Respiratory and Circulatory Functions

Lecture #8

Ms. Day/ Honors Biology

Circulatory and Respiratory Systems

They work together to help maintain homeostasis in the body.

What do they help to regulate?Body tempHeart rateBreathing rateO2 and CO2 levels in cells

Function of Respiratory and Circulatory Systems

Main job of Respiratory System Transport gases to and from the circulatory

system What gases?

Get oxygen (O2) into the body and remove waste gases (CO2) out of the body

Main job of Circulatory System Moves blood to all parts of the body.

Get oxygen (O2) into the body and remove waste gases (CO2) out of the body

These systems work together!

Where do the gases come from? Where do the gases come from? Why do we need them? Why do we need them?

Cellular Respiration: creates ATP from food

O2 = Needed for cellular respiration to make ATP (energy)

You breath in O2 from air

CO2 = waste product

The overall process is:Macromolecules + Macromolecules + OO22 COCO22 + H+ H22O + energy (ATP)O + energy (ATP)

Carbohydrates, fats, and proteins can all be used as the fuel, but most useful is glucose.

Respiratory and Circulatory Systems

Components of Respiratory NoseMouthPharynxTracheaLungsDiaphragm

Components of CirculatoryHeartBloodBlood Vessels

ArteriesVeinsCapillaries

Respiratory System (in detail)

RESPIRATORY SYSTEM

Respiratory surface = the exchange of gases between the atmosphere and the blood (entirely dependent on diffusion!!!)

Movement of substance from high concentration to low concentration

Mucous membranes are found through the respiratory system thin, warm and moist needed for diffusion

External Respiration Pathway

Pathway of Air into the Body1. Nose/Mouth-external opening to allow

entry Air is filtered, cleaned, warmed,

moistened2. Air moves through pharynx to trachea

Trachea (windpipe) traps the inhaled particles with cilia and mucus

Mucustraps foreign particles

Cilia“sweep” foreign material away

from lungs to be swallowed

Pathway of Air into the Body (continued)

3. Enters a series of tubes Protected by cartilage to

keep tubes firm/open

1st = Enters trachea which branches out into

2nd = two bronchi that also branches out into even smaller tubes called bronchioles

4. Bronchioles end up in air sacs called alveoli, where all exchange of gases occur.

Structure of Alveoli(ends of bronchioles)

• Small air sacs covered in mucus• Wrapped in tiny blood vessels called capillaries

•300 to 600 million in a pair of lungs•Great deal of surface area•Actual site of gas exchange

How do we breath? Involves muscles of the rib cage and the

diaphragm Diaphragm: dome shaped skeletal muscle at

the base of the rib cageInhale (take air into lungs)

muscles contract, expand rib cage, diaphragm moves down

Exhale (release air from lungs)muscles relax, contract rib cage, diaphragm moves

up

Ventilation (Inhalation/Exhalation) Diagram

Recall: Gas Exchange

3 principles for gas exchange:O2 and CO2 are carried by the blood

Opposite directions

Gas moves by diffusion (moves from area of high to low concentration)

Lining of the alveoli must be moist to help gases diffuse

Diffusion of gases Gases always move from areas of high

concentration to areas of low concentration O2 concentration is higher in alveoli than

blood oxygen diffuses into blood

At body cells, O2 concentration is higher in blood oxygen diffuses out of blood and into cells

Gas Exchange

O2 alveoli capillaries red blood cells

CO2 red blood cells capillaries alveoli

Hemoglobin and Gas Exchange

Oxygen diffuses into red blood cell (RBC’s) where there is hemoglobin (a protein in RBC)

Hemoglobin contain iron atoms, which bind to oxygen gas

Carbon Dioxide Transport Hemoglobin ALSO helps transport

CO2!!7% of CO2

transported as dissolved CO2 in blood plasma (water portion of blood)

23% binds to hemoglobin70%

transported in the form of bicarbonate ions (HCO3

-)CO2 (g) + H20 (l) H+ + HCO3

-

Oxygen/Carbon Dioxide Transport

1. O2 diffuses from alveoli to blood2. Blood travels to heart and body

3. In tissues, O2 levels are lower, so RBCs release O2 to cells

4. In tissues, CO2 levels are higher, so CO2 diffuses from cells to blood

5. CO2 travels in blood to heart

6. Heart pumps blood to lungs where CO2 is released

1. REMEMBER: TOO MUCH CO2 CAUSES BLOOD ACIDIC!

WHY DOES BLOOD BECOMES ACIDIC WITH TOO MUCH CO2?

CO2 causes blood to become ACIDIC because:

CO2 (g) + H20 (l) H+ + HCO3-

Lots of CO2 indicates lots of cell respiration need for O2

Control centers in brain regulateCalled Medulla oblongata and pons

Maintain homeostasis by monitoring CO2 levelMain cue is pH change in blood

Gas Exchange and the Nervous System

What happens when you exercise? Start breathing faster Heart beats faster

Why? Your muscles cells are running out of oxygen, so the

heart and lungs have to work harder to deliver the necessary oxygen

The rate of respiration is controlled by automatic regulators in your brain stem (medulla and pons) Stimulates nerves in the diaphragm and ribcage to

breathe harder and faster

Gas Exchange Animation

http://highered.mheducation.com/sites/0072495855/student_view0/chapter25/animation__gas_exchange_during_respiration.html Complete the quiz questions 1-5 after we’ve watched the

animation.

https://www.youtube.com/watch?v=AJpur6XUiq4 https://www.youtube.com/watch?v=YUg-AVMh9Uc https://www.youtube.com/watch?v=hc1YtXc_84A

Health of Respiratory System

Diseases can interfere with gas exchange Pneumonia

Caused by virus or bacteria, Inflammation of alveoli

Weak and tired due to less oxygen exchange

BronchitisCaused by bacteria or virus (cold or flu),

Inflammation of bronchiCough to clear excess mucus

Health of Respiratory System

AsthmaMay be allergic, response to stress, etc.Narrowed breathing passages (bronchi)Treated with drugs that relax air passages

EmphysemaLung disorder usually caused by smokingAlveoli are destroyed and cells can’t get

enough oxygen

Cancer and emphysema