Circulatory system cont’d
HypertensionCause:◦ Chronic high blood pressure (~140/90) ◦ Damages heart and blood vessels◦ Can lead to coronary heart disease and stroke
Treatments:◦ Diet◦ Exercise◦ Medication (vasodilators, diuretics, etc.)
Coronary heart diseaseCause:◦ Build-up of plaque (over many years) in the
coronary arteries◦ Plaque hardens and narrows arteries◦ Full blockage can cause angina or a heart attack
Treatments:◦ Diet/exercise◦ Medication◦ Surgery
StrokeCause:◦ Loss of brain function due to a
disturbance in blood supply to the brain◦ Can cause temporary or permanent
damage or even death◦ Symptoms = loss of speech,
understanding and memory, facial drooping and vision impairment
Treatment:◦ None◦ Prevention with medication is possible
Heart attackCause:◦ Plaque-blocked coronary artery leads to heart
muscle injury/death◦ Heart is weakened and fails to move blood as
appropriate
Treatment:◦ Medication
(some claim daily Aspirin dose is preventative)◦ Surgery to clear arteries
Technology Bypass surgery
◦ Used if vessels to your heart are narrowed/damaged
◦ Vein transplanted from extremity to ‘bypass’ damaged/blocked vessels and supply your heart with enough O2
Pacemaker◦ Used to treat arrhythmias ◦ Sets pace of contraction impulse◦ New models can record data that can be
downloaded
Technology Cardiac catheterization
◦ Also called angioplasty◦ Narrowed or damaged arteries are
reopened/held open to allow proper flow◦ Wire mesh, or stent, implanted
Comparative anatomy
Insects Tubular heart circulates hemolymph around organs
Hemolymph returns to heart through pores
OPEN CIRCULATION!
Pumping is facilitated by muscle contractions and usually during movement
Earthworm
Pseudohearts/auxillary hearts circulate blood through 2 main vessels
CLOSED CIRCULATION!
Primary function of circulatory system is delivery of digested nutrients (gas exchange occurs through skin)
Fish Two-chambered heart pumps blood to gills and body (in that order)
IS THIS CLOSED OR OPEN CIRCULATION?
Frogs/amphibians
IS THIS CLOSED OR OPEN CIRCULATION?
Try this… Pg. 340, #1, 3 – 4 Pg. 344, #1, 7 - 8