Lecture 4 - Respiratory System Flashcards
1
Q
Respiration System Functions
A
- Gas exchange O2 and CO2
- Warming and moistening air
- Removal of inhaled particles
- Voice production and olfaction
2
Q
Name the components/path of the respiratory system
A
- Nose
- Paranasal sinuses
- Pharynx (throat)
- Larynx (voice box)
- Trachea (windpipe)
- Bronchi (left and right)
- Bronchioles
- Alveoli (air sacs - where gas exchange takes place)
3
Q
3 types of respiration
A
- External - blood and lungs (air) - ventilation (breathing)
- Internal - exchange of gases between blood and cells
- Cellular - metabolic process - energy (ATP) is obtained by metabolising carbohydrates, fats and proteins
4
Q
Mechanism by which particles in mucous are moved by cilia up the oesophagus where it can be coughed up or swallowed
A
Mucociliary Escalator
5
Q
Nasal cavity functions
A
- Filter
- Warm
- Moisten
- Sneezing reflex
- Olfaction
6
Q
Paranasal sinuses - function
A
- Resonance in speech
- Lighten cranial mass
- Tears drain from eyes via nasolacrimal ducts
- Moisten air
7
Q
3 parts of pharynx
A
- Nasopharynx
- Oropharynx
- Laryngopharynx - contains eustachian tubes - equalise pressure
8
Q
Pharynx - functions
A
- Tube for swallowing food
- Warm and moisten air
- Taste
- Hearing
- Equalisation of pressure
- Immune protection - tonsils
- Speech - resonating chamber
9
Q
Larynx contains
A
- 9 pieces of cartilage
- Vocal chords
- Relaxed muscles - low tone
- Contract muscles - high tone
10
Q
Larynx - functions
A
- Sound and speech
- Protection - epiglottis (prevents food entering lungs)
- Air passageway
- Warm and moisten
11
Q
Trachea
A
- Windpipe
- 12cm long C-shaped rings of hyaline cartilage
- Smooth muscle
- Sympathetic - dialtion
- Parasympathetic contraction
12
Q
Trachea - functions
A
- Air flow
- Mucociliary escalator
- Cough reflex
- Warm, moisten, filter
13
Q
Coughing reflex
A
- Irritation of mucous membrane
- Nerve impulse sent from vagus nerve to respiratory centre in brain
- Deep inhalation
- Glottis closed off
- Respiratory muscles increase pressure
- Forced removal of irritant
14
Q
What is the substance made from lipids and proteins that forms a surface film in alveoli?
What is its purpose?
A
Pulmonary surfactant
Reduces surface tension, preventing alveoli from collapsing
15
Q
Pleura
A
- Serous membranes that surround the lungs
- Visceral and parietal layers separated by serous fluid to prevent friction
16
Q
Bronchi
A
- Trachea divides into left and right bronchi at T5
- Deliver air into lungs
- Lined with ciliated epithelium
- Right bronchus - shorter, more vertical - aspirated object more likely here
- Carina - ridge where bronchi branch into two - most sensitive part for cough reflex
17
Q
How does structure of alveoli facilitate gas exchange?
A
- Large surface area
- Walls very thin
- Moist (gases exchange more easily when in water)
18
Q
Gas Exchange
A
- Oxygen and carbon monoxide exchanged between blood and air
- Oxygen moves from alveoli into blood ⇢ oxygenated blood
- Carbon dioxide moves from blood to alveoli ⇢ exhaled
- Movement occurs via diffusion
19
Q
2 primary muscles of ventilation
A
- Intercostal muscles
- Diaphragm
(Secondary muscles - neck and chest - can be over-recruited
20
Q
Inhalation & Exhalation activity
A
Inhalation - active - requires muscles
Exhalation - passive - muscles rela
21
Q
What does oxygen bind to in the blood?
A
Haemoglobin (Hb)
Iron is the pigment which makes blood red
22
Q
Where is carbon dioxide carried in the body?
A
- 70% found in plasma as HCO3 - bicarbonate (buffer)
- 23% in RBCs (bound to haemaglobin)
- 7% dissolved in plasma (water component of blood)
23
Q
Bicarbonate buffer reaction
A
CO2 + H20 ⇠⇢ H2CO3 ⇠⇢ HCO3 + H+
- CO2 diffuses down concentration gradient from tissue to blood
- High water content of blood ⇢ CO2 combines with water to produce carbonic acid H2CO3
- Carbonic acid is unstable - decomposes into bicarbonate and H+
- Hydrogen is exhaled and excreted into urine to reduce acidity
- Also, the bicarbonate formed is alkaline which ‘buffers’ the acidity of blood to keep pH stable
24
Q
Respiratory Acidosis
A
Elevated CO2 in blood ⇡ H+ ions - increase in acidity
25
How to regulate blood pH - manage increase in acidity in blood
1. Buffer systems (bicarbonate)
2. Increased exhalation of CO2 (exercise)
3. Kidney excretion of H+
26
Cell Respiration
* Glucose metabolised for ATP production
* Fats and proteins also used
* Aerobic respiration (with oxygen) - 38 net ATP + water + CO2
* Anaerobic respiration (no oxyten) - 2 ATP + lactic acid
27
Investigations - respiratory problems
* Medical
* Blood test (inflammatory markets, WBCs)
* Biochemistry tests
* Stuptum analysis
* Imaging (x-ray, MRI)
* Physical
* Percussion (tapping chest)
* Ausculation (using stethescope)
28
Rhinitis
* Inflammation of nasal mucosa ⇡ volume and viscosity of mucus
* Causes
* Immune compromise leading to viral/bacterial infections
* Allergies
* Pollution, diet, drugs NSAIDS, stress
* Complications
* Nasal polyps
* Ear infections
* Loss of smell
29
Influenza
* Acute respiratory disease, flu virus
* Systemic symptoms
* Sudden onset, fever, malaise, muscle pain, rhinitis, sore throat
* Complications
* Secondary infections
* Post-viral syndrome (chronic fatigue syndrome)
* Morbidity / mortality
30
Sinisitis
* Inflammation of membrane lining the sinuses
* Acute or chronic (\> 3months)
* Symptoms - sinus pain, congestion, headaches, fever
31
Nasal polyps
* Soft, benign masses of nasal mucosa
* Cause - end product of chronic inflammation - viral, bacterial, fungal
* Pathophysiology -
* chromic inflammation ⇢
* blood vessels in nasal lining to become more permeable ⇢
* water accumulates in cells
* Gravity pulls down on waterlogged tissues
* Polyps
* Signs - difficulty breathing, runny nose, stuffiness, sinus infections, dull headaches, snoring, sleep apnoea
32
Tonsillitis
* Inflammation of tonsils (lymphoid tissue - immune system)
* Viral or bacterial (streptococci)
* Short incubation period
* Sore throat, worse when swallowing, Fever, coughing, headache, red/inflamed tonsils
* Complications - middle ear infection, quinsy
33
Pharyngitis
* Acute inflammation of mucous membrane of pharynx
34
Laryngitis
* Inflammation of larynx
* Acute - viral, bacterial
* Chronic - overuse (strain, irritants, smoke/fumes, acid reflux)
* Signs - hoarseness, weak voice, voice loss, dry/tickly throat, dry cough
35
Atopic triad
* Hayfever
* Asthma
* Eczema
36
Pneumonia
* Infection of alveoli and terminal bronchioles, mostly bacterial
* Infiltration of neutrophils (type of WBC)
* Signs/symptoms - could, purulent (green/yellow sputum) which may be blood-stained
* Breathless, fever, tachypnoea, crepitations on auscultation
37
Pulmonary fibrosis
* Gradual replacement of the epithelial cell lining in alveoli with fibrotic tissue
* Fibrotic (scar tissue) less able to exchange oxygen and CO2
* Cause
* Idiopathic (unknown, genetic)
* Smoking, asbestos, some drugs, radiation therapy
* Signs/Symptoms - progressive dyspnoea, chronic cough, fatigue, discomfort i chest, loss of appetite, weight loss
38
Obstructive Sleep Apnoea
* Intermittent and repeated upper airway collapse during sleep leading to interrupted breathing
* Causes - obesity, male, middle-aged, smokers, alcohol, sedatives, polyps
* Signs - loud snoring, daytime sleepiness, morning drowsiness, nocturnal choking
* CPAP (continuous positive airway pressure)
39
Pneumothorax
* Air accumulation within the pleural cavity, causing part of all of lung to collapse
* Air enters in defect in pleura (i.e. rib fracture)
* Causes - spontaneous (cystic fibrosis, emphysema) or traumatic (fracture, surgical complication)
* Symptoms - Dyspnoea, sharp chest pain, cyanosis, loss of consciousness, coma
* Signs - Reduced breath sounds, decreased cardiac output
40
Pleurisy
* Pleural inflammation
* Causes - tumour or infection
* Signs/Symptoms - dyspnoea, sharp chest pain while breathing, aggravated by coughing sneezing moving around, dry cough, may be relieved with shallow breathing
41
Pulmonary Embolism
* Obstruction within pulmonary arterial tree
* Embolus (mobile clot) resulting from thrombosis travelling from one of the deep veins in leg (DVT)
* Fat embolism following fracture
* Symptoms - dyspnoea, pleuritic chest pain, cough, coughing blood, calf pain (if DVT)
* Signs - tachypnoea, tachycardia, chest crackles
42
Cystic Fibrosis
* Multi-organ genetic disease that affects chloride channels and exocrine glands
* Chloride channels help maintain balance of salt and water within a cell. Genetic mutation causes dysfunction.
* Mucous - thick and clog up lungs and some digestive organs
* Chronic respiratory infections and pancreatic enzyme insufficiency
* Lung disease - principal cause of death
* Respiratory symptoms - persistent cough, sputum, recurring lunch infections, wheezing
* GIT symptoms - bloating, obstruction, bleeding, malnutrition
