chapter 18 learning objectives

18.1 overview of arteries and veins

Compare and contrast the structures of arteries and veins, and of arterioles and venules

arteries and arterioles are high-pressure, thick wall vessels that transport blood away from the heart

veins and venules are low-prssure, thin-walled vessels that returns blood to heart

Define vascular anastomosis, and explain the significance of anastomoses

present w/i the coronary cirulation

neighboring veins are connected by sm collaterals

18.2 physiology of blood flow

Describe the factors that influence blood flow, blood pressure, and peripheral resistance (ask her)

hemodynamics is the study of blood flow

BP: force that blood exerts on the wall of blood vessles

Explain the relationships between vessel diameter, cross-sectional area, blood pressure, and blood velocity

fig 18.5

Explain how blood pressure varies in different parts of the systemic and pulmonary circuits

Describe how blood pressure changes in the arteries, capillaries, and veins

pressure does change signigcantly as blood travels through the systemic circuit.

Explain how the mean arterial pressure is calculated

MAP is calculated by adding one-third of the pulse pressure to the diastolic pressure

ex: BP 120/80

MAP= 80 mm Hg+1/3(120mmHg-80mmHg)=93mmHg

Describe the mechanisms that assist in the return of venous blood to the heart

venous valves, venoconstriction, skeletal muscle pumps, and the respiratory pump help return venous blood to the heart

18.3 Maintenance of BP

Describe the role of arterioles in regulating tissue blood flow and systemic arterial blood pressure

by vasoconstriction and vasodilation, they both control perfusion and regular systemic arterial BP

Describe the local, hormonal, and neural factors that affect and regulate blood pressure

BP is regulated by complex interplay of local metabolic factors, hormones & neural mechansims acting on CA and peripheral reistance

Explain the main effects and importance of the baroreceptor reflex

BP is monitored by ANS w/ specailized mechanoreceptors in the vessles called baroreceptors

Explain how the respiratory and cardiovascular systems maintain blood flow to tissues via the chemoreceptor reflex

receports respond mostly to the level of O2 in blood

Describe common causes of and treatments for hypertension

tx of HTN depends on the stage at which it is diagnosed

1. lifestyle modifications, like smoking, cessation, weight loss, limit alcohol intake and increase physical activity

2. dietary modification, decrease salt, cholesterol, and sat FST intake

18.4 Capillaries and Tissue Perfusion

Describe the different types of capillaries, and explain how their structure relates to their function

continous capillary

fenestrated capillary

sinusidal capillary

table 18.3

Explain the roles of diffusion, filtration, and osmosis in capillary exchange

diffusion and osmosis through gasps and fenestrations: tight junctions btw mant endothelial cells are incomplete & leave sm gasps btw endothelial cells

diffusion through the membranes of endothelial cells: lipid-soluble substances such as O2, CO2, & certain lipids can enter or exit the capillary

transcytosis: lg substances must cross the endothelial cells by transcytosis

fig 18.12

Describe how autoregulation controls blood flow to tissues

ensures that the correct amount of blood is delivered to match a tissues level of activity

18.5 Capillary Pressure and H2O movement

Describe hydrostatic pressure and colloid osmotic pressure

HP: force of a fluid on the walls of its container

Colloid osmotic pressure: OP gradient created by proteins w/i the plasma, H2O moves into the plasma from the interstitial fluid due to plasma higher COP

Explain how net filtration pressure across the capillary wall determines fluid movement across the wall

lost vol, of water is eventually returned to the blood vessels of the lymphatic system

Explain how changes in hydrostatic and colloid osmotic pressure may cause edema

HTP-HP

liver failure-COP

18.6 Anatomy of Systemic Arteries

Describe the patterns of arterial blood flow for the head and neck, the thoracic cavity, the abdominopelvic cavity, and the upper and lower limbs

AA serves the head, neck and upper limbs

descendign thoracic and AOA supplies the trunk and organs

Common iliac arteries branch to supply pelvic region LL

Identify major arteries of the systemic circuit

fig 18.16

Identify the major pulse points

fig 18.23

18.7 Anatomy of Systemic veins

Describe the patterns of venous blood drainage for the head and neck, the thoracic cavity, the abdominopelvic cavity, and the upper and lower limbs

venous blood from the head/neck and UL drain SVC

LL and abdominopelvic organs drain into the IVC

Identify major veins of the systemic circuit

18.24

Describe the structure and function of the hepatic portal system

HPS: system that delivers blood from the digestive organs and the spleen to hepatocytes via the HPV for processing of nutrients, wastes, and toxins

18.8 putting it all together: the big pic of blood vessel anatomy

Describe the pathway of blood flow through the body

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  Identify the arteries and veins of the body

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