Download Unit 11 Assignment 1

Name: Lilian Zhang
Date: Nov 25, 2016
Biology 12 Unit 11 Assignment 1: Respiratory System Virtual Lab
Instructions:
Please complete the Respiratory System Virtual Lab.
External Link:
http://www.glencoe.com/sites/common_assets/science/virtual_labs/LS24/LS24.html
Read the information and procedures provided in the lab and complete the journal questions
(provided below). Please note you should be answering your questions in detail, by providing
support in the form of data values (external or from the lab) and/or scientific
information/research to explain your statements.
Journal Questions:
1. How does the diaphragm work to change air pressure in the lungs, and as a result, cause
breathing?
-- When the carbon dioxide and hydrogen ions concentration reach certain level, the
breating centre, medulla oblongata in the brain will send an nerve impulse to the rib cage
and diaphragm, to stimulate the intercostal muscles contract to expand the thoracic cavity,
and the diaphragm stretch to be flat and move downward. The volume of the lungs
increase, and the pressure in the lungs decrease, the pressre is much lower than external
pressure, it suck the air rush into the lungs to rebalance the pressure,and cause breathing.
Reference:
Michanics of Breathing. Retrieved from:
http://www.teachpe.com/anatomy/breathing.php
2. List the structures of the respiratory system in the order that they function for inhalation.
Describe each structure’s function in detail.
Diaphragm: The diaphragm is a large sheet of muscle, seperation of the thoracic cavity
and abdormal cavity. When the diaphragm became flat, and go downward, the pressure in
the lungs decrease, is much lower than the external pressure, so it suck the air rush into
the lungs, to rebalance the pressure. When the diaphragm relaxes into its dome-shaped
position during exhalation, pressure in the chest cavity increases, forcing air out.
Nosal Cavity: The passageway of the air flow, the hair in the nosal cavity lines with
sticky mucous membrane, can capture the particles, such as polen, dust, cleasing the air.
Pharynx: At the back of the throat, the common passageway of the air and the food.
When the debris is detected by the pharynx, cause caughing to get rid of the debris or
swallow it to the esphogus.
Larynx: The voice box, produce the sound when air pass through, at the junction of the
air and the food passageway.
Trachea: The air passgeway, carries air to the lungs, covered with epiglottis. It lined with
cilia and sticky mucous membrane, can capture unwanted foreign particles, and propell
them upward to the pharynx, and caugh them out or swallow to the esphogus.
Lungs: located at thoracic cavity, surrounded with rib cage. The place gases exchange,
provide oxygenated blood for the entire body.
3. While you were investigating the inhalation sequence, did you change the order of any of
he steps you initially selected? If so, which steps did you rearrange, and why?
-- I don’t think should change the order of any of the steps I initially selected, because
that is the sequence when inhalation happens. The breathing center medulla oblongata
send an impulse to the rib cage and the diphragm, cause the contraction, to decrease the
air pressure in the lungs, and the air in the outside was sucked into the lungs, and the air
pass the nosal cavity, pharynx, larynx, trachea and lungs.
4. Which structures of the respiratory system trap and eliminate harmful substances from
the air, such as dust, smoke, pollen, and bacteria? Describe how these structures filter air
as it is inhaled.
--First the nosal cavity, it has hair, lined with sticky mucous membrance, to filter the air.
--Then are trachea and bronchial, they have cilia and lined with the sticky mucous
membrane, can capture unwanted dust, smoke, pollen and etc. The cilia propel the
unwanted particles upward to the pharynx, once the particles are detected by pharynx,
they will be cough out or swallow down to the stomach.
Image of your Lab:
Please either complete the following image (label the respiratory steps from #1-6) or include your
own completed screenshot of your virtual lab.