Respiration: involves

1. Breathing

2. transport of gases

3. exchange of gases: O2 for cellular respiration and removal of waste CO2

RESPIRATORY SYSTEM

1. Breathing: active pumping of air in and out– Inhalation- muscular contraction causes chest cavity to expand– Exhalation- ribs and diaphragm return to their original position

• human breath: moves 0.5 L of air-tidal volume• extra amount forced into and out of the lung, 4.5 L in men and

3.1 L in women- vital capacity• air remaining in the lung, 1.2 L-residual volume or dead

volume

2. Transport of gases

- air inhaled through the nostrils

- Passes through the pharynx and larynx

- into the trachea, bronchi, and bronchioles

• Lungs: air inhaled mixes with old air already in the lung

• inner surface many small chambers called alveoli

-

(Heart)

Diaphragm

Bronchiole

Bronchus

Right lung

Trachea

Larynx(Esophagus)

Pharynx

Nasalcavity

Left lung

3. The bronchioles end in clusters of tiny sacs called alveoli: Where gas exchange occurs

0

Blood transports respiratory gases:

• The heart pumps oxygen-poor blood to the lungs>>>> picks up O2 and drops off CO2

• Then the heart pumps the oxygen-rich blood to body cells>>> drops off O2 and picks up CO2

Exhaled air Inhaled air

Air spacesAlveolarepithelialcells

CO2 O2

CO 2 O2

CO2-rich,O2-poorblood

O2-rich,CO2-poorblood

HeartTissue

capillariesCO2

O 2

Interstitialfluid

CO2 O2

Tissue cellsthroughout body

Alveolarcapillaries of lung

• Hemoglobin, in red blood cells, carries O2 and helps transport CO2 and buffer the blood

0

Iron atom

Heme group

O2 loadedin lungs

O2 unloadedin tissues

Polypeptide chain

Smoking

342,000 Americans

die of lung disease

90% lung cancer cases due

to smoking

Other cancers: mouth, throat,

bladder, pancreas, other organs

Smoking

Lung and air sacs are very delicate!!!

Particles easily produce damage

Healthy Lung Diseased LungSmoker’s Emphysema

DeoxygenatedBlood

OxygenatedBlood

OxygenatedBlood

DeoxygenatedBlood

Circulation and Respiration

functions

1) Transports O2 and CO2

2) Distributes nutrients

3) Transports waste products/toxic substances

4) Distributes hormones

5) Regulates body temperature

6) Clots blood

7) Protects body (immune system)

CIRCULATORY SYSTEM

circulatory system (cardiovascular system) parts:– heart—a muscular

pump that pushes blood through the body

– blood—fluid that circulates through the vessels

– blood vessels—a network of tubes through which the blood moves

heart• contraction of the

muscle • Parts: 2 top

atria, 2 bottom ventricles

• Valves: heart flaps that maintain direction of blood flow

Right Atrium

Right Ventricle

Left Atrium

LeftVentricle

RIGHT

ATRIUMLEFT

ATRIUM

RIGHT

VENTRICLE

LEFT

VENTRICLE

Blood Vessels

Artery Artery

Vein Vein

Blood

• Blood plasma • metabolites and wastes:

glucose, vitamins, hormones• salts and ions: sodium, chloride,

and bicarbonate• Proteins: help osmotic balance,

antibodies, fibrinogen for blood clotting

Blood – Red Blood Cells (RBC)

Function: carries O2 in blood

99% cells

Hemoglobin

Blood – White Blood Cells

Function: Protection from foreign invasion

Blood - Platelets

Function: Blood clotting

Blood Vessels

Network of channels where blood flows through

Arteries = carry blood away from heart

Veins = carry blood towards heart

Capillaries = thin vessels

Molecule exchange

The structure of blood vessels

- Artery- layers of the arterial wall are elastic to expand with the pressure caused by contraction of the heart- Veins- return blood to the heart, walls are thin, have unidirectional valves that prevent the flow of blood backwards- Arterioles and venules- small in diameter

-Capillaries-where oxygen and food molecules are transferred from the blood to the body’s cells-narrow and thin walls>> slow blood flow, one cell at a time

Cardiovascular Diseases

Disease of heart and blood vessels: Leading cause of death in US (871,500 in 2004)

• Hypertension – high blood pressure• heart attacks- insufficient blood reaching heart• Strokes- interference in blood to the brain• Atherosclerosis- accumulation within the

arteries that cause a reduction in blood flow

Atherosclerosis – hardening of arteriesPlaques form and clot the blood flow

IMMUNOLOGY

• Innate defenses against infections>> include the skin and mucous membranes, phagocytic cells, and antimicrobial proteins

>> present and effective long before exposure to pathogens

• world’s 7 deadliest diseases

Viral Diseases

• Infect-kill many more people

• Ex: – Influenza: biggest killer virus worldwide– West Nile– SARS – hepatitis – HIV

DEFENSES

• Physical defense:– Skin

• chemical defense: – oil glands make the skin surface very acidic– sweat contains enzyme lysozyme, which attacks and digests the

cell walls of many bacteria– Eyes: tears contain lysozyme to fight bacteria– digestive tract: stomach acid and digestive enzymes provide

protection in the digestive tract– respiratory tracts: sticky mucus traps most microrganisms in the

respiratory tract

• Lymphatic system

SKIN:– epidermis:

• 10 to 30 cells thick• cells are shed

continuously

– dermis:• 20 times thicker• structural support • fat-rich cells for shock

absorbers and insulation

LYMPAHTIC SYSTEM

- crucial battleground during infection

- is a network of:- lymphatic vessels - organs

- Major functions:1. central storage and distribution

of white cells2. returns proteins to circulation,

if remain in the tissues causes swelling or edema

3. transports fats absorbed from the intestine

Adenoid

Tonsil

Lymph nodes

Right lymphatic duct, entering vein

Thymus

Appendix

Thoracic duct

Bone marrow

Lymphatic vessels

Spleen

Thoracic duct, entering vein

Lymph node

Masses of lymphocytes and macrophages

Valve

Lymphatic vessel

Blood capillary

Tissue cells

Interstitial fluid

Lymphatic capillary

- vessels collect fluid from body tissues>>> return it as lymph to the blood- Lymph organs, spleen and lymph nodes, are packed with white blood cells that fight infections

•The immune response – The immune system encounters foreign

molecules called antigens

– The immune system reacts to antigens and “remembers” an invader

• The temperature response: fever:– body’s thermostat rises above the normal

37°C – human pathogenic bacteria do not grow

well at high temperatures– fever curbs microbial growth but it can be

dangerous because it might inactivate critical cellular enzymes

• The inflammatory response mobilizes nonspecific defense forces– Tissue damage releases signals, such as prostaglandins and

histamine– causes the blood flow to increase and capillaries stretch– phagocyte cells migrate to the site of infection and attack the invaders– many of these cells die and form the pus of the curing infection or

wound

White blood cells : to kill invading microbes:– Macrophages: ingest

bacteria– natural killer cells:

attack body cells that are infected by puncturing the membranes and allows water to rush in burst the cell (CANCEL CELLS)

White blood cells: LYMPHOCYTES– T cell :

– origin bone marrow,maturation in thymus

– Attack cells infected with pathogens

– B cell: • Origin+maturation in bone marrow• produce antibodies that attack

antigens

– Memory cells: derivatives from B/T cells after an exposure to an antigen

Bone marrow Thymus

Stem cell

Immature lymphocyte

B cellHumoral immunity

Via blood

Antigenreceptors

Via blood

T cellCell-mediated

immunity

Lymph nodes, spleen, and other lymphatic

organs Final maturation of B and T cells in lymphatic organ

Other parts of the lymphatic system

Antibodies– proteins in the immunoglobulin (Ig) family: IgA, IgD,

IgE, IgG, IgM; 109 diff Ab– promote agglutination, external secretions, release of

histamine

HIV• 2nd biggest killer virus:

people infected 42 mill• Drugs help live longer

• destroys T cells, compromising the body’s defenses opening the way for opportunistic infection>> Kaposi’s sarcoma

Vaccination

1. introduction of a dead or disabled pathogen

2. triggers immune response against the pathogen

3. body response by making: Ab and memory cells so second infection is halted much earlier

flu epidemic (1918) killed 20 million people

in 18 months

The house dust mite

Allergies are overreactions to certain environmental antigens due to abnormal sensitivities to antigens (allergens) in the surroundings

An allergic reaction

Resistance to Antibiotics

• Rabidly producing infectious bacteria are becoming genetically resistant to antibiotics due to:– Genetic resistance: Spread of bacteria

around the globe by humans, overuse of pesticides which produce pesticide resistant insects that carry bacteria.

– Overuse of antibiotics

• EX: Global Threat from Tuberculosis