Circulatory system cont’d. Hypertension Cause: ◦Chronic high blood pressure (~140/90) ◦Damages...

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