Activity 4.3.1

The Heart of the Matter

What types of muscles help move blood around the body?

Essential Question 1

Cardiac MuscleSmooth MuscleSkeletal Muscle

Cardiac Muscle

Cardiac muscle fibers are shorter in length and larger in diameter than skeletal muscle fibers.

Cardiac muscle fibers have actin and myosin filaments arranged in the same way as skeletal muscle, but usually only one nuclei.

In contrast to skeletal muscle, cardiac muscle does not fatigue, cannot be repaired when damaged and is regulated by the autonomic nervous system.

Gap junctions between the fibers allow ions to travel between cells to permit the rapid fire of action potentials.

Excitement of a single fiber results in stimulation of all the other fibers in the network (ALL OR NONE) . As a result, each network contracts as a functional unit.

Cardiac Muscle

Smooth Muscle

Arteries have smooth muscle that functions to regulate the flow of blood through the artery.

Contraction of the smooth muscle decreases the internal diameter of the vessel in a process called vasoconstriction.

Relaxation of the smooth muscle increases the internal diameter in a process called vasodilation.

Smooth Muscle

Where else can you find Smooth Muscles

.

Kidneys BladderUretersCiliary muscle

SphincterTracheaBile duct

Walls of stomach

UterusIntestinesIris of the eyeGI TractRespiratory Tract

Skeletal Muscle.

Veins pass between skeletal muscles. The contraction of skeletal muscle squeezes the vein.

Repeated cycles of contraction and relaxation of skeletal muscle, as occurs in the leg muscles while walking, helps facility blood back to the heart.

Skeletal Muscle

What do you remember from PBS about the heart?”

1_______________ 2____________ 3___________ 4___________ 5___________ 6___________ 7___________ 8___________ 9__________

Position and Shape of the Heart.

The heart is located in the thoracic cavity in between the lungs, 60% of it lying to the left of the median plane.

The heart is cone-shaped, with a broad base at the top from which the large blood vessels enter and exit.

The tip, known as the apex, points downwards and lies close to the sternum.

Pericardium

A membrane that surrounds and protects the heart. It is composed of two layers containing a small volume of fluid which serves as a lubricant, facilitating the movement of the heart by minimizing friction.

The inner layer is firmly attached to the heart wall and is known as the visceral layer or epicardium.

The outer layer is composed of relatively inelastic connective tissue and is termed the parietal layer.

Layers of the Heart Wall

The wall of the heart consists of three layers: epicardium (external layer), is the thin, transparent

outer layer of the wall and is composed of delicate connective tissue.

myocardium (middle layer), comprised of cardiac muscle tissue, makes up the majority of the cardiac wall and is responsible for its pumping action. The specific regions dictates the thickness of the myocardium.

endocardium (inner layer). is a thin layer of endothelium. It provides a smooth lining for the chambers of the heart and covers the valves. It is continuous with the endothelial lining of the large blood vessels attached to the heart

Fibrous Skeleton

In addition to cardiac muscle tissue, the heart wall also contains dense connective tissues that: forms the fibrous skeleton of the heart. forms rings that surround the four heart orifices.

The skeleton performs several functions: It serves as a point of attachment for the heart

valves. It prevents the valves from overstretching as blood

passes through them. It acts as an electrical insulator thereby preventing

the direct spread of action potentials from the atria to the ventricles.

Chambers of the Heart

The heart contains four chambers where the thickness of the myocardium of the chambers varies according to its function.

The two upper chambers are the atria. The atria are thin-walled because they deliver blood into the adjacent ventricles. On the upper surface of each atrium is a pouch-like appendage which is thought to increase the capacity of the atrium slightly.

The two lower chambers are the ventricles. The ventricles are equipped with thick muscular walls because they pump blood over greater distances.

Ventricles

The right and left ventricles act as two separate pumps that simultaneously eject equal volumes of blood. The right ventricle only pumps blood into the lungs, which are close by and present little resistance to blood flow so work load is less.

On the other hand, the left ventricle pumps blood to the rest of the body, where the resistance to blood flow is considerably higher. Therefore, the left ventricle works harder than the right ventricle to maintain the same blood flow rate. Consequently, the left ventricle is significantly thicker than that of the right.

Right Atrium (RA)

The right atrium forms the section of the base of the heart and receives blood from the superior vena cava, inferior vena cava and coronary sinus.

Blood flows from the right atrium to the right ventricle through the tricuspid valve (also know as the right atrioventricular valve).

The right atrium also houses the sinoatrial node.

Right Ventricle (RV)

The right ventricle forms most of the anterior surface of the heart and is crescent-shaped in cross-section.

The tricuspid valve provides the means for blood to leave the RA and move into the RV

The right ventricle is separated from the left by a partition called the interventricular septum.

Deoxygenated blood passes from the right ventricle through the pulmonary semi-lunar valve to the pulmonary trunk, which conveys the blood to the lungs.

Left Atrium (LA)

The left atrium forms the section of the base of the heart and is similar to the right atrium in structure and shape.

It receives oxygenated blood from the lungs via the pulmonary veins.

Blood passes from the left atrium to the left ventricle through the bicuspid or mitral valve.

The left atrium lies under the tracheal bifurcation and enlargement of this area of the heart can cause breathing difficulties.

Left Ventricle (LV)

The left ventricle forms the apex of the heart and is conical in shape.

Blood passes from the left ventricle to the ascending aorta through the aortic valve.

From here some of the blood flows into the coronary arteries, which branch from the ascending aorta and carry blood to the heart wall.

The remainder of the blood travels throughout the body.

Coronary vasculature

Conduction system

Animation: Conducting System of the Heart

Think about blood supply to....

EKG

Electrical Conduction

Essential Question 2 & 3

What is the relationship between the heart and the lungs?

What is the pathway of blood in and out of the heart in pulmonary and systemic circulation?

Activity 4.3.2

Varicose Veins

Varicose Veins

Normally, one-way valves in the veins keep blood flowing from your legs up toward your heart.

Varicose veins are caused by weakened valves in the veins in your legs.

When these valves do not work as they should, blood collects in your legs, and pressure builds up.

Varicose Veins

As pressure builds in the veins, the walls of the veins become weak, dilated, and twisted.

Venous return is slowed, causing blood to become sluggish.

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Causes of Varicose Veins

Varicose veins often run in families. Aging increases your risk. Increased pressure on leg veins

from Being overweight Pregnancy Or having a job where you must stand

for long periods of time.

The structure of blood vessels is in direct relationship to the function it

performs

CapillaryVeinArtery

Cross section of an artery

Why don’t we get varicose arteries.

Essential Question

4. How do the structure of arteries, veins and capillaries relate to their function in the body?

5. What unique features of veins help move blood back to the heart?

6. What are varicose veins?7. Why don’t we ever hear about

varicose arteries?

View Vessel Slides

Draw in your journal what you saw in the slides

With team of 4 devise a way to explain how varicose veins form and why we done get varicose arteries.

Final product could be drawing, diagram, information brochure, clay model, or a letter to your grandmother to answer her questions about varicose veins.

Present your findings to the class

Activity 4.3.3

Go With the Flow

The Flow

Blood vessels move blood from the heart to the lungs to pick up oxygen and deliver this oxygen to all of the tissues of the body.

Arteries flow away from the heart and branch into smaller vessels called arterioles.

Arterioles lead into the capillary beds, thin nets of vessels where gas exchange occurs.

Blood then converges back into small veins called venules and eventually back into the major veins to be returned to the heart.

Vessel size varies dramatically along this path.

Make paper Flag for these vessels

Ascending Aorta Renal artery/vein Descending Aorta Iliac artery/veinBrachiocephalic artery Femoral artery/veinSubclavian artery/vein Popliteal artery/veinCarotid artery vein Posterior Tibial

artery/veinRadial artery/vein Superior Vena CaveUlnar artery/vein Inferior Vena CavaCommon Iliac Vein Internal Jugular vein Superficial palmar arch

Build this on Maniken

One Brachiocephalic Artery

The aorta is the largest artery in the body about the diameter of a garden hose.

The capillaries, on the other hand, are so tiny that about ten of them would be as thick as one of the hairs on our head.

The structure of blood vessels relates directly to their particular function and to the amount of pressure exerted on the vessel walls.

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Essential Question

8. What are the major arteries and veins in the body and which regions do they serve?

Arteries in the arm

Veins in the Arm

Veins more superficial

Activity 4.3.4

Cardiac Output

Cardiac Output

Cardiac Output is a measure of how much blood the heart can pump in one minute by the ventricles.

Cardiac Output (ml/min) = Stroke Volume (75ml/beat) X Heart Rate (BPM)

What are some diseases that affect CO if dependent on SV &

HR hypertension heart failure infection and sepsis cardiomyopathy rhythm disturbances coronary artery disease

Essential Question

9. What is cardiac output?

10. How does cardiac output help assess overall heart health?

11. How does an increased or decreased cardiac output impact the body?

Changes in cardiac output

often signal diseases of the heart and these changes can impact the function of other body systems.

Increased blood pressure in vessels can indicate possible blockages, and these blockages can interrupt blood flow to an organ or limb

Increased BP decreases Cardiac Output in a diseased heart

Activity 4.3.5

Smoking Can CostYou an Arm and a Leg!

Essential Question

12. What is blood pressure?

13. How can the measurement of blood pressure in the legs be used to assess circulation?

Blood Pressure

When your heart beats, the contraction forces blood through the arteries to the rest of your body. This pressure created on the arteries is called systolic blood pressure, and measured in (mm Hg)

A normal systolic blood pressure is below 120.

The diastolic blood pressure number or the bottom number indicates the pressure in the arteries when the heart rests between beats.

A normal diastolic blood pressure number is less than 80.

http://www.sirweb.org/video/Peripheral_Arterial_Disease_Smoking.mpg

http://www.sirweb.org/video/Peripheral_Arterial_Disease_Smoking.m

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http://www.sirweb.org/news/videoClips.shtml

Complete Part I and share your findings with class before receiving part IIPart II-Draw a feedback loop to show the body responds to an increase in BP

Part III- Take ABI measurements

Example of BP feedback loop

In the example to the right blood pressure has increased. Receptors in the carotid arteries detect the change in blood pressure and send a message to the brain. The brain will cause the heart to beat slower and thus decrease the blood pressure. Decreasing heart rate has a negative effect on blood pressure.

FYI Renin-Angiotensin-Aldosterone System

Decreased blood volume or blood pressure stimulates the release of Renin that starts the process

The glomulerus, a bundle of capillary blood vessels found in the kidney, senses a drop in blood flow or a drop in sodium and secretes an enzyme called renin into the bloodstream.

Renin moves to the liver where it converts the inactive peptide angiotensiongen to angiotensin I.

Angiotensin I travels to the lungs where another enzyme converts it to angiotensin II.

Angiotensin II makes its way to the adrenal glands at the top of the kidneys where it stimulates the production of aldosterone.

Aldosterone helps the kidneys conserve sodium and water, leading to increased fluid volume and sodium levels.

NOTE: If blood flow to the kidneys or the amount of sodium increases, less renin is produced in an attempt to normalize blood pressure.

Animation: http://www.people.vcu.edu/~elmiles/hormones/KidneyHormones3.html

Ankle Brachial Index (ABI)

A test done by measuring blood pressure at the ankle and in the arm while a person is at rest.

Measurements are usually repeated at both sites after 5 minutes of walking on a treadmill.

A slight drop in the ABI with exercise, even if you have a normal ABI at rest, means that you probably have PAD.

Part IV Activity 4.3.5

Doppler ultrasound device Activity 4.3.5 Student Resource

Sheet – ABI Worksheet.

Project 4.4.1

The Body’s Response to Exercise

Essential Question

1. What is the connection between power and movement in the body?

ATP

Recall how the body generates ATP.

Food (primarily glucose) and oxygen are both vital to the assembly of ATP

ATP is always stored in the body but the amount in the body can only last 2 or 3 seconds. When it is used it is broken down from one adenozine and three phosphate molecules into adenzine diphosphate (2 phosphate molecules) and a separate phosphate molecule. This reaction is exothermic and produces energy.

There are three main ways it can be resynthesised and these are by using the phospho-creatine system, the lactic system and the aerobic system.

Aerobic resipration is much more complicated as oxygen is present. It starts the same way as lactic respiration but as oxygen is present, there is no lactic acid formed, instead pyruvic acid is converted into acetyle CoA by the enzyme coenzyme A. The acetyle CoA is then converted into citric acid by oxaloacetic acid. The citric acid then goes through something called the Krebs cycle where everything produced in respiration except the energy is removed. This leaves 2 ATP molecules. The hydrogen removed from the reaction then is converted using something called an electron transfer chain into 34 ATP molecules and water.

Essential Question

2. How does the body maintain a supply a ATP during exercise?

Exercise requires the coordinated effort of many human body systems including nervous system, muscular system, skeletal system, cardiovascular system, respiratory system.

Cellular respiration is the process by which ATP is Produced ATP is the main energy source used by the

cells Organic molecules such as glucose, lipids,

and proteins are broken down to produce ATP 3 stages of cellular respiration, Glycolysis,

Krebs cycle, Electron Transport Chain (ETC) http://www.sophia.org/tutorials/biology-

amanda-3-atp-production-video-overview-det

ATPA nucleotide used by cells as a

form of energy. Cellular Respiration -Process that occurs in cells to produces ATP for cells in order to carry out all cell functions. -ATP is produced by the breaking down of organic molecules such as glucose, lipids and proteins 3 Stages of Cellular Respiration -Glycolysis is the first stage -Krebs Cycle is the second stage -Electron Transport Chain is the third stage ATP -ATP is a nucleotide with a ribose sugar, adenine base and 3 phosphate groups -Energy stored between 2nd and 3rd phosphate group Glycolysis -1st step of cellular respiration -Occurs in cytoplasm of the cell -Glucose is broken down into a smaller molecule -Products of gylcolysis move into the next step The Krebs Cycle -2nd step of cellular respiration -Occurs in the mitochondria -The mitochondria is the “powerhouse” of the cell ETC -3rd step of cellular respiration -Occurs in the mitochondria -1 molecule of glucose yields 36 molecules of ATP -Most of the ATP is being produced by the ETC -A minor amount of ATP is produced in glycolysis and the Krebs cycle Source: Amanda Soderlind, Author

Activity 4.4.2

Mind Over Muscle

Problem 4.4.4

Training a Champion

Essential Questions

What is peripheral artery disease? Why can smoking lead to

peripheral artery disease?

Key Terms

Aorta -The large arterial trunk that carries blood from the heart to be distributed by branch arteries through the body.

Arteriole- Any of the small terminal twigs of an artery that ends in capillaries

Artery- Any of the tubular branching muscular- and elastic-walled vessels that carry blood from the heart through the body.

Arteriosclerosis-A chronic disease characterized by abnormal thickening and hardening of the arterial walls with resulting loss of elasticity

Atherosclerosis- A cardiovascular disease in which growths called plaques develop on the inner walls of the arteries, narrowing their inner diameters.

Atrium- A chamber of the heart that receives blood from the veins and forces it into a ventricle or ventricles.

Key Terms

Blood pressure-The hydrostatic force that blood exerts against the wall of a vessel.

Capillary-Any of the smallest blood vessels connecting arterioles with venules and forming networks throughout the body.

Cardiac muscle-Striated muscle fibers (cells) that form the wall of the heart; stimulated by the intrinsic conduction system and autonomic motor neurons

Cardiac output -The volume of blood ejected from the left side of the heart in one minute.

Circulation-The movement of blood through the vessels of the body that is induced by the pumping action of the heart and serves to distribute nutrients and oxygen to and remove waste products from all parts of the body.

Coronary Artery-Either of two arteries that arise one from the left and one from the right side of the aorta immediately above the semilunar valves and supply the tissues of the heart itself

Key Terms

Heart rate- A measure of cardiac activity usually expressed as number of beats per minute

Peripheral artery disease- A form of peripheral vascular disease in which there is partial or total blockage of an artery, usually one leading to a leg or arm.

Peripheral vascular disease- Vascular disease affecting blood vessels outside of the heart and especially those vessels supplying the extremities.

Pulmonary Circulation- The passage of venous blood from the right atrium of the heart through the right ventricle and pulmonary arteries to the lungs where it is oxygenated and its return via the pulmonary veins to enter the left atrium and participate in the systemic circulation

Pulse - A regularly recurrent wave of distension in arteries that results from the progress through an artery of blood injected into the arterial system at each contraction of the ventricles of the heart.

Key terms

Smooth muscle A tissue specialized for contraction, composed of smooth muscle

fibers (cells), located in the walls of hollow internal organs, and innervated by the autonomic motor neurons

Stroke volume The volume of blood pumped from a ventricle of the heart in one

beat Systemic Circulation The passage of arterial blood from the left atrium of the heart

through the left ventricle, the systemic arteries, and the capillaries to the organs and tissues that receive much of its oxygen in exchange for carbon dioxide and the return of the carbon-dioxide carrying blood via the systemic veins to enter the right atrium of the heart and to participate in the pulmonary circulation

Key Terms

Valve A bodily structure (as the mitral valve) that closes temporarily a

passage or orifice or permits movement of fluid in one direction only. Varicose vein An abnormal swelling of a superficial vein of the legs. Vein Any of the tubular branching vessels that carry blood from the

capillaries toward the heart and have thinner walls than the arteries and often valves at intervals to prevent reflux of the blood which flows in a steady stream and is in most cases dark-colored due to the presence of reduced hemoglobin.

Ventricle A chamber of the heart which receives blood from a corresponding

atrium and from which blood is forced into the arteries. Venule Any of the minute veins connecting the capillaries with the larger

systemic veins