functions of the circulatory system - edl · pdf filefunctions of the circulatory system ......

30.3 The Heart and Circulation

Functions of the Circulatory System

– collecting waste materials– maintaining body temperature

– transporting blood, gases, nutrients

37.1 The Circulatory System


The circulatory system moves blood to all parts of the body.

• Circulatory system includes - heart- blood vessels- blood



KEY CONCEPT The heart is a muscular pump that moves the blood through two pathways.

NORMAL HUMAN HEART



left atrium

left ventricle

right atrium

right ventricle

• The heart has four chambers:- 2 atria: right & left atrium (upper collecting chambers)- 2 ventricles: right & left ventricles (lower pumping

chambers)

• The heart is made up of cardiac muscle.



aortic valve

left atrium

mitral valve

left ventricle

septum

pulmonary valve

right atrium

tricuspid

right ventricle

• The heart is divided into two sides by the septum– Right side = pumps deoxygenated blood to lungs– Left side = pumps oxygenated blood to body

• One-way valves separate chambers and prevent backflow of blood.



The heart pumps blood through two main pathways. • Pulmonary circulation occurs between the heart and the

lungs.• Systemic circulation occurs between the heart and the rest

of the body.



• Blood flows through the heart in a specific pathway.

1

2 4

3



Blood flow through the heartSuperior / Inferior Vena Cava (biggest veins)right atriumright ventricle pulmonary arteryto the lungs (pick up O2)pulmonary veinleft atriumleft ventricleaorta

(biggest artery)to the rest of the body

Oxygenated blood

Deoxygenated blood


30.3 The Heart and Circulation 37.1 The Circulatory System


KEY CONCEPT The circulatory system transports materials throughout the body.



Arteries, veins, and capillaries transport blood to all parts of the body.

• Arteries carry blood away from the heart.– blood under great pressure– thicker, more muscular walls

ARTERY VEINCAPILLARIES

arteriole venule

endothelium

connective tissuesmooth muscle

valve



• Circulatory diseases affect mainly the heart and the arteries.– artery walls become thick and inflexible– plaque blocks blood flow in arteries



• Veins carry blood back to the heart.– blood under less pressure– thinner walls, larger diameter– valves prevent backflow


arteriole venule

endothelium

connective tissuesmooth muscle

valve



• Varicose veins are enlarged veins that are raised abovethe skin.

• Valves in the veins do not function properly causing blood to remain in the veins.



• Capillaries move blood between veins, arteries, and cells.- thinnest blood vessels- gas exchange take place


arteriole

endothelium

connective tissue

smooth muscle

venule

valve



• Blood pressure is a measure of the force of blood pushing against artery walls. – systolic pressure:

left ventricle contracts

– diastolic pressure: left ventricle relaxes

• High blood pressure can precede a heart attack or stroke.


30.5 Blood

KEY CONCEPT Blood is a complex tissue that transports materials.

37.2 Blood and The Lymphatic System

30.5 Blood

Blood is composed mainly of cells, cell fragments, and plasma.

• Whole blood is made up of different materials.– plasma– red blood cells – white blood cells – platelets

red blood cells,white blood cells,and platelets

plasma


30.5 Blood

Blood is composed mainly of cells, cell fragments, and plasma.

1. Plasma– approx. 55% of blood volume– Carries nutrients (amino acids, glucose)

and wastes– 90% water– Remainder consists of minerals,

proteins, and other compounds– Proteins assist in clotting, maintaining

water balance and fighting disease


30.5 Blood

• Protein markers define blood types and Rh factors.

– ABO blood group the most common– Rh factor can be negative or positive– blood types must be compatible for transfusions


30.5 Blood

2) Red blood cells – make up 40-45 % of all blood cells– produced in bone marrow– transport oxygen to cells and carry away carbon dioxide– have no nuclei and contain hemoglobin (binds with O2)


30.5 Blood

3. White Blood Cells - approx 1% along with platelets of blood volume- body’s main defense against disease- some “eat” pathogens by phagocytosis- some are lymphocytes (B-cells and T-cells) involved inimmune response

red blood cell

platelet

white blood cell


30.5 Blood

red blood cell

platelet

white blood cell

4) Platelets

– cell fragments that aid in blood clotting


30.5 Blood

• Platelets help form clots that control bleeding.

platelets

fibrin

red blood cell

white blood cell


30.2 Respiration and Gas Exchange

KEY CONCEPT The respiratory system exchanges oxygen and carbon dioxide.

37.3 The Respiratory System


– picks up O2 from inhaled air– expels CO2 and water– where gas exchange takes place

nose

sinus

mouthepiglottis

trachea

lungs

Functions of the respiratory system



Structures of the Respiratory System


Nasal cavity

pharynxlarynx

esophagustrachea

right lung

left lung

bronchusbronchiole

diaphragm heart


Pathway of Air

1) Nasal Cavity (nose)- mucus warms and moistens air to prevent damage to

lungs- cilia filter air and trap

particles2) Pharynx

- directs air into respiratory tract and food into digestive tract

3) Larynx (voicebox)- sound is produced when air is forced through vocal cords



Pathway of Air

4) Trachea (windpipe)- located in the center of chest cavity- tube made of rings of cartilage

5) Bronchi/Bronchioles- trachea branches into left and right bronchus- each bronchus branches off

into smaller bronchioles6) Alveoli

- tiny air sacs at the end of bronchioles

- capillaries surround alveoli for gas exchange (CO2/O2)



Pathway of Air7) Lungs

- right lung has 3 lobes; left lung has 2 lobes- located inside thoracic (chest) cavity- entire cavity is enclosed by the pleura= double membranes that secrete mucus to

reduced friction during breathing

Healthy lungs Smoker’s lungs



Gas exchange occurs in the alveoli of the lungs. • Oxygen and carbon dioxide are carried by the blood to and

from the alveoli.– oxygen diffuses from alveoli into capillary – oxygen binds to hemoglobin in red blood cells – carbon dioxide diffuses from capillary into alveoli

ALVEOLI

capillaries

GAS EXCHANGES

alveolus

capillary

co2

o2

Co2 diffusesinto alveolus.

O2 diffusesinto blood.



Gas exchange occurs in the alveoli of the lungs. • Breathing is regulated by the brain stem.

midbrainpons

medulla oblongata

spinal chord



Mechanisms of breathing• Breathing involves the diaphragm and muscles of the

rib cage. • diaphragm = a layer muscle tissues beneath the lungs

that contract or relax to help in breathing

Air inhaled.

Muscles contract andrib cage expands.

Diaphragm flattensand moves downward.

Air exhaled.

Muscles andrib cage relax.

Diaphragm relaxesand rises.

Inhalation Exhalation



Respiratory diseases interfere with gas exchange.

• Lung diseases reduce airflow and oxygen absorption.– Emphysema destroys

alveoli.– Asthma constricts

airways.– Cystic fibrosis produces

sticky mucus.

• Smoking is the leading cause of lung diseases.


functions of the circulatory system - edl · pdf filefunctions of the circulatory system ......

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