Structure of the

Respiratory systemP6 M3

Respiratory System: • Intakes oxygen• Releases carbon dioxide

wasteCirculatory system:• Transports gases in blood

between lungs and cells

Respiratory system works with the Cardiovascular system…

Structure of the RESPIRATORY system (RS)

Task…

In order to gain a head start on the assessment you guys need to find a blank pictures of the various respiratory system structures and begin to label them:

nasal cavityepiglottispharynxlarynxtracheabronchusbronchioleslungs (lobes, pleural membrane, thoracic cavity, visceral pleura, pleural fluid, alveoli) diaphragmintercostal muscles (external and internal)

• If respiratory system and/or circulatory system fails, death will occur

• Cells need O2 for work; release CO2 as a waste product

• Accumulation of excess CO2 is toxic to cells and MUST be removed

The Importance of the RS

• Nasal cavity– Space above and behind the nose– Made of cartilage and bone– Divided into 2 by a cartilaginous septum– Hairs within the nostrils filter out dust etc

before air passes into two nasal cavities. – Designed to warm, moisten, and filter air

before it passes to the nasopharynx– A mucous layer

Respiratory Structures and Organs: Explained

• Pharynx – (throat)– Funnel shaped– Connects to larynx and oesophagus– Small muscular tube

– conducts food and air– exchanges air with Eustachian

tube to equalize pressure

• Larynx – (voice box) – Connects the pharynx and

the trachea. – Made of cartilage and

muscle– contains vocal cords– Helps us to speak

• Epiglottis― flap of cartilage that covers

trachea ― ensures food travels down the

esophagus

Respiratory Structures and Organs: Explained

larynx

trachea

bronchi

bronchioles

Respiratory Structures and Organs: Explained

• Trachea – (windpipe) – Tubular passageway (12

cm long 2 cm diameter) to carry air towards the lungs

– C-shaped cartilage rings to keep it open

– Divides at end into : Bronchi

Respiratory Structures and Organs: Explained

• Bronchi: – Pair of tubes that branch from trachea and enter lungs– Have cartilage plates to keep them open– Lining is ciliated & secretes mucus– By now air is warm, moist and free from most impurities

• Each bronchi divides into:– Lobar bronchi– Segmental bronchi– 23 branches in total– Tree

• Bronchioles – – tiny tubes extend from the bronchi– lacking cartilage and cilia– possess smooth muscle

bronchiole

smooth muscle

Respiratory Structures and Organs: Explained

– They about 1mm diameter

– Terminate in clusters of alveoli

Lungs– Two cone shaped organs suspended

in the pleural cavities– Surrounded by a pleural membrane– Made of elastic tissue– Divide into lobes– Right is larger as left has to

accommodate the heart• This space is known as the

cardiac notch

Respiratory Structures and Organs: Explained

• Lungs - lobes–Each lung is divided

into lobes. –The right lung has

three lobes–The left lung has only 2

lobes.

Respiratory Structures and Organs: Explained

• Pleural membrane– The lungs are surrounded by

membranes known as pleura– These contain a cavity with

fluid that lubricates the surfaces as the lungs expand and contract.

– Their main job is to prevent friction and keep the lungs airtight,

• Visceral Pleura– Is the innermost of the two

pleural membranes. It covers the surface of the lung

•Pleural Fluid– The pleural membrane produces pleural

fluid, which fills the space between the visceral and parietal pleura. This lubricating fluid allows the lungs to glide over one another easily.

• Thoracic Cavity– This is the full name for the

chamber of the chest that is protected by the thoracic wall. It is protected from the abdominal cavity by the diaphragm

Respiratory Structures and Organs: Explained

Alveoli • Around the bronchioles are 600 million alveoli in each lung.• Each one is in contact with a capillary• This is where exchange of O2 and CO2 takes place.

Alveoli • Cup shaped structures that resemble bunches of grapes

• covered with SURFACTANT that keep them from collapsing

• Provide a huge area for gas exchange

Respiratory Muscles

• Intercostal muscles– External intercostals

• Contract to pull the rib cage up when we breathe in

– Internal intercostals• Contract to pull the rib

cage down when we breathe out

– Attach between the ribs

• Diaphragm– Dome shaped muscle at the bottom of the ribcage– Breathing in - Contracts – flattens, making chest cavity larger and drawing air in.

Anatomy of the Respiratory system…

• Air enters through the Mouth & Nose.

• Passes through the Pharynx (back of throat).

• Passes through the Larynx (responsible for your voice production).

• Air passes over the Epiglottis (stops food going down our windpipe/trachea).

• Air enters the Trachea, membranous tube that delivers air to the lungs.

• Trachea divides into 2 Bronchi, one into each lung.

• 2 main Bronchi divide into Bronchioles, which further subdivide 23 times into 8 million bronchioles in each lung.

• Around the Bronchioles you will find groups of air sacs called Alveoli (600 million in each lung).

• Alveoli are the catalyst for gas exchange (O2 and CO2), as they are in contact with the capillaries.

Describe the (1) Structure with

all the parts named BELOW and (2) Function (1-4 BELOW) of the respiratory system.

2. Function: 1. Gaseous exchange2. Mechanisms of breathing (inspiration and expiration)3. Lung volumes: e.g. tidalvolume, vital capacity, residual volume 4. Control of breathing (neural and chemical)

1. Structure of the respiratory system: • Nasal cavity • Epiglottis• Pharynx• Larynx• Trachea• Bronchus• Bronchioles• Lungs (lobes, pleural membrane, thoracic cavity,

visceral pleura, pleural fluid, alveoli)• Diaphragm• Intercostal muscles (external and internal)

Examine the respiratory system

and explain how it works and how each part of the system is

designed to meet its function