Topic 1-6 Control of the Heart

Home is where the heart is

Control of the Heartbeat• Internal control

– Cardiac muscle (aka myogenic muscle) differs from other muscles in the body because it contracts without external stimulation

– Contractions are due to electrical impulses from two nodes located in the heart

• External control– Other factors outside the heart

including nervous stimulation, exercise and hormones can influence heart rate

Internal Control - 2 nodes exist in heartSinoatrial node (SA node) – Starts electrical signal

– Bundle of nerves and muscles– Also known as the pacemaker - sets the tempo of the heart

(approximately 70 beats per minute and 70-mL of blood at each beat)

– Located in the right atrium– Starts contraction of the atria, pushing blood into ventricles– Nerve impulse travels from SA node to other muscle cells by

modified muscle tissues

http://www.youtube.com/watch?v=GbttJ-5do9M&safety_mode=true&safe=active

Bill Nye- Valves and pump 1:55 – 3:44Heart beat; sympathetic NS 4:30 – 5:17 SA node 5:29 – 6:33

Internal ControlAtrioventricular node (AV node)

– Picks up the impulse from the SA node

– Causes contraction of the ventricles

– Sends blood out to lungs and body

– Passes nerve impulses along special fibers (Purkinje fibers) along septum and muscle tissue

Electrical Activity

Artificial Pacemaker - Link• An artificial pacemaker is used to emit electrical impulses when the SA node is not functioning properly

• Arrhythmia = irregular heartbeat

http://www.youtube.com/watch?v=rpwryb5o8s4&feature=related&safety_mode=true&persist_safety_mode=1

Video: Pacemaker Video:http://www.youtube.com/watch?v=IR0nWe47eek&feature=related&safety_mode=true&persist_safety_mode=1

External Control

Nervous Stimulation– Two regulatory nerves of the

autonomic nervous system help to control heart rate

• Sympathetic nerves• Parasympathetic nerves

– Responds to the needs of the body by conducting impulses from the medulla oblongata (brain) to the pacemaker (SA node) .

Nervous StimulationSympathetic

– stimulated in times of stress

• “Fight or flight”• Increases heart rate• Blood flow to tissue increases

Parasympathetic– Relaxation– Slows heart rate

Adjustment Due to Exercise• Increase in carbon dioxide

in the blood due to exercise stimulates the medulla oblongata of the brain

• The medulla sends a nerve impulse to the SA node to increase the heart rate

• The increased heart rate circulates the blood to the lungsremoving the excess carbon dioxide

Other Factors• high temperature increases heart rate• release of hormones (such as adrenaline)

also increases heart rate.

Synthetic Estrogen

Disorders of the Circulatory System

• Buildup of fatty material inside arteries

• Arteries become hard • Causes high blood pressure, or

hypertension• Arteries can rupture or blood clots

can form

Atherosclerosis

Angina• Chest pain due to poor blood

circulation to the heart• Not enough oxygen to the heart

What is a heart attack?• Caused by a blockage

of the coronary arteries

• This reduces blood flow to the heart = NO oxygen = HEART DIES!!

• Heart attacks can be caused by high cholesterol and smoking!

http://www.youtube.com/watch?v=RiYOuI7iyp8&safety_mode=true&safe=active

Bill Nye – clots; heart surgeon 4:30 – 7:58

CPR – Stayin’ Alive. http://www.youtube.com/watch?v=n5hP4DIBCEE&safety_mode=true&safe=active

The result of a heart attack could be complete stoppage (cardiac arrest – lack of a pulse) or reduced

function of the heart.

Stroke • Occurs when blood clot

lodges in a blood vessel in the brain or if a blood vessel ruptures

• Tissue damage becomes significant after about 4 minutes

• Can result in death or mental/physical problems

• Symptoms: – Weakness on one side,

trouble speaking, paralysis on one side.

– Unequal pupils, facial problems (facial muscle weakness, swallowing problems, drooling)

http://www.youtube.com/watch?v=AVKDm4PhEwI&safety_mode=true

News reporter has stroke on air?

No – actually, the new reporter had a migraine.

Stroke

Embolus• A blood clot that dislodges and later jams in another vessel

Causes aBulge in

artery wall

If left undiscovered, can be extremely dangerous –

rupture may cause instant death

Aneurysms are due to a weak spot in an artery.

Topic 1-8: Lymphatic System• The lymphatic and circulatory

system are closely related– intertwined and similar to the

circulatory system• The lymphatic system returns

extracellular fluid (protein and bacteria) leaked from capillaries back to circulatory system– Lymph is fluid (protein)

leaked from the capillaries

Some fluid seeps through cap wall &

is called lymph

This fluid isreturned to the

blood via thelymphatic

system

In blood, the fluid is called plasma .

When it leaves the capillaries, it is called lymph.

Lymphatic System

• Fluid moves through lymph vessels by skeletal muscle contractions– No backflow due to one way system of valves (similar to

veins in this way)

Lymphatic System

Lymph Nodes• Before lymph is returned to the

blood it passes through lymph nodes

• Nodes contain white blood cells (which combat infections!)

• The WBCs filter lymph for invaders– Will destroy foreign particles by

phagocytosis• Lymph is returned to the

circulatory system through ducts

http://www.youtube.com/watch?v=B658Yn3INYc&safety_mode=true

Bozeman interstitial fluid 4:54

What role does the lymphatic system serve in delivering digested fat to the

tissues of the body?• Digested fats that are

absorbed by the small intestine through the lacteals (lymphatic system) ALSO enter the blood.

Lacteals

Topic 1-9 Blood Structure & Function

Components of BloodWhat is blood made up of?

1. Plasma (water like) 55% 2. white blood cells (WBCs)3. red blood cells (RBCs)4. platelet cells (clotting factors)

(45%)

RBC (44%)

Plasma (55%)

WBC + Platelets (1%)

Blood Slide View

Erythrocyte

(RBC)

Leucocyte

(WBC)

Leucocyte

(WBC)

Leucocyte

(WBC)

Leucocyte

(WBC)

Leucocyte

(WBC)

Platelets

Plasma

Composition of Blood PlasmaPlasma

– 92% water, 8% dissolved molecules

•Proteins (fibrinogen)•Glucose•Vitamins•Minerals •Gases•Waste products•nutrients

Blood Cells

RBC

WBC

Platelets

Erythrocytes (RBC) Structure• Biconcave disks• No nucleus when mature-

– Blood can carry more O2

• Short lifespan – 120 days• Contain hemoglobin

– Pigment (makes blood red)

– Contains iron which absorbs O2

Erythrocytes Function• RBC’s carry O2 to tissue

–Exchange for CO2 to be respired

• Anemia• RBC deficiency • Not enough iron = decreased

O2 to cells

• Low energy levels

RBCs are formed from stem cells in the bone marrow

Blood Cell Production• All blood cells come from stem cells located in

bone marrow!!

Leukocytes• White blood cells (WBCs)• Ratio of red to white = 700:1

Structure• Have a nucleus, largest of blood cells

Function• Engulf invading cells through phagocytosis

– Digests microbe – forms pus– Pus – used up WBC’s, dead tissue and bacteria

• make antibodies (various specialized cells – immune response)

• Also originate from stem cells (like RBCs)...

PlateletsStructure:• Small• Fragile• Contain specialized proteins

(thromboplastin)Function:• Start clotting

– Join with calcium in plasma

– First step in clotting• Also originate from stem cells

(like RBCs, WBCs)...

1. Platelets hit a rough edge of a injured blood vessel, rupture and release thromboplastin.

2. Thromboplastin (platelet) and Ca2+ (from blood) convert fibrinogen into fibrin!

3. Fibrin is a stretchy net that traps RBCs and seals wound.

Fibrinogen Thromboplastin Fibrin(Blood protein) (From platelet) (Blood clot)

Ca2+

(in blood)

Video: How does blood clot? 2:00https://www.youtube.com/watch?v=--bZUeb83uU

fibrin

Blood Typing• There are four different blood

types: – A, B, AB, O

• Each blood type is determined by antigens (markers) on the cells:– Antigens stimulate the

formation of antibodies– Ex: Antigen A = blood type A

• Antibody in plasma must be opposite so Type A has anti-B antibodies

Antigens

ABO Blood System

Type A blood contains anti-B antibodies that will attack type B antigens. Type B blood contains anti-A antibodies that will attack type A antigens.

Antibodies• Antibodies are produced in

response to an invader• Attach to antigens --- causes

clumping

• Wrong blood type during a transfusion?– Blood will clump (clot) -

agglutinate– Blockages will occur

Blood Type

Antigens on Surface of Red

Blood Cell

Antibodies in Blood

Can Receive Blood from

Groups:

Can Give Blood to Groups:

A

B

AB

O

ABO System

A B antibodies

A and B antibodies

B B, ABA antibodies

A, O A, AB

B, O

none

ABA, B, AB, OnoneBoth A and B

O A, B, AB, O

Four Blood Types: Antigens/Antibodies

Distribution of blood groups around the world: most people are Type 0!!

Universal Acceptor vs. DonorABAB OO

Universal acceptorBoth antigens are presentOnly donate to ABCan accept blood from A, B, AB or O

Universal donor No antigens are present Will not bind to antibodies Only accept O Can donate blood to A, B, AB

or O

Rhesus (Rh) Factor• Rh Factor = Another

antigen on RBC’s• If present = Rh+

– ~ 85% of people • If absent = Rh-

– ~15% of people• Humans have no

natural antibodies for Rh– But they can be

produced later on in life

A

A

A

Rh

Rh

Rh

A

A

A

A + blood A - blood

What antibodies would each have?

Rh and pregnancy

• If have a Rh- mother and Rh+ father– Baby can be Rh+!!!

• First child (Rh+) – no problem– No mixing of blood until birth– During birth, blood will mix– Mother’s immune system creates

Rh+ antibodies– No harm to baby

Erythroblastosis FetalisSecond child– If child is Rh+ = problem– Mother has Rh+ antibodies– If they enter baby, blood will

clump– Reduced O2 delivery– “blue baby”– Solution – transfuse baby w/

Rh- blood

Blood typing game on next page.

https://www.youtube.com/watch?v=KXTF7WehgM8

Bozeman blood typing video 10:45

Do the blood typing lab

http://www.nobelprize.org/educational/medicine/bloodtypinggame/

Paper towel

Mr. Smith Ms. Jones

Mr. Green Ms. Brown

A

B

Rh

A

B

Rh

A

B

Rh

A

B

Rh

Then do the blood typing game:

Sickle Cell Anemia

Hemoglobin is defective – causes red blood cells to bend into sickle shape, which causes blood to be blocked at capillaries

Normal & Abnormal Red Blood Cells

Notice how a minor change in the DNAcauses a radical change in hemoglobin structure

Cannot clot blood – life threatening –

transfusions can help

Hemophilia

Cancer of the white blood cells... The number of leukocytes in the blood increases, but the cells

do not function normally

Leukemia

Topic 1-10 Immunity

What are Pathogens??• Pathogen = A

bacteria, fungi, virus or protozoan that can cause disease

Athlete’s Foot fungus!

Defense: Barrier ResponsesFirst Line of defense against infection

Skin•Layers of dead cells

•Oil

•Sweat

Gas Exchange

•Hair

•Cilia

•Mucus

•Coughing and sneezing

DigestiveSystem

•Stomach acid

•Enzyme

Urinary System•Mucus

•Periodic flow of urine

Non-Barrier Responses

Inflammation

Antibody production

Inflammatory Response• Microbe penetrates body’s first line of defense• Triggers series of changes leading to inflammation at point

of entry

1. WBCs squeeze out of capillaries

capillary

2. WBCs engulf bacteria by

phagocytosis

3. Enzymes

from lysosomes kill/digest bacteria

4. Pus forms

Inflammatory Response• Microbe penetrates body’s first line of defense• Triggers series of changes leading to inflammation at point

of entry

Immune Response• Immune response is

triggered when the inflammatory response fails

• Antigen = Marker on surface of all cells (viruses, bacteria, body cells) that helps to identify the type of cell

• Antibodies = Y-shaped proteins produced by blood cells due to exposure to an antigen

Immune Response1. When foreign antigens enter the

body, it causes lymphocytes to make antibodies

• The shape of an antibody is determined by the foreign antigens, therefore antibodies are antigen specific

• When an antibody attaches to a foreign antigen, it destroys the cell attached to it

2. Antibodies cause several antigens to clump together, making it easier for macrophages (type of white blood cell) to capture them!!

Antigencombines with

antibody at antigenbinding site

Immune Response – in detail!!!

Antigen enters the bodyStep 1:

Helper T-cells tell B-cells

to make antibodies

Step 4:

Macrophage engulfs antigen and pushes antigen marker to the outer surface

Step 2:

Helper T-cells copy the antigen shape

Step 3:

Helper T cell B cell

Okay!

Make antibodies

Immune Response – in detail!!!

Antibodies attach to antigens

Step 5:

Step 6: Macrophage engulfs antigenOR

KillerT cell

Killer T-cells puncture membrane of bacteria = bacterial DEATH!!!

https://www.youtube.com/watch?v=HNP1EAYLhOs

Killer T cell video

https://www.youtube.com/watch?v=I_xh-bkiv_c

Macrophage digesting bacteria:

Mwah, ha, ha, ha!

Immune Response – in detail!!!

Step 7: Suppressor T-Cells stop the response,

STOP

and memory T-cells remember the antigen so that antibodies are produced faster next time

Suppressor T-cell

Memory T-cell

Bozeman immune system video: 13:47 min

http://www.youtube.com/watch?v=z3M0vU3Dv8E&safety_mode=true

Review of Functions of WBCsMacrophage engulfs antigen and

pushes antigen marker to the outer surface

Helper T-cells copy the antigen shapeKiller T-cells puncture membrane of

bacteria

B-cells make antibodies Memory T-cells remember the

antigen so that antibodies are produced faster next time

Suppressor T-Cells stop the response

Watch the first 10 minutes of the video of

the “Magic Doctor”Summarize the

functions of each type of white blood cell.

Magic Doctor video

Why can’t our immune system destroy HIV (Human Immunodeficiency Virus)?

• Usually viruses leave their outer protein coat in the entry port on cells

• This way it is recognized by the body’s lymphatic system and phagocytosed

• However, HIV does not leave its protein coat on the cell and it invades Helper T-cells

• Helper T-cells mistake the virus for a needed substance and phagocytoses it...allowing the virus to enter the WBC!

How does HIV spread?

• Helper T-cells create both killer T-cells as well as B-cells!

• HIV can live in T-cells for days or even years without becoming active

• When it does become active, it uses the helper T-cell’s DNA to reproduce

• When the helper T-cell bursts, HIV spreads to other T-cells

HIV invades Helper T cells and take over T cell metabolic machinery

HIV virus replicates using host DNA

How does the flu enter your body?

The flu attacks! How does it enter your

body?

http://www.youtube.com/watch?v=Rpj0emEGShQ&feature=related&safety_mode=true&persist_safety_mode=1&safe=active

Vaccines• Vaccine = dead or weakened

virus is injected into the body– Body produces antibodies to

prevent future infections

• First successfully doneby Edward Jenner (1800)

• Vaccines contain destroyed antigens that triggerantibody production

https://www.youtube.com/watch?v=jJwGNPRmyTI

Edward Jenner (2:31)

Vaccines

Second vaccination

First vaccination

AntibioticsAntibiotic = drug made from bacteria or fungi – Used to only kill diseases

caused by bacteria

Danger of antibiotic overuse:– Over time, bacteria become

antibiotic resistant– Antibiotics cannot cure

viruses– Can cause serious side effects

like allergic reactions

Involves B cell activation