MYTUTOR SUBJECT ANSWERS

973 views

Explain the mechanism of breathing

Breathing consists of two phases called inhalation and exhalation.

Inhalation

In order for air to be drawn into the lungs during inhalation the volume of the thorax must increase. This is brought about due to the contraction of respiratory muscles. The diaphragm contracts and flattens and the intercostal muscles contract to pull the ribs up and out. The increased volume within the thoracic cavity lowers the pressure within the lungs with respect to the atmospheric pressure. Consequently, air is drawn into the lungs down a pressure gradient.

Exhalation

Inhalation is now complete and the next step is exhalation. The diaphragm relaxes and moves up and the relaxation of the intercostal muscles moves the ribs in and down. This has the effect of decreasing the volume within the thoracic cavity and increasing the pressure within the lungs with respect to atmospheric pressure. As a result, air moves out of the lungs down a pressure gradient.

Lauren M. Mentoring -Medical School Preparation- tutor, Uni Admission...

2 years ago

Answered by Lauren, an A Level Biology tutor with MyTutor


Still stuck? Get one-to-one help from a personally interviewed subject specialist

122 SUBJECT SPECIALISTS

£20 /hr

Runzhi C.

Degree: Medicine (Bachelors) - Imperial College London University

Subjects offered: Biology, Maths+ 3 more

Biology
Maths
Chemistry
-Personal Statements-
-Medical School Preparation-

“Hi there, I am a first year medical student at Imperial College London and I have lived in the UK all my life. I enjoy studying medicine because it encompasses both scientific knowledge and social aspects. I am relatively new to tutor...”

£20 /hr

Lucy W.

Degree: Conservation Biology and Ecology (Masters) - Exeter University

Subjects offered: Biology, Science+ 4 more

Biology
Science
Maths
History
Extended Project Qualification
Chemistry

“Hello! My name's Lucy, and I'm a first year student at Exeter university, studying for aMSci in Conservation Biology and Ecology. I've always had a love and fascination for the outdoors and the world around me, and as I learnt more t...”

£24 /hr

Hinsum W.

Degree: Medicine (Bachelors) - Edinburgh University

Subjects offered: Biology, Maths+ 3 more

Biology
Maths
Chemistry
-Personal Statements-
-Medical School Preparation-

“Hi, I'm a first year medic at Edinburgh. I've had 7 years' worth of experience teaching children Maths and English and have mentored lower school peers, so I'm bound to have an approach that will suit your learning style!”

About the author

Lauren M.

Currently unavailable: for new students

Degree: Veterinary Medicine (Bachelors) - Cambridge University

Subjects offered: Biology, Maths+ 3 more

Biology
Maths
Chemistry
.BMAT (BioMedical Admissions)
-Medical School Preparation-

“Hi, I'm Lauren, and I'm a second year veterinary student at Cambridge University. I tutor Maths and Science at GCSE and A-level and can also help with university applications.”

MyTutor guarantee

You may also like...

Other A Level Biology questions

What is the key difference between the rough endoplasmic reticulum (RER), and smooth endoplasmic reticulum (SER)?

What is Exocytosis?

What are the events in synaptic transmission?

What is a hormone?

View A Level Biology tutors

Cookies:

We use cookies to improve our service. By continuing to use this website, we'll assume that you're OK with this. Dismiss

mtw:mercury1:status:ok