Transcript Respiratory System

Brief Anatomy of your lungs
Primary Function of Respiratory
System
 The respiratory system supplies the blood
with oxygen so that the blood can deliver
oxygen to all parts of the body.
 It also removes carbondioxide waste that
cells produce.
Respiratory System Structure
 Nasal Cavity: Passes air through the nose
 Mouth: Passes air through
 Pharynx: The throat. It is a cone shaped passage way




leading to the trachea.
Trachea: The windpipe. It is the main tube connecting nose
or mouth to the lungs.
Epiglottis: A flap that covers the entrance to the trachea.
Lungs: Main organ of the respiratory system.
Diaphragm: Main muscle of the respiratory system that
supports breathing.
 Bronchi: Two tubes inside the lungs that air passes




through to the bronchioles.
Bronchioles: Small branching out tubes divided into
alveoli.
Alveoli: Tiny air sacs that do the oxidation and the
exhale of carbon dioxide.
Capillaries: Blood vessels that are imbedded in the
walls of the alveoli. While in the capillaries the blood
discharges carbon dioxide into the alveoli and takes up
oxygen from the air in the alveoli.
Cilia: Hair like structures that remove dust and dirt
from air.
How does the respiratory system
works
 Air flowing from the mouth or nasal cavity travels
through the pharynx and moves down to the trachea.
Then air moves to the bronchi tubes as they enter the
lungs. Once air gets in the lungs, the air enters
separate branches called the bronchioles. Carbon
dioxide passes from the blood into the alveoli and is
then exhaled.
Once in your lungs, oxygen travels from your
lungs through the bloodstream to the cells
in all parts of the body. Cells use oxygen as
fuel and give off carbon dioxide as waste gas.
The waste gas is carried by the bloodstream
and back to the lungs to be exhaled.
Gaseous exchange
 When oxygen flows into the body, it travels
from the nasal or oral cavity down to the
esophagus. From there the air travels down
the trachea where it is separated into two
bronchi. The bronchi then branches out into
several bronchioles with small sacs called
alveoli. In the alveoli is where the exchange
of gases occur.

 Each alveolus is surrounded by a network of small
blood vessels. Like the alveoli, these small blood
vessels have extremely thin walls. Blood that enters the
vessels has a high level of carbon dioxide, which it
picked up from the body tissues. It contains little
oxygen. The carbon dioxide leaves the blood and
moves through the walls of the blood vessels and
alveoli into the lungs. Oxygen from the air in the lungs
then passes through the walls of the alveoli and blood
vessels and into the blood. The blood, now rich in
oxygen, leaves the lungs and travels to the heart. The
heart then pumps it to cells throughout the body. The
carbon dioxide is finally expelled from the lungs when
we exhale.
So what is the respiratory system?
 Exchange gases throughout the body.
 Helps breathe
 Gives oxygen to cells
 Provides oxygen for blood
i- Oxygenated blood: blood with oxygen
ii- Deoxygenated blood: blood without oxygen
THE HEART
Functions of the circulatory system
 Brings blood containing oxygen, nutrients, and
hormones to cells.
 Transports carbon dioxide and other wastes away from
the cell.
 Other functions may include:
- fights infection
- regulates body temperature
- helps stabilize ph and ionic concentration of body
fluids.
Components of the circulatory
system
Heart
Blood
Vessels : - arteries


- veins
- capillaries
The Heart
 A muscular pump
 Moves blood through the body
 Is suspended in the pericardial sacs
 Composed of four chambers
 Divided into right and left halves
 Made up of cardiac muscle cells
 Pericardium: protective sac of
connective tissue, surrounds the
Heart, and filled with fluid.
Structures of the heart
 The Chambers
1. Atria – (2 upper chambers)
 Thin walled
 Receive blood from veins
 Send blood to ventricles
2. Ventricles – (2 lower chambers)
 Thick walled
 Receive blood from atria
 Pump blood out through arteries
3. Septum
 Wall that divides heart into right and left halves.
Functions
 Valves: - Prevents backflow of blood
- Keeps blood moving in one direction
- Located between the chambers
- At junctions of artery of chambers
Cardiac Cycle
 Refers to the events occurring from the beginning of




one heart beat to the beginning of the next.
When cardiac muscles contract it does so as a single
unit, creating a heart beat
One heart beat consists of 2 parts: systole and diastole
Diastole; is the period of time when the heart relaxes
after contraction
Systole; it starts when the atria contract at the end of
the diastole.
 The coordinated contractions of atria and ventricles
produce the cardiac cycle
– The heart beats in a coordinated fashion
–Both atria contract and pump blood into the
ventricles
–Both ventricles contract and pump blood into
the arteries that exit the heart
–All chambers relax briefly before the cycle
repeats
– This cardiac cycle lasts less than 1 second
Pathway of Circulation
 Oxygen poor blood draining from the body through
veins into the superior and inferior vena cava flows to
the right atrium, through the tricuspid valve, and into
the right ventricle.
 As the right ventricle contracts, oxygen poor blood
passes through the pulmonary valve into the
pulmonary arteries and onto the lungs to receive
oxygen.
 Oxygen rich blood from the lungs enter the heart





through the pulmonary veins, passing into the left
atrium.
Then through the mitral valve to the left ventricle.
Contraction of the left ventricle forces blood through
the aortic valve into the aorta.
Various arteries branch off from the aorta to supply
blood to all parts of the body.
Aorta branch into smaller and smaller vessels (
arteries)
They eventually become capillaries, which supply
blood to all body parts.
Capillaries join into veins and carry blood back to the
heart.
Ordered pathway
Vena cava  Heart Right atrium 
Tricuspid valve  Right ventricle 
Pulmonic valve  Pulmonary arteries
 lungs  Pulmonic veins  Left
atrium Mitral valve  Left ventricle
 Aortic valve  Aorta
Blood Pressure
 It refers to the force exerted by circulating blood on
the walls of blood vessels.
 The pressure of the circulating blood decreases as
blood moves to through the arteries, arterioles,
capillaries, venules, and veins.
 Blood pressure is most commonly measured by
sphygmomanometer ( blood pressure cuff)
Types of pressure
 Systolic pressure; defined as the maximum
pressure in the arteries exerted during
ventricular contraction.
 Diastolic pressure; is the minimum pressure
exerted when the ventricles relax and fill.
 Blood pressure readings = S/D
Vasoconstriction and Vasodilatation
 Vasoconstriction is the narrowing of blood vessels.
When blood vessels constricts, the flow of blood is
restricted or slowed. |(Blood pressure increases)|
 Vasodilatation is where the blood vessels in the
body becomes wider following relaxation of smooth
muscle in vessel walls, this reduces blood pressure .
Blood
 Consists of 2 major components;
1.
A liquid, called plasma, which comprises about
55% of total blood volume
2. The cell-based portion, which is about 40–45%
of total blood volume and consists of:
–Red blood cells
–White blood cells
–Platelets
Functions of the blood
 Supply oxygen to tissues
 Supply nutrients like glucose, amino acids, and fatty
acids to tissues.
 Removal of wastes such as carbon dioxide, urea, and
lactic acid from tissues.
 Circulates white blood cells, and detects foreign
material by antibodies.
 It is a messenger function, including
transport of hormones and signaling
tissues.
 Regulates body temperature.
 Regulates body ph and ion
concentration.
Types of blood
 Red blood cells (RBC)
 White blood cells (WBC)
 Platelets
What is plasma?
 A clear, straw colored fluid
 It contains 90% of water
 What is in the plasma?
1. Dissolved gases
2. Vitamins
3. Minerals
4. Salts
5. Nutrients
6. Enzymes
7. Hormones
8. Waste products
9. Plasma proteins