Lectures this week: Cardiovascular 15 November 2010 Lectures this week: Cardiovascular Lab this week: EKG, blood pressure, and heart sounds. Wear clothes and shoes that will allow you to run during a portion of lab to look at the effects of exercise on heart rate and EKG waveforms. Read about EKGs on p. 371-373 of text. Measuring blood pressure on p. 387

1QQ # 28 for 8:30 1. Capillaries have The slowest blood flow velocity of any vessel type The smallest diameter of any blood vessel type the highest resistance of any vessel type on an individual basis Pulsatile blood flow Smooth muscles and endothelial cells. The aorta and the largest arteries have Low compliance Low resistance Low pressure Rigid, inelastic walls

1QQ # 28 for 9:30 1. Capillaries have The slowest blood flow velocity of any vessel type The smallest diameter of any blood vessel type the highest cumulative cross sectional area when all are considered together Pulsatile blood flow Smooth muscles and endothelial cells. The aorta and the largest arteries have High compliance Low resistance High pressure Elastic walls

Cardiovascular responses to Exercise: A Real World Example Actions of Hormones (Cortisol, EPI, Glucagon, Insulin) and effects on cardiac muscle, cardiac conduction system, arteriolar smooth muscle, adipose tissue…) Q to GI tract, skeletal muscles, brain Effects on HR, SV, EDV, CO, TPR, MAP Intrinsic and extrinsic control of blood flow to capillaries Absorptive and post-aborptive phase; uses of fuels during exercise.

Fig. 12.36 S 12 No parasympathetic innervation of arterioles! Metabolic vasodilators No parasympathetic innervation of arterioles! Importance of sympathetic “tone.” 12.36.jpg Metabolic autoregulation, flow autoregulation, myogenic autoregulation

Figure 12.02 Arteries = 10% of Blood Volume Veins = 60% of Blood Volume Arterioles = Resistance vessels Capillaries = 5% of Blood Volume

S 14 Capillaries: Continuous, discontinuous, and fenestrated capillaries: Ex: brain and liver Figure 12.38 Generate vasodilators and vasoconstrictors Arterioles: 1) Extrinsic control by hormones and nerves 2) Intrinsic (local) control by …..a) metabolic autoregulation, …..b) flow autoregulation, and …..c) myogenic autoregulation.

Diffusion, mediated transport, bulk flow