1
Q
Functions of the respiratory system
A
- Gas exchange – intake of O2 for delivery to body cells and removal of CO2 produced by body cells
- Contains receptors for the sense of smell, filters inspired air, produces sound, and excretes small amounts of water and heat
- Helps regulate blood pH
2
Q
Organization of the respiratory system
A
Structurally
1. Upper respiratory tract
2. Lower respiratory tract
Functionally
1. Conduction zone
2. Respiratory zone
3
Q
Pharynx
A
- Nasopharynx
- Oropharynx
- Laryngopharynx
4
Q
Larynx
A
- Short tube of cartilage
- Connects pharynx to the trachea
- Epiglottis prevents food and liquid from entering the larynx
- Vocal folds produce sounds during speaking and singing
5
Q
Structures of voice production
A
- A column of air pressure is moved towards the vocal folds
- Air is moved out of the lungs and towards the vocal folds by coordinated action of the diaphragm, abdominal muscles, chest muscles, and rib cage
- Vocal fold vibration
6
Q
Epiglottis
A
- Elastic cartilage
- Extends from back of tongue to top of thyroid cartilage
- Open when breathing
- Swallowing epiglottis tips to keep food out
7
Q
Trachea
A
- Tubular passageway for air
- Bifurcates at the carina
- Supported by C-shaped cartilage
- Mucous membrane composed of ciliated columnar epithelium
8
Q
Respiratory zone
A
- Where gas exchange occurs
9
Q
Alveoli
A
- Type I alveolar cells – simple squamous – main site of gas exchange
- Type II alveolar cells – secrete alveolar fluid – keeps cells moist, contains surfactant (reduces surface tension)
- Alveolar macrophage – remove dust and other debris
- Around the alveoli, the pulmonary arteries and veins form lush networks of blood capillaries
10
Q
The structure of the respiratory epithelium at different sites within the respiratory tract
A
- A respiratory mucosa, with mucous cells and the mucus escalator, lines the nasal cavity and the superior portion of the pharynx
- A stratified squamous epithelium lines the inferior portions of the pharynx, protecting the epithelium from abrasion and chemical attack
- A typical respiratory mucosa lines the conducting portion of the lower respiratory tract
- In the finer bronchioles, the epithelium becomes cuboidal
- The gas exchange surfaces consist of a delicate simple squamous epithelium. Here the distance between the air and the blood in adjacent capillaries is generally less than 1 um
11
Q
Blood supply
A
- Pulmonary vessels unique
- Arteries = deoxygenated
- Veins = oxygenated
12
Q
Pulmonary ventilation
A
Pulmonary ventilation → the flow of air between the atmosphere and lungs, which occurs due to differences in air pressure
13
Q
Boyles law
A
- At a constant the amount of pressure exerted by a given mass of gas is inversely proportional to the size of its container
14
Q
Inspiration
A
- Inspiratory muscles contract
- Thoracic cavity volume increases
- Lungs are stretched, and intrapulmonary volume increases
- Intrapulmonary pressure drops
- Air flows into the lungs
15
Q
Expiration
A
- Inspiratory muscles relax
- Thoracic cavity volume decreases
- Lung’s recoil, intrapulmonary volume decreases
- Intrapulmonary pressure rises
- Air flows out of lungs
16
Q
Daltan’s law
A
- Each gas in a mixture of gases exerts its own pressure as if no other gases were present
- P total = P gas 1 + P gas 2 + P gas 3
17
Q
Henry’s law
A
- The quantity of a gas that will dissolve in a liquid is proportional to the partial pressure of the gas and its solubility coefficient when the temperature remains constant
- When a mixture of gases is in contact with a liquid, each gas will dissolve in the liquid in proportion to its partial pressure
18
Q
Partial pressure
A
- The pressure exerted by an individual gas in a mixture is its partial pressure
- A gas will diffuse from an area where its partial pressure is high to an area where its partial pressure is low
19
Q
External respiration
A
- Diffusion of oxygen from the alveoli into pulmonary capillaries and the diffusion of carbon dioxide in the opposite direction
- Diffusion occurs because gas molecules move from areas of high concentration (pressure) to low concentration (pressure)
- O2 diffuses from alveolar air, where Po2 is 105mm Hg, into the blood in pulmonary capillaries, where Po2 is about 40mm Hg
- CO2 diffuses from the blood in the pulmonary capillaries, where Pco2 is 45mm Hg, into the alveolar air, where Pco2 is about 40mm Hg
20
Q
Internal respiration
A
- Diffusion of oxygen from systemic capillaries into the tissue cells, and the diffusion of carbon dioxide in the opposite direction
- Diffusion occurs because gas molecules move from areas of high concentration (pressure) to low concentration (pressure)
- Cells are continually using O2 and producing CO2
- O2 levels within tissues are always lower than within blood
- CO2 level within tissues are always higher than within blood
21
Q
The components of external respiration include
A
- Alveolar surface area
- Ventilation and perfusion matching
- Partial pressure gradients
22
Q
Oxygen transport
A
- Dissolved in blood plasma (1.5%)
- Bound to hemoglobin (98.5%)
23
Q
Carbon dioxide transport
A
- Dissolved in blood plasma (7%)
- Bound to hemoglobin (23%)
- Transported as bicarbonate (70%)
24
Q
Control of breathing
A
- The size of the thoracic cavity is altered by the action of the inspiratory muscles
- These muscles contract as a result of nerve impulses from the brain stem (respiratory center)
- Central chemoreceptors (medulla oblongata) respond to changes in PCO2 and/or h+
- Peripheral chemoreceptors (aorta and carotid arteries) respond to changes in PO2, PCO2, and/or h+
25
Neural control
Respiratory centres
- Responsible for generating and maintaining the rhythm of respiration
- Adjusting homeostatic response to physiological changes
Medullary
- Dorsal respiratory group – fundamental role in the control of respiration, initiating inspiration
- Ventral respiratory group – exhalation area of respiratory control
Pontine
- Smooth transitions between inspiration and expiration
26
Layers of heart wall
1. Epicardium (outer) visceral serous pericardium
2. Myocardium (middle) - cardiac muscle
3. Endocardium (inside) - smooth endothelial layer
27
Right atrium
- Superior vena cava (from upper body)
- Inferior vena cava (from lower body)
- Pumps blood to right ventricle
28
Right ventricle
- Receives deoxygenated blood from right atrium
- Pumps deoxygenated blood to pulmonary trunk
29
order of blood in the heart
Body – right atrium – right ventricle – pulmonary trunk – pulmonary arteries (left and right) - lungs
30
Left atrium
- Receives oxygenated blood from pulmonary veins (from lungs)
- Pumps oxygenated blood to left ventricle
31
Auricles
- Auricle = ear-like
- On anterior surface of each atria
- Wrinkled pouchlike structures
- Increases volume of the atria
32
Left ventricle
- Recieves oxygenated blood from left atrium
- Pumps oxygenated blood to aorta -> body
33
Semilunar valves
- Between an ventricles and blood vessel
- Pulmonary valve – right ventricle and pulmonary trunk
- Aortic valve – left ventricle and aorta
- Prevent back flow of blood into ventricles
34
ECG
Recording of the electrical signals as they move through the heart
35
Electrical events
1. Atrial depolarization – movement of action potential through atria
2. Ventricle depolarization – movement of action potential through ventricle
3. Ventricle repolarization – recharging of ventricles after action potential
36
Cardiac cycle
1. Relaxation period (0.4 sec) – all 4 chambers in diastole. Blood flows into atria
2. Atrial systole (ventricle diastole) (0.1sec) – atria contract and force blood into ventricles. AV valve are open
3. Ventricular systole (atrial diastole) (0.3 sec) – ventricles contract and force blood into arteries. AV Valves are closed. SL valves are open
37
Heart sounds – auscultations
- Turbulent. Blood hitting against the closed valves
- Two sounds that be heard with a stethoscope
- S1: Lubb – blood hitting closed AV valves (ventricular systole)
- S2: Dupp – blood hitting closed SL Valves (ventricular diastole)
- Pause – relaxation phase
38
Cardiac output (CO)
Volume of blood ejected from the left (OR right ventricle) each min
Stroke volume – the volume of blood ejected from the left (or right) ventricle during each contraction (mL/beat)
Heart rate (HR) - the number of beats per minute (beats/min)
CO = SV x HR
39
Cardiovascular center – medulla oblongata
- Receives input from
- Sensory receptors (chemoreceptors, baroreceptors)
- Higher brain centers (limbic system and cerebral cortex)
40
Basic blood vessel structure
1. Tunica interna (inner layer) - direct contact with the blood, single layer of endothelium, connective tissue and elastic fibers
2. Tunica media (middle layer) - consists of smooth muscle and elastic fibers, regulate the size of the lumen (space inside the vessel), greatest variation between different types of vessels
3. Tunica externa (external layer) - connective tissue – elastic and collagen fibers, contains nerves and blood vessels, anchors vessels to surrounding tissue
41
Types of blood vessels
1. Arteries
2. Arterioles
3. Capillaries
4. Venules
5. Veins
42
Types of arteries
Elastic
muscular
arteriole
capillaries
venules
veins
venous valves
43
Blood pressure
The pressure exerted by blood on the walls of a blood vessel (mm Hg) generated by contraction of ventricles
44
Factors that affect blood pressure
1. Blood volume – total amount of blood in the cardiovascular system
2. Cardiac output – volume of blood being ejected from left ventricle per minute
3. Vascular resistance – opposition to blood flow due to friction between blood and the walls of blood vessels
45
Vascular resistance
Opposition of blood flow due to friction between blood and the walls of blood vessels
Depended on
1. Size of the lumen – vasodilation and vasoconstriction
2. Blood viscosity (thickness)
3. Total vessel length)
46
Neural regulation of blood pressure
- Cardiovascular center (medulla oblongata)
- Cardiac output – heart rate and stroke volume
- Vascular resistance – vasoconstriction and vasodilation
- Input from
- Higher brain centers
- Baroreceptors – pressure
- Chemoreceptors – chemical
47
Functions of blood
1. Transportation – O2, CO2, nutrients, hormones
2. Regulation – pH and temperature
3. Protection – clotting, antibodies and white blood cells
48
Physical properties of blood
- Connective tissue – cells surrounded by liquid matrix (plasma)
- Viscous and sticky
- Temperature is 38C
- Slightly alkaline (pH 7.35 - 7.45)
- Color depends on O2 saturation – saturated = bright red, unsaturated = dark red
49
Components of blood
1. Plasma (55%) - liquid extracellular matrix
2. Formed elements (45%) - red blood cells (erythrocytes), white blood cells (leukocytes), platelets
50
Red blood cells (RBC)
- Transport O2 and CO2
- Biconcave disk – increases surface area and flexibility
- No nucleus or other organelles – saves space for oxygen
- Contain hemoglobin – oxygen (and carbon dioxide) carrying problem
51
Hemoglobin (Hb)
- RBCs contain the protein hemoglobin
- Carries oxygen, and 23% of carbon dioxide
- Each RBC has about 280 million hemoglobin molecules
52
White blood cells (WBC)
- Immune function – combat invading microbes
- Contain nucleus and organelles
- No hemoglobin
- Elevated levels can indicate an infection
53
types of WBC
1. Neutrophils
2. Lymphocytes
3. Monocytes
4. Eosinophils
5. Basophils
54
Hemopoiesis
- Formation of the formed components of blood – RBC, WBC, platelets
- Occurs in red bone marrow
- Pluripotent stem cells – differentiate into all blood cells
55
Erythropoiesis: production of RBCs
- Starts in red bone marrow – pluripotent stem cells
- Precursor cell called proerythroblast
- Proerythroblast divides and ejects nucleus becoming a reticulocyte
- Reticulocyte enters circulation and mature into RBC within 1-2 days
56
Regulation of erythropoiesis
- RBCs have a life span of approximately 120 days – production usual matches destruction
- If production is less than destruction oxygen carrying capacity of blood falls – results in hypoxia (low oxygen levels)
- Hypoxia wills stimulate the release of hormone erythropoietin (EPO) from the kidneys
- EPO stimulates erythropoiesis in the red blood marrow
57
Haemostasis
- Sequence of responses that stops bleeding
Process involves
1. Vascular spasm – contraction of smooth muscle in vessel walls to reduce blood flow
2. Platelet plug formation – plug fills the gap in the injured blood vessel wall – slows bleeding
3. Blood clotting (coagulation) - plugs the injured blood vessel and stops blood loss
58
Platelets
Help stop blood loss by forming a platelet plug
1. Platelets stick to damaged vessel
2. Start to release chemicals
3. Chemicals activate nearby platelets, and these platelets stick to original platelets
4. Platelet plug is formed
59
Blood clotting (coagulation)
- Platelets alone cannot stop bleeding from vessel wall – clot must form at the site of injury
- Coagulation is the process of turning liquid blood into a gel
- Series of chemical reactions that results in the formation of fibrin threads
- Fibrin threads trap the formed elements of blood and creates a blood clot
60
Blood groups
- Blood is categorized into different blood groups
- Surface of RBC contain antigens (agglutinogens)
- Blood groups determined by presence or absence of these antigens
- Main two blood groups – ABO (A, B, AB or O), Rh (positive or negative)
61
ABO
- Blood plasma contains antibodies called agglutinins
- Agglutinins react with the A or B antigens if the two are mixed
62
Blood transfusions
- Blood is the most easily shared of human tissues
- Whole blood or blood components (RBC or plasma only)
- Transfusions must be from a compatible blood type
- Incompatible transfusions can result in agglutination (clumping)
63
Rh blood group
- Named after Rh antigen – found in the Rhesus monkey
- Rh+ (Rh positive) - RBCs have Rh antigen
- Rh- (Rh negative) - RBCs lack Rh antigen
- Normally blood does not contain any Rh antibodies
- But if Rh – receives an Rh+ transfusion the immune system starts to make anti-Rh antibodies that will remain in the blood
64
Lymphatic system
4 components
- Lymph
- Lymphatic vessels
- Lymphatic tissues
- Red bone marrow
65
Lymph
- After interstitial fluid passes into lymphatic vessels, it is called lymph (LIMF = clear fluid)
- The major difference between interstitial fluid and lymph is location: interstitial fluid is found between cells, and lymph is located within lymphatic vessels and lymphatic tissue
66
Lymphatic vessels
- Lymphatic vessels begin as lymphatic capillaries, these capillaries which are located in the spaces between cells, are closed at one end
- At intervals along the lymphatic vessels, lymph flows through lymph nodes, encapsulated bean-shaped organs consisting of masses of B cells and T cells
67
Lymphatic organs and tissues
- Lymphatic organs are classified into two groups based on their functions
- Primary lymphatic organs = red bone marrow ands the thymus
- Secondary lymphatic organs and tissues = lymph nodes, spleen and lymphatic nodules
68
The lymphatic system has three primary functions
1. Drain excess interstitial fluid
2. Transports dietary lipids from the gastrointestinal tract to the blood
3. Protects against invasion through immune responses
69
Red bone marrow
- Pluripotent stem cells in red bone marrow give rise to mature, immunocompetent B cells and to pre-T cells
