Chapter 42 Flashcards
Open System
Open system - organs are soaked in blood
- Body fluid id called hemolymph
- Sinuses interconnecting systems where blood flows - these are the spaces
around the organs.
Closed System
Closed systems - blood confined to vessels
- Blood is separate from interstitial fluid
Cardiovascular system
Human heart - 2 atrium - blood in
- 2 ventricle - blood out
Arteries
the thickest and largest
- Carries oxygenated blood
Veins
large but not as thick
- Carries de-oxygenated blood
Capillaries
smallest and thinnest
- All gas exchange takes place here
- Network of capillaries is called a capillary bed, these spread through tissue
Blood has an up-stream and a downstream, the arterioles are the up stream and blood flows
down stream through the venules. This is relationship to the blood in the capillaries.
Fish
2 chamber heart, 1 atrium and 1 ventricle
- Blood flows from the ventricle to the gills where it becomes oxygenated,
carbon dioxide leaves through the capillary walls.
- Systemic circulation - oxygen rich blood fills the capillary beds, then carbon
dioxide rich blood travels to the atrium
- Gill circulation - blood flows over the gills from the ventricles
Frog
3 chamber heart , 2 atrium and 1 ventricle
- The ventricle pumps the blood into a forked artery then into pulmocutaneous
and systemic circulation.
- Pulmocutaneous circulation - capillaries in gas exchange organs pick up
oxygen then travel to the left atrium. From here it travels to the capillary beds
then to the right atrium
Mammals
4 chamber, 2 atriums and 2 ventricles right ventricle to lungs - blood flows to left
atrium then to left ventricle and into body. Flows through body and deoxygenated blood now
enters the right atrium and back to the right ventricle.
Heart
pumps and relaxes in a rhythmic cycle
- Contracts - pumps blood
- Relaxes - chambers fill with blood
One cycle is called the cardiac cycle
Contraction is systole
Relaxation is diastole
Cardiac output
volume pumped by the left ventricle per minute. To calculate the cardiac output you multiply the stroke volume by the heart rate
Rate of contraction
heart rate ( # of beats per minute )
Stroke volume
amount of blood pumped by the left ventricle each contraction
Atrioventricular valve ( AV )
between atrium and ventricle
- Ventricle contraction closes them. This prevents flow back into atrium
Semilumar valves
this is where the aorta leaves the ventricle
- contraction forces these to open, during relaxation blood starts
to flow back and causes valves to close
Heart murmur
a defect in one or more valves
- You hear a hissing sound, this is the leak
Sinoatrial Node ( SA )
sets the rate for all of the cardiac muscle to contract at the same time
- Also known as the pace maker
- Generates an electrical pulse
- Also controls closing of the AV by impulse
Electrocardiogram ( ECG or EKG )
records impulses
Law of continuity
if the flow is constant, blood will flow faster through capillaries then arteries.
Veins and Arteries - there are 3 layers
- Outer - connective tissue
- Inner - endothelium
- Middle - smooth muscle
Blood pressure
higher in arteries, highest during contraction ( systolic pressure )
- Arteries stretch from pressure of entering blood and retract as blood enters arterioles. This is called peripheral resistance.
Capillaries - 5% to 10% have blood at any time, but there are so many that organs receive enough blood flow or gas exchange.
- Body will divert blood flow to capillaries as needed ( ex. Digestive system )
- About 85% of fluid that leaves the blood at arteriole end of capillaries will re-enter at the venuole end.
Lymphatic system
vessels and lymph nodes, separate from the circulatory system
- Fluids enter the system by diffusion into the lymph capillaries
helps fight infection
Lymph
colorless fluid - formed by interstitial fluids in the lymphatic system
Lymph node
organs located along lymph vessels.
- Filter lymph and help attack bacteria and viruses
Blood
90% water
- Ph of 7.4 ( slightly basic )
Immunoglobulins
bulky proteins (Quaternary protein)
Fibrinogens
proteins involved in clotting (clots blood)
Red Blood Cells
Erythrocytes
contain hemoglobin - an iron containing protein that binds to Oxygen
- 25 trillion in the body
- Bi concave disk
- No nucleus or mitochondria
- Live about 120 days
- Recycled in the liver and spleen
White Blood Cells
Leukocytes
there are 5 types
- Monocytes, neutrophils, basophils, eosinophils, lymphocytes
Platelets
Stops the bleeding
Fragments of cells
- Pinched off cytoplasmic fragments in bone marrow
- Enter blood and aid in clotting
Stem Cells
found in the red marrow of bones
- Can differentiate - white, red or platelets
Erythropoietin
plasma protein hormone
- Stimulates production of red blood cells
- Production of erythropoietin is regulated by the oxygen levels
Fibrinogen
active form is fibrin - forms clots
Hemophilia
Lack of fibrinogen
blood does not clot
Thrombus
clot in vessel
Heart attack
caused by blockage of artery
- Lack of oxygen to heart
Stroke
blockage or rupture of artery in the brain
Arteriosclerosis
plaque build up (lipids )
Hypertension
high blood pressure
LDL - low density lipoproteins
BAD
- Plaque build up
- Most common cause is smoking
HDL - high density lipoproteins
good
Reduces plaque
- Exercise helps increase it
Gas Exchange
Gills - the warmer and saltier the water the less Oxygen available
Ventilation - increased flow through the gills
Counter current exchange - blood flows opposite the direction of the water, over the gills
Tracheal system - Insects - air tubes through the body
Breathing
Positive pressure - found in frogs - inhale and fill the oral cavity, this forces the air down
Negative Pressure - Humans - pull air into lungs
- Diaphragm forces air out
Tidal volume
volume inhaled and exhaled in each breath
Vital capacity
maximum amount that can be inhaled
- 3.4 – 4.8 liters, depending on the person
Residual volume
small amount of air that remains in the lungs
Para bronchi
tiny channels for air flow and gas exchange in birds
- This is a one way system
Myoglobin
oxygen storing protein in the blood
