chapter 11 part b

Chapter 11

Part B: (Mostly) Blood Vessels

1.     The heart

a.    Cardiac output (CO) defined: Amount of blood pumped by each side (ventricle) of the heart in one minute

b.    Stroke volume defined: volume of blood pumped by each ventricle in one contraction (each heartbeat)

                                         i.    Remains relatively constant

                                        ii.    70 mL of blood is pumped out of the left ventricle/heartbeat

c.    Heart rate: how many beats per minute…typically 75 beats per minute

d.    CO = HR x SV.. 75x70=5250 mL/min

                                         i.    Volume

                                        ii.    Starling’s law of the heart- the more the cardiac muscle is stretched, the stronger the contraction

                                      iii.    Changing heart rate is the most common way to change cardiac output

2.    Regulation of heart rate

a.    Increased heart rate by the

                                         i.    Crisis-more blood needed

                                        ii.    Low blood pressure

                                      iii.    Hormonal control:

1.     Epinephrine= adrenalin

2.    Thyroxine= thyroid gland, general metabolism

                                       iv.    Exercise

                                        v.    Low blood volume

b.    Decreased heart rate by the

                                         i.    High blood pressure or blood volume

                                        ii.    Low venous return

3.    Blood vessels = the vascular system

a.    General purpose= transport blood to the tissue and back

b.    Classified by direction

                                         i.    Carry blood away from heart=arteries, arterioles(small arteries)

                                        ii.    Exchanges between tissues and blood: capillary beds

                                      iii.    Return blood toward heart: venules, veins(big)

c.    Structure of walls: three layers = tunics

                                         i.    Intima(inner layer)

1.     Endothelium= simple squamous epithelium

                                        ii.    Media(middle)

1.     Tissue= smooth muscle, connective tissue

2.    Controlled by sympathetic nervous system

                                      iii.    Externa(outside)

1.     Tissue= mostly fibrous connective tissue

d.    Differences between vessels

                                         i.    Arteries-walls are the thickest, more elastic

                                        ii.    Veins-lumens are larger…larger veins have valves to prevent backflow, skeletal muscle “milks” blood in veins toward the heart

                                      iii.    Capillaries

e.    Movement of blood through

                                         i.    Arteries

                                        ii.    Veins

f.    Capillary beds

                                         i.    Two types of vessels: vascular shunt= vessel directly connecting an arteriole to a venule, true capillaries= exchange vessels.

                                        ii.    Oxygen and nutrients cross to cells and leave the blood.

                                      iii.    Carbon dioxide and waste produce products cross into blood and leave the cells.

                                       iv.    Materials exchanged due to concentration gradients:

                                        v.    Exchange mechanisms are done by direct diffusion across plasma membrane.

1.     Endocytosis: when things are being taken INTO cells

2.    Exocytosis: when things are being taken OUT of the cell

3.    Interstitial fluid is where materials move through to get to cells.

g.    Major arteries: Aorta

                                         i.    Largest artery in the body

                                        ii.    Leaves from the left ventricle of the heart

                                      iii.    Regions

1.     Ascending aorta- leaves the left ventricle

2.    Aortic arch- 180 degrees to the left

3.    Thoracic aorta- travels downward through the thorax

4.    Abdominal aorta- passes through the diaphragm into the abdominopelvic cavity

                                       iv.    Systemic arteries

1.     Branches of the aorta

                                        v.    Pulmonary

1.     Branches of the pulmonary arteries

2.    Study figure 11.12

h.    Major veins

                                         i.    Systemic circulation

1.     Right atrium- where superior and inferior vena cava enter

2.    Superior vena cava drains the head and arms

3.    Inferior vena cava drains the lower body

                                        ii.    Pulmonary circulation- enter the left atrium

i.     Fetal circulation

                                         i.    Placenta- fetus receives exchanges of gases, nutrients, and wastes through the placenta

                                        ii.    Umbilical cord contains three vessels:

1.     Umbilical vein=toward the heart-carries blood rich in nutrients and oxygen to the fetus

2.    Umbilical arteries=away from heart(2)-carry carbon dioxide and debris-laden blood from fetus to placenta

                                      iii.    Bypass of the (nonfunctional) lungs

1.     Foramen ovale- blood travels through the foramen ovale to get from right atrium to the left atrium

2.    Pulmonary artery-blood from pulmonary artery goes directly into aorta

j.     Hepatic portal circulation

                                         i.    Portal circulation defined=extra set of veins and capillaries

                                        ii.    Drainage of hepatic portal system-digestive organs, spleen, pancreas.

                                      iii.    Hepatic portal vein carries this blood to the liver

                                       iv.    Importance of liver for nutrients-helps maintain proper glucose, fat, and protein concentrations in blood

4.    Pulse

a.    Defined=pressure wave of blood

b.    Unit = beats/minute

c.    Monitored at “pressure points” in arteries where pulse is easily palpated

d.    Averages- 70-76 beats per minute

5.    Blood pressure

a.    Measured by professoionals are made on the pressure in large arteries

b.    Sphygmomanometer-measures blood pressure

c.    Systolic-pressure at the peak of ventricular contraction

d.    Diastolic- pressure when ventricles relax

e.    How to write it: systolic over diastolic…(120/80 mm Hg)

f.    Pressure in vessels decreases as you go further away form heart

g.    Effects of factors

                                         i.    Affected by age, weight, time of day, exercise, body position, emotional state, genetics

                                        ii.    CO = cardiac output- amount of blood pumped out of left ventricle per minute

                                      iii.    PR = peripheral resistance- the amount of friction blood encounters as it flows through the vessels

1.     Increased by narrowing of blood vessels which increase PR

                                       iv.    BP = blood pressure

                                        v.    BP= COxPR

                                       vi.    Neural

1.     Autonomic

                                     vii.    Renal =

1.     Regulated by

2.    Rennin

                                   viii.    Temperature

1.     Heat

2.    Cold

                                      ix.    Chemicals

                                        x.    Diet

                                      xi.    Genetic predisposition

h.    Variations

                                         i.    Normal

1.     Systolic:

2.    Diastolic:

                                        ii.    Hypotension

1.     Low

2.    Associated

                                      iii.    Hypertension

1.     High

2.    Can be