Respiratory and CirculatorySystems

Objectives

14. I can state the function of the respiratory system

15. Identify where gas exchange occurs

16. Explain how gases move between body cells and alveoli

Major Functions of Respiratory System

Where gas exchange takes place

Oxygen (O2) and Carbon Dioxide (CO2)

Lungs are the only place where gases from the blood and gases from air are exchanged

RED BLOOD CELLS: - Pick up oxygen from lungs and transports it to cells - Picks up carbon dioxide from cells and transports it back to lungs

Respiratory Structures

SinusNoseMouthTracheaLungsDiaphragm

Gas Exchange occurs in Alveoli

3 key principles:

1. O₂ and CO₂ are carried by the blood

2. Lining of alveoli must be moist

3. Gases move by diffusion

- move from area of higher concentration to lower concentration

How it works?

Capillaries, which carry blood, surround and penetrate alveoli.

O₂ concentration in alveoli is higher

= O₂ diffuses from alveoli into blood

CO₂ concentration is higher in blood = CO₂ diffuses from blood into alveoli

Diaphragm

Muscle that controls breathingContracts and moves down during

inhalation (breathing in)Relaxes and moves up during

exhalation (breathing out)

Meet The Lungs

Circulatory System

Your Heart

Beats about 100,000 times a day and circulates all 5 liters of blood every 60 seconds

Diameter of aorta is about the same size around as a garden hose

Human circulatory system is a closed systemLeading cause of death in the US is heart

disease

Major Functions of Circulatory System

1. Carries nutrients and wastes

2. Transports gases (carbon dioxide and oxygen)

3. Carries hormones (endocrine)

4. Distributes heat

Structures

4 chambered heart ValvesArteries, veins and capillariesBlood

Heartbeat

SA node gives off an electrical signal that starts wave of contractions

Pacemakers replace SA nodes

‘Roads’ That Carry Blood

Arteries = carry blood away from heart Thick walls, under great pressure

Veins = carry blood to the heart Thin walls; contain valves

Capillaries = networks that move blood in and out of organs and tissue Thin walls allow diffusion in and out of blood

Valves

Flaps of tissue that prevent blood from flowing backward

Pathway of Blood

Heart pumps blood twice per cycle

First through lungs to add oxygen and remove carbon dioxide

Second time to distribute oxygenated blood throughout body

Heart Diseases: leading cause of death in U.S.

Arteriosclerosis is when artery walls become thick and inflexible.

Arthrosclerosis is when blood flow is partially or fully blocked by plaque.

Both diseases can lead to heart attack, stroke or kidney damage

Your HeartHow the Heart Works

Blood

Delivery system = fluids, gases, nutrients, distributes heat, components fight infection and control bleeding

Composed of: Red Blood Cells

White Blood Cells

Platelets

Plasma

Red Blood Cells

Function: carry oxygen and carbon dioxide40-50% of blood compositionProduced from stem cells in bone marrowBiconcave shape = like donut with solid centerLive for 120 days; recycled by liver/spleenHemoglobin = part that attaches to oxygen and

carbon dioxide

White Blood Cells

Function: defend against infectionVery small amount of total blood composition

1 WBC for every 700 RBC Different types of white blood cells play

different rolesAlso part of the immune system: able to pass

into lymphatic system and attack pathogens

Platelets

Function: form clots to control bleeding Made in bone marrowVery small amount of total blood compositionForm complex net to seal wound and begin

repair processDisorders include forming large clots (in

arteries) and the inability to clot (hemophilia)

Plasma

Function: transports fluids and molecules throughout the body

55% of total blood compositionMostly water: also glucose,

vitamins, minerals, proteins, electrolytes, hormones and wastes

Is blood ever blue?

NoIt’s always varying shades of redThe iron in hemoglobin on red blood cells

give it the red colorBecomes bright red when it absorbs

oxygenPublishers use blue color to distinguish blood

with low oxygen from blood with high oxygen

Explaining Blood Flow of Heart

Right Side of the HeartDeoxygenated Blood from the body flows into the Right Atrium of the heart then gets pumped from the Right Ventricle to the Lungs

Left Side of the HeartOxygenated Blood flows from the lungs into the Left Atrium of the heart then gets pumped from the Left Ventricle through the Aorta to your Body