Cardiovascular system

Question 1

structural components- heart

Answer 1

involuntarily (myogenically) stimulated.
form of striated muscle similar to skeletal muscle.
single cells (each with a nucleus) are branched and joined by intercalated discs.

Question 2

contraction of the heart- diastole

Answer 2

when the heart is in a state of relaxation.
Average: 80
Normal- 75-85 mmHg

Question 3

contraction of the heart-Systole

Answer 3

when the heart is in a state of contraction.
Average- 120mmHg
Normal-110-130mmHg

Question 4

intrinsic conduction

Answer 4

-SA node (pacemaker,100-110bpm, intrinsic/spontaneously)
-AV node (0.13s delay/40-60pm)
-Bundle of his (30-40bpm)
-LBB & RBB
-Anterior superior fascicle
-Posterior inferior Fascicle
-purkinje fibers (6 times faster transmission) 30-40 bpm

Question 5

moderation of heart rate-parasympathetic nervous system

Answer 5

acts through the vagus nerve to decrease heart rate and force of contraction (predominates at rest-vagal tone)
-neurotransmitter: Acetylcholine

Question 6

moderate of heart rate-sympathetic nervous system

Answer 6

is stimulated by stress: increase in heart rate and force of contraction.
-neurotransmitter: Adrenaline & Noradrenaline

Question 7

cardiac cycle

Answer 7

1-events that occur between two consecutive heartbeats (systole to systole/RR interval)
2-Diastole- relaxation phase during which the chambers fill with blood (T wave to QRS)-62% of cycle duration
3-systole-contraction phase during which the chambers expel blood (QRS to T wave) 38% of cycle duration

Question 8

cardiac cycle-stroke volume

Answer 8

1-volume of blood pumped per contraction (ml)
2-End-diastolic volume(EDV)-Volume of blood in ventricle before contraction.
3-End-systolic volume(ESV)-volume of blood in ventricle after contraction.

Question 9

Cardiac cycle-equation

Answer 9

SV=EDV-ESV
Cardiac output= HR X SV

Question 10

cardiac output (Q)

Answer 10

total volume of blood pumped by the left ventricle per minute.
Q= HR(f) x SV

Question 11

cardiac output( ejection fraction)

Answer 11

proportion of blood pumped out of the ventricle each beat.
EF=SV/EDV (Averages 60% at rest)

Question 12

vascular network/ blood

Answer 12

vascular system-
1-Arteries
2-Arterioles

Capillaries-
1-venules
2-veins

Question 13

vascular system

Answer 13

systolic blood pressure(SBP) is the highest pressure.
diastolic blood pressure (DBP) is the lowest pressure.

Question 14

vascular system

Answer 14

mean arterial pressure (MAP)- average pressure exerted by the blood as it travels through arteries.
MAP=DBP+ (0.333 x (SBP-DBP).
Blood vessel constriction increases blood pressure, dilation reduces blood pressure.

Question 15

composition of the blood

Answer 15

-solid portion of the blood.
-red blood cells (99%)
-white blood cells (1%)
-platelets (1%)
liquid portion of the blood-plasma (55%)
Plasma proteins(7%)