Module 1.05 Flashcards
name the laryngeal cartilleges
- thyroid
- cricoid
- epiglottis
- arteynoid x2
- corniculate x2
- cuneform x2
what makes up waldeyers ring?
- pharyngeal tonsils
- palatine tonsils
- lingunal tonsils
At what spinal level is the tip of the epiglottis?
C5
At what spinal level is the inferior border of the cricoid cartillege?
C6
what is the upper respiratory tract made up of?
- nasal cavity
- pharynx
- larynx
How does the counter current exchange system prevent excessive heat loss from the body core?
- nasal membranes moisten and humidify the entering air, can heat inspired air from 6°C to 30°C
- inhaled air is then fully humidified to body temp as it passes through the trachea
- Expired air is always slightly below body temp as it gives up heat when it leaves the nasal passages
what are the characteristics of the pharynx?
- divided by soft palette into nasopharynx and oropharynx
- contains lymphoid structures such as adenoids and tonsils
At what vertebral level does the trachea begin?
C6
lower border of cricoid cartilege
what are the lobes of the right and left lung?
- The right lung is divided into three lobes: upper, middle and lower
- The left lung has only two lobes: upper and lower
what fissures are found on the lungs?
left lung: oblique fissure seperates the upper and lower lobe
right lung: horizontal fissure splits upper and middle lobe, oblique fissure seperates middle and lower lobes
hoe does the trachea divide? (the tracheobronchial tree)
trachea -> 2 main bronchi -> 4 lobar bronchi -> 16 segmental bronchi -> bronchioles -> terminal bronchioles -> respiratory bonchioles -> alveoli
describe the arrangment of muscle in tracheobronchioles tree?
. The bronchial smooth muscle is arranged in clockwise and anticlockwise helical bands and there is a matrix of elastic tissue supporting the muscles.
describe the epithelium from the nasal cavity to the bronchioles?
cilliated columnar epithelial cells
what happens to foreign particles which are unable to be expelled by the cillia?
- macrophages in the lower respiratory tract
- estimates to be 16 macrophages per alveolus in the human lung
- macrophages immobilise and destroy bacteria and carry out phagocytosis
describe the role of goblet cells in the respiratory tract and where are they found?
- Goblet cells are found predominately in the epithelium from the nose to the bronchi (columnar tapering towards the base)
- function is the secretion of mucus
- Along with the cilia, mucus is part of the airway’s defence. Inhaled particles, macrophages, cell debris and bacteria are trapped in the sticky mucus to be swept away on the mucociliary escalator .
what are clara cells?
- Clara cells are found mainly in the distal conducting airways, the terminal bronchioles and alveolar ducts
- non ciliated cells, have short microvilli
- granules which store Clara cell secretory protein (CCSP) and a solution similar to lung sufactant
what are the functions of clara cells?
- control of inflammatory processes
- Assist in the mucociliary clearance of environmental particles
describe type 1 alveolar cells (aka type 1 pneumocytes)
- large, flat, squamous cells with few organelles and thin cytoplasm
- cover majority of alveolar surface
- Their primary purpose is air–blood gas exchange
- narrow junctions between cells (prevents fluid entering alveolus)
describe type 2 alveolar cells (aka type 2 pneumocytes)
- domed cuboidal cells in the alveolar epithelium
- containing lamellar bodies that secrete surfactant
- Surfactant is continuously synthesised and secreted by type II alveolar cells
- covers only a small portion of alveoli but surfacant forms a thin film which covers the whole alveolar surface
what is the function of surfactant?
- reduces alveolar surface tension
- Prevent the basically spherical alveoli from collapsing during expiration as they have water-soluble and oil-soluble components
- Decrease the effort needed to expand the alveoli at the next inspiration (increase pulmonary compliance )
How is the pons and medulla oblangata involed in controlling respiration?
- In medulla oblangata there is the medullary respiratory centre which is split into ventral and dorsal groups: ventral group controls the rythmcity of breathing
- in the pons the pontine respiratory centre communicates with the medullary centre to smooth respiration
what factors can influence respiratory rate?
- peripheral chemoreceptors
- voluntary control
- pain
- emotion
- temprature
Where are peripheral chemorecptors found?
- carotid and aortic bodies
what is the function of chemorecetors?
- chemorecpetors detect a change in the blood
- lower oxygen, lower pH (increased H+) and increased CO2, causes chemoreceptors to send signals to stimulate the respiratory centre and increase respiration rate
- allowing you to breathe in more oxygen and breathe out more CO2
Where are central chemoreceptors found?
Medulla
what receptors are found in the lungs and what are their effect on respiration rate?
- irritant receptors, when stimulated they slow down respiration (supress respiratory centre)
- stretch receptors, hering- brever reflex, protective against over inflation of lungs and slows down respiration rate
What nerves innervate the diaphragm?
phrenic nerve which is formed in the neck within the cervical plexus and contains fibres from spinal roots C3,C4,C5.
How do glomus type 1 cells work?
- peripheral chemoreceptors
- a decrease in oxygen or an increase in CO2 causes the cell to become depolarised and an action potential is fired to the respiratory centre to increase respiration