Campbell Biology Chapt 42 Part Ii

Front 1

Physical principles

Back 1

Hose example: steady rate of water until the end which increases the velocity and rate

Front 2

Endothelium

Back 2

Layer that lines blood vessels which encases lumen

Smooth and minimizes resistance

Front 3

Arteries and veins

Back 3

Both have endothelium, smooth muscle, and connective tissue

Arteries have thicker walls to handle more pressure of blood

Veins 3x thinner than arteries and blood flows back mostly from muscle contraction rather then pressure

Veins also have valves to prevent blood from flowing back with gravity

Front 4

Capillaries

Back 4

Only slightly wider than a red blood cells

Just simple squamous epithelium lining and connective tissue (basal laminate), no muscle

Front 5

Blood flow velocity

Back 5

Movement of fluids through pipes affect blood flow and bp

Blood velocity drops in capillary beds as a result of:

-high resistance (crashing into walls causing slowing down)

-large total cross-sectional area (large area of capillaries, so many branches)

Slow flow is needed for exchange of materials

Front 6

Blood pressure

Back 6

A force exerted in all directions, including against the walls of blood vessels

Flow from high p to low p

Recoil of elastic arterial walls play a role in maintaining blood pressure

Resistance to flow in narrow diameters of tiny capillaries and arterioles dissipates much of the pressure

Front 7

Systolic pressure

Back 7

Pressure in arteries during ventricular systole

Highest pressure in the arteries (because it is pumping blood into the artery)

Front 8

Diastolic pressure

Back 8

Pressure in the arteries during diastole

Lower than systolic pressure (it when the heart relaxes)

Front 9

Pulse

Back 9

Rhythmic bulging of artery walls snapping back with each heartbeat

Narrowing helps to maintain blood pressure

Front 10

Homeostatic mechanisms regulate arterial bp by...

Back 10

Vasodilation: relaxation of smooth muscle layer in arterioles, expands and decreases bp

Vasoconstriction: contraction of smooth muscle layer to make diameter smaller, increasing bp

Front 11

Signaling molecules for vasoconstriction and dilation

Back 11

Nitric oxide: vasodilation

Endothelin (peptide): vasoconstriction

Molecules are Coupled with cardiac output

ie: vasodilation during exercise to get more blood to muscles. Open equals lower bp. Heart rate increases to keep bp up. If you stop suddenly, can cause heart failure because muscle stops pumping, bp is low, and heart rate is still high

Front 12

Bp and gravity

Back 12

Bp is measured in upper arm, same height as heart

Bp for 20 year old is 120/70 mm Hg (+/- 10)

When standing, need 20 mmHg to get blood to brain, fainting retires quickly

Front 13

Fighting gravity

Back 13

Animals with long necks require high systolic p. (250mm Hg)

For lower portion of body, one way valves prevent back

Also enhanced by smooth and skeletal muscles to pump it up

Front 14

Capillary function

Back 14

Only is 5-10% at any given time

In major organs, capillaries are usually filled to capacity(brain heart liver kidneys)

Blood supply varies in other sites (skin, digestion, skeletal muscle)

Regulates by nerve impulses hormones and other chemicals

Front 15

2 mechanisms that regulates capillary beds

Back 15

1. Construction or dilation of arterioles that supply beds

2. Precapillary sphincters that control flow of blood btw arterioles and venules

ie: histamine is released when wounded. Tells smooth muscle to relax capillary sphincters so white blood cells and nutrition can combat infection

Front 16

Osmolarity

Back 16

Thin wall of capillary allows for diffusion of liquids

More pressure at arterial end which pushes fluid out into interstitial fluid

This is counteracted by high solute of blood which draws fluid back in ( higher osmolarity in blood due to proteins being to big to pass through)

Osmotic pressure does not change

Front 17

Lymphatic system

Back 17

Returns fluid that leak out from capillary beds

Fluid lost by capillary: lymph

Drains into veins in neck, contains valves, and relies on muscle like veins to pump

Front 18

Edema

Back 18

Swelling caused by disruptions in flow of lymph

Damage, parasites, remove part of it

Front 19

Lymph nodes

Back 19

Organs that filter lymph

Play role in body’s defense

When body is fighting infection, lymph nodes call for more white blood cells to fight infection, enlarging nodes

Front 20

Plasma

Back 20

Connective tissue consisting of several kinds of cells suspended in a liquid matrix

Cells and cell fragments are 45% of blood volume

Front 21

Plasma is 55% and cell elements 44%

Back 21

A

Front 22

The other 45%

Back 22

Back (Definition)

Front 23

Plasma

Back 23

Contains inorganic salts as dissolved ions (electrolytes)

Plasma protein changes blood pH, maintains osmotic balance btw blood and interstitial fluid

Certain plasma proteins function in lipid transport immunity and blood clotting

Plasma has higher protein concentration than interstitial fluid

Front 24

Cellular elements in plasma

Back 24

Red blood cells (erythrocytes) transport O2

White blood cells(leukocytes) defense

Platelets-clotting

Front 25

Blood smear

Back 25

Back (Definition)

Front 26

Erythrocytes

Back 26

Numerous, red blood

Contain Hemoglobin, iron-containing protein (both transport O2)

Molecule of hemoglobin can bind up to 4 O2

Mature rBCs lack nuclei (cannot replicate) and mitochondria so it does not take O2 for cellular res.

have 250 million molecules of hemoglobin (can carry one billion O2 molecules)

Front 27

Sickle cell disease

Back 27

Point mutation in hemoglobin genes

Caused by an abnormal hemoglobin protein that form aggregates

Aggregates deform into sickle shape

Sickle cells rupture (20 days compared to normal rbc at 120 days) and block which can create swelling and pain

Front 28

Leukocytes

Back 28

Five types:

Monocytes

Neutrophils

Basophils

Eosinophils

Lymphocytes

Phagocytizing bacteria and debris or by mounting immune repsonses against foreign bodies

Found in both in and outside circulatory system

Front 29

Platelets

Back 29

Fragments of cells and function in blood clotting

Pinched off from Megakaryocytes in bone marrow

Front 30

Blood clotting

Back 30

Coagulation is the formation of a solid clot from liquid blood

A cascade of complex reactions converts inactive protein fibrinogen to fibrin, forming a clot

“Gen” means inactive protein

Front 31

Thrombus

Back 31

A blood clot formed in blood vessel

Can block blood flow

Front 32

Image of clotting

Back 32

Back (Definition)

Front 33

Clotting cascade

Back 33

Enzymatic cascade leads to prothrombin being turned into thrombin which converts fibrinogen to fibrin and provides positive feedback to make more prothrombin

Other factors eventually stop clotting which can cause stroke or heart attack

Front 34

Hemophilia

Back 34

Inability to clot blood

Could be due to genetic problem in cascade

Front 35

Stem cells

Back 35

In red marrow of bones (ribs, vertebrate, sternum, and pelvis)

Create rbc, wbc, and platelets

Front 36

Stem cells

Back 36

In red marrow of bones (ribs, vertebrate, sternum, and pelvis)

Create rbc, wbc, and platelets

Multipotent

Front 37

Erythropoietin EPO

Back 37

Hormone

Stimulates rbc production and O2 delivery is low (your body secretes this when you travel high altitudes)

Physicians can use it to treat people with amnesia

Front 38

Cardiovascular Disease

Back 38

Disorders of heart and blood vessels

1/2 of deaths in US

Can range In seriousness

Front 39

Atherosclerosis

Back 39

Caused by build up of fatty deposits (plaques)on smooth epithelial lining in arteries (leukocytes put the fatty plaques there)

Cholesterol (lipid hydrophobic) is key player (blood is mostly water).

Inflammation is also a factor

Increases with high LDL to HDL ratio

Front 40

LDL vs HDL

Back 40

LDL: low density lipoprotein carries cholesterol to cells for membrane production (leukocytes use this to make plaques=bad kind)

HDL: high density lipoprotein scavenger for excess cholesterol to return to liver( good kind)

Front 41

Heart attack

Back 41

Myocardial infarction

Death of cardiac muscle tissue resulting from blockage of one or more coronary arteries

Angina pectoris: chest pain caused by partial blockage of the coronary arteries

Front 42

Stroke

Back 42

Death of nervous tissue due to rupture (usually caused by pressure) or blockage of arteries in head (thrombosis)

Where blockage is will determine how severe it is

Front 43

Stent

Back 43

To for artery that’s blocked

Front 44

Risk factors and tx

Back 44

Exercise, avoid smoking, and trans fats

Statins are drugs that reduce LDL levels and risk of heart attacks

1 in 4 people have familial hypercholesterol

Aspirin inhibits inflammation

Front 45

Hypertension

Back 45

High blood pressure

Contributes to heart attack and stroke

130/80 mm Hg (having elevated diastolic number when heart is resting-most damaging)

Can be controlled with meds, diet, exercise