and veins
◦ Wall has 3 layers
 Endothelium (innermost layer, 1 cell thick)
 Middle layer (Smooth muscle + Elastic fibres)
 External layer (Connective tissue)
◦ Lumen
 Space enclosed by the wall

15.  Definition: Blood vessels that carry blood
AWAY from the heart
 Structure
◦ Thick, muscular and elastic walls
◦ Elastic wall much thicker in
arteries near the heart
◦ No valves
◦ Lumen smaller than that of vein with same diameter

16.  Definition: Blood vessels that carry blood
BACK to the heart
 Structure
◦ Middle wall layer much thinner
 Less muscular
 Less elastic tissue
◦ Has semilunar valves
◦ Skeletal muscles present around the veins
◦ Lumen larger than that of artery with same diameter

17.  Definition: Microscopic thin-walled blood
vessels that carry blood from
an arteriole to a venule
 Structure
◦ Walls have 1 layer
 Endothelium only
 1-cell thick
 Small gaps
between cells
◦ Extensive network

18. A. Structure and composition of blood
◦ Plasma
◦ Red Blood Cells
◦ White Blood Cells
◦ Platelets
B. Functions of blood
◦ Transport
◦ Protection

19.  Microscope picture of blood smear
◦ Different types of blood cells
◦ Blood is a tissue
because it
contains cells
(Cells make up a
tissue. A tissue can
contain different
kinds of cells)

20.  Transport medium – plasma
Blood
55% plasma 45% blood cells and platelets
90% water 10% dissolved substances
Antibodies
Digested food
Mineral salts
Proteins for blood clotting
Excretory products
(Pale yellowish liquid)

21.  Protection against disease-causing organisms –
white blood cells
◦ Lymphocytes
 Produce antibodies when stimulated by bacteria entering the
bloodstream, which can
 Cause clumping/agglutination
 Cause bacterial cell membranes to rupture
 Neutralize toxins
 Make viruses unable to bind to their host cells
 Antibodies have long-term protection: they remain in the
blood long after the infection is over

22.  Heart disease = cardiovascular disease
◦ cardio = heart
◦ vascular = related to the vessels around the heart
 Types of heart disease
◦ Coronary heart disease
 includes coronary artery disease, myocardial infarction
(heart attack), thrombosis and angina
◦ Irregular heart beat (arrhythmias)
 Includes cardiac arrest

23.  While there are different kinds, they are all caused
by blockage or narrowing of coronary arteries
 Angina: (a feeling)
◦ Chest pains due to lack of oxygen to cardiac muscle
 Heart attack: (an event)
◦ Blood flow to parts of the heart are blocked
◦ Cardiac muscle does not receive oxygen and nutrients
◦ Cardiac muscle dies (this is irreversible)
◦ This can be fatal

24.  Healthy diet
◦ Balanced
◦ Low in cholesterol (LDL only, not HDL)
◦ Low in saturated fats
◦ Rich in fibre
 Stress management
 Stop smoking
 Exercise
 If already at risk
◦ Medication e.g. statins lower cholesterol levels