Tuesday, May 17, 2011


How is the heart rate controlled?
pacemaker- sets tempo of heart beat
sends impulses through walls of atria making atria contract
AV node delays the contractions to make sure atria are empty

Ways to increase heart rate
-epinepherine- adrenaline, hormone released during stress

*increasing heart rate transports more oxygen to muscles

ECG and EKG detect electrical impulses from the pacemaker

Blood Vessels
-Arteries carry blood away from heart, high blood pressure and velocity
outer layer: elastic tissue
middle layer: smooth muscle
inner layer: epithelium
-Veins carry blood to heart, low blood pressure and velocity
inner layer: epithilium
one way valves to prevent back-flow
vessels expand and store
-Capillaries allow for diffusion between blood and tissue cells

Blood Flow
Blood pressure- force that blood exerts against walls of blood vessels
Pulse-rhythmic stretching of arteries
reading blood pressure: 120/80
hypertension-high blood pressure
hypotension-low blood pressure
Capillaries-steady blood flow that's increases around digestive tract after eating and skeletal muscle during excercise
Vein- blood moves against gravity, contractions push blood

90% water
10% salt, proteins, nutrients, hormones, waste
RBC- erythrocytes, determine blood type, have hemoglobin, increased surface area form bioncave disk
Hemoglobin- iron with protein that transports oxygen
Anemia- low amount of hemoglobin or RBCs


  1. I think it would have been cool to see a side-view cross section for the blood vessels, showing all of the layers in conjunction with each other.

    Good organization of information, I LIKE it.