Respiration Flashcards
What are the 2 types of respiration ?
Internal - Within the cell,
CO2 produced – Glycolysis Krebs Cycle
O2 consumed – Oxidative Phosphorylation.
External - Ventilation
Exchange and transport of gases around the body
What are the 2 types of respiration ?
Internal - Within the cell,
CO2 produced – Glycolysis Krebs Cycle
O2 consumed – Oxidative Phosphorylation.
External - Ventilation
Exchange and transport of gases around the body
What is the Conducting Zone ?
conducting zones provide pathways to get air to and from respiratory zone where gas exchange takes place
Conducting zone – transports gases into the respiratory zone, upper airways, trachea, mouth and throat.
It warms incoming air to body temp
Nose Nasopharynx (Mouth) Oropharynx Pharynx Larynx Trachea Bronchial Tree to respiratory bronchioles
Why do you not want cold air entering a warm blood supply ?
When u get to the exchange, don’t want cold gases entering a warm blood supply. Important to stop the lower airways drying out and becoming desiccated. By humidifying it u prevent desecration of the lower airways.
What is the structure of Bronchiol Wall ?
Reinforced with cartilage rings - helps prevent airways from collapsing
Smooth Muscle
Mucous glands - traps particles
Elastic
What is the structure of Bronchiol Wall ?
Reinforced with cartilage rings - helps prevent airways from collapsing
Smooth Muscle
Mucous glands - traps particles
Elastic
What does the Respiratory Epithelium consist of ?
Ciliated Epithelia
Goblet cells
Sensory Nerve Endings - helps direct smoke and CO in the airways
What happens if Bronchioles lack cartilage support ?
Lack cartilage support – more subject to collapsing, elastic surrounding tissue nature which keeps bronchioles open
What happens if Bronchioles lack cartilage support ?
Lack cartilage support – more subject to collapsing, elastic surrounding tissue nature which keeps bronchioles open
What are the main features of alveoli ?
Large surface area
Fed from terminal bronchiole
Thin walled provides huge area and small distance for diffusion
3 million alveoli in lungs
How is the air blood barrier formed ?
A ‘sandwich’ created by flattened cytoplasm of type I pnemuocyte and the capillary wall
How is the air blood barrier formed ?
A ‘sandwich’ created by flattened cytoplasm of type I pnemuocyte and the capillary wall
What happens during inspiration ?
During inspiration: Atmospheric pressure is greater than lung pressure so air moves into the lungs
Pressure in alveoli is less than atmospheric pressure so air moves down into the lungs.
What happens during expiration ?
During expiration: lung pressure is greater than atmospheric pressure so air moves out of the lungs
Pressure in alveoli is greater than atmospheric pressure so air moves down alveoli out of lungs.
How does air movement follow principles of Boyle’s Law ?
The increase in volume, leads to a reduction in pressure. Air moves into the lungs down the pressure gradient
What happens to the lungs and diaphragm during inspiration ?
Rib muscles contract during inspiration and moves down, lungs expand, pressure inside lungs is lower than atmospheric so air moves into lungs.
External Intercostal muscle is in between the ribs, when they contract it helps move the ribcage up and expand the thoracic body.
Increase in lung and thoracic volume and air moves in
What are Scalenes and what do they do ?
Scalene muscles in the neck that attach to top of ribcage. Contracting of these helps move the ribcage up and forward, helping with expansion of thoracic capacity.
What are Scalenes and what do they do ?
Scalene muscles in the neck that attach to top of ribcage. Contracting of these helps move the ribcage up and forward, helping with expansion of thoracic capacity.
How does Quiet Expiration work ?
Quiet expiration is a passive process using elastic recoil
There are no primary muscles of expiration.
Relaxation of external intercostal muscles
Recoil of the lungs (elastic forces returning lungs to original size)
Diaphragm relaxes
What is the Pleura and how does ?
Pleura cavity filled with secretions.
It prevents lungs from sticking to the chest wall.
Does this by allows the lung and chest wall to move over each other an expand together, prevents them sticking together
How do forces in lungs and chest balance ?
At rest these inward and outward forces balance – as a result the pressure in the intrapleural space is less than atmospheric pressure.
Forces in the chest wall are normally working in an outwards direction.
Elastic nature of lungs pull inwards, chest pushes outwards and interpleural space between them.
Very slight vacuum exits in that interpleural space, but its crucial for maintaining lung volume (negative pressure)
How do forces in lungs and chest balance ?
At rest these inward and outward forces balance – as a result the pressure in the intrapleural space is less than atmospheric pressure.
Forces in the chest wall are normally working in an outwards direction.
Elastic nature of lungs pull inwards, chest pushes outwards and interpleural space between them.
Very slight vacuum exits in that interpleural space, but its crucial for maintaining lung volume (negative pressure)
How can a Pneumothorax (collapsed lung) arise ?
Some kind of trama has created a breach in the chest wall, broken the pleural membrane on the chest side. Equilibrium at atmospheric pressure means you will lose the pressure and air inside the lungs and lungs will collapse. Could put a test tube in and evacuate air from the interpleural space, drive air out of this space, reestablish the partial vacuum.
What is Compliance ?
Measure of elasticity
The ease with which lungs and thorax expand during pressure changes
What is the difference between low and high compliance ?
low compliance - more work required to inspire
eg. pulmonary fibrosis – lung paranchyma is more rigid
high compliance - often also involves more difficulty expiring (loss of elastic recoil), breakdown of tissue
eg. emphysema
What are the 2 major components to the elastic recoil of the lungs ?
‘Anatomical’ component – elastic nature of cells and extracellular matrix.
Elastic recoil due to surface tension generated at air-fluid interface
What is Surfacant and what is it produced by ?
Surfactant produced by Type II pneumocytes. It is composed of a number of lipids and proteins
What problem is overcome with surfactant ?
The problem of smaller alveoli collapsing is overcome by the production of surfactant.
What does the presence of surfactant do for alveoli ?
Small alveoli will have a higher density of a surfactant compared to a larger alveoli, this balances out the surface tension between all alveoi and stops small alveoli collapsing.
How can we measure lung volume ?
Spirometer