Ch 38 Circulatory System AP Lecture

4 chamber heart is double pump = separates oxygen-rich & oxygen- poor blood; maintains high pressure What’s the adaptive value of a 4 chamber heart? 234 low pressure to body low O 2 to body high pressure & high O 2 to body

Background  Function: transport gases, hormones, blood, nutrients, ect.  Parts  Heart- muscular pump  Blood – fluid  Blood vessels – conduits of fluid

Open Circulatory System  Fluid leaves the vessels and bathes the tissues then returns back to the heart  Ex: arthropods and mollusks

Closed Circulatory System  Blood vessels keep fluids contained  Ex: annelids and vertebrates

Mammal Heart  Arteries- carry blood away from the heart  Stronger; endure more pressure  Veins – carry blood back to heart  Assisted by gravity and skeletal muscle  Capillaries- thin walled; exchange between blood and interstitial fluid

Blood vessels arteries arterioles capillaries venules veins artery arteriolesvenules veins

 4 chambered heart  Pulmonary – lungs  Systemic – body

Movement in mammal heart  Blood from the body enters the right atrium via vena cavae (oxygen poor)  Blood enters the right ventricle through the atrioventicular (AV) valve (oxygen poor)

3. Right ventricle pumps blood through pulmonary artery to the lung (poor oxygen) 4. Bloods moves from lung to left atrium via pulmonary vein (oxygen rich)

5. Blood moves into the left ventricle via the AV valve (oxygen rich) 6. Left ventricle pumps blood to body through aorta (oxygen rich)

Mammalian circulation What do blue vs. red areas represent? pulmonary systemic

 animations.blogspot.com/200 8/04/human-heart-how-it- pumps.html animations.blogspot.com/200 8/04/human-heart-how-it- pumps.html

Cardiac Cycle  Systole – ventricle contracts Which means the AV valves close “lub”  Diastole – ventricle relaxes Which means the aortic and pulmonary valves close “dub”

Measurement of blood pressure  High Blood Pressure (hypertension)  if top number ( systolic pumping) > 120  if bottom number ( diastolic filling) > 80

AV SL AV

Blood  Cells suspended in plasma  RBC (erythrocytes)  WBC (leukocytes)  Platelets- blood clotting

Lymphatic System  Collects excess fluid and returns it to the blood  Lymph nodes- produce and house lymphocytes that fight pathogens in the lymph fluid

Lymph system Production & transport of WBCs Traps foreign invaders lymph node lymph vessels (intertwined amongst blood vessels)