The respiratory system Flashcards
Why do we breath?
to get oxygen into our bodies
Why is oxygen needed?
Oxygen is needed to obtain energy from food through the process called aerobic cellular respiration
Energy is released into the cell when glucose reacts oxygen to form carbon dioxide and water
Glucose reacts with oxygen to form what?
carbon dioxide and water
Energy is Stored in the cell in the form of
Adenosine Triphosphate (ATP)
Gas exchange occurs when..
oxygen diffuses into the body’s cells and carbon dioxide diffuses out of the cells
Gas exchange occurs at 2 locations:
1) The lungs: Oxygen diffuses from the air into the bloodstream. CO2 diffuses from the blood stream into the lungs and back into the air
2) The body’s cells: Oxygen diffuses from the blood into the cells and CO2 diffuses from the cells back into the blood stream
Ventilation(breathing)
Ventilation is the process of moving oxygen rich air into the lungs and carbon dioxide rich air out of the lungs
Our respiratory has 4 features that help it properly function..
- A thin permeable respiratory membrane through which diffusion can occur
- A large surface area for gas exchange
- A good supply of blood
- A breathing system for bringing oxygen rich air to the respiratory membrane
Nose
- Lined with hair to trap large dust particles
- Nasal passage also covered with mucus membranes which help warm and misidentified air as well as trap smaller dirt particles
- Ciliated cells line the nasal passages (whip like hairs to move the mucus to the throat (pharynx) to be swallowed
The mouth
-Slightly warms the air but it doesn’t add much moisture or filter out dirt and dust particles
The pharynx
Connects the nose to the mouth
The epiglottis
closes the trachea during swallowing but during breathing it stays open
The larynx
Contains thin membrane(vocal cords) that are stretched across the larynx. They vibrate to make sounds when you exhale
The trachea
-The “windpipe” which allows passage of air into the bronchi
-Contains cartilage rings to prevent collapse
-Walls have mucus producing cells and cilia(small hair like structures) which protect the lung from foreign matter
-Divides into 2 bronchi
The bronchi
-Passage of air into lungs
-Branch into smaller bronchioles
The bronchioles
pass air into the alveoli
The alveoli
-Site of gas exchange
-Moist sac that expand like a balloon when we inhale
-Membranes are one cell thick and surrounded by capillaries for efficient diffusion of O2 and CO2
-Lined with lipoprotein based lubricating film to prevent collapse
Breathing
-The mechanism by which animals ventilate their lungs
- Accomplished by 2 muscular structures: intercostal muscle and diaphragm
- Based on principle that air flows from region of high pressure to region of low pressure
Intercostal muscles
-Muscles of the rib cage that work to expand and contract the rib cage
Diaphragm
-Muscle layer that separates region of the lungs from the region of the stomach and liver
-World to expand and contract chest cavity
Composition of Inhaled and Exhaled air
- [O2] in inhaled air > [O2] in blood
-[CO2] in blood > [CO2] in inhaled air
-O2 diffuses across capillary wall from air to blood
-CO2 diffuses across alveoli from blood to air
Inhalation
-Intercostal muscles contract: expand rib cage
-Diaphragm contracts and moves down in chest cavity
-Lungs expand outward
-Volume of chest cavity increases
-Air pressure decreases in cavity
-Air pressure in lung is less than external environment
-Air enters lung
Exhalation
-Intercostal muscles relax
-Diaphragm relaxes and moves up in the chest cavity
-Lungs move inward
-Volume of chest cavity decreases
- Air pressure increases in cavity
-Air pressure in lung is more then external environment
-Air is expelled from lungs
