Endocrine and Circulatory Systems

Endocrine SystemThe endocrine system is a system of glands,

each of which secretes a type of hormone to regulate the body.

The endocrine system is an information signal system much like the nervous system.

Hormones regulate many functions of an organism, including mood, growth and development, tissue function, and metabolism.

The field of study that deals with disorders of endocrine glands is endocrinology, a branch of the wider field of internal medicine.

Major endocrine glands. (Male on the left, female on the right.)

1. Pineal gland 2. Pituitary gland 3. Thyroid gland 4. Thymus 5. Adrenal gland 6. Pancreas 7. Ovary 8. Testis

Endocrine SystemThe endocrine system is used for

communication, throughout your body. The main communication system within

your body is the nervous system. The nervous system works in a similar

manner as a telephone. Messages are sent from one place to

another place, much in the same way that a telephone carries a message from you to your friend.

Endocrine SystemBut suppose you want to tell more than just

one person. You could call all your friends one at a time, but this would take a very long time. By the time you got the message out, it might be too late.

So how can you get a message to all your friends quickly? Suppose that you drive to your local radio station, and broadcast your message. Doing this allows all your friends to hear your message at the same time.

Endocrine SystemYour endocrine system is similar to a radio

broadcast. Instead of using radio waves to transmit messages, your endocrine system uses chemicals. These chemicals are called hormones. Hormones travel through the blood stream, and effect the activities of the various cells within your body.

GlandsWhere are these chemicals produced? Throughout your body, from your head,

down to your waist there are a number of small organs called glands.

These glands each produce one or more hormones.

These hormones are released into the bloodstream via small tubes called ducts.

Once in the bloodstream, these hormones effect every cell they come in contact with, telling them to do something.

Circulatory SystemThink of a large city.A city is a community of people who work

together to support each other, and make life possible. Each person has a different job. Some are builders, others work in markets, while others clean up. Every job is important. Suppose you work in an office building on the 86 th floor, and decide that you are hungry. How will you get food?

Circulatory SystemYou walk down the narrow hallway, climb

into an elevator, and go down to the main floor.

From there you walk out into the street, and continue towards your favorite lunch spot.

Using hallways, elevators, and roads, you eventually find your way to your lunch.

Circulatory SystemIn many ways, your body is like a city. Instead of millions of people, your body is

made up of trillions of cells, each with a different job.

What happens if a cell on the 86 th floor of your body gets hungry? How will it get food?

Circulatory SystemJust like a city with hallways, and roads,

your body has blood vessels, arteries, and veins that help move things around. Most of the cells inside of your body do not move.

If a cell is hungry, or needs to get rid of waste, it can’t simply move itself to the part of your body where it needs to go. Instead, your body must bring the food to your cells, and the waste away from them.

4 Processes of the Circulatory System

Four critical processesObtain energy and material

Ingest, digest, absorbObtain oxygen Dispose of nitrogenous waste

NH3, urea, uric acid

Dispose of CO2

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Circulatory System• Why have a circulatory System?• Small animals often don’t.• Cnidarians, flatworms, nematodes• Cells get sufficient O2, diffusion from environment• Cells dispose of wastes to environment• Cells get nutrients from gut by diffusion

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Circulatory System• Why have a circulatory System?

– Larger animals MUST have circulatory system• Most cells too far from surface and too far from gut

– Diffusion would take too long!!!• Circulatory systems bring O2, “food,” to all tissues

– All cells close enough to a capillary• Circulatory systems carry away metabolic wastes• Circulatory systems carry regulatory signaling molecules

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Organization of the Cardiovascular System

Heart = muscular double pumpBlood = circulating fluid tissueVessels

Arteries carry blood FROM the heart,Capillaries distribute O2, nutrient molecules, and pick

up wastes,Veins return blood TOWARD the heart

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Organization of the Cardiovascular System

Two circulationsPulmonary

To and from lungsSystemic

To and from all other tissues

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The Heart

The Heart• Mammalian heart

– Hollow, muscular– Double pump

• Right: Pulmonary circulation

• Left: Systemic circulation

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The Heart• Location

– Thoracic region in pericardial sac, between lungs

– 2/3 of mass left of midsagittal plane

– Apex = lower tip of left ventricle

– Base = “flat” superior side, tops of atria.

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The Heart• Chambers

– 2 Atria • receive venous return

– 2 Ventricles • receive blood from atria, • pump blood out through

major arteries

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The Heart• Valves direct blood flow

through the heart• 2 Atrioventricular

valves– Tricuspid– Bicuspid or Mitral

• 2 Semilunar valves– Pulmonary– Aortic

– Operation of valves

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HeartYour heart is broken into two

sides, separated by a septum. The Left side of your heart is

filled with oxygen rich blood, while the right side of your heart is filled with oxygen poor blood.

Each side of your heart is further broken into two chambers, known as the atrium, and the ventricle.

Each side of the heart has an atrium and a ventricle for a total of four chambers.

HeartYour right atrium takes in

the oxygen poor blood. It is then pumped to your

lungs via the right ventricle.

In your lungs, your blood again fills up with oxygen, and returns to your heart.

Your blood now enters the left atrium of your heart. It is then pumped out to your body via your left ventricle.

Arteries/veinsUsing billions of tiny

tubes, your body is constantly pumping blood throughout your body.

On the way out, your blood is loaded with the things that your body needs, like food, oxygen, and other chemicals.

On the way back, your blood is full of things that the cells of your body need to get rid of, like waste.

Blue Blood?What color is blood? Well, that depends. Sometimes it is red, and sometimes it is

blue. Look at your arm. Can you see the blue veins? Why are they blue? When blood is full of oxygen it is red, but

when it is low on oxygen it turns bluish. Why don’t I ever see blue blood? Because as

it leaves your body, it quickly turns red, as it takes in oxygen.

The job of your heart is to pump blood through your body. Even in your sleep, your heart keeps beating, or pumping blood.

If it stopped, you would quickly die.

VesselsArteries

Carry blood from heartThick muscular wall

VeinsCarry blood to heartThis nwall

CapillariesExtremely thin

membrane for exchange

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VesselsCapillary Exchange

Filtration & bulk flowDiffusion Osmosis

Excess fluid picked up by lymphatic system

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VesselsVenous return

Low venous pressuresVenous “pumps”

Muscular pumpRespiratory pump

Valves

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Arteries, Capillaries and VeinsYour arteries carry blood from your heart, out to the

rest of your body. They have very thick walls, which allow them to

withstand the immense pressure created as your heart pumps blood forcefully.

As blood travels outward the arteries become smaller and smaller until eventually the blood enters into what are known as capillaries.

Capillaries are so tiny that blood usually can only get through one cell at a time.

It is within the capillaries that oxygen is taken by the cells, and waste, such as carbon dioxide is released into the blood.

CapillariesEventually the

capillaries get bigger and bigger, and then the blood enters into veins. As the blood travels back to the heart your veins get larger and larger

The Lymphatic System: Recovering Lost FluidThe cardiovascular system is very

leakyfrom capillary exchange, the body loses

about 4 liters of fluid each dayto collect and recycle this fluid, the body

uses a second circulatory system called the lymphatic systemthe lymphatic system is also a network of

vessels filled with a fluid called lymphultimately the lymph reenters the bloodstream

through veins in the neck

The Lymphatic System: Recovering Lost Fluid

The lymphatic system has three important functionsit returns proteins to circulation

if this protein remains in the tissues, it would cause swelling or edema

it transports fats absorbed from the intestine

it aids in the body’s defenseswellings along lymph vessels called lymph

nodes and a lymph organ called the spleen are where bacteria and dead blood cells are destroyed

the thymus produces white blood cells

Blood PressureDuring each heartbeat, BP varies

between a maximum (systolic) and a minimum (diastolic) pressure.

The mean BP decreases as the circulating blood moves away from the heart through arteries, has its greatest decrease in the small arteries and arterioles, and continues to decrease as the blood moves through the capillaries and back to the heart through veins

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VesselsBlood pressure

SystolicDiastolic

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Tips to lower your Blood Pressure

Reduce the sodium (salt) in your diet Choose fresh foods.Avoid adding salt at the table. Use herbs and

spices liberally.Limit canned soups, frozen dinners and entrees

and vegetables with sauces. Choose "low-sodium" products. You may rinse canned foods with water.

Reduce your intake of bacon, sausage, hot dogs and luncheon meats such as corned beef, pastrami, bologna, ham, processed turkey and salami.

Avoid smoked, pickled and cured foods.

Tips to lower your blood pressureAchieve a healthy body weight

Reduce your calories by choosing low-fat foods and eating smaller portions.

Increase dietary fiber. Try to get 20-35 grams of fiber daily.

Exercise regularly: your goal is 30 minute aerobic exercise daily.

Walk at least 10K steps per day.

Tips to lower your blood pressureIncrease foods that are high in calcium

Low-fat/fat-free dairy products dailysupplements

Increase foods that are high in potassium, magnesium and fiber Nuts, seeds, dried beans, and peasPotatoes, tomatoes, bananas

(potassium)100% whole grains (fiber &

magnesium)

Tips to lower your blood pressureReduce Caffeine

Choose decaffeinated coffee, teas and sodas

Avoid medications (if possible) that have caffeine in themDristanExcederinMidol

Tips to lower your blood pressureDrink plenty of fluids

As a good rule of thumb, drink 8 cups of water per day

HINT: always keep a bottle water near you at all times…that way you are reminded to drink it.

QUIT SMOKINGI know this one is NOT easyThe first step is to pick a day…only if you are

willing to quit.

Tips to lower your blood pressureIf you are on medications for your blood

pressureDon’t skip your medicine

If you notice any side effects, notify your doctor.

Discuss the use of drugs called "NSAIDs" such as ibuprofen (Advil, Motrin), naproxen (Aleve) and ketoprofen (Orudis-KT) with your physician. NSAIDs appear to raise blood pressure in older people with hypertension. They may also blunt the action of certain antihypertensive medications.