EXAMPLE - Pacemaker cells have a depolarising pre-potential due to - - PowerPoint PPT Presentation

▶
example
SMART_READER_LITE
LIVE PREVIEW

EXAMPLE - Pacemaker cells have a depolarising pre-potential due to - - PowerPoint PPT Presentation

Mar 02, 2024 226 likes •358 views

Key points EXAMPLE - Pacemaker cells have a depolarising pre-potential due to high sodium permeability - End-diastolic volume ( pre-load ) determines force of contraction by controlling myocyte length - Sympathetics increase SAN rate , reduce AVN

slide-1
SLIDE 1

One 2 One Medicine: Pre-clinical science revision course 2013

Key points

  • Pacemaker cells have a depolarising pre-potential

due to high sodium permeability

  • End-diastolic volume (pre-load) determines force of

contraction by controlling myocyte length

  • Sympathetics increase SAN rate, reduce AVN delay

and increase ventricular contractility

  • Heart failure causes right- & down-wards shift on

Frank-Starling curve

EXAMPLE

slide-2
SLIDE 2

Anatomy Myocytes Cardiac cycle Baroreflex Coronary circulation Capillaries Temperature Exercise Vasovagal syncope

  • utline

Module

One-2-One Medicine: Pre-clinical science revision course 2014

EXAMPLE

slide-3
SLIDE 3

haemodynamics Vessel

Total cross-sectional area (cm2) Velocity (cm/s) Blood pressure (mmHg) Elastic arteries Arterioles Capillaries Venules Veins Muscular arteries

One-2-One Medicine: Pre-clinical science revision course 2014

EXAMPLE

slide-4
SLIDE 4

haemodynamics Vessel

Flow = Arterial BP - Venous BP Resistance

Perfusion pressure (ABP - VBP) Flow Low resistance High resistance

One-2-One Medicine: Pre-clinical science revision course 2014

EXAMPLE

slide-5
SLIDE 5

haemodynamics Vessel

↑ resistance ↑ pressure ↓ pressure! ∴ ↓ flow Flow

Vasoconstriction

Flow = Arterial BP - Venous BP Resistance

One-2-One Medicine: Pre-clinical science revision course 2014

EXAMPLE

slide-6
SLIDE 6
  • f blood pressure

Determinants

Systolic blood pressure - stroke volume Diastolic blood pressure - heart rate & total peripheral resistance

Blood pressure *SBP *DBP

One-2-One Medicine: Pre-clinical science revision course 2014

EXAMPLE

slide-7
SLIDE 7

Blood pressure *SBP *DBP

Systolic blood pressure - stroke volume Diastolic blood pressure - heart rate & total peripheral resistance

  • f blood pressure

Determinants

One-2-One Medicine: Pre-clinical science revision course 2014

EXAMPLE

slide-8
SLIDE 8
  • f blood pressure

Determinants

Systolic blood pressure - stroke volume Diastolic blood pressure - heart rate & total peripheral resistance

Blood pressure *SBP *DBP

One-2-One Medicine: Pre-clinical science revision course 2014

EXAMPLE

slide-9
SLIDE 9

Blood pressure *SBP *DBP

Systolic blood pressure - stroke volume Diastolic blood pressure - heart rate & total peripheral resistance

  • f blood pressure

Determinants

One-2-One Medicine: Pre-clinical science revision course 2014

EXAMPLE

slide-10
SLIDE 10

Blood pressure *SBP *SBP *DBP *SBP *SBP

Systolic blood pressure - stroke volume Diastolic blood pressure - heart rate & total peripheral resistance

  • f blood pressure

Determinants

One-2-One Medicine: Pre-clinical science revision course 2014

EXAMPLE

slide-11
SLIDE 11

arteriolar tone Factors influencing

  • 1. ENDOTHELIAL SUBSTANCES
  • 2. MYOGENIC TONE
  • 3. AUTONOMIC EFFECTS
  • 4. METABOLIC HYPERAEMIA
  • 5. HORMONES
  • 6. PLATELETS: serotonin → vasoconstriction

One-2-One Medicine: Pre-clinical science revision course 2014

EXAMPLE

slide-12
SLIDE 12

endothelial substances

Arteriolar tone

↑ Shear stress → NO → Relaxation

↑ NO + ↑ PG

Endothelial cell Vascular smooth muscle cell

↑ shear stress

↓[Ca2+] Relaxation

↑sGC ↑ cGMP ↑AC ↑ cAMP

One-2-One Medicine: Pre-clinical science revision course 2014

EXAMPLE