respiration Flashcards
what is respiration
interchange of gases (oxygen and carbon dioxide) between air and blood in the lungs
what is ventilation
inhalation and exhalation of air into and out of the lungs through the respiratory tract
in what two ways is the respiratory tract divided into
- functionally
- clinically
functionally ; what is the conducting portion
- it is the tubes that lead from the mouth and nose to the lungs - allows air to move down and allow gas exchange to occur
conducting portion - how to control w pressure changes
- during inhalation and exhalation pressure changes occur in the tubes
- trachea is held open with rings of cartilage and to prevent their collapse and blockage of the airway the tubes are reinforced with bone
- which is lined with respiratory mucosa
what is respiratory mucosa made up of
- made up of one layer of columnar cells with cilia on their luminal surface
- with secretory (goblet) cells are distributed and secrete mucus on the surface
purpose of mucus from nose to respiratory bronchioles
- traps inhaled particles that may be harmful to the lower respiratory tracts
- the cilia move the material up or backwards into the pharynx - can then be swallowed or spat out
how many respiratory tracts are there and the names
2
- upper respiratory tract
- lower respiratory tract
what makes up the upper respiratory tract
- nose
- mouth
- pharynx
- larynx
what makes up the lower respiratory tract
- trachea
- bronchi
- bronchioles
purpose of nose
- as air is filtered through the nose hairs and as it passes through the nose air twists
- air hits the walls of your nose allowing particles to be trapped
- cilia cleans the air
- air is warmed by blood vessels
- and humidified as it is breathed in
purpose of mucus being sticky
- can trap particles
what is the airway designed to do
- trap dust, dirt and potential pathogens
structure and role of pharynx
- muscular tube and shared by the respiratory and gastrointestinal tracts
- food a drink exit the pharynx to the oesophagus
- air exits into the larynx
what is the larynx
- larynx is a tube reinforced with cartilage that move relative to each other and contain vocal folds
purpose of vocal folds
- protect lower airway from food ingestion during swallowing
- generate sound for speech
how many lobes does each side of the lungs have
- right lung has three lobes
- left lung has two lobes
what are the bronchioles
small tubes without cartilage. the smooth muscle regulates air flow into the alveoli
name the three parts of the bronchi
- main bronchi
- lobar bronchi
- segmental bronchi
how many different cell types in the lungs
- 40 different cell types
properties of ciliated cells
- around 300 cilia per cell
- moves mucus at 2cm per minutes
- beats in one direction
- if you have a respiratory infection leads to loss of cell activity
- microvilli helps increase SA of cells
properties of mucous goblet cells
- secrete mucus that traps particulate matter
- very little microvilli
properties of brush cell
columnar epithelial cells with blunt microvilli on surface
properties of basal short cell
- replace damaged cells (acts similar to stem cells)
- located at base of epithelium and do not reach lumen
properties of small granule cells
- contains granules at base of cells
- thought to have neuroendocrine function
properties of clara cells/club cells
- secrete lypoprotein - surface active agent similar to mucus but with different structure
- progenitor cell acts as a basal type cell
- xenobiotic metabolism - removing harmful things out the system
what are the two types of cells involved in gas exchange
- type 1 cells (pneumocytes)
- type 11 cells
what occurs in type 1 cells and structure
- where gas exchange takes place
- v thin epithelial cells
- covers 95% of gas exchange surface
- organelles near nucleus
what do type 11 cells do and where are they found
- replace damaged type 1 cells
- found in corner of alveoli
- produce a surface active agent
- acts as a progenitor and xenobiotic metabolism
- covers 5% of gas exchange surface
3 structures of the lungs
- alveolar sac are tiny air sacs
- alveolar walls are v thin allowing rapid diffusion of oxygen from air to blood and carbon dioxide from blood to air
- they are formed by pneumocytes and blood capillaries
what does smoking do to the alveoli
- breaks down alveoli
- sa for gas exchange is reduced
- bigger holes in lungs breaking down lung tissue
what does cystic fibrosis affect and how do you get CF
- need to have 2 defective genes inherited
- affects pancreas and respiratory cells
- affects fertility
what are the lungs separated from the thoracic wall by
the pleura
name the two types of pleura
what is the space called between the two layers
- parietal pleura (line thoracic cavity - outer layer)
- visceral pleura (cover the lungs - inner layer)
- pleural cavity
what does the pleura fluid
- lubricant so that the two layers can slide over each other during ventilation
- acts as an adhesive agent sticking the two layers together
- when the parietal pleura moves with the thoracic wall , the visceral pleura and therefore lungs follow the movement
the thoracic wall is formed by what 4 things
- ribs and sternum
- intercostal muscles
- diaphragm
- accessory muscles
what are the two layers on intercostal muscles
- internal
- and external intercostal muscles
what is the diaphragm and what does it separate and what is attached to
- thin muscular sheet
- separates the thorax from the abdomen
- attached to ; lower ribs, tip of sternum, vertebral column
inspiration
- size of chest cavity is increased by the intercostal muscles
- diaphragm contracts and flattens
- chest volume increases and pressure reduced so air is drawn in
forced ventilation
- homeostatic mechanism to restore body to normal state
- when body needs more oxygen eg after exercise, emotional response
what muscles does forced inspiration use
- intercostal muscles and diaphragm to their max
- accessory muscles may be used
- total lung volume depends on age, sex, fitness
forced expiration what muscles are requires
- intercostal muscles relax
- lungs deflate to normal position
