STATION #1 - PowerPoint Presentation

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STATION #1 Multipurpose bodies

Sponges, jellyfish, and flatworms don’t have a separate circulatory system. That means that when water moves through the pores of sponges, these can be used as a gastrovascular cavity.What does this mean, you say?Their blood moves through the same openings used to eat and poop. Imagine if your body had food and poop circulating throughout your body!!Slide2

STATION # 2 Open or closed?

Larger animals require a separate circulatory system for nutrient and transport. However, this circulatory system can be open in some organisms (mainly arthropods and some molluscs) and have no distinction between circulating and extracellular fluid. The fluid that pertains to the open circulatory system is called hemolymph. In addition to the

hemocytes suspended in it, there are also other chemicals. One protein in particular, hemocyanin, gives the hemolymph a blue color when oxygenated as opposed to the red color of our blood. Hmmm… why were royalty called blue blooded then? Slide3

STATION #3 The evolution of the heart

Fishes evolved a true chamber-pump heart. However, you must keep in mind that since life originated in the ocean, fish evolved first. This means that they only developed a two-chambered heart. The first chamber contains the sinous venosus and the atrium, while the second chamber contains the ventricle and conus arteriosus.

The chambers will contract to pass blood, first through the gills, and then to the rest of the body.Slide4

STATION #4 Then came the lungs

With the advent of the lungs animals required a second pumping circuit, or double circulation. Pulmonary circulation moves blood between the heart and the lungs while systemic circulation moves blood between the heart and the rest of the body.Slide5

STATION #5- Amphibian

and Reptilian HeartsIf lungs evolved in amphibians how did this affect the heart? Well, you might have guessed it already. Instead of having only 2 chambers like fish, amphibians and most reptiles developed 3 chambers. Two atria and one ventricle.

Most reptiles differ from amphibians by having a septum that partially subdivides the ventricle, thereby further reducing the mixing of blood in the heart. Amphibians

living in water obtain additional oxygen by diffusion through their

skin.Slide6

STATION # 6- Are we done evolving yet?

Well, not quite. You should already know that after the fish, the amphibians, and the reptiles came the mammals. All mammals (yes the furry ones) have a four-chambered heart.But wait! Mammals aren’t the only ones with a 4 chambered heart. Birds and crocodilians do so as well.Slide7

STATION # 7- How does my heart work?

Mammals, birds, and crocodilians have 2 separate atria and 2 separate ventricles.The r

ight atrium receives deoxygenated blood from the body and delivers it to the right ventricle, which pumps it to the lungs.

The left atrium receives oxygenated blood from the lungs and delivers it to the left ventricle, which pumps it to rest of the body.Slide8

STATION # 8 – Is my blood pressure normal?

Arterial blood pressure can be measured with a sphygmomanometer. (Try saying it out loud. No, seriously. I want to hear you)Systolic pressure is the peak pressure at which ventricles are contracting. On the other hand, d

iastolic pressure is the minimum pressure between heartbeats at which the ventricles are relaxed.Blood pressure is written as a ratio of systolic over diastolic pressure. If you’ve been to the doctor they’ll usually say it’s around 120 over 80. That is within normal range.Slide9

STATION # 8- CONTINUED

Using the sphygmomanometer and stethoscope try measuring your partner’s blood pressure.Place the cuff around your partner’s upper arm. Now place the stethoscope’s osculation part inside the cuff.You’ll be squeezing the pressure until you don’t hear any more blood rushing. This will happen very quickly so you must keep your eyes on the gauge. The second measurement will happen when you release the pressure and hear blood rushing through the veins again.Slide10
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STATION # 9-Vasoconstriction and Vasodilation

Vasoconstriction and vasodilation are important means of regulating body heat in both ectotherms and endotherms.

Endotherms or warm-blooded animals as you might have called them in 7th

grade regulate their temperature using vasodilation when the environment is hot and vasoconstriction when the environment is cold.

Ectotherms or cold-blooded animals have no internal heat regulation mechanisms and rely heavily on external heat sources. Have you even seen a lizard basking in the sun?

Jump to long image descriptionSlide12

STATION #10- Heart Attack

Did you know that heart

attacks (myocardial infarctions) are the main cause of cardiovascular deaths in U.S

. ?

More than a million Americans have heart attacks each year, and some heart attacks will be silent. Women are more at risk of dying from a heart attack because of their higher tolerance to pain.

Symptoms

Discomfort, pressure in the chest (known as angina pectoris), indigestion, sweating, nausea, dizziness, vomiting, weakness, anxiety and shortness of breath.Slide13

STATION # 11- Blood

Flow and Blood PressureReflexes everywhere!

Your body has a baroreceptor reflex that affects your blood flow. To reach homeostasis, a negative feedback

loop

responds to blood pressure

changes.

Using baroreceptors that

detect changes in arterial blood

pressure, if

blood pressure decreases, the number of impulses to cardiac center is

decreased and ultimately

resulting in blood pressure

increase. If

blood pressure increases, the number of impulses to cardiac center is

increased, ultimately

resulting in blood pressure

decrease.Slide14

Figure 49.17

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STATION #12- I thought diffusion was over!

Gases diffuse directly into unicellular organisms. However, most multicellular animals require adaptations to enhance gas exchange. For example, amphibians respire across their skin. That is why frogs have a very thin skin and must be protected by a mucus secretion to avoid dehydration.Other animals have other means of regulating has diffusion. Echinoderms have protruding papulae, insects have extensive tracheal system, fish use gills, and mammals have alveoli.Slide16

STATION #13- Gills. Aren’t they all the same?

Gills are specialized extensions that project into the water and increase surface area for diffusion. Some amphibians and immature fish have external gills. Animals with external fish must constantly move them to ensure contact with oxygen-rich fresh water, and they are easily damaged.The axolotl, is a Mexican salamander known as a walking fish. The axolotl never reaches metamorphosis, and instead of developing lungs as ann adult, they remain in the water and keep their gills.Slide17

STATION #14- Gills. Again?

Fish gills are the most efficient of all respiratory organs. Within each gill lamellae, blood flows in the opposite direction of water movement. This increases the change in pressure and maximizes oxygenation of blood.Slide18

STATION #15- Insects and other terrestrial arthropods

The respiratory system consists of air ducts called trachea, which branch into very small tracheoles. Tracheoles are in direct contact with individual cells. Spiracles can be opened or closed by valves. Slide19

STATION #16- Lungs replaced gills

Why were gills replaced in terrestrial animals? Since air is less supportive than water and water evaporates, the lung minimizes evaporation by moving air through a branched tubular passage.SO are all lungs the same? Just like gills, they are not.Frogs have saclike outpouchings of the gut. They force air into their lungs by creating a positive pressure in the buccal cavity. Slide20

STATION#17- Mammalian lungs

The lungs of mammals are packed with millions of alveoli, which is where the actual gas exchange occurs. Inhaled air passes through the larynx, glottis, and trachea. From there, the trachea splits into two bronchi, and then subdivide into bronchioles. Slide21

STATION #18- Neurons control my respiration?

Yes! Each breath is controlled by neurons in a respiratory control center called the medulla oblongata. This center stimulates the intercostal muscles and diaphragm so that they contract. Once the neurons stop producing impulses, the muscles relax and exhalation occurs. So what happens when I hold my breath?Too much carbon dioxide will increase the production of carbonic acid and lower the blood pH.

This will stimulate neurons to increase the rate of breathing, thus lowering carbon dioxide. Slide22

STATION#19- Hemoglobin

Hemoglobin is a protein that has an affinity for oxygen. It is affected, however, by pH and temperature. When the carbon dioxide increases, the hydrogen ions (H⁺) increase as well causing the affinity to oxygen to be reduced. Increasing the temperature has a similar effect. Slide23

STATION #20- Emphysema

Emphysema causes the alveolar walls to break down and the lungs end up with less but larger alveoli. This means that the lungs become less elastic.People with emphysema become exhausted very easily because they spend 3-4 times the amount of energy to breathe. Eighty to ninety percent of emphysema deaths are caused by smoking.