The Cardiovascular System: Blood Vessels and Circulation © 2013 Pearson Education, Inc

Home , Tunica externa, Tunica intima, Tunica media, Venae cavae

PowerPoint® Lecture Slides prepared by Meg Flemming Austin Community College

C H A P T E R 13

• 13-1 • Distinguish among the types of blood vessels based on their structure and function. • 13-2 • Explain the mechanisms that regulate blood flow through blood vessels, and discuss the mechanisms that regulate movement of fluids between capillaries and interstitial spaces. • 13-3 • Describe the control mechanisms that interact to regulate blood flow and pressure in tissues, and explain how the activities of the cardiac, vasomotor, and respiratory centers are coordinated to control blood flow through tissues.

• 13-4 • Explain the cardiovascular system's homeostatic response to exercising and hemorrhaging. • 13-5 • Describe the three general functional patterns in the pulmonary and systemic circuits. • 13-6 • Identify the major arteries and veins of the pulmonary circuit. • 13-7 • Identify the major arteries and veins of the systemic circuit.

• 13-8 • Identify the differences between fetal and adult circulation patterns, and describe the changes in the patterns of blood flow that occur at birth. • 13-9 • Discuss the effects of aging on the cardiovascular system. • 13-10 • Give examples of interactions between the cardiovascular system and the other organ systems.

• Arteries leave the heart and branch into:

• Arterioles feed parts of organs and branch into:

• Capillaries, where chemical and gaseous exchange occurs, and which drain into:

• Venules, the smallest vessels of the venous system, which drain into:

• Veins, which return blood to the atria of the heart

1. Tunica intima (or tunica interna)

• Has endothelial lining and elastic connective tissue

2. Tunica media

• Has smooth muscle with collagen and elastic fibers

• Controls diameter of vessel

3. Tunica externa (or tunica adventitia)

• Sheath of connective tissue may anchor to other tissues

Tunica externa Tunica externa Tunica media Tunica media Tunica intima Tunica intima

Smooth muscle Lumen of vein

Smooth Muscle

Lumen of artery Endothelium Endothelium

Elastic fiber

ARTERY Artery and vein LM x 60 VEIN

• First type of arteries leaving the heart

• Examples are pulmonary trunk, aorta, and major branches

• Have more elastic fibers than smooth muscle

• Absorb pressure changes readily

• Stretched during systole, relaxed during diastole

• Prevent very high pressure during systole

• Prevent very low pressure during diastole

• Muscular arteries

• Examples are external carotid arteries

• Tunica media contains high proportion of smooth muscle, little elastic fiber

• Arterioles

• Tunica media has only 1–2 layers of smooth muscle

• Ability to change diameter controls BP and flow

• Tunica interna only

• Endothelial cells with basement membrane

• Ideal for diffusion between plasma and IF

• Thin walls provide short diffusion distance

• Small diameter slows flow to increase diffusion rate

• Enormous number of capillaries provide huge surface area for increased diffusion

Large Vein Elastic Artery Internal elastic layer Tunica Tunica externa Endothelium intima Tunica media Tunica media Endothelium Tunica intima Tunica externa

Medium-Sized Vein Muscular Artery

Tunica externa Tunica externa Tunica media Tunica media Endothelium Endothelium Tunica intima Tunica intima

Venule Arteriole Smooth muscle cells (Tunica media) Tunica externa Endothelium Endothelium Basement membrane Capillary

Endothelial cells Basement membrane

• An interconnected network of capillaries

• Entrance to bed is regulated by precapillary sphincter, a band of smooth muscle

• Relaxation of sphincter allows for increased flow

• Constriction of sphincter decreases flow

• This occurs cyclically, referred to as vasomotion

• Control is local through autoregulation

Vein Collateral Smooth arteries muscle cells Venule Small artery Arteriole

Capillaries

Arteriole Section of a precapillary sphincter

Small venule

Capillary Capillary bed LM x 125 beds

This micrograph shows a number of capillary beds. Precapillary sphincters KEY Consistent blood flow Arteriovenous anastomosis Variable blood flow Features of a typical capillary bed. Solid arrows indicate consistent blood flow; dashed arrows indicate variable or pulsating blood flow.

• Formed by anastomosis, a joining of blood vessels

• Arteriovenous anastomosis bypasses capillary bed, connecting arteriole to venule

• Arterial anastomosis occurs where arteries fuse before branching into arterioles

• Ensures delivery of blood to key areas, brain, and heart

• Collect blood from tissues and organs and return it to the heart

• Venules are the smallest and some lack tunica media

• Medium-sized veins

• Tunica media has several smooth muscle layers

• In limbs, contain valves

• Prevent backflow of blood toward the distal ends

• Increase venous return

• Large veins

• Thin tunica media and thick collagenous tunica externa

• Thinner walls than arteries because of low pressure

Valve closed

Valve opens above contracting muscle

Valve closed

1. List the five general classes of blood vessels. 2. A cross section of tissue shows several small, thin-walled vessels with very little smooth muscle tissue in the tunica media. Which type of vessels are these? 3. What effect would relaxation of precapillary sphincters have on blood flow through a tissue? 4. Why are valves found in veins, but not in arteries?

• Flow maintains adequate perfusion of tissues • Normally, blood flow equals cardiac output (CO) • Increased CO leads to increased flow through capillaries • Decreased CO leads to reduced flow • Capillary flow influenced by pressure and resistance • Increased pressure increases flow • Increased resistance decreases flow

• Liquids exert hydrostatic pressure in all directions

• A pressure gradient exists between high and low pressures at different points

• Circulatory pressure, high in aorta vs. low in venae cavae

• Arterial pressure is blood pressure

• Capillary pressure

• Venous pressure • Flow is proportional to pressure gradients

• Any force that opposes movement

• Circulatory pressure must be high enough to overcome total peripheral resistance

• Highest pressure gradient exists in arterioles due to high peripheral resistance

• Vascular resistance

• Viscosity

• Turbulence

• Largest component of peripheral resistance • Caused mostly by friction between blood and vessel walls • Amount of friction due to length and diameter of vessel • Length doesn't normally change • The longer the vessel, the higher the resistance • Arteriolar diameter is primary source of vascular resistance • The smaller the diameter, the greater the resistance

• Due to interactions between molecules and suspended materials in a liquid

• Low-viscosity fluids flow at low pressures

• High-viscosity fluids flow only under high pressures

• Blood viscosity is normally stable

• Changes in plasma proteins or hematocrit can alter viscosity and, therefore, flow

• Eddies and swirls in fluid flow

• In smooth-walled vessels turbulence is low

• Slow flow near the walls, faster flow in center

• Injured or diseased vessels or heart valves show increase in turbulence and decrease in flow

• Turbulent blood flow across valves produces the sound of heart murmurs

• Blood pressure is maintained by hormonal and neural mechanisms

• Adjusting diameter of arterioles to specific organs:

• Regulates peripheral resistance

• Regulates flow

• Allows for matching flow and perfusion to tissue needs

• Arterial pressures fluctuate

• Systolic pressure (SP) is peak and occurs during ventricular contraction

• Diastolic pressure (DP) is the minimum and occurs at the end of ventricular relaxation

• Recorded as systolic over diastolic (e.g., 120/80 mm Hg)

• Pulse is alternating changes in pressures

• The difference between systolic and diastolic pressures

• Pulse pressure = SP – DP

• Diminishes over distance, eliminated at the capillary level

• Arterial recoil or elastic rebound occurs during diastole

• Adds additional push or squeeze on blood

• Results in fluctuation of pressures

Systolic

120

Pulse 100 pressure

Diastolic 60 Blood pressure (mm Hg) 40

0 -

Aorta

Elastic

arteries

Venules

Medium

Muscular

Arterioles

Capillaries

sizedveins

• Drops from 35 to 18 mmHg along capillary length

• Capillaries are permeable to ions, nutrients, wastes, gases, and water

• Capillary pressures cause filtration out of bloodstream and into tissues

• Some materials are reabsorbed into blood

• Some materials are picked up by lymphatic vessels

1. Maintains constant communication between plasma and IF

2. Speeds distribution of nutrients, hormones, and gases

3. Assists movement of insoluble molecules

4. Flushes bacterial toxins and other chemicals to lymphatic tissues for immune response

• Diffusion of solutes down concentration gradients

• Filtration down fluid pressure gradients

• Osmosis down osmotic gradient

• Water is filtered out of capillary by fluid or hydrostatic pressures

• Water is reabsorbed into capillary due to osmotic pressure

• Tends to push water out of plasma into tissues at arteriolar end, favoring filtration

• Blood osmotic pressure (BOP) is higher than in interstitial fluid

• As CHP drops over length of capillary, BOP remains the same, favoring reabsorption

KEY

CHP (Capillary hydrostatic pressure) Return to BOP (Blood circulation osmotic pressure) 3.6 L/day flows into lymphatic vessels

Arteriole Venule

Filtration Reabsorption No net fluid 24 L/day movement 20.4 L/day 35 25 25 25 18 25 mm mm mm mm mm mm Hg Hg Hg Hg Hg Hg

CHP > BCOP CHP = BCOP BCOP > CHP Fluid forced No net Fluid moves out of capillary movement into capillary of fluid

• Gradient is low compared to arterial side

• Large veins provide low resistance ensuring increase in flow despite low pressure

• When standing, blood flow must overcome gravity

• Muscular compression pushes on outside of veins

• Venous valves prevent backflow

• Respiratory pump due to thoracic pressures

5. Identify the factors that contribute to total peripheral resistance. 6. In a healthy individual, where is blood pressure greater: at the aorta or at the inferior vena cava? Explain. 7. While standing in the hot sun, Sally begins to feel light-headed and then faints. Explain what happened.

• Affected by:

• Cardiac output, peripheral resistance, and blood pressure

• Regulated to ensure blood flow changes occur at:

• Appropriate time, in right location, and without negative effect on pressure and flow to vital organs

• Accomplished through:

• Autoregulation, neural and hormonal input

• Immediate and localized changes in: • Vasoconstrictors, factors that stimulate constriction • Vasodilators, factors that promote dilation

• Tissue temperature, low O2 or pH, high CO2 cause: • Capillary sphincter dilation causing: • Peripheral resistance decrease causing: • Increase in flow through capillary beds

• Cardiovascular (CV) centers in medulla oblongata

• Adjust cardiac output • Vasomotor center in medulla oblongata

• Controls diameter of arterioles and peripheral resistance

• Controls venoconstriction

Autoregulation

HOMEOSTASIS DISTURBED Start • Physical stress (trauma, high temperature) • Chemical changes

(decreased O2 or pH, increased CO2 or prostaglandins) • Increased tissue activity. Inadequate local blood pressure and HOMEOSTASIS blood flow Normal blood pressure and volume Local decrease in resistance and increase in HOMEOSTASIS blood flow RESTORED HOMEOSTASIS RESTORED

If autoregulation is ineffective

Neural and Hormonal Mechanisms

Endocrine Long-term increase response (see in blood volume Figure 13-12a) and blood pressure

Endocrine mechanisms

Stimulation of Activation of Short-term elevation receptors sensitive cardiovascular of blood pressure to changes in centers in the by sympathetic systemic blood medulla stimulation of the Neural pressure or oblongata heart and peripheral mechanisms chemistry vasoconstriction

• Receptors monitor degree of stretch

• Aortic sinuses

• Located in pockets in walls of ascending aorta

• Aortic reflex adjusts flow through systemic circuit

• Carotid sinuses

• Very sensitive to ensure adequate flow to, and perfusion of, brain

Cardioinhibitory centers stimulated Cardioacceleratory Decreased Responses to Increased centers inhibited cardiac Baroreceptor Stimulation Vasomotor center output inhibited Baroreceptors Vasodilation stimulated occurs

HOMEOSTASIS HOMEOSTASIS DISTURBED RESTORED Rising blood Blood pressure pressure declines

Start HOMEOSTASIS

Normal range Start of blood pressure HOMEOSTASIS HOMEOSTASIS DISTURBED RESTORED Falling blood Blood pressure pressure rises

Vasoconstricti- Baroreceptors on occurs inhibited Vasomotor center stimulated Increased Responses to Decreased cardiac Baroreceptor Stimulation Cardioacceleratory centers stimulated output Cardioinhibitory centers inhibited © 2013 Pearson Education, Inc. Chemoreceptor Reflexes (13-3)

• Receptors • Sensitive to changes in carbon dioxide, oxygen, and pH in blood and CSF • Located in carotid and aortic bodies, medulla oblongata

• Decrease in pH or plasma O2, increase in plasma CO2 stimulate increase in heart rate and arteriolar constriction • Result is increase in BP

• E and NE trigger rapid increase of cardiac output and vasoconstriction

• Long-term

• Antidiuretic hormone (ADH), angiotensin II, EPO

• Raise BP when too low

• Atrial natriuretic peptide (ANP)

• Lowers BP when too high

• Decrease in blood volume

• Increase in blood osmolarity

• Presence of angiotensin II

• Results in:

• Vasoconstriction

• Conserving water by kidneys, increasing blood volume

• Cascade of reactions forms angiotensin II

• Angiotensin II

• Stimulates CO, arteriolar constriction

• Immediately increases BP

• Stimulates release of ADH and aldosterone

• Stimulates thirst center

• BP drops

• Plasma oxygen drops

• Stimulates:

• RBC production

• Increases blood volume

• From stretch of atrial wall due to more venous return

• Effects

• Increases sodium (and therefore water) loss by kidneys

• Reduces thirst

• Blocks release of ADH, aldosterone, E, NE

• Stimulates arteriolar dilation

HOMEOSTASIS

Normal blood pressure and HOMEOSTASIS volume DISTURBED HOMEOSTASIS Start RESTORED Blood pressure and volume fall Blood pressure and volume rise Decreasing blood pressure and Short-term volume Long-term

Combined Short-Term Sympathetic activation and Long-Term Effects and release of adrenal hormones E and NE Increased Increased blood blood pressure volume Endocrine Response Increased cardiac of Kidneys output and peripheral Renin release leads vasoconstriction to angiotensin II activation

Erythropoietin (EPO) Angiotensin II Effects is released Antidiuretic hormone released

Aldosterone secreted

Factors that compen- Thirst stimulated sate for decreased blood pressure and volume Increased red blood cell formation

Increased Na+ loss in urine

Increased water loss in urine

Reduced thirst Combined Effects Atrial natriuretic peptide (ANP) Inhibition of ADH, aldosterone, Reduced blood released by epinephrine, and volume the heart norepinephrine release

Peripheral vasodilation

HOMEOSTASIS HOMEOSTASIS DISTURBED RESTORED

Rising blood Declining blood pressure and pressure and volume volume HOMEOSTASIS Increasing blood pressure and Normal volume blood pressure and volume

8. Describe the actions of vasodilators and vasoconstrictors.

9. How would slightly compressing the common carotid artery affect your heart rate?

10.What effect would vasoconstriction of the renal artery have on systemic blood pressure and blood volume?

• Increased O consumption

• Causes lower peripheral resistance

• Resulting in increased flow

2. Increased venous return

• Due to skeletal muscle and respiratory "pumps"

© 2013 Pearson Education, Inc. Four Cardiovascular Responses to the Stress of Exercise (13-4) 3. Increased cardiac output • Frank-Starling principle due to increased venous return • Arterial pressures are maintained • Increased CO balances out decrease in peripheral resistance 4. Shunting of blood flow away from nonessential organs • Ensures adequate perfusion of heart and skeletal muscles

• Carotid and aortic reflexes increase cardiac output and peripheral resistance

• Venoconstriction accesses venous reserve

• Sympathetic activation triggers arteriolar constriction

• All mechanisms function to elevate BP

• Fluids are accessed from interstitial space

• ADH and aldosterone promote fluid retention

• Thirst increases

• EPO triggers RBC production

• All mechanisms lead to increase in volume and BP

11. Why does blood pressure increase during exercise?

12. Name the immediate and long-term problems related to the cardiovascular response to hemorrhaging.

13. Explain the role of aldosterone and ADH in long-term restoration of blood volume.

2. Single vessel may undergo name changes as it crosses anatomical boundaries

3. Anastomoses of arteries and veins reduce threat of temporary blockage of vessel to organ

Brain Upper limbs

Pulmonary Pulmonary circuit circuit (arteries) (veins)

Lungs

LA RA Systemic Left circuit Right ventricle (arteries) ventricle Systemic circuit (veins)

Kidneys Spleen

Digestive Liver organs

Gonads Lower limbs

14. Identify the two circuits of the cardiovascular system.

15. Identify the three general functional patterns of the body's blood vessels.

• Blood exits right ventricle through pulmonary trunk • Branches into left and right pulmonary arteries • Enter lungs, arterial branching nearly parallels branching of respiratory airways • Smallest arteriole feeds capillary surrounding alveolus • Oxygenated blood returns to left atrium through left and right, superior and inferior pulmonary veins

Aortic arch

Ascending aorta Pulmonary trunk

Superior vena cava Left lung

Right lung Left pulmonary arteries Right pulmonary Left pulmonary arteries veins

Right pulmonary veins

Alveolus

Alveolar capillary

O2 Inferior vena cava CO2

Descending aorta

16. Name the blood vessels that enter and exit the lungs, and indicate the relative oxygen content of the blood in each.

17. Trace the path of a drop of blood through the lungs, beginning at the right ventricle and ending at the left atrium.

• Supplies oxygenated blood to all non-pulmonary tissues • Oxygenated blood leaves left ventricle through aorta • Returns deoxygenated blood to right atrium through superior and inferior venae cavae, and coronary sinus • Contains about 84 percent of total blood volume

Vertebral Right subclavian Right common carotid Brachiocephalic Left common carotid trunk Left subclavian Aortic arch Axillary Ascending Descending aorta aorta Diaphragm Celiac trunk Renal Superior mesenteric Brachial Gonadal Inferior mesenteric Radial Common iliac Ulnar Internal iliac External iliac Deep femoral Palmar arches Femoral

Popliteal

• Ascending aorta is first systemic vessel

• Begins at aortic semilunar valve

• Left and right coronary arteries branch off near base of aorta

• Aortic arch curves across top of heart

• Descending aorta drops down through mediastinum

1. Brachiocephalic trunk • Branches to form right common carotid artery and right subclavian artery 2. Left common carotid 3. Left subclavian • This is an example of non-mirror-image arrangement • From here on, arteries are the same on both sides of the body • Designation of right and left not necessary

• Supply arms, chest wall, shoulders, back, and CNS • Internal thoracic artery •  Vertebral artery •  Thyrocervical trunk • Supply pericardium, chest, neck, shoulder, CNS • Becomes axillary artery •  Brachial artery •  Radial and ulnar arteries •  Form anastomoses, the superficial and deep palmar arches. •  Digital artery • Supply upper limbs

Thyrocervical trunk Right common carotid Right subclavian Left common carotid Vertebral Axillary Brachiocephalic trunk Left subclavian Aortic arch Ascending aorta Deep brachial Descending aorta Heart

Intercostal arteries Internal thoracic Brachial Descending aorta

Radial

Ulnar

Palmar arch Digital arteries

• Common carotids ascend up into the neck and divide

• External carotid artery

• Supplies pharynx, esophagus, larynx, and face

• Internal carotid artery

• Enters skull, supplies brain and eyes

• Two pathways

• Vertebral arteries enter skull and fuse to form one basilar artery

•  Posterior cerebral artery

•  Posterior communicating artery

• Cerebral arterial circle

• Ring-shaped anastomosis encircling the infundibulum of the pituitary

Anterior cerebral Middle cerebral Cerebral arterial Branches of the circle External Carotid Superficial Posterior temporal cerebral Maxillary Basilar Occipital Facial Internal carotid External carotid Carotid sinus Vertebral

Thyrocervical Common carotid trunk Subclavian Internal Brachiocephalic thoracic trunk Second rib The general circulation pattern of arteries supplying the neck and superficial structures of the head

Cerebral Arterial Circle Anterior Anterior cerebral communicating Internal Anterior cerebral carotid (cut) Posterior communicating Middle cerebral Posterior cerebral

Posterior Basilar cerebral Vertebral

The arterial supply to the brain

• Descending aorta

• Thoracic aorta within thoracic cavity

• Abdominal aorta after passing through diaphragm

• Phrenic artery

• First branch off abdominal aorta

• Supplies diaphragm

• Supply blood to all digestive organs

• Celiac trunk

•  Left gastric artery

•  Splenic artery

•  Common hepatic artery

• Superior mesenteric artery

• Inferior mesenteric artery

• Gonadal arteries • Testicular in male, ovarian in female • Adrenal arteries • Supply adrenal glands • Renal arteries • Supply kidneys • Lumbar arteries • Supply spinal cord and abdominal wall

• Abdominal aorta branches to the:

• Common iliac artery

• Branches to:

• Internal iliac artery

• Supplies pelvis

• External iliac artery

• Supplies lower limbs

THORACIC AORTA

Conducting

Bronchial passages of

arteries respiratory Intercostal Vertebrae, tract spinal cord, arteries back muscles, Pericardial (paired, body wall, Pericardium segmental) and skin arteries

Superior Esophageal Esophagus arteries phrenic Diaphragm

Unpaired Unpaired (multiple) arteries Mediastinal Mediastinal arteries structures

Stomach, Left adjacent ABDOMINAL gastric portion of AORTA esophagus

Inferior Spleen, Celiac Diaphragm, Splenic stomach, phrenic inferior portion pancreas trunk arteries of esophagus Liver, Paired Common stomach, gallbladder, Adrenal Adrenal hepatic duodenum, glands pancreas arteries

Pancreas, small Superior intestine, appendix, and first two-thirds Renal Unpaired Unpaired (single) mesenteric Kidneys of large intestine arteries

Last third of large intestine (left third Inferior of transverse colon, Gonadal Gonads (testes mesenteric descending colon, arteries or ovaries) sigmoid colon, and rectum) Lumbar Vertebrae, arteries spinal cord, (paired, and abdominal segmental) wall

Pelvis Left Right common and right Pelvis and left lower iliac lower common limb iliac limb

Pelvic muscles, skin, Right Left Right external viscera of pelvis (urinary Left external internal and reproductive organs), internal iliac perineum, gluteal region, iliac iliac and medial thigh iliac

Superior Hip muscles, hip joint gluteal Lateral rotators of Internal hip; rectum, anus, perineal muscles, Ilium, hip pudendal external genitalia and thigh Obturator muscles, hip joint and femoral head Lateral Skin and muscles of sacral sacrum

THORACIC AORTA

Conducting Bronchial passages of respiratory arteries Intercostal Vertebrae, tract spinal cord, arteries back muscles, (paired, Pericardial body wall, Pericardium segmental) and skin

arteries

Esophageal Superior

arteries Esophagus phrenic Diaphragm Paired

Unpaired (multiple) Unpaired arteries Mediastinal Mediastinal arteries structures

A flowchart showing major arteries of the trunk

Stomach, Left adjacent ABDOMINAL gastric portion of AORTA esophagus

Spleen, Inferior Diaphragm, stomach, Celiac inferior portion Splenic phrenic pancreas trunk arteries of esophagus

Liver, Paired stomach, Common Adrenal hepatic gallbladder, Adrenal duodenum, arteries glands pancreas Pancreas, small Superior intestine, appendix, Renal Unpaired (single) Unpaired mesenteric and first two-thirds Kidneys of large intestine arteries

Last third of large intestine (left third Gonadal Gonads Inferior of transverse colon, (testes mesenteric descending colon, arteries or ovaries) sigmoid colon, and rectum) Lumbar Vertebrae, arteries spinal cord, (paired, and abdominal segmental) wall A flowchart showing major arteries of the © 2013 Pearson Education, Inc. trunk Figure 13-19b Major Arteries of the Trunk. (3 of 3)

Pelvis Left Pelvis and Right common and right common left lower iliac lower limb limb iliac

Right Pelvic muscles, skin, Right external viscera of pelvis (urinary Left Left external internal and reproductive organs), internal iliac perineum, gluteal region, iliac iliac and medial thigh iliac

Superior Hip muscles, hip joint gluteal Lateral rotators of Internal hip; rectum, anus, pudendal perineal muscles, Ilium, hip external genitalia and thigh Obturator muscles, hip joint and femoral head Skin and Lateral muscles of sacral sacrum

• External iliac artery forms:

• Deep femoral artery

• Femoral artery

•  Popliteal artery

•  Anterior tibial, posterior tibial, and fibular arteries

• Two anastomoses connect anterior tibial

•  Dorsalis pedis arteries and two branches of posterior tibial

•  Dorsal arch on top of foot

•  Plantar arch on bottom of foot

Vertebral External jugular Internal jugular Subclavian Brachiocephalic Axillary Cephalic Superior vena cava Basilic Intercostal veins Brachial Hepatic veins Inferior vena cava Renal Median cubital Gonadal Radial Lumbar veins Median antebrachial Left and right Ulnar common iliac External iliac Palmar venous arches Internal iliac Digital veins Deep Great saphenous femoral Femoral

Popliteal

Small saphenous Posterior tibial Anterior tibial Fibular KEY Superficial veins Plantar venous arch Deep veins Dorsal venous arch

• Venous network returns blood to heart

• Arteries and veins run parallel, often similar names

• Major veins in neck and limbs different than arteries

• Arteries are located deep

• Veins usually a set of two

• One deep and the other superficial

• Aids in body temperature control

• SVC

• Receives blood from:

• Head and neck

• Upper limbs, shoulders, and chest

• Small veins in brain drain into dural sinuses • Largest is superior sagittal sinus •  Internal jugular veins • External jugular veins • Collect blood from superficial head and neck • Vertebral veins • Collect blood from cervical spinal cord and posterior skull

Superior sagittal sinus Temporal Great cerebral Maxillary Dural sinuses

Facial

Vertebral External jugular Internal jugular

Right subclavian Right brachiocephalic Left brachiocephalic Superior vena cava Internal thoracic

•  Cephalic vein

•  Basilic vein

• Median cubital

• Connects cephalic and basilic veins

• Site of venous blood sample tap

•  Brachial vein joins basilic vein to form:

•  Axillary vein

•  Subclavian vein • Meet and merge with internal and external jugular veins • Creates large brachiocephalic vein  SVC • Azygos vein drains chest wall  SVC

• IVC

• Collects blood from organs below diaphragm

• Plantar veins on the sole of the foot

•  Plantar venous arch drains into:

•  Anterior tibial vein

•  Posterior tibial vein

•  Fibular vein

• Dorsal venous arch drains into:

•  Great saphenous vein and small saphenous vein

• Behind knee small saphenous, tibial, and fibular veins connect

•  Popliteal vein

•  Femoral vein

• Great saphenous and deep femoral vein join femoral vein

•  External iliac vein

• Joins internal iliac vein to become common iliac vein

•  IVC

• As IVC ascends toward heart it collects blood from:

• Lumbar vein

• Gonadal vein

• Renal and adrenal veins

• Phrenic vein

• Hepatic vein

SUPERIOR Vertebral VENA CAVA Internal jugular External jugular Mediastinal Subclavian veins Highest intercostal Esophageal Brachiocephalic veins Axillary Azygos Cephalic Internal Hemiazygos thoracic Brachial Hepatic Intercostals veins INFERIOR VENA CAVA Renal veins Basilic Gonadal veins Phrenic veins Lumbar Adrenal veins veins Median cubital Common iliac Cephalic Internal iliac Radial Basilic External iliac Median antebrachial Ulnar KEY Superficial veins Deep veins Palmar venous arches Digital veins

Right Left Collects blood from cranium, spinal vertebral vertebral cord, vertebrae

Right Right Left Collects blood Left Collects blood from external internal internal from cranium, face, external neck, face, salivary jugular jugular jugular and neck jugular glands, scalp

Left and Collect blood Right Right right internal from structures Left Left of anterior subclavian brachiocephalic thoracic brachiocephalic subclavian veins thoracic wall

Right Through Left Left Collects blood from forearm, wrist, and axillary highest axillary brachial intercostal vein hand Mediastinal Collect blood from the SUPERIOR veins mediastinum Veins of the VENA CAVA Left cephalic Left basilic right upper Collects blood Collects blood limb from lateral from medial RIGHT surface of upper surface of upper ATRIUM limb limb Right Collect blood Left Radial Left Ulnar side of side of intercostal from vertebrae Azygos radial ulnar and body wall Hemiazygos Interconnected by median forearm forearm veins cubital vein and median antebrachial network

KEY Left Superficial veins Esophageal Collect blood Collect blood from the intercostal from vertebrae Venous network veins Deep veins esophagus veins and body wall of wrist and hand

Tributaries of the superior vena cava

RIGHT ATRIUM

INFERIOR VENA CAVA

Hepatic Collect blood from veins the liver Phrenic Collect blood from veins the diaphragm Gonadal Collect blood from the gonads (testes Collect blood from veins or ovaries) Adrenal the adrenal veins glands Lumbar Collect blood from the spinal cord Collect blood from veins and body wall Renal veins the kidneys

Right Left common common iliac iliac

Right Left external Right internal Left internal external iliac iliac iliac iliac Collect blood from the pelvic muscles, skin, urinary and reproductive organs of pelvic cavity Blood from Blood from veins in right veins in left lower limb lower limb

Lateral Superior Internal Obturator sacral gluteal pudendal veins veins veins veins

• Portal system is two capillary beds in series connected by portal vessel

• Blood going through capillaries of digestive organs absorbs nutrients, some wastes, some toxins

• Blood is processed by liver before entering general circulation

• Capillaries from: • Lower large intestine  inferior mesenteric vein • Spleen, stomach, pancreas  splenic vein • Stomach, small and large intestines  superior mesenteric vein • All three  hepatic portal vein • Blood from gastric vein and cystic vein added • Blood enters liver capillaries  hepatic vein  IVC

Esophagus Inferior vena cava Aorta Hepatic veins Liver Stomach Gastric veins Cystic Hepatic portal Spleen Gastroepiploic veins

Pancreas Splenic

Superior mesenteric Left colic

Inferior mesenteric Colic veins Ascending colon Descending colon Sigmoid veins Intestinal veins

Small intestine Superior rectal veins

18. A blockage of which branch of the aortic arch would interfere with blood flow to the left arm? 19. Why would compression of the common carotid arteries cause a person to lose consciousness? 20. Grace is in an automobile accident, and her celiac trunk is ruptured. Which organs will be affected most directly by this injury? 21. Describe the general distribution of major arteries and veins in the neck and limbs. What functional advantage does this distribution provide?

• Biggest difference is sources of respiratory and nutritional support

• All nutrients and blood gases supplied from mother through diffusion across placenta

• Placenta is unique part of uterine wall

• Maternal and fetal circulatory systems in close contact

• Low O2 fetal blood flows through umbilical arteries • At placenta:

• CO2 and wastes cross to mother

• O2 diffuses into fetal blood • Returns to fetal circulation through umbilical vein • Some blood goes to liver • Rest goes to IVC through ductus venosus

• An interatrial opening

• Flap that acts as one-way valve from right to left atrium

• Allows blood to bypass pulmonary circuit

• Ductus arteriosus

• Short vessel that takes most of blood from right ventricle directly to aortic arch of systemic circuit

Aorta Foramen ovale (open) Ductus arteriosus (open) Pulmonary trunk

Liver Inferior Umbilical vena cava vein Ductus venosus Placenta

Umbilical Umbilical cord arteries

Pulmonary trunk

Left atrium Foramen ovale (closed) Right atrium Left ventricle Right ventricle Inferior vena cava

Blood flow through the heart of a

• Infant takes first breath

• Pulmonary vessels expand

• Ductus arteriosus contracts

• Blood flows into pulmonary trunk

• Remnants convert to ligamentum arteriosum

• Flap across foramen ovale closes

• Residual indentation is the fossa ovalis

22. Name the umbilical vessels that constitute the placental blood supply. 23. A blood sample taken from the umbilical cord contains high levels of oxygen and nutrients, and low levels of carbon dioxide and waste products. Is this sample from an umbilical artery or from the umbilical vein? Explain. 24. Name the structures that are vital to fetal circulation but cease to function at birth. What becomes of each of these structures?

• Lower hematocrit

• Formation of a thrombus, or stationary blood clot

• Can detach becoming an embolism

• Pooling of blood in veins of leg

• Due to ineffective venous valves

• Reduction in maximum cardiac output

• Changes in nodal and conducting cells

• Reduction of elasticity of cardiac skeleton

• Progressive atherosclerosis

• Serious if found in coronary circulation

• Replacement of damaged cardiac muscle with scar tissue

• Arteriosclerosis or thickening and toughening of wall

• Inelastic walls of arteries less tolerant of pressure increase

• Can lead to local dilation, an aneurysm

• Calcium salts deposited on walls

• Can lead to stroke or myocardial infarction

• Thrombi can form at atherosclerotic plaques

25. Identify components of the cardiovascular system that are affected by age.

26. Define thrombus.

27. Define aneurysm.

• Oxygen

• Hormones

• Nutrients

• White blood cells

• Removes:

• Carbon dioxide and metabolic wastes

Body System Cardiovascular System SYSTEM INTEGRATOR Cardiovascular System Body System

- Stimulation of mast cells produces Delivers immune system cells to injury sites; - localized changes in blood flow and clotting response seals breaks in skin surface;

capillary permeability carries away toxins from sites of infection;

Integu

Page Page 138)

Mentary Integu

provides heat (

mentary

Provides calcium needed for normal cardiac muscle Transports calcium and phosphate for bone contraction; protects blood cells developing in red deposition; delivers EPO to red bone marrow,

bone marrow parathyroid hormone, and calcitonin to Skeletal

osteoblasts and osteoclasts (Page 188)

Skeletal

Skeletal muscle contractions assist in moving blood Delivers oxygen and nutrients, removes carbon through veins; protects superficial blood vessels, dioxide, lactic acid, and heat during skeletal

especially in neck and limbs muscle activity

(Page (Page 241)

Muscular

Controls patterns of circulation in peripheral Endothelial cells maintain blood–brain barrier; tissues; modifies heart rate and regulates blood helps generate CSF

pressure; releases ADH

Nervous

(Page (Page 302)

Nervous

Erythropoietin (EPO) regulates production of Distributes hormones throughout the body; heart -

RBCs; several hormones elevate blood pressure; secretes ANP Ine

ine epinephrine stimulates cardiac muscle, elevating

Endocr Endocr

heart rate and contractile force (Page 376) The CARDIOVASCULAR

System

The section on vessel -

distribution demonstrated the ge ge 500)

extent of the anatomical atic a

connections between the Lymph (P

cardiovascular system and other

organ systems. This figure summa- - rizes some of the physiological

relationships involved. tory

Respira

The most extensive communication (Page 532)

occurs between the cardiovascular and - lymphatic systems. Not only are the two

systems physically interconnected, but tive

cells of the lymphatic system also move Diges

from one part of the body to another (Page 572)

within the vessels of the cardiovascular system. We examine the lymphatic system in detail, including its role in the

immune response, in the next chapter.

Urinary

(Page (Page 637)

ctive

Reprodu (Page (Page 671)

28. Describe what the cardiovascular system provides for all other body systems.

29. What is the relationship between the skeletal system and the cardiovascular system?