Cardiovascular System

Question 1

Heart overall structure and function

Answer 1

Divided into 4 chambers, right and left ventricles, pumps for 2 circulations: systemic circulation and pulmonary circulation, removes CO2 while supplying fresh oxygen

Question 2

Heart chambers

Answer 2

2 upper superior chambers is the atria that divides the left and right chambers through the interatrial septum

Holding areas for blood returning from the body (right atrium) and the lungs (left atrium)

Blood movement from the top to bottom chambers pull down by low pressure

Ventricles begin with a muscular separator as a single chamber is separated into the right and left chambers (interventricular septum)

Question 3

Cardiac valves

Answer 3

Regulate blood flow from one chamber to the next to ensure that it only flows in one direction

Atria tp antriventricular valves in both canals control ventricle blood movement, similarly structured valves

The most open path from the ventricle to the atrium is through these valves , under susps, inflated and moved toward the atrium

Cusps have papillary, without these, blood would flow backward muscles that act as the strings that keep the cusps into place, without these blood would blow back to areium, pulling on papillary muscles close off this valve

Question 4

Process of heartbeats

Answer 4

Between the atrium and ventricles, these is the antriventricular node, to control timing of the hearts contractions, this pauses the electrical signal, allowing the atria to pump blood into the ventricles, ventricles fill with blood AV sends message to the AV bundle of fibers, AV bundle of fibers signals ventricles , ventricles then contract

Question 5

Process of increased HR

Answer 5

The heart does not know when to increase or decrease, it knows from the Autonomic nervous system

Facilitated by neurons that secrete norepinephrine and the adrenal glands secreting adrenaline, pacemaker cells will increase firing rate and beat faster. When asleep acytycholine is released, leading to a reduced HR

Question 6

Strength and contraction of the heart

Answer 6

Heart may contract harder to deliver more blood, built into the cardiac muscle, not influenced by neurons

In normal activity, myosin and actin filaments overlap so cross bridges with myosin can not be made with every action. Heart muscle increases with blood and fibers stretched can myosin be engaged and produce a conraction

Tropmyosin-block binding sites on actin preventing myosin from connecting

Troponin calcium ions during muscle contractions they bind to troponin causing a change that causes tropmyosin to move away from th binding site