Which blood vessel has the greatest resistance to flow?
What are the 2 flow factors in hemodynamics?
1. Velocity (how fast is blood moving) 2. Area (what size area is blood moving thru)
What type of circulatory system do mammals have? How does it operate?
Closed system -that uses heart as a pump. recieves blood at low hydrostatic pressure and increases pressure to drive blood thru the system
Where is the heart located in mammals? how are it's surfaces genreally named?
-Located in the mediastinum (extends from sternum to vertebral column, the first rib and between the lungs) -apex=tip of left ventricle -base= posterior surface
What are the 3 layers of the heart wall?
1. Epicardium (external layer): visceral layer of serous pericardium, allows heart to beat without friction 2. Myocardium (muscle layer): 95% is cardiac muscle 3. Endocardium (inner layer): smooth lining for chambers of heart, valves, continuous with lining of large blood vessels
What is the pericardium? What are the 2 types of pericardium?
-membrane surrounding and protecting the heart 1. fibrous pericardium (tough inelastic dense connective tissue/ prevents overstretching/ anchors heart) 2. Serous pericardium (thin delicate membrane/ parietal fused to fibrous pericardium & visceral called epicardium)
-Ventral aorta: blood leaving heart -Aortic arches: pass dorsally thru branchial arches and enter paired dorsal aorta -External Carotids: carries blood from ventral aorta to ventral head region -Internal Carotids: carries blood from dorsal aorta to brain -Dorsal Aorta: unite and form single aorta (distribute blood to posterior part of body) ends in caudal artery -Subclavian artery: supply anterior appendages -Iliac artery: supply posterior appendages -Renal artery: supply kidneys