All topics - Cardiovascular and Respiratory Systems Flashcards
1
Q
The CARDIOVASCULAR SYSTEM (2) (4)
A
- Composed of the heart, blood vessels, and blood.
- Main function (4):
→ Delivers oxygen, fuel, and other nutrients to the tissues of the body.
→ Removals of carbon dioxide and waste products from tissue.
→ Maintains a constant body temperature.
→ Prevents infections.
2
Q
The HEART (4)
A
- Made of specialized muscle tissue called MYOCARDIUM (cardiac muscle).
- Divided into halves: right and left
- RIGHT HALF: Pumps deoxygenated blood to the rest of the body (pulmonary circulation).
- LEFT HALF: Pumps oxygenated blood to the rest of the body (systemic circulation).
3
Q
LAYERS of the heart (4)
A
- PERICARDIUM: Outermost layer, tough protective sac surrounding heart.
- EPICARDIUM: Outer layer that lies against the pericardium.
- MYOCARDIUM: Heart muscle.
- ENDOCARDIUM: Layer that lines the inside of the heart.
4
Q
FOUR CHAMBERS (4)
A
- Upper chambers are called ATRIA.
- Lower chambers are called VENTRICLES.
- Atria and ventricles are separated by valves that allow the blood to flow only from the atria into the ventricles.
- These valves are called ATRIOVENTRICULAR (AV) valves.
5
Q
VALVES (4) (2)
A
- On the right side of the heart, the AV valve is called the TRISUCPID valve because it is composed of three flaps.
- On the left side of the heart, the valve is called the BICUSPID valve (or MIRTAL VALVE) because it is composed of two flaps.
- These valves are attached to muscular extensions of the ventricle walls (called PAPILLARY MUSCLES) by strands of tissue called CHORDAE TENDINAE.
- Valves are also found where the blood leaves the ventricles.
→ RIGHT SIDE = PULMONARY SEMILUNAR VALVE
prevents blood from flowing back from the pulmonary arteries into the right ventricles.
→ LEFT SIDE = AORTIC SEMILUNAR VALVE
separates the aorta from the left ventricle.
6
Q
PATH OF BLOOD through the heart (7)
A
→ Starting from the right side of the heart:
- Deoxygenated blood is delivered to the right atrium by the superior and inferior vena cava.
- From the right atrium. Blood passes through the tricuspid valve and enters the right ventricle.
- Blood is pumped through the pulmonary semilunar valve and out the pulmonary arteries to the lungs to become oxygenated.
→What happens on the left side:
- Blood returns from the lungs to through the pulmonary veins to the left atrium .
- Passes through the bicuspid valve and enters the left ventricle.
- Blood is then pumped out through the aorta.
- The aorta pumps blood to the body (systemic circulation) and eventually returns to the heart through the inferior and superior vena cava.
7
Q
EXCITATION of the heart (4)
A
- Muscle cells in the myocardium are excitable: with electrical stimulation, they will contract.
- Leads to contraction of the heart.
- Leads to pumping of blood.
- Does not require stimulation from CNS (involuntary)
8
Q
SINOARTIAL NODE (5)
A
- SA node aka “the pacemaker”.
- Founded within the wall of the right atrium.
- Where electrical signals are initiated.
- Sets heart rate.
- Controlled by the autonomic nervous system.
9
Q
INTERNODAL PATHWAYS (3)
A
- The electrical signals spread through both atria via the internodal pathways.
- Causes the atria to contract from the top down.
- When the atria contracts it forces blood into the ventricles.
10
Q
ATRIOVENTRICULAR NODE (4)
A
- AV node.
- Located at the bottom of the right atria.
- Passes the electrical signal from the atria to the ventricles.
- Also passes signals into a region of specialized tissue that runs down the ventricular septum: THE BUNDLE OF HIS.
→ Splits to form the right and left bundle branches.
11
Q
PURKINJE FIBRES (2)
A
- From the bundle of his, the branches pass the signal on the PURKINJE FIBRES.
- Purkinje fibres pass the electrical signal to the ventricles.
12
Q
CORONARY CIRCULATION (2)
A
- Blood is supplied to the heart by its own vascular system, through two main arteries: the tight and left coronary arteries.
- Branches off of the aorta and divide multiple times, supplying all regions of the myocardium with oxygenated blood.
13
Q
CARDIAC CYCLE (3)
A
- Defined as the series of events that occurs through one heartbeat.
- DIASTOLE: phase of relaxation.
→ Heart fills with blood - SYSTOLE: phase of contraction
→ Heart contracts and ejects blood
14
Q
PRESSURE (4)
A
- During the cardiac cycle there are dramatic changes in pressure
→ Pressure propels the blood through the circulation - SYSTOLIC BLOOD PRESSURE: pressure observed in the arteries during the contraction phase.
- DIASTOLIC BLOOD PRESSURE: pressure observed in the arteries during relaxation of heart.
- Normal BP is 120/80 (systolic over diastolic).
15
Q
The VASCULAR SYSTEM and BLOOD (3) (5)
A
- Vascular system is formed by a network of vessels that transport blood throughout the body.
- As you follow the path of blood through the body away from the heart, the vessels branch out and get smaller.
- Main categories of vessels (5):
→ Arteries
→ Arterioles
→ Capillaries
→ Venules
→ Veins
16
Q
ARTERIES (3)
A
- Carry blood away from the heart.
- Thick, muscular walls that are very elastic.
- Ability to stretch and reoil is important in assisting the movement of blood during diastole.
17
Q
ARTERIOLES (3)
A
- Smaller than arteries.
- Surrounded by rings of smooth muscle that can be contracted or relaxed.
- Nervous system can control the distribution of blood flow to different organs using arterioles.
18
Q
CAPILLARIES (3)
A
- Smallest vessel.
- Wall is very thin - one cell thick.
- Location of exchange of gases and nutrients.