CIRCULATORY SYSTEM

Jhia Anjela D. Rivera1

1BS Biology Graduate, Department of Biology, College of Science, Polytechnic University of the Philippines

CIRCULATORY SYSTEM

•Composed of CARDIOVASCULARand LYMPHATIC SYSTEM

CIRCULATORY SYSTEM

•Comprised of the heart, veins,capillaries, arteries, lymph vessels,and lymph glands, which worktogether to supply the bodytissues with nourishment andcollect waste materials

FUNCTIONS OF THE CIRCULATORY SYSTEM•Distribute nutrients• Transport and exchange oxygen andcarbon dioxide,•Remove waste materials•Distribute secretions of endocrine glands•Prevent excessive bleeding•Prevent infection•Regulate body temperature

CARDIOVASCULAR SYSTEM

•The Heart•Blood Vessels•Blood

CARDIOVASCULAR SYSTEM FUNCTIONS•Regulates blood supply•Generates blood pressure•Routes blood•Ensures 1 way blood flow

BLOOD

•Connective tissue•Sticky•Heavier than water•Temperature slightly higher thanrest of body•Males (5-6 L), females (4-5 L)

BLOOD

•Connective tissue•Sticky•Heavier than water•Temperature slightly higher thanrest of body•Males (5-6 L), females (4-5 L)

FUNCTIONS OF BLOOD

• Transport of gases, nutrients and wasteproducts• Transport of processed molecules• Transport of regulatory molecules•Regulation of pH and osmosis•Maintenance of body temperature•Protection against foreign substances•Clot formation

FUNCTIONS OF BLOOD

• Transport of gases, nutrients and wasteproducts• Transport of processed molecules• Transport of regulatory molecules•Regulation of pH and osmosis•Maintenance of body temperature•Protection against foreign substances•Clot formation

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Percentage by

body weight

Percentage by

volume

Plasma

(percentage by weight) Albumins

58%

Globulins

38%

Fibrinogen

4%

Ions

Nutrients

Waste products

Gases

Regulatory

substances

White blood cells

Neutrophils

60%–70%

Lymphocytes

20%–25%

Monocytes

3%–8%

Eosinophils

2%–4%

Basophils

0.5%–1%

Red blood cells

4.2–6.2million

Formed

elements

45%

Buffy

coat

Plasma

55%

Proteins 7%

Water

91%

Other solutes 2%

Formed elements

(number per cubic mm)

Platelets

250–400 thousand

White blood cells

5–10 thousand

(left): © liquidlibrary/PictureQuest RF

COMPOSITION OF BLOOD

•Plasma:• 55% of total blood•pale, yellow liquid that surrounds cells• 91% water, 7% proteins, and 2% other

•Formed Elements:• 45% of total blood•cells and cell fragments•erythrocytes, leukocytes, thrombocytes

COMPOSITION OF PLASMA

•Albumin:• 58% of plasma proteins•helps maintain water balance

•Globulins:• 38% of plasma proteins•helps immune system

•Fibrinogen:• 4% of plasma proteins•aids in clot formation

CHARACTERISTICS OF RBC

• Shape: biconcave disc• Size: 7.5 µm in diameter• 2 µm at thickest point• 1 µm in the center• Ideal volume – surface ratio

• Easy diffusion of gases• Provides deformability (passage through capillaries ofblood vessels)

ERYTHROCYTES

•Red blood cells (RBC)•Disk-shaped with thick edges•Nucleus is lost during development•Live for 120 days•Function:• Transport O2 to tissues

LEUKOCYTES (WBC)

•White blood cells (WBC)•Lack hemoglobin•Larger than erythrocytes•Contain a nucleus•Functions:

- fight infections- remove dead cells and debris by

phagocytosis

TYPES OF LEUKOCYTES

•Granulocytes-contain granules

1. Neutrophils:- most common - remain in blood for 10-12 hours

then move to tissues phagocytes

TYPES OF LEUKOCYTES

2. Eosinophils:- reduce inflammation

3. Basophils:- least common- release histamine and heparin

TYPES OF LEUKOCYTESAgranulocytes

- no granules1. Monocytes :

- largest - produce macrophages

2. Lymphocytes:- immune response- several different types (T cells and B cells)- lead to production of antibodies

TYPES OF LEUKOCYTES

PLATELETS

- blood clotting cells- produced in red bone

marrow

HEARTCopyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Carotid artery

Jugular vein

Aorta

Pulmonary trunk

Heart

Brachial artery

Inferior

vena cava

Femoral

artery

and vein

HEART CHARACTERISTICS

Size:size of a fist and weighs less than

1 lb.Location:

between lungs in thoracic cavityOrientation:

apex (bottom) towards left side

Larynx

Trachea

Superior vena cava

Right lung

Right atrium

Right ventricle

RibVisceral pleuraPleural cavityParietal pleura

Diaphragm

Aortic arch

Pulmonary trunk

Midclavicular

line2nd intercostal

spaceSternum

Apex of heart5th intercostal

space(b)

Anterior view(a)

Left atriumLeft lung

Left ventricle

Apex of heart

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

HEART COVERINGS• Pericardium:

double-layered sac that anchors and protects heart

• Parietal pericardium:membrane around heart’s cavity

• Visceral pericardium:membrane on heart’s surface

• Pericardial cavity:space around heart

HEART LAYERS• Epicardium:surface of heart (outside)

• Myocardium:thick, middle layer composed of cardiac muscle

• Endocardium:smooth, inner surface

CHAMBERS AND BLOOD VESSELS

4 Chambers:- left atrium (LA)- right atrium (RA)- left ventricle (LV)- right ventricle (RV)

Coronary sulcus:separates atria from ventricles

ATRIA

•Upper portion •Holding chambers •Small, thin walled •Contract minimally to push blood into ventricles• Interatrial septum:

separates right and left atria

VENTRICLES

•Lower portion •Pumping chambers•Thick, strong walled •Contract forcefully to propel blood out of heart •Interventricular septum:• separates right and left ventricles

THE HEART

VALVES

• structures that ensure 1 way blood flow

•Atrioventricular valves (AV):-between atria and ventricles

• Tricuspid valve:- AV valve between RA and RV- 3 cusps

VALVES

•Bicuspid valve (mitral):- AV valve between LA and LV- 2 cusps

•Chordae tendineae:- attached to AV valve flaps - support valves

VALVES

•Semilunar valves:- Pulmonary: base of

pulmonary trunk

- Aortic: base of aorta

VALVES

RIGHT SIDE OF THE HEART

•Pulmonary circuit:- carries blood from heart to

lungs- blood is O2 poor, CO2 rich

RIGHT SIDE OF THE HEART• Right Atrium:• - receives blood from 3 places: superior and• inferior vena cava and coronary sinus• - Superior vena cava:• drains blood above diaphragm (head, neck, thorax,• upper limbs)• - Inferior vena cava:• drains blood below diaphragm (abdominopelvic• cavity and lower limbs)• - coronary sinus:• drains blood from myocardium

RIGHT SIDE OF THE HEART•Right Ventricle:

- opens into pulmonary trunk

- Pulmonary trunk:- splits into right and left pulmonary arteries

- Pulmonary arteries:- carry blood away from heart to lungs

LEFT SIDE OF THE HEART

•Systemic circuit:- carries blood from heart to

body- blood is O2 rich, CO2 poor

LEFT SIDE OF THE HEART• Left Atrium:• 4 openings (pulmonary veins) that receive blood from

lungs

• Left Ventricle: - opens into aorta- thicker, contracts more forcefully, higher blood pressure

than right ventricle has to get to body

• Aorta:- carries blood from LV to body

THE HEART

THE HEART

THE HEART

BLOOD FLOW

BLOOD VESSELS

Functions•1. Carry blood•2. Exchange nutrients, waste products, gases within tissues•3. Transport substances•4. Regulate blood pressure•5. Direct blood flow to tissues

VESSEL STRUCTURESArterties:

- carry blood away from heart- thick with a lot of elastic

Veins:- carry blood toward heart- think with less elastic

Capillaries:exchange occurs between blood and tissue

fluids

BLOOD FLOWBlood flows from arteries into arterioles

Arterioles into capillaries

Capillaries into venules

Venules to small veins

Veins return to heart

TYPES OF ARTERIESElastic arteries:

- largest in diameter- thickest walls- Ex. Aorta and pulmonary trunk

Muscular arteries:- medium to small size- thick in diameter- contain smooth muscle cells- can control blood flow to body regions

TYPES OF ARTERIES

CAPILLARIES

•Blood flows from arterioles into capillaries

•Capillaries branch to form networks

•Blood flow is regulated by smooth muscle cells, precapillary sphincters

CAPILLARIES

TYPE OF VEINS• Blood flows from capillaries into venules

• Blood flows from venules into small veins

• All 3 tunics are present in small veins

• Medium sized veins: collect blood from small veins and deliver to large veins

• Large veins:• contain valves

VEINS

BLOOD VESSELS OF PULMONARY CIRCULATION• Pulmonary circulation:

- blood vessels that carry blood from right ventricle to lungs and back from left atrium of heart• Pulmonary trunk:

- blood pump from right ventricle towards lung• Pulmonary veins:

-exit lungs and carry O2 rich blood to left atrium

BLOOD FLOW THROUGH THE CIRCULATORY SYSTEM

PARTS OF AORTA• Ascending:

- passes superiorly from left ventricle

• Aortic Arch:- 3 major arteries which carry blood to head

and upper limbs

• Descending:- extends through thorax and abdomen to

pelvis

PARTS OF AORTA

• Thoracic:- part of descending aorta that extends

through thorax to diaphragm

•Abdominal:- descending aorta that extends from

diaphragm where it divides at common iliac arteries

PARTS OF AORTA

ARTERIES OF HEAD AND NECK• Branches of aortic arch:

- brachiocephalic artery- left common carotid artery- left subclavian

• Brachiocephalic artery:- first branch off aortic arch- supplies blood to right side of head and

neck

ARTERIES OF HEAD AND NECK

• Left common carotid artery:- 2nd branch off aortic arch- supplies blood to the left side of head andneck

• Left subclavian artery:- 3rd branch off aortic arch- supplies blood to left upper limbs

ARTERIES OF HEAD AND NECK

• Right common carotid artery:- branches off brachiocephalic artery- supplies blood to right side of head andneck

• Right subclavian artery:- branches off brachiocephalic artery- supplies blood to right upper limbs

ARTERIES OF HEAD AND NECK

ARTERIES OF THE UPPER LIMBS

•Axillary arteries:- continuation of subclavian- supply blood deep in clavicle

• Brachial arteries:- continuation of axillary- where blood pressure measurements aretaken

ARTERIES OF THE UPPER LIMBS

•Ulnar arteries:- branch of brachial artery- near elbow

• Radial arteries:- branch of brachial artery- supply blood to forearm and hand- pulse taken here

ARTERIES OF HEAD AND NECK

ARTERIES OF ABDOMINAL AORTA

•Celiac trunk arteries:- supply blood to stomach, pancreas,

spleen, liver, upper duodenum• Superior mesenteric arteries:

- supply blood to small intestines and upper portion of colon• Inferior mesenteric arteries:

- supply blood to colon

ARTERIES OF ABDOMINAL AORTA• Renal arteries:

- supply blood to kidneys

• Hepatic arteries:- supply blood to liver

• Testicular arteries:- supply blood to testes

• Ovarian arteries:- supply blood to ovaries

ARTERIES OF ABDOMINAL AORTA

• Inferior phrenic arteries:- supply blood to diaphragm

• Lumbar arteries:- supply blood to lumbar vertebra and

back muscles

ARTERIES OF ABDOMINAL AORTA

ARTERIES OF PELVIS•Common iliac arteries:

- branches from abdominal aorta- divides into internal iliac arteries

• External iliac arteries:- division of common iliac artery- supply blood to lower limbs

• Internal iliac arteries:- division of common iliac- supply blood to pelvic area

ARTERIES OF LOWER LIMBS

• Femoral arteries:- supply to thigh

• Popliteal arteries :- supply blood to knee

•Anterior and posterior arteries:- supply blood to leg and foot

• Fibular arteries:- supply blood to lateral leg and foot

ARTERIES OF LOWER LIMBS

MAJOR ARTERIES

VEINS

• Superior vena cava:- returns blood from head, neck, thorax, and

right upper limbs- empties into right atrium of heart

• Inferior vena cava:- returns blood from abdomen, pelvis, lower

limbs- empties into right atrium of heart

VEINS OF HEAD AND NECK

•External jugular vein:- drain blood from head and neck - empties into subclavian veins

• Internal jugular vein:- drain blood from brain, face, neck- empty into subclavian veins

VEINS OF HEAD AND NECK

• Subclavian veins:- forms brachiocephalic veins

•Brachiocephalic veins:- join to form superior vena cava

VEINS OF THE HEAD AND NECK

VEINS OF UPPER LIMBS• Brachial veins:

- empty into axillary vein

•Cephalic veins:- empty into axillary vein and basilic vein

•Median cubital veins:- connects to cephalic vein - near elbow

VEINS OF THE UPPER LIMB

VEINS OF THORAX• Right and left brachiocephalic veins:

- drain blood from thorax into superior vena cava

• Azygos veins:- drain blood from thorax into superior vena

cava

• Internal thoracic veins:- empty into brachiocephalic veins

VEINS OF THORAX

•Posterior intercostal veins:- drain blood from posterior thoracic wall- drains into azygos vein on right side

•Hemiazygos vein:- receives blood from azygos vein of left

side

VEINS OF THE UPPER LIMB

VEINS OF ABDOMEN AND PELVIS

•Common iliac vein:- formed from external and internal iliacs- empty into inferior vena cava

•External iliac vein:- drains blood from lower limbs- empty into common iliac vein

VEINS OF ABDOMEN AND PELVIS

• Internal iliac vein:- drains blood from pelvic region- empties into common iliac vein

•Renal vein:- drains blood from kidneys

HEPATIC PORTAL SYSTEM

• Liver is a major processing center for substances absorbed by intestinal tract.•Portal system:

- vascular system that begins with capillaries in viscera and ends with capillaries in liver

- uses splenic vein and superior mesenteric vein

VEINS OF THE HEPATIC PORTAL SYSTEM

VEINS OF THE LOWER LIMBS

• Femoral veins:- drain blood from thigh and empty into

external iliac vein•Great saphenous veins:

- drain from foot and empty into femoral vein• Popliteal veins:

- drain blood from knee and empty into femoral vein

VEINS OF THE LOWER LIMBS

VEINS OF THE LOWER LIMBS

LYMPHATIC SYSTEMS

• includes lymph, lymphatic vessels, lymphatic tissue, lymphatic nodules, lymph nodes, tonsils, the spleen, and the thymus•body’s defense systems against threats arising from inside and outside the body

FUNCTIONS OF THE LYMPHATIC SYSTEMS1. Fluid balance

2. Fat Absorption

3. Defense

LYMPHATIC SYSTEM

COMPONENTS OF THE LYMPHATIC SYSTEMS• Lymph - fluid that enters lymphatic capillaries composed of water and some solutes

• Lymphocytes• Lymphatic vessels• Lymph nodes• Tonsils• Spleen• Thymus gland

LYMPHATIC CAPILLARIES AND VESSELS•Carries fluid in one direction from tissues to circulatory system

• Fluid moves from blood capillaries into tissue spaces

• Lymphatic capillaries: - tiny, closed-ended vessels - fluid moves easily into - in most tissues- join to form lymphatic vessels

LYMPHATIC CAPILLARIES AND VESSELS

• Lymphatic vessels:- resemble small veins- where lymphatic capillaries join- one way valves

• Right lymphatic duct:- where lymphatic vessels from right upperlimb and right head, neck, chest empty- empties into right subclavian vein

LYMPHATIC CAPILLARIES AND VESSELS

• Thoracic duct:- rest of body empties from lymphatic vessels- empties into left subclavian vein

LYMPHATIC SYSTEM

LYMPHATIC ORGANS• Tonsils:

- palatine tonsils on each side of oral cavity- pharyngeal tonsils near internal openingof nasal cavity (adenoid)- lingual tonsils posterior surface of tongue- form a protective ring of lymphatic tissue around nasal and oral cavities

TONSILS

LYMPH NODES• Lymph nodes:

- rounded structures that vary in size- located near lymphatic vessels- groin, armpit, neck- lymph passes through lymph nodes before

entering blood- lymph moves through and immune system

is activated (lymphocytes produced) ifforeign substances are detected- removal of microbes by macrophages

LYMPH NODES

SPLEEN• Spleen:

- size of clenched fist- located in abdomen- filters blood - detect and respond to foreign substances- destroy old red blood cells- blood reservoir- white pulp: lymphatic tissue surrounding

arteries- red pulp: contains macrophages and red

blood cells that connect to veins

SPLEEN

THYMUS GLAND

• Thymus gland:- bilobed gland- located in mediastinum behind the

sternum- stops growing at age 1- at age 60 decreases in size- produces and matures lymphocytes