Chapter 37 & 40.2THE CIRCULATORY, RESPIRATORY & IMMUNE SYSTEMS

HW: P. 950 #1-4

Chapter 37.1 The Circulatory System

CIRCULATORY = TRANSPORTATION

• Circulatory system is composed of the heart, blood vessels and blood that flows within.

• Main function is to transport oxygen and nutrients and dispose of waste.

THE HEART• The heart is an organ that

pumps blood. It is mostly composed of layers of muscle, myocardium.

• 4 Chambers:• Left/Right Atrium: receives blood• Left/Right Ventricle: pumps blood

out of heart• Left = oxygenated (red)• Right = deoxygenated (blue)

• Pulmonary Circulation: pumps blood between heart and lungs

• Systemic Circulation: pumps blood between heart and body

• Valves: close when ventricles contract; keep blood moving in one direction

THE HEARTBEAT• Pacemaker: group of

cells in the SA node that “set the pace” of the heart

• Impulse spreads from SA node to atria then to AV node and ventricles

BLOOD VESSELS (Fig. 37-5)

• Three Types:• Arteries: thick vessels that carry blood Away from the

heart; high pressure• Capillaries: smallest vessels; where exchange occurs• Veins: vessels that return blood to the heart; some

contain valves to keep blood flow in one direction; skeletal muscles increase venous return

BLOOD PRESSURE• Blood pressure: pressure

of blood on vessel walls• Sphygmomanometer:

device used to measure blood pressure• Normal measurement: 120/80• First measurement: systolic pressure• Second measurement: diastolic pressure

• Medulla oblongata regulates blood pressure with neurotransmitters

CIRCULATORY DISEASES• Atherosclerosis:

plaques (fat deposits) form on vessel walls

• Narrowed arteries make the heart work harder to pump blood

• Clots can form and break off into vessels of the brain, causing a stroke.

HW: P. 955 #1-4

37.2 BLOOD & THE LYMPHATIC SYSTEM

BLOOD PLASMA

• Blood collects…• Oxygen from lungs• Nutrients from digestive system•Waste from tissues

• Blood composition:• 45% cells• 55% plasma (fluid in blood, mostly water)

BLOOD CELLS• Red Blood Cells (RBCs):• Carry oxygen• Hemoglobin: iron-containing protein that binds oxygen• Biconcave shape• No nuclei; life cycle ~120 days

• White Blood Cells (WBCs):• Guard against infection, fight parasites and attack bacteria• Phagocytes “eat” pathogens• Lymphocytes: immune response (T-cell, B-cells)

PLATELETS AND CLOTTING• Platelets: fragments of

large cells found in bone marrow

• “sticky” platelets clump together and form a clot at damaged sites; a protein cascade forms tough fibers to seal the wound

• Can you think of a disease where clotting factors are mutated?

THE LYMPHATIC SYSTEM• Lymphatic system:

network of vessels, nodes, and organs that collect fluid lost by the blood and return it back to the circulatory system.

• Lymph carries lymphocytes throughout the body.

• Thymus: gland where T-cells mature

HW: P. 1042 # 1-4

Chapter 40.2: THE IMMUNE SYSTEM

THE IMMUNE SYSTEM• Function: to fight

infection through immunity, the production of cells that inactivate foreign substances or cells.

• Two types of defenses:• Nonspecific: keep things out (fortress walls)• Specific: track down pathogens that enter the body (security guards)

NONSPECIFIC DEFENSES

• 1st line of defense: skin, mucus, sweat and tears act as a barrier

• 2nd line of defense: inflammatory response (WBCs migrate to injury site)• Fever: increased body temperature can kill many pathogens

• Interferons: proteins that interfere with viral replication

SPECIFIC DEFENSES

Humoral immunity (fig. 40-9, p. 1039): B cells attack antigens in body fluids by producing antibodies, Y-shaped proteins that target pathogens for destruction

Cell-mediated immunity (fig. 40-10, p. 1040): killer T cells track down and destroy cells infected from the inside (assassins of the WBCs)

Immune Response: specific defenses that attack invading pathogens (antigens)

ACQUIRED IMMUNITY

• Active immunity: developed after exposure to an antigen (i.e. vaccines or natural exposure to infection cause the body to produce antibodies)

• Passive immunity: injection of antibodies from another organism (i.e. mother’s antibodies during breastfeeding temporarily provides immunity for the baby)

HW: P. 963 #1-4, P. 967 #1-10

Chapter 37.3 The Respiratory System

HUMAN RESPIRATORY SYSTEM

• Respiration:• Food Energy (cellular)• Gas exchange

• Function: gas exchange (O2 and CO2) between blood, the air, and tissues

• Organs: nose, pharynx (throat), larynx, trachea (windpipe), bronchi, and lungs

ORGANS OF THE RESPIRATORY SYSTEM

• Pharynx: passage of air and food

• Trachea: passage of air• Epiglottis: tissue blocks

trachea during swallowing (prevents choking)

• Cilia and mucus: warm, moisten, and filter air to keep lungs clean

• Larynx: vibration of vocal cords produce sound (voice box)

• Bronchi: branch into the lungs• Bronchi Bronchioles Alveoli• Alveoli: tiny air sacs surrounded by capillaries; where gas exchange occurs (fig. 37-14, p. 958)

GAS EXCHANGE• Occurs between the alveoli and capillaries•Oxygen: alveoli blood•Carbon dioxide: blood alveoli

BREATHING

• Diaphragm: flat muscle underneath lungs (CNS control)• Pressure controls breathing (high low)• Inhale (breath in): diaphragm contracts, chest rises, low

lung pressure• Exhale (breath out): diaphragm relaxes, chest lowers,

high lung pressure

TOBACCO & THE RESPIRATORY SYSTEM

• Nicotine: addictive chemical, increases heart rate and blood pressure• Carbon monoxide: prevents oxygen binding

to hemoglobin• Tar: cancerous compounds