Cardiovascular System (outline)

Cardiovascular System (outline)• Review types of tissues• Example of intestines as an organ with all 4 tissue types• Roles of the cardiovascular system & coordination of

other organ systemsAnatomy of the Cardiovascular system of animals• Evolutionary changes• Mammalian heart structures and function

Physiology of the Heart (lab)• Blood Pressure• Heart beat or rhythm• Heart attacks and atherosclerosis

ReviewTissues are groups of many similar cells that

perform the same specific function

Tissue types• Epithelial tissue• Connective• Muscle• Nervous

https://www.youtube.com/watch?v=tKWTJ3_-1E8

http://www.viddler.com/embed/%20c316f600%20/?f=1&player=arpeggio&secret=59037080

https://www.youtube.com/watch?v=tKWTJ3_-1E8

An organ is made of several tissues that collectively perform specific functions

Figure 20.9

Small intestine(cut open)

Lumen

Epithelial tissue(columnar epithelium)

Connective tissue

Smooth muscletissue (2 layers)

Connective tissueEpithelial tissue

Lumen

Cardiovascular System

• All cells need– Nutrients– Gas exchange– Removal of wastes

• Diffusion alone is inadequate for large and complex bodies• Most animals use a circulatory system

– Blood: Connective tissue with different cells within a liquid matrix

– Heart: Organ with 4 types of tissue – Blood vessels: Organs with 4 types of tissue

Classifying closed circulatory systems

Section 30.2

Closed circulatory systems are distinguished based on the number of heart chambers.

Figure 30.2

Fishes and larval amphibians Adult amphibians and most nonavian reptiles Birds and mammals

Birds and mammals have a four-chambered heart

Section 30.2

Birds and mammals have a four-chambered heart. Blood is pumped to the lungs and then returns to the heart to be pumped to the rest of the body.

Figure 30.2

Diffusion ofmolecules

Capillary

Interstitialfluid

Tissuecell

https://www.youtube.com/watch?v=q0s-1MC1hcE

Presenter

Presentation Notes

Figure 23.7B Diffusion between blood and tissue cells.

https://www.youtube.com/watch?v=q0s-1MC1hcE

A summary of the functions of the Cardiovascular System & coordination with other organ systems

Section 30.2 Table 30.1

TA B L E 30.1 Functions of Blood: A SummaryFunction Explanation

Gas exchange Carries O2 from lungs to tissues; carries CO2 to the lungs to be exhaled

Nutrient transport Carries nutrients absorbed by the digestive system throughout the body

Waste transport Carries urea (a waste product of protein metabolism) to the kidneys for excretion in urine

Hormone transport Carries hormones secreted by endocrine glands

Formation of interstitial fluid Blood plasma leaking out of capillaries becomes interstitial fluid that surrounds cells.

Maintenance of homeostasis (temperature, water, pH)

Absorbs heat and dissipates it at the body's surface; regulates cells' water content; buffers in blood help maintain pH of interstitial fluid and lymph.

Protection Blood clots plug damaged vessels; white blood cells destroy foreign particles and participate in inflammation.

Blood composition

Section 30.2

Blood consists of different cells with diverse functions suspended in a liquid extracellular matrixcalled plasma.

Figure 30.3

©National Cancer Institute/Getty Images

Plasma

Section 30.2

Plasma is mostly water but also contains antibodies and many other dissolved substances.

Plasma carries red blood cells, white blood cells, and platelets.

Figure 30.3

Red blood cells

Section 30.2

Red blood cells carry oxygen to body tissues.

Red blood cells contain hemoglobin, a protein that binds to oxygen at respiratory surfaces and “unloads” oxygen at body tissues.

Figure 30.3


Blood types

Section 30.2

A person’s blood type depends on what carbohydrates are on the surface of his or her red blood cells.

Figure 10.18

Genotypes PhenotypesSurface molecules ABO blood type

𝐼𝐼𝐴𝐴𝐼𝐼𝐴𝐴

𝐼𝐼𝐴𝐴iOnly A Type A

𝐼𝐼𝐵𝐵𝐼𝐼𝐵𝐵

𝐼𝐼𝐵𝐵iOnly B Type B

𝐼𝐼𝐴𝐴𝐼𝐼𝐵𝐵 Both A and B Type AB

ii None Type O

Agglutination

Section 30.2

The immune system reacts to blood cells with foreign carbohydrates. The foreign blood clumps together in a reaction called agglutination.

Figure 30.4

©Jean Claude Revy - ISM/Phototake

White blood cells

Section 30.2

White blood cells are part of the immune system. They provoke inflammation and destroy microbes, among many other functions.

Figure 30.3

©National Cancer institute/Getty Images

Platelets

Section 30.2

Platelets are cell fragments that initiate blood clotting.

Figure 30.3


Clotting

Section 30.2

Platelets adhere to each other at a break in a blood vessel. Plasma proteins called clotting factors reinforce the clot.

Figure 30.5

1. Break in vessel wall allows blood to escape; vessel constricts.

2. Platelets adhere to each other, to end of broken vessel, and to exposed collagen. Platelet plug temporarily helps control blood loss.

3. Exposure of blood tosurrounding tissue activates clotting factors. The resulting protein threads trap red blood cells, forming a clot.

(b): ©Steve Gschmeissner/Getty Images RF

Tissues types within the

Cardiovascularsystem and their

function

The cardiovascular system: an overview

Section 30.3

The heart pumps blood through three main types of blood vessels: • Arteries –away

from the heart• Capillaries-

smaller branches of arteries

• Veins – toward the heart

Figure 30.6

The mammalian heart– Two thin-walled atria that pump blood to ventricles– Thick-walled ventricles that pump blood to lungs and all other

body regionsRight atrium To lung

From lung

Semilunarvalve

Atrioventricular(AV) valve

Left atrium

To lung

From lung

Semilunarvalve

Atrioventricular(AV) valve

Rightventricle

LeftventricleBlood Anatomy and Circulation

http://www.youtube.com/watch?v=H04d3rJCLCE 3:29 mins

Flow through the Heart https://www.youtube.com/watch?v=7XaftdE_h607.5 mins

http://www.youtube.com/watch?v=H04d3rJCLCE

https://www.youtube.com/watch?v=7XaftdE_h60

The heart is a muscular pump

Section 30.4

The muscular heart pumps thousands of liters of blood through the body each day.

A thick layer of cardiac muscle called the myocardium makes up most of the wall of the heart.

Figures 25.6, 30.7

Type: Cardiac muscle tissueComposition: Short, branched cells, each containing one nucleus; striated Function: Contraction of atria and ventricles in heart (involuntary) Location: Walls of the heart

The pericardium

Section 30.4

The heart is surrounded by a sac made of dense and loose connective tissue called the pericardium, which anchors the heart but also allows it to beat without being obstructed.

Figure 30.7

The four chambers of the heart

Section 30.4

Blood passes through the four chambers of the human heart.

Figure 30.7

Superiorvena cava

Pulmonary artery

Capillariesof right lung

8

9

2

3

Aorta

4 510

1 6Pulmonary vein

9Right atrium

Inferiorvena cava

Right ventricle

4

8

3

Pulmonary artery

Capillariesof left lung

Aorta

Pulmonary vein

Left atrium

Left ventricle

27

Capillaries of head, chest, andarms

Capillaries of abdominal regionand legs

Presenter

Presentation Notes

Figure 23.2A The single circulation and two-chambered heart of a fish.

Blood Pressure

Blood pressure and velocity is a reflection of the heart and blood vessels function in blood circulationRhythmic heart contractions and relaxations

http://www.sumanasinc.com/webcontent/animations/content/bloodpressure.html

Blood pressure – The force blood exerts on vessel walls– Depends on

– Cardiac output– Resistance of vessels

– Decreases as blood moves away from heart Understanding Blood Pressure – Anatomy

http://www.youtube.com/watch?v=qWti317qb_w 2:48 mins

Presenter

Presentation Notes

Student Misconceptions and Concerns 1. Students often struggle to explain how blood is propelled up their legs to return to their hearts. Frequently, students will suggest that the heart itself must provide sufficient force to move blood completely around the body. However, such pressures would destroy their delicate capillaries. Other student hypotheses might include attributing a negative, siphoning effect to the heart. (Although the heart can generate a small pull, it is not sufficient to return blood up their legs and trunk to the heart.) Let them wonder long enough to stimulate critical thinking and motivate them to learn the answer. After explaining the role of skeletal muscles and one-way valves in veins, you might also note that it has been suggested that students will be more alert in class and even perform better on tests if they wiggle their legs. Challenge students to explain why this might work and why locking their knees when standing might have the opposite effect. (And enjoy watching some of your students deliberately wiggling their legs on the next exam!) 2. One function of the circulatory system that is rarely discussed is the transport of heat. Blood vessels near the surface of the body expand when we are overheated, releasing some of this excess to the environment. Conversely, during periods of exposure to cold, blood is shunted away from the skin to conserve heat. Teaching Tips 1. Veins on the back of our hands can reveal many of these same principles of venous blood flow. If students keep their hands down below their heart for several minutes, such as during note taking or typing, they might notice their veins starting to bulge. Students can watch the veins empty by simply lifting their hands up to eye level. As we get older, such phenomena are even easier to see. Some instructors may be comfortable enough (and old enough!) to demonstrate this effect to their students. 2. Contracting the hand into a fist helps propel blood back up the arms to the heart. Skin pulled tight on the back of the hand compresses veins against the underlying ligaments and bones. With this example “in hand,” students may better understand the propulsive forces moving venous blood back to the heart. 3. Students may not relate the structure of the walls of arteries to blood pressure. Consider noting the presence of smooth muscle in the walls of arteries (Figure 23.7C). If these muscles contract, they narrow the arteries and increase pressure.

http://www.sumanasinc.com/webcontent/animations/content/bloodpressure.html

http://www.youtube.com/watch?v=qWti317qb_w

• Blood pressure is – Highest in arteries– Lowest in veins

• Blood pressure is measured as – Systolic pressure—pressure caused by contraction

ventricles– Diastolic Right and left ventricles relax

Lub Dub https://www.youtube.com/watch?v=-4kGMI-qQ3I

Presenter

Presentation Notes

Student Misconceptions and Concerns 1. Students often struggle to explain how blood is propelled up their legs to return to their hearts. Frequently, students will suggest that the heart itself must provide sufficient force to move blood completely around the body. However, such pressures would destroy their delicate capillaries. Other student hypotheses might include attributing a negative, siphoning effect to the heart. (Although the heart can generate a small pull, it is not sufficient to return blood up their legs and trunk to the heart.) Let them wonder long enough to stimulate critical thinking and motivate them to learn the answer. After explaining the role of skeletal muscles and one-way valves in veins, you might also note that it has been suggested that students will be more alert in class and even perform better on tests if they wiggle their legs. Challenge students to explain why this might work and why locking their knees when standing might have the opposite effect. (And enjoy watching some of your students deliberately wiggling their legs on the next exam!) 2. One function of the circulatory system that is rarely discussed is the transport of heat. Blood vessels near the surface of the body expand when we are overheated, releasing some of this excess to the environment. Conversely, during periods of exposure to cold, blood is shunted away from the skin to conserve heat. Teaching Tips 1. Veins on the back of our hands can reveal many of these same principles of venous blood flow. If students keep their hands down below their heart for several minutes, such as during note taking or typing, they might notice their veins starting to bulge. Students can watch the veins empty by simply lifting their hands up to eye level. As we get older, such phenomena are even easier to see. Some instructors may be comfortable enough (and old enough!) to demonstrate this effect to their students. 2. Contracting the hand into a fist helps propel blood back up the arms to the heart. Skin pulled tight on the back of the hand compresses veins against the underlying ligaments and bones. With this example “in hand,” students may better understand the propulsive forces moving venous blood back to the heart. 3. Students may not relate the structure of the walls of arteries to blood pressure. Consider noting the presence of smooth muscle in the walls of arteries (Figure 23.7C). If these muscles contract, they narrow the arteries and increase pressure.

https://www.youtube.com/watch?v=-4kGMI-qQ3I

Semilunarvalvesclosed1 Heart is

relaxed.

AV valvesare open.

Diastole

0.4 sec

2 Atriacontract.

Systole0.1 sec

Semilunarvalvesare open.

3 Ventriclescontract.

AV valvesclosed

0.3 sec

Presenter

Presentation Notes

Figure 23.4 A cardiac cycle in a human with a heart rate of about 72 beats a minute.

An internal pacemaker sets the tempo of the heartbeat

The heart contracts and relaxes rhythmically under the effect of electrical signals received from specialized cardiac muscle cells and conducting fibers (not nervous tissue)

• pacemaker (SA node) which generates electrical signals in right atrium

• AV node then relays these signals to the ventricles

Cardiac conduction system and ECG.wmv https://www.youtube.com/watch?v=RYZ4daFwMa8

https://www.youtube.com/watch?v=RYZ4daFwMa8

Schematic illustration of the cardiac conduction system

http://emedicine.medscape.com/article/1922987-overview

http://emedicine.medscape.com/article/1922987-overview

Pacemaker(SA node) AV node

Rightatrium

1 Pacemakergeneratessignalsto contract

2 Signals spreadthrough atriaand are delayedat AV node

ECG

3 Signals relayedto apex of heart

4 Signals spreadthroughventricle

Apex

Specializedmuscle fibers

Cardiac Conduction Systemhttp://www.youtube.com/watch?v=Lt092HZCppo 1:03 minshttps://www.youtube.com/watch?v=RYZ4daFwMa8

http://www.youtube.com/watch?v=Lt092HZCppo

https://www.youtube.com/watch?v=RYZ4daFwMa8

depolarization of the heart’s atria depolarization

of the heart’s ventricles

Re-polarization of the ventricles

https://www.youtube.com/watch?v=lRHq7sMRWpUhttps://www.youtube.com/watch?v=FThXJUFWUrw

https://www.youtube.com/watch?v=lRHq7sMRWpU

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

What is a heart attack?• A heart attack is damage to cardiac muscle

typically from a blocked coronary artery• Stroke- Death of brain tissue from blocked

arteries in the head

Blockage

Deadmuscletissue

Right coronaryartery

Superior vena cava

Pulmonary artery

Aorta

Leftcoronaryartery

Presenter

Presentation Notes

Student Misconceptions and Concerns 1. Students often expect that the blood flowing through the heart supplies the heart muscle. The need for coronary arteries and veins is not clear to them. (The thickness of the walls of the heart does not permit efficient diffusion, and furthermore, the oxygen content of the blood in the right atrium and ventricle is very low.) 2. Students often develop an incorrect mental model of how atherosclerosis occurs. In a home, drainpipes grow narrower as materials accumulate on their inside surface. However, in atherosclerosis, the blood vessels narrow through an accumulation of materials within the walls themselves. In the pipe analogy, atherosclerosis is a pipe with thicker walls, which shrink the size of the lumen. 3. One function of the circulatory system that is rarely discussed is the transport of heat. Blood vessels near the surface of the body expand when we are overheated, releasing some of this excess to the environment. Conversely, during periods of exposure to cold, blood is shunted away from the skin to conserve heat. Teaching Tips 1. Strokes can result from the blockage of or rupture of a blood vessel in the brain. Thus, clot-busting drugs may either help resolve a brain clot or lead to disastrous bleeding. 2. Cardiovascular disease affects more than the blood vessels of the heart and brain. Many of the same risk factors that promote cardiovascular disease are associated with erectile dysfunction (the male inability to get and keep an erection).

What is a heart attack?

• Atherosclerosis– Plaques develop inside inner walls of blood vessels– Plaques narrow blood vessels– Blood flow is reduced

PlaqueEpitheliumConnectivetissue

Smoothmuscle

Presenter

Presentation Notes

Student Misconceptions and Concerns 1. Students often expect that the blood flowing through the heart supplies the heart muscle. The need for coronary arteries and veins is not clear to them. (The thickness of the walls of the heart does not permit efficient diffusion, and furthermore, the oxygen content of the blood in the right atrium and ventricle is very low.) 2. Students often develop an incorrect mental model of how atherosclerosis occurs. In a home, drainpipes grow narrower as materials accumulate on their inside surface. However, in atherosclerosis, the blood vessels narrow through an accumulation of materials within the walls themselves. In the pipe analogy, atherosclerosis is a pipe with thicker walls, which shrink the size of the lumen. 3. One function of the circulatory system that is rarely discussed is the transport of heat. Blood vessels near the surface of the body expand when we are overheated, releasing some of this excess to the environment. Conversely, during periods of exposure to cold, blood is shunted away from the skin to conserve heat. Teaching Tips 1. Strokes can result from the blockage of or rupture of a blood vessel in the brain. Thus, clot-busting drugs may either help resolve a brain clot or lead to disastrous bleeding. 2. Cardiovascular disease affects more than the blood vessels of the heart and brain. Many of the same risk factors that promote cardiovascular disease are associated with erectile dysfunction (the male inability to get and keep an erection).

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Cardiovascular System (outline)