Respiratory System

Do Now A student eats a sandwich for lunch: digested starch  bloodstream  cell  cell organelle  ATP Identify the molecules used to digest starch. Identify the molecules produced when starch is digested. Explain why starch must be digested before it can enter the bloodstream. Identify the structure in the cell that will produce ATP from the starch building blocks. State why ATP is important to cells.

How does the Respiratory System help maintain homeostasis? Take in oxygen (O2) for cellular respiration. This allows ATP to be produced and available for life functions. Excrete carbon dioxide (CO2) as a waste product.

Respiratory system consists of two lungs & a system of tubes that carry air from the external environment to internal membranes (alveoli) for gas exchange. Predict the path air takes to completely enter the lungs

The Path Air Takes WHY Air enters through the nasal cavity: Nose is adapted for warming, moistening and filtering the air Blood vessels warm cold air Mucous adds moisture to dry air Mucous also traps dust and pathogens (sneezed out or swallowed)

The Path Air Takes Air passes from your nose to the pharynx , past the larynx (voice box) and into the trachea (windpipe). The trachea (windpipe) forks to form two bronchi Each bronchi branches into many bronchioles (smaller tubes) The bronchioles end in clusters of tiny sacs called Alveoli (air sacs)

Nose  Pharynx  Larynx  Trachea  Bronchi  bronchioles  Alveoli

How do we get air to enter our lungs? The action of your diaphragm and surrounding muscles between your ribs enable you to breath in and out. Breathing – the alternation of inhaling and exhaling Is your diaphragm a muscle?

How do we inhale and exhale? Diaphragm contracts and moves downward Muscles between the ribs move the rib cage up and outward Exhale: Diaphragm relaxes and moves up Muscles between the ribs relax

Do Now What is the name of the tube that air uses to travel to the lungs? What is the name of the tube that food uses to travel to the stomach? How does air enter our bodies? Why must we inhale Oxygen? Why does our body produce Carbon Dioxide?

Inhaled Air *Air breathed in has: Lots of O2 Little CO2 Final destination of inhaled air are the Alveoli sacs in lungs. Alveoli are thin-walled sacs in the lungs surrounded by a network of capillaries Capillaries are very thin blood vessels *Air breathed in has: Lots of O2 Little CO2

Gas Exchange in Alveoli Inhale Oxygen diffuses from alveoli into capillaries (blood) O2 is absorbed Alveoli Exhale Carbon Dioxide diffuses from capillaries (blood) into alveoli CO2 is excreted Gases move by diffusion from high to low concentration

Diffusion of Gases Capillaries in LUNGS Capillaries in MUSCLE High O2 Low O2 High O2 Low O2 Why? Low CO2 High CO2 Low CO2 High CO2 Blood Blood Body / Muscles Lungs

Gas Exchange Summary Blood going towards lungs from the heart ______ in Oxygen ______ in Carbon Dioxide Blood going away from lungs towards the heart ______ in Oxygen ______ in Carbon Dioxide Blood is pumped from the heart to the lungs… why? Blood goes from the lungs back to the heart… why?

What gas do the alveoli pass into the capillaries? oxygen What gas do the capillaries pass into the alveoli? Carbon dioxide

Do Now Organ systems of the human body interact to maintain a balanced internal environment. As blood flows through certain organs of the body, the composition of the blood changes because of interactions with those organs. State one change in the composition of the blood as it flows through the respiratory system.

Control of Respiration Breathing is usually an involuntary process Partially controlled by an internal feedback mechanism This involves signals being sent to the brain about the chemistry of your blood

Feedback Mechanism ___ CO2 = ____ pH (acid) = _____ Breathing rate Carbon dioxide dissolves in blood increasing acidity (low pH) Signal sent rib muscles & diaphragm to contract Person inhales to excrete CO2 and absorb O2

Breathing and Homeostasis Keeping the internal environment of the body balanced Need to absorb oxygen and excrete carbon dioxide Need to balance energy (ATP) production What happens to your breathing when you run?

Exercise and Respiration When you exercise (run, jump…dance) you breathe faster WHY do you breathe faster? Breathe faster: Need – Bring in – Excrete – More ATP / Energy More Oxygen Excess Carbon Dioxide

How does the Respiratory system help maintain homeostasis?

Failure of Homeostasis Asthma – is a severe allergic reaction in which the constriction of the bronchioles make breathing difficult

Bronchitis – is an inflammation of the linings of the bronchial tubes Bronchitis – is an inflammation of the linings of the bronchial tubes. The air passages become swollen and clogged with mucus causing coughing and difficulty breathing

Emphysema – is a lung disorder in which the walls of the air sacs break down and there is less respiratory surface of the lungs. Often caused by smoking A failure in the respiratory system leads to an imbalance in energy production