1.4 – Interaction of Respiratory & Circulatory Systems

Circulatory SystemTransports dissolved gases & nutrients to cells

in the bodyHeart muscle contractions produce pressure so

that blood can be pumped around the body Valves close after blood is pushed through them

to prevent blood from flowing backwardsArteries carry oxygen-rich blood and nutrients

like glucose to cellsVeins carry oxygen-poor (deoxygenated) blood

and wastes like CO2 that need to be removed from body

The Heart: The Body’s Pump

Before being dispersed through the body, blood flows through:all 4 chambers of

the heart the lungs

The Workhorse of the Circulatory System

1 – from body to

right atrium2 – right ventricle

to lungs for gas exchange

3 – from lungs to left atrium

4 – left ventricle to body

1

2

3

4

The Path of Blood in the Body

Blood from body:Vein (vena cava) Right atrium Right ventricle Lungs (pulmonary

arteries, then pulmonary veins)

Left atrium Left ventricle Artery (aorta) Blood circulates to body

Blood in the Heart & Lungs

Blood returning from the body is oxygen-poorcarries CO2 waste

from cell respiration

Blood returning from the lungs is oxygenatedbright red due to

the high O2 contentThe circulatory system and respiratory

system work together

Teamwork is a Beautiful Thing

The circulatory system and respiratory system work together to deliver nutrients to the body’s cellsblood is a part of the circulatory systemlungs are a part of the respiratory system

gas exchange = taking in oxygen and releasing carbon dioxide in the lungs

Gas Exchange

Capillaries

Networks of very thin blood vessels (only 1 skin cell thick!)

They deliver oxygen & nutrients and pick up waste materials from cells in tissues in every organ in the body

Trace the path of blood in the diagram with your finger, starting at one point and returning to it

KAP-ill-air-eez

Quiz time!

1. Name the circulatory system’s major job.

2. Name the 4 main chambers of the heart.

3. What do the valves in the heart do?

4. What system does the circulatory system work with so gas exchange can take place?

5. What are capillaries? What do they do?

Respiratory SystemResponsible for gas exchange (O2 in, CO2 out) so

the body’s cells can:gain the nutrients they needs get rid of the wastes they produce

Consists of the lungs & airwaysThe diaphragm can also be considered part of

this systemit’s a muscle that contracts when you breatheallows room for your lungs to expand so they can

take in airwhen you breathe in, your rib cage moves up & out,

causing pressure to build upthis causes air to be pulled into your body through

your nose or mouth

Use Your Nose!

The air your breathe in passes by epithelial cells in your nasal cavity cells have tiny, hair-like

projections called ciliathey also secrete mucus

Both cilia & mucus keep foreign particles like allergens, bacteria, and toxins out of your body

Pharynx Trachea Bronchi

Air moves from the throat (pharynx) to your windpipe (trachea)a small flap called the

epiglottis opens and closes so no food ends up in the trachea

From the trachea, the single pipe splits into two, called bronchieach bronchi goes to a

lung

Bronchi Bronchioles Alveoli

Bronchi then branch out into smaller tubes called bronchiolesbronchioles are woven into the lung tissue

Bronchioles divide into tiny sacs called alveoli

Capillaries surround the alveoliit is here that gas

exchange takes place

Alveoli

Tiny clusters of air sacs in the lunghave a very thin epithelial (skin)

layergases can cross, but bacteria and

other harmful substances cannot

O2 and CO2 are exchanged with blood (red blood cells) in the capillariesO2 diffuses from alveoli to blood

CO2 diffuses from blood to alveoli to be exhaled from the lungs

RBCs contain hemoglobin, which binds O2 so that it can be carried through the body

Alveoli are the tiny heroes of the respiratory system!

Alveoli Mouth

When your diaphragm & chest muscles relax, you exhaleCO2 gathered by the alveoli

is expelled through the lungs by breathing out

When CO2 levels get too high, your breathing rate increases so CO2 can be expelled quicker

The Path of Gases into Your Body

Air outside body

Nose / Mouth

Throat (pharynx)

Windpipe (trachea)

Bronchi

Lungs (bronchioles)

Alveoli

Gas exchange

Review #2… yahoo!

1. Name 2 major organs of the respiratory system.

2. Why should you always breathe in through your nose?

3. What is the structure in the lung where gas exchange takes place? Name 2 gases that are exchanged here.

4. Why does your breathing rate increase when you’re exercising?

Systems Interactions

1. How are the circulatory & respiratory systems related?

2. Name the tiny structures in each system that work together so humans can get the nutrients they need to their cells to survive.

3. Are there machines that can do the job of the heart or lungs? If so, name or explain them.

Make a Set of Lungs

Refer to p. 66 of your textbook to make yourself a pair of lungs that mimic our lungs

Already done this activity in elementary school? Try the activity on p. 67make a scaled version of our digestive systems

using the measurements given to you in your textbook and the materials on the front bench