introduction for diploma and undergraduate pharmacy student

1. INTRODUCTION
CARDIOVASCULAR SYSTEM
BY
DR. HARSHIKA PATEL
KeMU
PHRM 321 PHARMACOLOGY AND THERAPEUTICS

2. CLEAR THE HUMAN ANATOMY AND
PHYSIOLOGY OF CARDIVASCULAR
SYSTEM FROM ANY RECOMMENDED
TEXT BOOK

3. INTRODUCTION – GENERAL PROPERTIES
Cardiovascular system: a group of two components =
cardio (heart) + vascular (blood vessels)
Heart has property of auto-rythemicity  generate own
electrical impulses
They are supplied with two different system:
Sympathetic: activate the function
Parasympathetic: suppress the function
SINOATRIAL (SA) node: called pacemaker
Function of heart: delivery of blood, oxygen and
nutrients

4. Contd’…
Factors affecting heart rate(60-90 b/m)
1. Autonomic activity (adrenal gland  inc HR  inc blood
circulate to full filled demand)
2. Circulatory hormones: inc HR ( EG. autacoids)
3. Physical activity: required o2 demand and supply  inc HR
4. Age: small population  have higher but become stable at
adult age
5. Baroreceptors: sense the suppress the blood circulation in
blood vessel and show the effects on blood pressure
6. Emotion: eg: anger  HR inc’

5. Blood pressure: 120/80 mm/Hg
 Pressure of blood in blood vessels
 Systolic: heart is in contraction mode : 120mm/Hg  always
variable eg. Standing lying, working mode of body
 Diastolic: relaxation of heart: 80mm/Hg
 Because of constant variation in pressure, according to the
physical activity  need to measure the blood pressure of
constant time (to avoid the fluctuation in reading)


6. Common disorders of heart
when the heart can
no longer pump
enough blood to
meet the metabolic
demands of the
body
when blood
volume is great
compared to the
space available
inside blood
vessels
HEART
FAILURE
HYPERTENSION
THINK ABOUT
HYPOTENSION TOO

7. When the
electrical
conduction
pathways
malfunction
The heart’s way of
signaling that
some of the cells
are not getting
enough oxygen
ARRHYTHMIA
ANGINA

8. when oxygen
starved
areas of
the heart begin
dying
when you
broke
with
someone…
MYOCARDIAL
INFARCTION

9. Cardiac Electrophysiology
1. Impulse generation:
1. Non-automatic fiber: ordinary working myocardial
fibres  cannot generate an impulse of their own.
2. Automatic fiber (caused automaticity): present in SA
and A-V nodes, and in the His-Purkinje system, i.e.
specialized conducting tissue

10. • Normally, the SA node  has steepest phase- 4 depolarization,
undergoes self-excitation and propagates the impulse to rest of the
heart --. and acts as the pacemaker
• Two types of AP are possible  see the diagram
• The slow channel AP is characterised by:
• Initiation at a higher threshold (less negative level).
• Slower depolarization during 0 phase.
• Less overshoot, low amplitude.
• Very slow propagation, decremental conduction and a low safety
factor for conduction.
• Can arise and propagate in fibres too depolarized to support fast
channel responses.
Contd’…

11. Contd’…
• Slow channel AP in SA node, A-V node  has shorter
duration and phases 1–3 are not clearly demarkated.
• Slow channel AP can occur in Purkinje fibres (PF) also, but
this has a much longer duration with a prominent plateau
phase

12. 2. Conduction
 A more completely polarized membrane depolarizes
faster because more Na+ channels have recovered
(voltage-dependent reactivation).
 In atrial, ventricular and Purkinje fibres (fast channel
fibres which depolarize by Na+ current), oppositely,
in SA and A-V nodal cells which remain refractory for
some time even after attainment of maximal resting
potential (Ca2+ channel reactivation is time-
dependent).
 A drug which reduces the slope of 0 phase (at any
given resting membrane potential) will shift the
membrane responsiveness curve to the right and
impede conduction.
 This curve can also be altered by disease.

13. 3. Excitability –
“the strength of stimulus required to elicit a
response or to produce an AP”
4. Refractory periods:
minimum interval between two propagation

14. Understand this too:

15. Reference:
Katzung pharmacology textbook
Lippincott’s illustrated pharmacology
K.D. Tripathi medicinal Pharmacology
Internet

16. Let’s Continue….. With
disorders…..>