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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

-caffeine

-excercise

*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

120=systole

80=diastole

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

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