Human physio 2

• Thermoregulation is when blood goes to core organs to maintain a constant temperature
• The heart is located on the left side of the body, protected by the ribs
• The heart invades the space of the left lung a bit, creating a shape different from the right
• Pulmonary artery carries deoxygenated blood from the heart to the lungs
• After lungs oxygenated blood goes to the left atrium and then the left ventricle then finally the aorta
• Blood enters the right atrium by the superior and inferior vena cavas,
• Blood that is pumped out the pulmonary arteries to taken to the lungs
• The left ventricle is thicker because it must generate more pressure to pump blood to the whole body
• Blood from right ventricle goes to the lungs only
• Resting membrane potential is when the membrane is at a negative potential
• Depolarization is the process of returning a membrane to its resting potential
• Repolarization is negative while depolarization is positive
• Sodium channels open once voltage gated channels reach optimal charge
• Ligand channels have chemicals such as Ca and Na
• SA node stands for sinoatrial node
• SA node is the pacemaker of the heart
• Auto rhythmic means that the heart rate is controlled by the ANS and this means the heart depolarized on its own
• Threshold for SA node is 50 to 60 bpm
• The AV node is located between atria and ventricles, it has slow conduction velocity and acts like a gatekeeper
• AV node slows down impulse so that both chambers contract together
• Purkinje fibers are found in the ventricle walls and they conduct action potential quickly
• Conduction system is made up of specialized cardiac muscle cells with fast action potentials
• Heart cells have leaky sodium channels which makes cells more positive
• Calcium current goes inside heart cells and causes the heart to contract through depolarization
• Contraction causes blood to go from top to bottom of heart
• Atria fill with blood, then atrioventricular valves open allowing blood into ventricles
• Ventricles fill with blood, then semilunar valves close preventing backflow of blood
• A contraction is when pressure develops to eject blood to aorta and pulmonary trunk to vessels and finally the body
• The heart is shaped like a pinecone
• Blood flows from right side of heart to left side of heart via lungs
• Right side of heart pumps deoxygenated blood to lungs where it picks up oxygen and releases carbon dioxide
• Left side of heart receives oxygen rich blood from lungs and pumps it out to rest of body
• Heart has four chambers - two atria (right and left) and two ventricles (right and left)
• Each chamber has its own wall called septum which separates them
• Ventricles are thicker walled and have more muscle than atria
• The heart is located in the thoracic cavity
• Athletes have larger hearts
• The pulmonary circuit transports oxygenated blood from the heart to the lungs and back to the heart
• Pulmonary circuit picks up O2 and delivers CO2 for exhalation
• Systematic circuit transports oxygenated blood to tissues of body, returns deoxygenated blood and carbon dioxide to heart to send back to the pulmonary circuit