Introductory Questions #1

1) Before any type of circulatory was established, how did organisms move substances throughout the body as with sponges, cnidarians, flatworms, and nematodes

2) Define the following: Hemolymph, hemocoel, hemocyanin, and interstitial fluid.

3) What is the difference between an open and closed circulatory system?

4) List all of the structures that a red blood cells will encounter as it circulates throughout the body beginning with the Vena cava.

5) Give three differences between an artery and a vein.

Transport Systems & Immunity Chapters 42 & 43

Evolution & Types Main structures (Heart) Cardiac cycle Pathway of Blood flow Artery vs. Vein Blood Exchange @ Capillary level Lymphatic system Immune Response

SEVERAL TYPES OF INTERNAL TRANSPORT HAVE EVOLVED IN ANIMALS

The gastrovascular cavity functions in both digestion internal transport

Mouth

Circularcanal

Simple diffusion: substances move from environment directly into the cells. (2 –3 cells thick)

Gastrovascular cavity (cnidarians, flatworms)

Circulation System Evolution

Open circulatory hemolymph (blood & interstitial fluid) sinuses (spaces surrounding organs): hemocoel

Closed circulatory blood confined to vessels

Most animals have a separate circulatory system, either open or closed

Open systems A heart pumps blood through open-ended vessels

into spaces between cells

Figure 23.2B

Pores

Tubular heart

Closed systems

A heart pumps blood through arteries and capillary beds

The blood returns to the heart via veins

Figure 23.2C

Artery(O2-rich blood)

Arteriole

Capillary beds

Venule

Vein

Atrium

VentricleHeart

Artery(O2-poor blood)

Gillcapillaries

Circulation System Evolution

Cardiovascular system heart (atria/ventricles) blood vessels -arteries -arterioles -capillary beds -venules -veins blood (circulatory fluid)

Circulation System Evolution

Amphibians: •3-chambered heart •2 circuits of blood flow- •Circulation is “Pulmocutaneous” (lungs and skin)•Some mixing of blood

Fish: •2-chambered heart• single circuit of blood

flow

Mammals: •4-chambered heart •Double circulation •Complete separation between oxygen-rich and oxygen poor blood

Double circulation

From right ventricle to lungs via pulmonary arteries through semilunar valve (pulmonary circulation)

Capillary beds in lungs to left atrium via pulmonary veins

Left atrium to left ventricle (through atrioventricular valve) to aorta

Aorta to coronary arteries; then systemic circulation

Back to heart via two venae cavae (superior and inferior); right atrium

Figure 23.4A

Pulmonaryartery

Superiorvena cava

RIGHTATRIUM

Pulmonaryveins

Semilunarvalve

Atrioventricularvalve

Inferiorvena cava

Aorta

Pulmonaryartery

LEFTATRIUM

Pulmonaryveins

Semilunarvalve

Atrioventricularvalve

RIGHTVENTRICLE

LEFTVENTRICLE

Internal Structure of the Heart

Valves within the Heart

Systole:Contraction of heart chambers

Diastole:Dialated/relaxed heart chambers

A heart attack is damage that occurs when a coronary feeding the heart is blocked

What is a heart attack?

Figure 23.8A

Rightcoronaryartery

Aorta

Leftcoronaryartery

Blockage

Dead muscle tissue

Video: “A Heart Attack” Write 10 statements

Figure 23.4B

RIGHT VENTRICLE

1

23

Capillariesof right lung

3

Capillariesof left lung

4

LEFT ATRIUM5

LEFT VENTRICLE

6

Aorta

7Capillaries ofHead and arms

8

Capillaries ofabdominal organsand legs

9

Superiorvena cava

10

Inferiorvena cava

11

RIGHT ATRIUM

Pulmonaryvein

Aorta

Pulmonaryvein

Pulmonaryartery

Pulmonaryartery

The Thoracic Cavity

RBC Pathway through the Circulatory System Blood from Systemic Circuit

Vena cava (inferior & superior)

Right atrium

(Tricuspid valve-AV valve)

Right ventricle (Pulmonary semilunar valve)

Pulmonary circuit –Lungs (P. arteries LungsP. veins)

Left atrium

(Bicuspid “Mitral” valve)

Left Ventricle (Aortic semilunar valve)

Aorta (arch, coronary, carotid, & abdominal, renal, mesenteric, iliac arteries)

Posterior view of the Heart

Facts about the Circulatory System

Blood volume in the heart per contraction 70 ml (Stroke volume) Total blood volume in a human 5 Liters

(1.32

Gal) Normal Beats per minute (BPM) 72 Bpm Normal Blood pressure 120/80 mm Hg

Starling’s Law: when more blood is delivered to the heart, the heart stretches more and contracts with greater force which pumps more blood into arteries.

Cardiac Output The volume of blood pumped out by the left

ventricle Determined by:

(Stroke volume) x (Heart rate)Ex. 70 ml (per beat) x 72 BPM = 5040

ml/min

Approx. 5 Liters per minute

Diastole Blood flows from the

veins into the heart chambers

The Heart Contracts and Relaxes Rhythmically

Figure 23.6

Heart isrelaxed.AV valvesare open.

1 2

3

Atriacontract.

Ventriclescontract.Semilunarvalvesare open.

SYSTOLE

DIASTOLE

0.4 sec

0.1 sec

0.3 sec

Systole The atria briefly

contract and fill the ventricles with blood

Then the ventricles contract and propel blood out

Figure 23.4A

Pulmonaryartery

Superiorvena cava

RIGHTATRIUM

Pulmonaryveins

Semilunarvalve

Atrioventricularvalve

Inferiorvena cava

Aorta

Pulmonaryartery

LEFTATRIUM

Pulmonaryveins

Semilunarvalve

Atrioventricularvalve

RIGHTVENTRICLE

LEFTVENTRICLE5. chamber

1. vessel 10. vessel

11. vessel

9. vessels

8. valve

7. valve

2. chamber

3. valve

4. vessel

6. chamber

IQ #2

The Heartbeat Sinoatrial (SA) node (“pacemaker”): bundle of nerve fibers that sets rate

and timing of cardiac contraction by generating electrical signals Atrioventricular (AV) node: relay point (0.1 second delay) spreading

impulse to walls of ventricles Electrocardiogram (ECG or EKG)

Component of the electrical sequence

Association in the heart

P Wave Firing of the SA node and depolarization of the atria.

PR Interval Delay of the electrical impulse at the AV node and the depolarization of the atrium.

QRS Complex

•Ventricular depolarization •Q-wave = first negative deflection •R-wave = first positive deflection •S-wave = second negative deflecton

ST Segment The beginning of ventricular repolarization. Should be isoelectric (flat at baseline).

T Wave Ventricular repolarization.

A single layer of epithelial cells forms capillary walls

Arteries and veins have smooth muscle and connective tissue Valves in veins prevent the backflow of blood

The Structure of blood vessels

fits their Functions

Capillaries are microscopic blood vessels They form an intricate network among the tissue

cells

The circulatory system associates Intimately with all body tissues

Figure 23.1A

Redbloodcell

Capillary

Blood Vessel Structural Differences Capillaries

•endothelium; basement

membrane

Arteries •thick connective tissue; thick

smooth muscle; endothelium; basement membrane

Veins •thin connective tissue; thin smooth muscle; endothelium; basement membrane

Cardiovascular disease

Cardiovascular disease (>50% of all deaths)

Heart attack- death of cardiac tissue due to coronary blockage

Stroke- death of nervous tissue in brain due to arterial blockage

Atherosclerosis: arterial plaques deposit

Arteriosclerosis: plaque hardening by calcium deposits

Hypertension: high blood pressure

Hypercholesterolemia:LDL,HDL

Blood pressure depends on Cardiac output Blood volume Resistance of vessels

Blood Exerts Pressure on Vessel Walls

Pressure is highest in the arteries

It drops to zero by the time the blood reaches the veins

Figure 23.9A

Diastolicpressure

Systolicpressure

Relative sizes andnumbersof blood vessels

Blood pressure is measured as systolic and diastolic pressures

Connection: Measuring Blood Pressure can Reveal Cardiovascular Problems

Figure 23.10

Blood pressure120 systolic80 diastolic(to be measured)

1 2 3 4

Rubber cuffinflated with air

Pressurein cuffbelow120

Pressurein cuffbelow 80

Artery

Pressurein cuffabove120

Soundsaudible instethoscope

Soundsstop

Arteryclosed

Hypertension is persistent systolic pressure higher than 140 mm Hg and/or diastolic pressure higher than 90 mm Hg

It is a serious cardiovascular problem

Three factors keep blood moving back to the heart

muscle contractions breathing one-way valves

Figure 23.9B

Direction ofblood flowin vein

Valve (closed)

Skeletal muscleValve (open)

Muscular constriction of arterioles and precapillary sphincters controls the flow through capillaries

Smooth Muscle Controls the Distribution of Blood

1 Sphincters relaxed 2Sphincters contracted

Precapillary sphincters Thoroughfarechannel

CapillariesArteriole Venule Arteriole Venule

Thoroughfarechannel

Review of Blood Pressure Key factors that effect BP (CO, BV, R) Regulated by a hormone called Renin Renin released by the kidneys Causes other proteins to increase in

concentration and constrics the vessels

-Angiotension

-Aldosterone (hormone released by adrenal glands)

Figure 23.13

Withdrawblood

Place in tube

PLASMA 55%

CONSTITUENT MAJOR FUNCTIONS

WaterSolvent forcarrying othersubstances

Salts

Osmotic balance,pH buffering, andregulation ofmembranepermeability

SodiumPotassiumCalciumMagnesiumChlorideBicarbonate

Plasma proteins

Osmotic balance,pH bufferingClottingImmunity

Albumin

FibrinogenImmunoglobins(antibodies)

Substances transported by bloodNutrients (e.g., glucose, fatty acids, vitamins)Waste products of metabolismRespiratory gases (O2 and CO2)Hormones

Centrifuge

CELLULAR ELEMENTS 45%

CELL TYPE NUMBER(per mm3 of blood)

FUNCTIONS

Erythrocytes(red blood cells) 5–6 million Transport of

oxygen (and carbon dioxide)

Leukocytes(white blood cells) 5,000–10,000

Defense andimmunity

Basophil

Eosinophil

Neutrophil

Lymphocyte

Monocyte

Platelets 250,000–400,000

Blood clotting

Pg. 880

Red blood cells transport oxygen

Figure 23.14

-Hemoglobin transport of O2

-Red blood cells contain hemoglobin (250-300 million)

-RBC count:

4.2 – 6.2 million cells per mm3. (adult males & females)

-Average Lifespan: 120 days

-33% of RBC volume is hemoglobin

-2.4 million are destroyed per second and are replaced in the bone marrow

-No nucleus or mitochondria

White blood cells help defend the body

Figure 23.15

White blood cells function both inside and outside the circulatory system They fight infections and cancer

Basophil

Neutrophil

Monocyte

Eosinophil

Lymphocyte

WBC TYPE AND FUNCTION WBC count: 7000 per µL (1:700 RBC’s) Neutrophils: -most abundant phagocytic cells in the blood

-their death produces pus -(60-70% of all WBC’s)

Eosinophils: contains oxidases & peroxidases -increase during allergic reactions -parasitic infections

Basophils: also important in allergic reactions -do not contain lysosomes -release histamine in the cytoplasm (inflamm.) -heparin acts as an anticoagulant (prevents blood clots)

Lymphocytes: produce antibodies attack bacteria & virusestwo types of cells form (B cells & T cells)

Monocytes: Largest of all WBC’s that become macrophages (about 5% of all WBC’s)

Differentiation of Blood Cells in the Bone Marrow Pg. 881

Stem cells offer a potential cure for leukemia and other blood cell diseases

Figure 23.17

All blood cells develop from stem cells in bone marrow Such cells may prove

valuable for treating certain blood disorders

Blood clots plug leaks when blood vessels are injured

Figure 23.16B

When a blood vessel is damaged, platelets respond They help trigger the

formation of an insoluble fibrin clot that plugs the leak

Figure 23.16A

Platelet releases chemicalsthat make nearby platelets sticky

Injury to lining of bloodvessel exposes connectivetissue; platelets adhere

1 2 3Platelet plug forms Fibrin clot trapsblood cells

Connectivetissue

Plateletplug

Clotting factors from:

Platelets

Damaged cells

Calcium andother factorsin blood plasma

Prothrombin(Liver, Vit K)

Thrombin

Fibrinogen Fibrin

Ca ions, clotting factors

Pg. 882

Fluid Exchange at the Capillary level (pg. 879)

No substance has to diffuse far to enter or leave a cell

Figure 23.1B

Capillary

INTERSTITIALFLUID

Tissuecell

Diffusion ofmolecules

The transfer of materials between the blood and interstitial fluid can occur by

leakage through clefts in the capillary walls diffusion through the wall blood pressure osmotic pressure

Capillaries allow the Transfer of Substances Through Their Walls

Figure 23.12A

Arterialend of

capillary

Tissue cells

Osmoticpressure

INTERSTITIALFLUID NET PRESSURE

OUT

Bloodpressure

Bloodpressure

Osmoticpressure Venous

end ofcapillary

NET PRESSUREIN

Two Major Forces: Blood Pressure and Osmotic Pressure

Filtration Absorption

plasma

BP: +40Osm out: +3 Osm in: -28

Net Balance: +15 -10

BP: +15Osm out: +3

Osm in: -28

+15 -10

Interstitial fluid

Fluid Exchange Occurs between the capillary and interstitial fluid Two Major forces:

-Blood pressure (hydrostatic pressure)-Osmotic Pressure

Arterial end Venous End-BP higher -BP lower

-Osm. press. Lower -Osm. press. Pushes in -Filtration occurs -Absorption occurs(net pressure out) (net pressure in)

**Important note: not all the fluid returns back in the blood vessels. So fluid accumulates outside and is circulated by the lymphatic system. (approx. 10%)

Introductory Questions #3 (See chapters 42 & 43)1) In the cardiac cycle how is systole different from diastole?

2) Where is the SA and AV node located? What do these structures do?

3) Name three factors that can affect your blood pressure.

4) Blood is composed of a variety of things. Make a list of cellular and non-cellular substances present in blood.

5) Briefly explain how blood clots. (pg. 882) What proteins and cell parts are required for blood to clot?

6) What forces are involved in the exchange of gases and solutes at the capillary level? (pg. 879)

7) What areas of the body do we find a high number of lymph nodes?(pg. 901)

8) How are B cells different from T cells?

Chapter 43 ~ The Body’s Defenses

(pgs. 898-919)

Introductory Questions #3 (See chapters 42 & 43)1) In the cardiac cycle how is systole different from diastole?

2) Where is the SA and AV node located? What do these structures do?

3) Name three factors that can affect your blood pressure.

4) Blood is composed of a variety of things. Make a list of cellular and non-cellular substances present in blood.

5) Briefly explain how blood clots. (pg. 882) What proteins and cell parts are required for blood to clot?

6) What forces are involved in the exchange of gases and solutes at the capillary level? (pg. 879)

7) What areas of the body do we find a high number of lymph nodes?(pg. 901)

8) How are B cells different from T cells?

Our immune systems responds to foreign molecules called antigens

Infection or vaccination triggers active immunity

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

We can temporarily acquire passive immunity

The Immune Response Counters Specific Invaders

Lymphatic System (accessory nervous system) Lymph: clear, watery fluid formed by interstial fluid

Nodes & Nodules: composed of lymphocytes filters lymph

Key organs: tonsils, adenoids, thymus, spleen and appendix

Has “dead end” vessels that are similar to veins3 Major Functions:

-collects & returns interstitial fluid and protein to blood

-launches the immune response: defends the body

-absorb lipids from digestive tract

Figure 23.3

Right lymphaticduct, enteringvein

Thoracicduct

Appendix

Adenoid

Tonsil

Lymph nodes

Thoracic duct,entering vein

Thymus

Spleen

Bonemarrow Lymphatic

vessels

LYMPHATICVESSEL

VALVE

Bloodcapillary

Tissue cells

Interstitialfluid

LYMPHATICCAPILLARY

Masses oflymphocytes andmacrophages

This lymphatic vessel is taking up fluid from tissue spaces in the skin

It will return it as lymph to the blood Lymph contains less oxygen and fewer nutrients

than interstitial fluid

Figure 23.3B

LYMPHATICVESSEL

VALVE

Bloodcapillary

Interstitialfluid

LYMPHATICCAPILLARY

Tissue cells

Lymph nodes are key sites for fighting infection

They are packed with lymphocytes and macrophages

Figure 23.3C, D

Masses oflymphocytes andmacrophages

Lymphocytes

Macrophages

Outer capsule oflymph node

Lines of Defense

Video: “The Immune System”

(10 Statements)-Body Story

The Inflammatory Response Tissue injury; release of chemical signals~

• histamine (basophils/mast cells): • prostaglandins: increases blood flow & vessel permeability

Dilation and increased permeability of capillary~ • chemokines: secreted by blood vessel endothelial cells

mediates phagocytotic migration of WBCs Phagocytosis of pathogens~ • fever & pyrogens: leukocyte-released molecules increase body temperature

Capillaries allow the Transfer of Substances Through Their Walls

Figure 23.12A

Phagocytic and Natural Killer CellsNeutrophils 60-70% WBCs; engulf and

destroy microbes at infected tissue- “Short lived”

Monocytes (long lived) 5% WBCs; develop into

macrophages which enzymatically destroy microbes

Eosinophils 1.5% WBCs; destroy large parasitic invaders (blood flukes)

Natural killer (NK) cells destroy virus-infected body cells &

abnormal cells

Macrophages Wander in the Interstitial Fluid (Moncytes)

They “eat” any bacteria and virus-infected cells they encounter

Figure 24.1A

Interferon and complement proteins are activated by infected cells

Figure 24.1B

1

2

3

4

Interferongenesturned on

Interferonmolecules

5 Interferonstimulatescell to turnon genesfor antiviralproteins

HOST CELL 2Protected against virusby interferon from cell 1

HOST CELL 1Makes interferon;is killed by virus

Antiviral proteins blockviral reproduction

VIRUS Viral nucleic acid

mRNA

New viruses

6

Lines of Defense

Specific Immune Response

Lymphocytes: B & T cells found in lymph nodes Cell-mediated Immunity (T cells)

-Helper T cells

-Cytotoxic T cells

-Macrophages (antigen presenting cell) Antibodies (B cells): “Humoral immunity” Memory cells (clonal selection)- B cells

Specific Immunity Lymphocyctes

•pluripotent stem cells...• B Cells (bone marrow)• T Cells (thymus)

Antigen: a foreign molecule that elicits a response by lymphocytes (virus, bacteria, fungus, protozoa, parasitic worms)

Antibodies: antigen-binding immunoglobulin, produced by B cells

Antigen receptors: plasma membrane receptors on b and T cells

Two kinds of lymphocytes carry out the immune response B cells secrete

antibodies that attack antigens

T cells attack cells infected with pathogens

Lymphocytes Mount a Dual Defense

Figure 24.5

BONE MARROW

Stem cell

Immaturelymphocytes

Viablood

Antigenreceptors

B cell

HUMORALIMMUNITY

CELL-MEDIATEDIMMUNITY

T cell

THYMUS

Viablood

OTHER PARTSOF THE

LYMPHATICSYSTEM

Lymph nodes,spleen, and otherlymphatic organs Final

maturation of B and T cellsin lymphatic organ

Types of immune responses Humoral immunity B cell activation Production of antibodies Defend against bacteria,

toxins, and viruses free in the lymph and blood plasma

Cell-mediated immunity T cell activation Binds to and/or lyses cells Defend against cells infected

with bacteria, viruses, fungi, protozoa, and parasites; non-self interaction

In the primary immune response, clonal selection produces memory cells These cells may confer lifelong immunity

The initial immune response results in a type of “memory”

Figure 24.8A

Triggered by a specific antigen, a B cell differentiates into an effector cell The effector cell is called a plasma cell The plasma cell secretes antibodies

B cells are the main warriors of humoral immunity

When an antigen enters the body, it activates only lymphocytes with complementary receptors B and T cells multiply into clones of specialized

effector cells that defend against the triggering antigen

This is called clonal selection

Clonal selection musters defensive forces against specific antigens

Clonal Selection Effector cells: short-lived cells

that combat the antigen Memory cells: long-lived cells

that bear receptors for the antigen

Clonal selection: antigen-driven cloning of lymphocytes

“Each antigen, by binding to specific receptors, selectively activates a tiny fraction of cells from the body’s diverse pool of lymphocytes; this relatively small number of selected cells gives rise to clones of thousands of cells, all specific for and dedicated to eliminating the antigen.”

Figure 24.7

Antigen molecules

Variety ofB cells in a lymph node

Cell growthdivision, anddifferentiation

Clone of manyeffector cellssecretingantibodies

Antibodymolecules

Antigen receptor(antibody oncell surface)

Endoplasmicreticulum

Antigenic determinants are the molecules to which antibodies bind

Antigens have specific regions where antibodies bind to them

Figure 24.6

Antibody Amolecules

Antigen

Antibody Bmolecule

Antigenicdeterminants

Antigen-bindingsites

Pg. 903

An antibody molecule has antigen-binding sites specific to the antigenic determinants that elicited its secretion

Figure 24.10B

Antigen-bindingsites

Lightchain

Heavychain

Pg. 904

An antibody molecule

Antibodies are the weapons of humoral immunity

Figure 24.10A

Induction of Immune Responses Primary immune response: lymphocyte proliferation and

differentiation the 1st time the body is exposed to an antigen Plasma cells: antibody-producing effector B-cells Secondary immune response: immune response if the

individual is exposed to the same antigen at some later time~ Immunological memory

When memory cells are activated by subsequent exposure to an antigen, they mount a more rapid and massive secondary immune response

Figure 24.8B

Unstimulated lymphocyte

First exposure to antigen

FIRST CLONE

Memory cells

Effector cellsSecond exposure to antigen

SECOND CLONE

More memory cells

New effector cells

Ch. 43-Immunity Video1. What epidemic was discussed in the video?2. What process does Edward Golub explain in the video?3. Name the first line of defense explained by Vet. Scott

Weldy4. Name the cells mentioned by Dr. Galph that are

considered to be “front line soldiers” of the immune system. What disease did Dr. Galph contract when he was a child?

5. Name the specific cell that HIV attacks.6. What does the final segment investigate? Name the

disorder that “Carolyn” had. *Important Test Pages: **Write the title for each segment and FIVE statements for

each segment.

Figure 24.9

PRIMARY RESPONSE(initial encounterwith antigen)

Antigen

Antigen receptoron a B cell

Antigen bindingto a B cell

Memory B cell

Antibodymolecules

Plasma cell

Cell growth,division, anddifferentiation

SECONDARY RESPONSE(can be years later)

Cell growth,division, and furtherdifferentiation

Larger cloneof cells

Plasma cell

Antibodymolecules

Later exposure to same antigen

Memory B cell

Clone ofcells

Antibody Structure & Function (pg. 904) Epitope: region on antigen surface recognized by antibodies

2 heavy chains and 2 light chains joined by disulfide bridges Antigen-binding site (variable region) Gene Rearrangement plays a major role in generating a diverse

amount of lymphocytes & secreted antibodies (pg. 906)

Figure 24.11

Binding of antibodies to antigensinactivates antigens by

Neutralization(blocks viral binding sites;

coats bacterial toxins)

Agglutinationof microbes

Precipitation ofdissolved antigens

Activationof complement

Virus

Bacterium

Bacteria

Antigenmolecules

Complementmolecule

Foreign cell Hole

Enhances

Phagocytosis

Macrophage

Cell lysis

Leads to

5 classes of Immunoglobins (pg. 912) IgM: 1st to circulate; indicates infection; too large to cross placenta (complements)

IgG: most abundant; crosses walls of blood vessels and placenta; protects against bacteria, viruses, & toxins; activates complement (Fetus immunity)

IgA: produced by cells in mucous membranes; prevent attachment of viruses/bacteria to epithelial surfaces; also found in saliva, tears, saliva and perspiration

IgD: do not activate complement and cannot cross placenta; found on surfaces of B cells; probably help differentiation of B cells into plasma and memory cells

IgE: very large; small quantity; releases histamines-allergic reaction from

mast cells

These molecules are produced by fusing B cells specific for a single antigenic determinant with easy-to-grow tumor cells

Monoclonal antibodies are powerful tools in the lab and clinic

Figure 24.12A

Antigen injectedinto mouse

Tumor cells grownin culture

B cells(from spleen)

Tumor cells

Cells fused togenerate hybridcells

Single hybrid cellgrown in culture

Antibody

Hybrid cell culture,producing monoclonal antibodies

These cells are useful in medical diagnosis

Example: home pregnancy tests

They are also useful in the treatment of certain cancers

Figure 24.12B

Immunity in Health & Disease

Active immunity/natural: conferred immunity by recovering from

disease Active immunity/artificial: immunization

and vaccination; produces a primary response

Passive immunity: transfer of immunity from one individual to another• natural: mother to fetus; breast milk

• artificial: rabies antibodies ABO blood groups (antigen presence) Rh factor (blood cell antigen); Rh-

mother vs. an Rh+ fetus (inherited from father)

Lines of Defense

List of Key Terms & Substances for Non-Specific Defense Mechanisms Histamine (mast cells)

Heparin Antimicrobial proteins (complements)

Examples: Interferon

Lysozymes (skin & mucous membranes)

Chemokines (direct phagocytic cells) Natural Killer cells (apoptosis) antigens

Specific Defense Mechanisms Involves B cells & T cells-----------Lymphocytes Production of Antibodies (B cells)-humoral Production of T cells-activation of Cytotoxic T cells –

cell mediated Cloning includes: effector cells & memory cells

-B cells, Cytotoxic T cells, or a Helper T cell APC: antigen presenting cell (macrophage) or

sometimes referred to as a dendritic cell MHC: antigen complexes on an APC Cytotoxic T cells make CD8-------class I MHC Helper T cells make CD4----------class II MHC

Helper T cells and cytotoxic T cells are the main effectors of cell-mediated immunity

Helper T cells also stimulate the Humoral responses

T cells mount the Cell-mediated defense and aid humoral immunity

Helper T lymphocytes Function in both humoral & cell-mediated immunity Stimulated by antigen presenting cells (APCs) T cell surface protein CD4 enhances activation Cytokines secreted (stimulate other lymphocytes):

a) interleukin-2 (IL-2): activates B cells and cytotoxic T cellsb) interleukin-1 (IL-1): activates helper T cell to produce IL-2

Humoral Response w/B cells & Helper T cellsAntigen---APC

Helper T cell (CD4)

Cytokines released

Helper T cells Divide

Helper T & B-Cell

MHC II (complex)

B cells Divide & grow

Antibodies Released

Antibody Mediated Immunity

The helper T cell’s receptors recognize the self-nonself complexes on the APC

The interaction activates the helper T cells The helper T cell can then activate cytotoxic T

cells with the same receptors

Figure 24.13B

Self proteindisplayingan antigen

T cellreceptor

Interleukin-2stimulatescell division

CytotoxicT cell

Interleukin-2activatesother T cellsand B cells

Cell-mediatedimmunity(attack oninfected cells)

Humoralimmunity(secretion ofantibodies byplasma cells)

B cell

HelperT cell

APC

Interleukin-1activateshelper T cell

cytokines

Cytotoxic T cells bind to infected body cells and destroy them

Figure 24.13C

Cytotoxic T cell bindsto infected cell

1 2 3Perforin makes holesin infected cell’s membrane

Infected cell is destroyed

INFECTED CELL

Perforinmolecule

CytotoxicT cell

Foreignantigen

Holeforming

Perforin released

Cytotoxic T cells may attack cancer cells The surface molecules

of cancer cells are altered by the disease

Cytotoxic T Cells may help Prevent Cancer

Figure 24.14

Cell-mediated immunity

An antigen-presenting cell (APC) first displays a foreign antigen and one of the body’s own self proteins to a helper T cell

Figure 24.13A

1

2 3

4

Microbe

Macrophage (will become APC)

Antigen from microbe(nonself molecule)

Self protein

Self proteindisplayingantigen T cell receptor

Bindingsite for self protein

HelperT cell

Binding sitefor antigenAPC

Cell-mediated: Cytotoxic T cells

The immune system normally reacts only against non-self substances It generally rejects transplanted organs The cells of transplanted organs lack the recipient’s

unique “fingerprint” of self proteins

The immune system depends on our Molecular Fingerprints

Self/Non-self Recognition Self-tolerance: capacity to distinguish self from non-self Autoimmune diseases: failure of self-tolerance; multiple sclerosis, lupus,

rheumatoid arthritis, insulin-dependent diabetes mellitus Major Histocompatability Complex (MHC): body cell surface antigens

coded by a family of genes Class I MHC molecules: found on all nucleated cells Class II MHC molecules: found on macrophages, B cells, and activated T

cells Antigen presentation: process by which an MHC molecule “presents’ an

intracellular protein to an antigen receptor on a nearby T cell Cytotoxic T cells (TC): bind to protein fragments displayed on class I

MHC molecules Helper T cells (TH): bind to proteins displayed by class II MHC molecules

Autoimmune diseases The system turns against the body’s own molecules

Immunodeficiency diseases Immune components are lacking, and infections

recur Physical and emotional stress may weaken the

immune system

Malfunction or failure of the immune system causes disease

Overview of Human Immune System Function

Abnormal immune function Allergies (anaphylactic shock): hypersensitive responses to environmental

antigens (allergens); causes dilation and blood vessel permeability (antihistamines); epinephrine

Autoimmune disease: multiple sclerosis, lupus, rheumatoid arthritis, insulin-dependent diabetes mellitus

Immunodeficiency disease: SCIDS (bubble-boy); A.I.D.S.

Acquired immune deficiency syndrome (AIDS) is epidemic throughout much of the world

14,000 people are infected with the AIDS virus every day HIV is the virus that causes AIDS HIV is transmitted mainly

in blood and semen Former L.A. Laker Magic

Johnson is one of 900,000 Americans who are HIV-positive

The Continuing Problem of HIV

Our immune system is a specific defense system

It backs up several mechanisms of nonspecific resistance

HIV attacks the immune system It eventually destroys the body’s ability to fight

infection

The AIDS virus attacks helper T Cells This cripples both cell-mediated and humoral

immunity So far, AIDS is incurable

Drugs and vaccines offer hope for the future Practicing safer sex could save many lives

AIDS leaves the body defenseless

Chapter 42: Respiratory System

Introductory Questions #41) Give two reasons as to why gas exchange

in the air is more advantageous than in the water.

2) Name the four types of surfaces used for gas exchange in animals.

3) Why must there be a countercurrent flow of blood and water over the gill filaments in fish?

4) When exhaling air, does your diaphragm contract or relax? Explain what tidal volume, vital capacity and residual capacity mean.

Respiratory surfaces must:

-have a large surface area

-be moist

-allow diffusion to occur easily (thin)

-have a good blood supply

Requirements for Gas Exchange

Land animals exchange gases by breathing air Air contains more O2 and is easier to move than

water But water loss from the respiratory surfaces can be a

problem

The Tracheal System of Insects ProvidesDirect Exchange Between the Air and Body cells

In insects, a network of tracheal tubes carries out gas exchange

O2 diffuses from the finely branched tubes directly into cells

Figure 22.5B

Some animals use their entire skin as a gas-exchange organ

Example: earthworms

Figure 22.2A

Cut

Cross sectionof respiratorysurface (theskin coveringthe body)

Capillaries

CO2

O2

Figure 22.5A, C

Air sacs

Openingfor air

Tracheae

Bodycell

Tracheole Airsac

Trachea

Air Body wall

In humans and other mammals, air enters through the nasal cavity It passes through the pharynx and larynx into the

trachea The trachea forks to form two bronchi Each bronchus branches into numerous bronchioles

Terrestrial Vertebrates have Lungs

In most animals, specialized body parts carry out gas exchange

Gills in fish

Figure 22.2B

CapillariesCO2

O2

Respiratorysurface(gill)

Body surface

Gas Exchange

Blood flows through the lamellae in a direction opposite to water flow This countercurrent

maintains a diffusion gradient that maximizes the uptake of O2

Countercurrent flow in the gills Enhances O2 transfer

Figure 22.4

Blood flowthroughlamellae

Water flowoverlamellae

Other organisms, such as birds, have air sacs

These structures act as bellows that keep air flowing through the lungs

However, they do not function directly in gas exchange

Figure 22.8B

EXHALATION:Air sacs empty; lungs fill

INHALATION:Air sacs fill

Anteriorair sacs

Posteriorair sacs

Lungs

Trachea

Air

Lungs

Airtubesin lung

Air

1 mn

Geese have adaptations that allow them to fly over the Himalayas

Their efficient lungs draw more oxygen from the atmosphere

Their hemoglobin has a high affinity for oxygen They have a large

number of capillaries to deliver this oxygen-rich blood to tissues and muscles

Mammalian Respiratory Systems Larynx (upper part of

respiratory tract) Vocal cords (sound

production) Trachea (windpipe)

Bronchi (tube to lungs) Bronchioles Alveoli (air sacs) Diaphragm (breathing

muscle)

The bronchioles end in clusters of tiny sacs called alveoli Alveoli form the respiratory surface

of the lungs Oxygen diffuses

through the thin walls of the alveoli into the blood

Figure 22.6C

Figure 22.6B

Oxygen-richblood Oxygen-poor

blood

Alveoli

Blood capillaries

Bronchiole

Ch. 43-Immunity Video1. What epidemic was discussed in the video?2. What process does Edward Golub explain in the

video?3. Name the first line of defense explained by Vet. Scott

Weldy4. Name the cells mentioned by Dr. Galph that are

considered to be “front line soldiers” of the immune system.

5. What does the final segment investigate?

*Important Test Pages: 935, 937, and 944 **Write the title for each segment and FIVE statements

for each segment.

Cummulative Topics to Review-Test #3Alternation of Generation CSF

Protein Structures (amino acids) Genetic crossesMonocots & dicots Behavior (learning)Plant hormones Glycolysis (enzymes)Flower structures Endo/Ecto thermsAcid/base-define Muscle contractionSympathetic/parasympathetic NS Natural SelectionEye, Ears, Nose, Throat struct. Water potentialStriated/non-striated muscle tissue Cell juntionsPrimary/Secondary growth-plants Sarcomere struct.Action potential (wave) Electron acceptorsMajor parts of the brain (4) Plant groupsKreb cycle Genetic DisordersPhotosythesis (2) Mutations Genetic variation (causes) Hardy-WeinbergMeiosis Mitosis

Breathing Positive pressure breathing: pushes air into lungs (frog) Negative pressure breathing: pulls air into lungs (mammals) Inhalation: diaphragm contraction; Exhalation: diaphragm relaxation Tidal volume: amount of air inhaled and exhaled with each breath

(500ml) Vital capacity: maximum tidal volume during forced breathing

Regulation: CO2 concentration in blood (medulla oblongata)

Smoking causes lung cancer and contributes to heart disease

Smoking also causes emphysema Cigarette smoke

makes alveoli brittle, causing them to rupture

This reduces thelungs’ capacity for gas exchange

Figure 22.7A, B

The human respiratory system

Figure 22.6A

Nasalcavity

Left lung

Pharynx(Esophagus)

Larynx

Trachea

Bronchus

Bronchiole

Diaphragm

(Heart)

Rightlung

Figure 22.1

1 Breathing

2 Transportof gases bythe circulatorysystem

3 Servicing ofcells withinthe bodytissues

Lung

O2

CO2

Circulatorysystem

Capillary

Cell

CO2

O2

Mitochondria

The air at the height of the world’s highest peak, Mt. Everest, is very low in oxygen Even expert mountain climbers do not always

survive the journey Thin air can weaken

muscles, damage the digestive system, cloud the mind, and sometimes fill the lungs with blood

Surviving in Thin Air

Volumes for Air Exchange Vital Capacity: 4500 cm3 Breath out all

the air you can Tidal volume: 500 cm3 Normal breath Inspirational reserve: 3000 cm3 Excess air you

can still breath in-------------------------------------------------------------------------------------- Residual air left over: 1200 cm3 (cannot be forced out)

*Lungs will collapse, alveoli require this amount of air at all times.

Breathing is the alternation of inhalation and exhalation

Breathing ventilates the lungs

Figure 22.8A

Rib cageexpands asrib musclescontract

Airinhaled

Lung

Diaphragm

INHALATIONDiaphragm contracts

(moves down)

EXHALATIONDiaphragm relaxes

(moves up)

Rib cagegets smalleras rib musclesrelax

Airexhaled

Breathing control centers are located in the pons and medulla of the brain These automatic controls keep breathing in tune with

body needs

Breathing is automatically controlled

During exercise, the CO2 level in the blood rises, lowering the blood pH

This triggers a cascade of events

Figure 22.9

Brain

Cerebrospinal fluid

BREATHING CONTROLCENTERS—stimulated by:

CO2 increase / pH decreasein blood

Nerve signalindicating lowO2 level

O2 sensorin artery

Pons

Medulla

Nerve signalstriggercontractionof muscles

Diaphragm

Rib muscles

How Changes in Blood pH occur

Normal blood pH is: 7.4 More CO2, causes the blood to be more acidic In the Erythrocyte:

(carbonic anhydrase)

CO2 + H2O H2CO3 H+ and HCO3-

HCO3- is carried in the plasma & Cl- takes its place

(Chloride shift) H+ causes the O2 to be released by the hemoglobin Hemoglobin acts as a buffer by binding to the H+’s present CO2 is transported through the blood in the form of a

bicarbonate ion HCO3-.

Hemoglobin is a protein in red blood cells

It carries most of the oxygen in the blood

Figure 22.10B

Hemegroup

Ironatom

Polypeptide chain

O2 loadedin lungs

O2 unloadedin tissues

O2

O2

Most CO2 in the blood combines with water to form carbonic acid

The carbonic acid breaks down to form H+ ions and bicarbonate ions

These help buffer the blood

Figure 22.11A

TISSUE CELL

CO2 produced

INTERSTITIALFLUID

CO2

CO2

CO2

BLOODPLASMAWITHINCAPILLARY

Capillarywall

H2O

H2CO3

Carbonic acid

REDBLOODCELL

HCO3– + H+

Hemoglobinpicks upCO2 and H+

Bicarbonate

HCO3–

Most CO2 is transported to the lungs in the form of bicarbonate ions

Figure 22.11B

ALVEOLAR SPACE IN LUNG

CO2

CO2

H2O

H2CO3

HCO3– + H+

HemoglobinreleasesCO2 and H+

HCO3–

CO2

CO2

Respiratory Pigments: Gas Transport Oxygen transport-

Hemocyanin: found in hemolymph of arthropods and mollusks (Cu)

Hemoglobin: vertebrates (Fe)

Carbon dioxide transport- Blood plasma (7%) Hemoglobin (23%) Bicarbonate ions (70%) Deep-diving air-breathers- Myoglobin: oxygen storing protein

Video: Gas Exchange

Write 10 Statements from the video

As with all land animals, the giraffe and the corn snake are constantly subject to the force of gravity

How Does Gravity Affect Blood Circulation?

The circulatory system keeps blood pumping despite gravity’s pull

Muscle contractions help blood travel uphill in the veins of a giraffe’s long legs

The wriggling of the corn snake squeezes its veins and increases circulation

Mucus and cilia in the respiratory passages protect the lungs Pollutants, including tobacco smoke, can destroy

these protections Smoking kills about 430,000 Americans each

year

Smoking is one of the Deadliest assaults on our Respiratory System

Vital capacity is the maximum volume of air we can inhale and exhale

But our lungs hold more than this amount The alveoli do not completely collapse A residual volume of “dead” air remains in the lungs

after exhalation

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

In the tissues, cells pick up CO2 and drop off O2

Gases diffuse down pressure gradients in the lungs and the tissues

Blood Transports the Respiratory Gases, with Hemoglobin carrying the oxygen

A human fetus depends on the placenta for gas exchange

The Human Fetus Exchanges Gases with the mother’s bloodstream

Figure 22.12

Placenta, containingmaternal blood vesselsand fetal capillaries

Umbilical cord,containing fetalblood vessels

Amnioticfluid

Uterus

A network of capillaries exchanges O2 and CO2 with maternal blood that carries gases to and from the mother’s lungs

At birth, increasing CO2 in the fetal blood stimulates the fetus’s breathing control centers to initiate breathing

Cummulative Topics to Review-Test #3Alternation of Generation CSF

Protein Structures (amino acids) Genetic crossesMonocots & dicots Behavior (learning)Plant hormones Glycolysis (enzymes)Flower structures Endo/Ecto thermsAcid/base-define Muscle contractionSympathetic/parasympathetic NS Natural SelectionEye, Ears, Nose, Throat struct. Water potentialStriated/non-striated muscle tissue Cell juntionsPrimary/Secondary growth-plants Sarcomere struct.Action potential (wave) Electron acceptorsMajor parts of the brain (4) Plant groupsKreb cycle Genetic DisordersPhotosythesis (2) Mutations Genetic variation (causes) Hardy-WeinbergMeiosis Mitosis