Chapter 14: Blood Vessels and Blood Circulation

Overview

Key Terms aorta endothelium vasomotor arteriole pulse vein artery sinusoid vena cava baroreceptor sphygmomanometer vasodilation capillary valve venule compliance vasoconstriction elasticity venous sinus

The Vascular System A closed system of vessels that transports blood to and from the lungs and body tissues

Figure 14-1 The cardiovascular system. Which vessels carry blood away from the heart? Which carry blood toward the heart?

Overview of Blood Vessels Learning Outcomes Differentiate among the five types of blood vessels with regard to structure and function. Compare the pulmonary and systemic circuits relative to location and function.

Overview of Blood Vessels Blood Vessel Types Arteries Arterioles Capillaries Venules Veins

Figure 14-2 Sections of small blood vessels. Which vessels have valves that control blood flow? 8

Overview of Blood Vessels Blood Circuits The pulmonary circuit Pulmonary artery and its branches Capillaries in lungs Pulmonary veins The systemic circuit Aorta Systemic capillaries Systemic veins

Figure 14-1 The cardiovascular system. Which vessels carry blood away from the heart? Which carry blood toward the heart?

Overview of Blood Vessels Vessel Structure Three tunics (coats) of arteries and veins Inner (endothelium) Middle (smooth [voluntary] muscle) Controlled by autonomic nervous system Thinner in veins Outer (supporting connective tissue)

Figure 14-3 Cross section of an artery and vein. Which type of vessel shown has a thicker wall? 12

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Overview of Blood Vessels ✓ Overview of Blood Vessels Checkpoints 14-1 What are the five types of blood vessels? 14-2 What are the two blood circuits and what areas does each serve? 14-3 What type of tissue makes up the middle tunic of arteries and veins, and how is this tissue controlled? 14-4 How many cell layers make up the wall of a capillary? 14

Systemic Arteries Learning Outcomes Name the four sections of the aorta and list the main branches of each section. Trace the pathway of blood through the main arteries of the upper and lower limbs. Define anastomosis, cite its function, and give several examples.

Systemic Arteries The Aorta Largest artery Receives blood from left ventricle Branches to all organs Parts of the Aorta Ascending aorta Aortic arch Thoracic aorta Abdominal aorta

Systemic Arteries Branches of the Ascending Aorta and Aortic Arch Left and right coronary arteries Aortic arch Brachiocephalic artery Right subclavian artery Right common carotid artery Left common carotid artery Left subclavian artery

Systemic Arteries Branches of the Thoracic Aorta Branches to chest wall, esophagus, and bronchi Intercostal arteries

Systemic Arteries Branches of the Abdominal Aorta Celiac trunk Left gastric artery Splenic artery Hepatic artery Superior mesenteric artery Inferior mesenteric artery

Systemic Arteries Branches of the Abdominal Aorta (continued) Paired lateral branches Phrenic arteries Suprarenal arteries Renal arteries Ovarian and testicular arteries Lumbar arteries

Figure 14-4 The aorta and its branches. How many brachiocephalic arteries are there? 21

Systemic Arteries Arteries to the Pelvis and Leg Internal iliac arteries External iliac arteries Femoral artery Popliteal artery Tibial arteries Dorsalis pedis

Systemic Arteries Arteries That Branch to the Arm and Head External carotid artery Internal carotid artery Subclavian artery Vertebral artery Axillary artery Brachial artery Radial artery Ulnar artery

Figure 14-5 Principal systemic arteries. What large vessels branch from the terminal aorta? 24

Systemic Arteries Anastomoses A communication between two vessels Examples Circle of Willis Superficial palmar arch Mesenteric arches Arterial arches

Figure 14-6 Arteries that supply the brain. 26

✓ Systemic Arteries Checkpoints 14-5 What are the subdivisions of the aorta, the largest artery? 14-6 What are the three branches of the aortic arch? 14-7 What areas are supplied by the brachiocephalic artery? 14-8 What is an anastomosis? 27

Systemic Veins Learning Outcomes Compare superficial and deep veins and give examples of each type. Name the main vessels that drain into the superior and inferior venae cavae. Define venous sinus and give several examples of venous sinuses. Describe the structure and function of the hepatic portal system.

Systemic Veins Superficial veins Cephalic, basilic, median cubital veins Saphenous veins Deep veins Femoral and iliac vessels Brachial, axillary, subclavian vessels Jugular veins Brachiocephalic vein

Systemic Veins The Venae Cavae and Their Tributaries Superior vena cava Head, neck, upper extremities Azygos vein Chest wall Inferior vena cava Right, left veins from paired parts, organs Unpaired veins from spleen, digestive tract

Figure 14-7 Principal systemic veins. How many brachiocephalic veins are there? 31

Systemic veins Venous Sinuses Coronary sinus Cranial venous sinuses Cavernous sinuses Petrosal sinuses Superior sagittal sinus Confluence of sinuses Transverse sinuses (lateral sinuses)

Systemic Veins The Hepatic Portal System Carries blood from abdominal organs to liver Superior mesenteric vein Splenic vein Gastric, pancreatic, inferior mesenteric veins Sinusoids

Figure 14-8 Hepatic portal system. What vessel do the hepatic veins drain into? 34

✓ Systemic Veins Checkpoints 14-9 What is the difference between superficial and deep veins? 14-10 What two large veins drain the systemic blood vessels and empty into the right atrium? 14-11 What is a venous sinus? 14-12 The hepatic portal system takes blood from the abdominal organs to which organ? 35

Circulation Physiology Learning Outcomes Explain the forces that affect exchange across the capillary wall. Describe the factors that regulate blood flow. Define pulse and list factors that affect pulse rate.

Circulation Physiology Blood exchanges oxygen, carbon dioxide, other substances generated by cells Tissue fluid (interstitial fluid) is exchange medium

Circulation Physiology Capillary Exchange How substances move between cells and capillary blood Diffusion Main process Blood pressure Moves material into tissue fluid Osmotic pressure Moves material into capillaries

Figure 14-9 The role of capillaries. 39

Circulation Physiology The Dynamics of Blood Flow Vasomotor center in medulla regulates vasomotor activities Vasodilation Vasoconstriction Precapillary sphincter

Circulation Physiology Return of Blood to the Heart Mechanisms that promote blood’s return to heart Contraction of skeletal muscles Valves Breathing

Figure 14-10 Blood return. Which of the two valves shown is closer to the heart? 42

Circulation Physiology ✓ Circulation Physiology Checkpoints 14-13 What force helps to push materials out of a capillary? What force helps to draw materials into a capillary? 14-14 Name the two types of vasomotor changes. 14-15 Where are vasomotor activities regulated? 43

Circulation Physiology The Pulse Ventricular contraction Wave of increased pressure Begins at heart and travels to arteries

Circulation Physiology The Pulse (continued) Influenced by various factors Body size Gender Age Muscular activity Emotion Body temperature Thyroid secretion

Circulation Physiology Learning Outcomes List the factors that affect blood pressure. Explain how blood pressure is commonly measured.

Circulation Physiology Blood Pressure Force exerted by blood against vessel walls Determined by Cardiac output Blood vessel resistance to blood flow

Figure 14-11 Blood pressure. In which vessels does the pulse pressure drop to zero? 48

Cardiac Output Volume of blood pumped out of each ventricle in one minute Heart rate Beats per minute Stroke volume Controlled by force of contractions

Circulation Physiology Resistance to Blood Flow Peripheral resistance is affected by Vasomotor changes Baroreceptors in large arteries Elasticity of blood vessels Viscosity Total blood volume

Circulation Physiology Blood Pressure Measurement Pressure is measured in the brachial arm artery using a sphygmomanometer. Systolic pressure Occurs during heart contraction Normal systolic: 120 mmHg Diastolic pressure Occurs during heart relaxation Normal diastolic: 80 mmHg

Figure 14-12 Measurement of blood pressure. 52

Circulation Physiology ✓ Circulation Physiology Checkpoints 14-16 What is the definition of pulse? 14-17 What is the definition of blood pressure? 14-18 What is the most significant factor in determination of peripheral resistance? 14-19 What two components of blood pressure are measured? 53

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Case Study Learning Outcome Referring to the case study, trace the pathway of an embolus from the femoral vein to the pulmonary artery. 55

Case Study Pathway of an Embolus From the Femoral Vein to the Pulmonary Artery Femoral vein  External iliac vein  Common iliac vein  Inferior vena cava  Right atrium  Right ventricle  Pulmonary trunk  Pulmonary arteries

Word Anatomy Learning Outcome Show how word parts are used to build words related to the blood vessels and circulation. 57

Word Anatomy Word Part Meaning Example brachi/o arm The brachiocephalic artery supplies blood to the arm and head on the right side. celi/o abdomen The celiac trunk branches to supply blood to the abdominal organs. enter/o intestine The mesenteric arteries supply blood to the intestines. phren/o diaphragm The phrenic artery supplies blood to the diaphragm. bar/o pressure A baroreceptor responds to changes in pressure. sphygm/o pulse A sphygmomanometer is used to measure blood pressure.

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