chapter 12 Flashcards

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1
Q

Two Types of Circulatory Systems

A
  1. Open System:
    Blood flows freely within the body cavity.
    Makes direct contact with organs and tissues.
    Example: Insects, crustaceans.
  2. Closed System:
    Blood is physically contained within vessels.
    Blood follows a continuous fixed path.
    Example: Earthworms, birds, humans.
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2
Q

Structure of the Heart

A
  • The heart consists of two double pumps separated by the septum.
  • The right pump receives deoxygenated blood to the lungs (pulmonary circuit).
  • The left pump receives oxygenated blood to the cells of the body (systemic circuit).
    -Blood flow through the heart is called the cardiac circuit.
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3
Q

Valves in the Heart

A

Atrioventricular Valves:
Tricuspid valve (right atrium to right ventricle).
Bicuspid valve (left atrium to left ventricle).
Semilunar Valves:
Aortic and pulmonary valves.
Valves control the flow of blood through the heart.
Heart murmur may occur if valves don’t close properly.

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4
Q

The Four Chambers of the Heart

A

The heart has four chambers: two atria and two ventricles.

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5
Q

Blood Vessels

A

Arteries:

Carry blood away from the heart at high pressure.
Made up of three strong layers.
Veins:

Carry blood towards the heart at lower pressure.
Thinner than arteries.
Have one-way valves to keep blood moving forward.
Capillaries:

Narrowest blood vessels.
Allow for slow blood flow and low pressure.
Facilitate gas exchange through diffusion.

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6
Q

Recap: Overall Flow

A

Arteries → Arterioles → Capillaries → Venules → Veins.

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7
Q

The Overall Path of Blood (in a closed system)

A

Arteries → Arterioles → Capillaries → Venules → Veins → Heart.

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8
Q

Components of Blood

A

Blood consists of plasma (55%) and cells (45%: RBCs, WBCs, and platelets).

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9
Q

Red Blood Cells (Erythrocytes)

A

-Made in bone marrow, contain hemoglobin.
-Biconcave shape for maximum O2 transport.
-Hemoglobin gives blood its red color.

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10
Q

Blood Doping

A

-Athletes may undergo blood doping to increase RBC count for enhanced performance.

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11
Q

Anemia

A

-Decreased hemoglobin in the blood.
-Can be caused by genetic disorders or lack of dietary iron.

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12
Q

White Blood Cells (Leukocytes)

A

-Made in bone marrow.
-Defend against foreign invaders.
-Some use phagocytosis to engulf pathogens

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13
Q

Platelets (Thrombocytes)

A

-Cell fragments that initiate blood clotting.
-Form a plug to prevent further bleeding.

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14
Q

Functions of Blood: Temperature Regulation

A

-Circulatory system regulates temperature by changing blood flow near the skin.
- Vasodilation releases heat, vasoconstriction conserves heat.

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15
Q

Cardiovascular Disease Risk Factors:

A

Smoking
Obesity or poor diet
Insufficient exercise
Genetics

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16
Q

Arteriosclerosis:

A

Thickening and loss of elasticity in
artery walls

Atherosclerosis: Plaque buildup leading to narrowed arteries, increased blood pressure

Potential outcomes: Angina, blood clots, shortness of breath, heart attack, heart failure

Prevention: Healthy lifestyle
Treatment: Aspirin, medications encouraging blood flow and thinning blood

17
Q

Angioplasty:

A

Tube inserted into a clogged artery

Tiny balloon inflates to force the artery open

Stent (wire-mesh tube) may be inserted to hold vessel open

18
Q

Coronary Bypass:

A

Rerouting blood flow around blocked arteries

Using artery or vein to create a new pathway for blood

Double, triple, or quadruple bypass depending on blockages

19
Q

Stroke:

A

Ischemic stroke: Blood vessel clot blocks blood flow to the brain

Hemorrhagic stroke: Brain blood vessel bursts, causing bleeding

Longer time without oxygen increases the risk of permanent damage

Treatment: Clot-busters or surgery, must begin immediately for effectiveness

20
Q

Aneurysm:

A

Artery bulge caused by weakened arterial wall

Blood pressure can cause aneurysm to grow larger, leading to bursting and internal bleeding

Most aneurysms occur in the aorta

Treatment: Surgery to replace portion with patch/graft made of synthetic material

21
Q

Heart Valve Diseases:

A

Regurgitation: Valves do not close completely, causing blood to flow backward

Left side results in deficiency of oxygenated blood

Causes: Aging, previous heart attack, or infection

Treatment: Repair or replacement with human, animal, metal, plastic, or synthetic alternatives

22
Q

Arrhythmia:

A

Problem with speed or rhythm of heart beat

Can lead to insufficient blood flow to the brain or other organs

Treatment: Medications or surgery to implant an artificial pacemaker

23
Q

Congenital Heart Defects:

A

Present since birth
Problems in walls dividing heart chambers, valves, and structure of heart blood vessels
Surgeons can often successfully repair or reduce damage

24
Q

Disorders of the Blood: Anemia:

A

Blood contains fewer than normal healthy red blood cells

Not enough iron/hemoglobin

Symptoms: Dizziness, fatigue, shortness of breath, headache, and cold extremities
Treatments: Dietary iron supplements

25
Q

Hemophilia:

A

Inherited sex-linked disorder

Blood is missing clotting proteins

Treatment includes clotting protein injections and lifestyle changes to avoid injury and continuous internal bleeding

26
Q

Leukemia:

A

Cancer of the white blood cells
Results in an overproduction of cells that do not fight infection
Treatments include blood transfusions, chemotherapy, or bone marrow transplant

27
Q

Diagnosing Disorders:

A

Coronary angiography: Maps coronary arteries by injecting a dye

Echocardiogram (ECHO): Determines the cause of a stroke and possible blood clots

Exercise electrocardiogram (ECG): Determines the cause of chest pain, irregular heartbeats, dizziness, or fatigue

28
Q

Treating Disorders: Organ Transplants:

A

Organs include lungs, liver, kidney, pancreas, corneas, stomach, heart valves, bone, skin, and heart

Many people die before a suitable organ is available

29
Q

Treating Disorders: Xenotransplants:

A

Xenotransplant = Transplant of tissues and organs from one species to another

Organ is called a graft

Recipient’s body must not reject organ, drugs developed to overcome this issue

Health, safety, legal, ethical, and regulatory issues to consider.

30
Q

Sinoatrial (SA) Node (Pacemaker):

A

Muscle tissue generating electrical signals

Stimulates muscle cells in the atria to contract and relax rhythmically

31
Q

Atrioventricular (AV) Node:

A

Muscle tissue transmitting signals through the bundle of His
Relay signals to Purkinje fibers initiating ventricular contraction

32
Q

Heartbeat Sounds:

A

“Lub” Sound:
Atria contract, pushing blood through AV valves to ventricles
Ventricles contract, closing valves, forcing blood into arteries

“Dub” Sound:
Semilunar valves prevent blood re-entering ventricles
Abnormal Heartbeat Sounds: Hissing/murmuring due to defective valves

33
Q

Electrocardiogram (ECG):

A

Records electrical impulses generated by nerves

Small voltage changes detected with electrodes on the skin

Helps determine if the heart is generating signals of normal strength, frequency, and duration

34
Q

Blood Pressure (BP):

A

Measures pressure exerted by blood against arteries during different times

Systolic Pressure: Contraction of the heart, pushing blood out

Diastolic Pressure: Relaxation (dilation) of the heart, filling cavities with blood
Measured with a sphygmomanometer in mmHg

35
Q

Causes of High Blood Pressure:

A

Genetics, poor diet, large sodium intake
Lack of exercise, large alcohol intake, stress, caffeine, vitamin D deficiency
Certain medications, hormonal problems, pregnancy

36
Q

Causes of Low Blood Pressure:

A

Standing up too quickly, standing in one position for too long

After an injury, loss of blood, person in “shock”
Being scared, lack of vitamin B12 leading to anemia