Final: Circulation 3 Flashcards
birds and mammals: heart structure (5)
- endothelium connective tissue which directly contacts blood
- endocardium
- myocardium
- coronary arteries
- pericardium consisting of: epicardium, pericardial fluid in pericardial cavity, and the parietal pericardium
fish: heart structure (6)
- endocardium that covers the trabeculae
- spongy myocardium
- compact myocardium
- coronary arteries (only in very active fish)
- pericardial cavity
- pericardium
which fish have coronary arteries and examples (2)
- very active fish; most don’t have coronary arteries
- eg. tuna and sharks
vertebrate heart walls (4)
- pericardium
- epicardium
- myocardium
- endocardium
vertebrate heart: pericardium (3)
- sac of connective tissue that surrounds the heart
- outer (parietal) and inner (visceral) layers
- space between the layers is filled with lubricating fluid
vertebrate heart: epicardium (2)
- outer layer of heart, continuous with the visceral pericardium
- contain nerves that regulate heart and coronary arteries
vertebrate heart: myocardium
- layer of heart muscle cells (cardiomyocytes)
vertebrate heart: endocardium (2)
- innermost layer of connective tissue covered by epithelial cells (called endothelium)
- directly contacts the blood
myocardium types (2)
- compact
- spongy
compact myocardium (2)
- tightly packed cells arranged in regular pattern
- much more muscle than spongy myocardium (more compact), increasing the ability to do work to support metabolism
spongy myocardium (3)
- meshwork of loosely connected cells
- cells get bathed by blood entering the heart to obtain O2 and get rid of CO2
- allows for greater surface area for gas exchange
myocardium: mammals
- mostly have compact myocardium
myocardium: fish and amphibians (2)
- mostly have spongy myocardium, but active fishes can have more compact myocardium
- arranged as trabecular that extend into chambers
why does oxygen needed to be supplied to the heart
- myocardium is extremely oxidative and has a high O2 demand
how do mammals and birds obtain O2 to the heart
- coronary arteries supply oxygen to compact myocardium
how do fish obtain O2 to the heart
- spongy myocardium obtains oxygen from blood flowing through the heart
fish hearts (3)
- chambers
- separation
- myocardium
- four chambers arranged in series
- only deoxygenated blood passes through the heart
- spongy myocardium
fish heart chambers (4)
- sinus venosus
- atrium
- ventricle
- bulbus arteriosus
amphibian hearts (3)
- chambers
- separation
- myocardium
- three-chambered heart
- partial separation of oxygenated and deoxygenated blood; the beginning of separation in heart
- spongy myocardium
amphibian heart: chambers (3)
- two atria
- one ventricle
- conus arteriosus
amphibian heart: ventricle (2)
- trabecular in ventricle
- helps to prevent mixing of oxygenated and deoxygenated blood in the ventricle
amphibian heart: right atrium (2)
- contains the sinus venosus
- receives deoxygenated blood
amphibian heart: left atrium
- receives oxygenated blood from the pulmonary vein
amphibian heart: conus arteriosus (2)
- contains a spiral fold
- helps direct deoxygenated blood to pulmocutaneous circuit and oxygenated blood to the systemic circuit