Transport System - QUIZ Flashcards
Identify all of the parts of the heart in a diagram.
On paper / online
What is the pathway of deoxygenated blood? (pulmonary circulation)
1 Vena cavae
2 Right atrium (thru AV valve)
3 Right ventricle (thru semilunar pulmonary valve)
4 Pulmonary artery
5 Lungs
What is the pathway of oxygenated blood? (systemic circulation)
1 Pulmonary Vein
2 Left atrium (thru AV valve)
3 Left ventricle (thru semilunar aortic valve)
4 Aorta
5 The body
Give reasons for double circulation / double pump.
- Deoxygenated blood pumped to lungs / oxygenated pumped to other organs
- Each side has atrium and ventricle
- Left atrium receives blood from lungs and right receives from body tissues
- Left ventricle pumps blood via aorta / right pumps via pulmonary artery
- Oxygenated/deoxygenated blood kept separate, all tissues receive blood w high oxygen
Explain the roles of valves in the heart.
- Maintain a one-way flow of blood // prevents back flow
- Opening / closing controls timing of blood flow
- closed valves allow ventricles to fill w blood
- valves open when pressure is higher upstream
Explain the events in one cardiac cycle / one heartbeat.
- The series of events from the beginning of one heartbeat to the next.
1 Blood flows freely into ventricles (diastole - 70%)
2 SA node fires - atrial systole
3 AV node “waits” then fires - ventricular systole
4 AV valves close
5 Semilunar valves close
6 Diastole - repeat
Explain Atrial and Ventricular systole.
- (after diastole) relaxed chambers filled with blood
- Atrial systole; contraction of atria, remaining blood is pushed into ventricles
- Ventricular systole; contraction of ventricles forcing the blood out through the aorta and pulmonary artery
Explain Atrial and Ventricular diastole.
- Atrial diastole: relaxation of the atria, the atria fill with blood from the vena cavae
- Ventricular diastole: ventricles to fill passively with blood from the atria.
Role of the Sinoatrial Node.
- Located in right atrium
- Bodys pacemaker
- Sends out electrical signal (action potential) that stimulates contraction the walls of both atria and then ventricles
- Epinephrin increases heart rate
Role of Atrioventricular Node.
- “waits”
- Sends signal thru bundle of his / purkinje fibers into ventricles to contract from bottom up
Outline the reasons for delay between atrial and ventricular contractions.
- Impulses from atria do not pass directly to ventricles
- Impulses travel via atrioventricular node in wall of right atrium
- Impulses from AVN sent along bundle of His/purkinje fibers
- Ensures atria have ejected their blood into ventricles first before they contract
Explain the heart sounds.
- Produced by the closing of valves
- First sound (lub) is closing of AV valves
- Second sound (dub) is closing of semilunar valves
- Healthy heart sounds like “lub-dub”
Review cardiac cycle diagram.
slay
Explain the control of the heartbeat / rate.
- Sinoatrial node is a specialized group of muscle cells
- SAN acts as pacemaker
- Sends out electrical signal which stimulates contraction of heart muscle
- Signal passes to AV node then thru walls of ventricles
- Medulla can change heart rate (increase/decrease) thru signal thru nerves (vagus nerve slows heart rate)
- Norepinephrine (from adrenal glands) increases heart rate (of contraction)
- Part of fight or flight
Explain how the structure of cardiac muscle cells are related to their function.
- Intercalated discs; join cells together/resist mechanical stress
- Gap junctions; allow coordinated contraction
- Thick/Thin muscle fibers; Forms mechanism for contraction
- Abundance of mitochondria; Supply energy for continuous contractions
- Y-Shaped cells; allows for faster coordinated contraction