Animal form and function- 2 Flashcards
1
Q
Why doesn’t clotting occur in the undamaged blood vessels?
A
because the lining of the vessels is very smooth and does not promote platelet aggregation or cell rupture.
Also some substances such as Heparin prevent clotting.
Heparin prevent the conversion of prothrombin into thrombin and fibrinogen to fi brin and is widely used clinically as an anticoagulant.
2
Q
What is clinically used as an anticoagulant?
A
Heparin
3
Q
What is vital during the blood transfusion?
A
Receiving of blood that is compatible with its own
Therefore prior to transfusion cross-matching is still required to ensure that there is no reaction between donor and recipient blood.
4
Q
When the blood transfusion is incompatible, what happens in the CVS?
A
a type of immune response occurs
This is because the donor’s red cell membranes possess glycoprotein which act as antigens and react with antibodies (agglutinin) in the recipient’s plasma.
The result is that the donor’s cells are agglutinated
5
Q
What organism is known as the universal recipient?
A
AB blood group
6
Q
What blood group is known as the universal donor?
A
O blood group
So these individuals having blood group O can donate blood to the persons with any blood group
7
Q
Why is the blood group O is known as the universal donor?
A
Individual with blood group O has neither antigen A nor antigen B on their plasma membrane of red blood cells.
But they do have antibodies (anti–A and anti-B) in their plasma
8
Q
In ABO blood group system, what are the four blood groups?
A
A
B
AB
O
9
Q
What are the antigens the individuals have on the surface of their RBC?
A
Rhesus factor
aggulitinogen
10
Q
What are the people having the rhesus factor on their RBC called?
A
Rh+
11
Q
What are the people that do not have the rhesus factor on the surface of their RBC called?
A
Rh-
12
Q
What individuals have anti rhesus antibodies in their plasma?
A
Rh- individuals
13
Q
How does Rh antibodies form in Rh- individuals?
A
if Rh + blood enters a Rh- negative individual the recipient responds by manufacturing Rh antibodies in
the blood plasma.
14
Q
What happens when a Rh- mother bears a Rh+ child?
A
When a Rh- mother bears a Rhesus positive (Rh+) child during delivery few Rh+ red blood cells of the fetus may enter the mother’s circulation and cause the mother to produce Rh antibodies in her plasma.
15
Q
What happens when a Rh- mom is pregnant for the second time with a Rh+ child?
A
If the mother is pregnant for the second time with a Rhesus positive fetus, the Rh antibodies developed in her plasma in response
to the first child’s red blood sells can pass across the placenta to the fetus and destroy fetal red cells.
Normally Rh antibodies are not formed in large enough quantities in the mother’s plasma to affect the first born child. However subsequent Rh+ children can suffer destruction of their red blood cells.
16
Q
Why are respiratory structures needed in animals?
A
*Respiratory gas exchange (uptake of oxygen into the body and release of carbon dioxide into the external environment) occurs by diffusion. In simple animals e.g. cnidarians and fl at worms every cell in the body is close enough to the external environment so that gas exchange can occur directly between all cells and the environment. Diffusion through body surface is adequate as these animals have a simple body form and low energy requirement.
*In large animals, body complexity and energy requirement is high and the bulk of the cells in the body lack immediate access to the external environment. Hence, gas exchange through the body surface is not adequate to full fill their energy requirements.
As a result, specialized surfaces referred to as respiratory surfaces have evolved where gaseous exchange occurs.
17
Q
Why are respiratory structures needed in animals?
A
*Respiratory gas exchange (uptake of oxygen into the body and release of carbon dioxide into the external environment) occurs by diffusion. In simple animals e.g. cnidarians and fl at worms every cell in the body is close enough to the external environment so that gas exchange can occur directly between all cells and the environment. Diffusion through body surface is adequate as these animals have a simple body form and low energy requirement.
*In large animals, body complexity and energy requirement is high and the bulk of the cells in the body lack immediate access to the external environment. Hence, gas exchange through the body surface is not adequate to full fill their energy requirements.
As a result, specialized surfaces referred to as respiratory surfaces have evolved where gaseous exchange occurs.
18
Q
What happens with the increase of size and complexity of animals?
A
the surface area to volume ratio (A/V) of animals decreases
19
Q
Why is a large surface area needed in complex (with high body size) organisms for efficient gas exchange?
A
A large surface area is required for efficient gas exchange.
Thus diverse respiratory structures with large surface area with folding and branching has evolved for efficient gas exchange.
20
Q
What are the examples of respiratory structures?
A
Gills
Trachea
lungs
21
Q
Why are external projections such as gills evolved in the aquatic organisms?
A
for efficient extraction of dissolved oxygen from water
22
Q
Why are surface invaginations like trachea and lungs were evolved in terrestrial animals?
A
for efficient extraction of oxygen from the atmosphere
23
Q
What organisms have a body surface as a respiratory structure?
A
Cnidarians
Flat worms
Earth worms
24
Q
What organisms use external gills as a respiratory surface?
A
marine annelids
25
What organisms use internal gills as a respiratory surface?
Fish
shrimp
prawns
26
What organisms use tracheal systems as the respiratory surface?
Insects
27
What organisms use lungs as the respiratory surface?
Mammals (Human)
Reptiles
Birds. (MBR)
28
What organisms use skin as the respiratory surface?
Amphibians
29
What organisms use book lungs as the respiratory surface?
Spiders
Scorpions
30
What does the human respiratory system include?
Nostrils
nasal cavity
pharynx
larynx
a series of branching ducts starting from the trachea
two bronchi one leading to each lung and smaller bronchioles,
air sacs called alveoli
31
Where are the alveoli and the bronchioles contained within?
paired, cone-shaped lungs located in the thoracic cavity
32
What lung is larger, left or right?
Right,
This is because the apex of the heart is slightly left to the median plane. Thus, the left lung is smaller
33
How many lobes does the right and left lung has?
Right lung- 3 lobes
left lung- 2 lobes
34
What is each lung surrounded by?
by two membranes.
The inner membrane, called the visceral pleura adheres to the outer surface of the lungs,
outer membrane called the parietal pleura adheres to the wall of the thoracic cavity
35
Between visceral and the parietal pleura, what can be seen?
thin, fluid filled space
36
What is the passage of air in the respiratory system?
nostrils ===> pharynx ===> larynx ===> trachea ===> bronchi ===> bronchioles
37
What is the common passage for both air and food?
Pharynx (air and the food passage cross each other)
38
What happens to the air of the nasal cavity?
In the nasal cavity air is filtered by hairs and is warmed and humidified as it travels through spaces in the nasal cavity.
39
What can be found in the larynx?
vocal cords which are made up of largely elastic fibers
40
What can be found in the larynx?
vocal cords which are made up of largely elastic fibers
41
How does vocal cords produce sound?
when expired air rushes across the stretched or tensed vocal cords, causing them to vibrate.
42
What does the epithelium found in the major respiratory tract contain?
cilia
thin film of mucus
43
What is the function of mucus in the respiratory systems' tract?
The mucus helps trap the dust and other particulate contaminants in the inhaled air
44
What happens when the cilia beats in the respiratory tract?
Then the beating of cilia moves this mucus upwards towards the pharynx where it is swallowed into the esophagus. This process is referred to as the “mucus escalator”.
45
What is the function of mucus escalator?
It helps clean the respiratory system.
46
What are the features of alveoli?
*The lungs contain millions of alveoli. This allows a large surface area for gas exchange.
*Each alveolus is also surrounded by a network of capillaries. Oxygen in the air that enters the alveoli dissolves in the moist film and rapidly diffuse across the thin epithelium into the capillaries. Meanwhile a net diffusion of carbon dioxide occurs from the capillaries into the alveoli.
*Since there are no cilia in the alveoli, there are white blood cells in the alveoli to engulf foreign particles.
*Alveoli are also coated with a surfactant that reduces the surface tension thereby preventing the collapse of alveoli due to high
surface tension.
47
How do the alveoli prevent the collapse due to high surface tension?
Alveoli are also coated with a surfactant that reduces the surface tension thereby preventing the collapse of alveoli due to high
surface tension.
48
How do the alveoli prevent the collapse due to high surface tension?
Alveoli are also coated with a surfactant that reduces the surface tension thereby preventing the collapse of alveoli due to high
surface tension.
49
Why is ventilation of lungs necessary?
Ventilation of the lungs is necessary to maintain high oxygen and low carbon dioxide concentrations in the alveoli or the gas exchange surface.
50
How is lung ventilation accomplished?
by breathing, which is the alternating movement of air into (inhalation) and out of (exhalation) the lungs.
51
What type of breathing do humans employ?
Negative pressure breathing
52
Are the below processes of breathing active or passive?
Inhalation
Exhalation
Inhalation- active process
Exhalation- passive process
53
What are the events taking place during the process of inhalation?
*Contraction of rib muscles or intercoastal muscles and the diaphragm which is a sheet of skeletal muscle that forms the bottom of the thoracic cavity leads to the expansion of the thoracic cavity.
• The visceral and parietal pleurae surrounding the lung stick together due to the surface tension of the fluid between these two membranes.
*This allows the two membranes to slide smoothly past each other. Hence, as the volume of the
thoracic cavity increases, the lung volume increases as well.
• As a result, the pressure within the lungs decrease relative to the outside air.
• This creates a pressure gradient between the atmosphere and the lungs.
• Thus, air flows from a high pressure gradient in the atmosphere to a lower pressure gradient in the lungs.
54
What events take place during exhalation?
*The rib muscles and the diaphragm relax.
*This cause the volume of the thoracic cavity to reduce.
• As a result, the pressure inside the lungs increase in relation to the air outside.
*This pressure forces air to move out of the lungs through the respiratory tubes
into the atmosphere.
55
When a man is at rest, what is enough for breathing process?
When a man is at rest contraction of rib muscles and contraction of diaphragm
56
What are the additional muscles that aid in the breathing process?
muscles of the neck, back and chest.
57
What do the muscles of the chest, back and neck increase?
These muscles further help to increase the volume of the thoracic cavity by raising the rib cage. e.g.
during exercise
58
Why do the lungs act as efficient respiratory surfaces?
• Alveoli create a large surface area for gas exchange.
• Alveoli and capillary walls are both lined by simple squamous epithelia which
reduce the distance the gasses need to travel by diffusion.
• The alveoli surface is moist to dissolve respiratory gasses for diffusion.
• Alveoli are highly vascularized which enables the maintenance of a steep
diffusion gradient of respiratory gasses
59
What is the difference between internal and external breathing?
It requires transport of O2 from the lungs to the blood and movement of CO2 from the blood
(referred to as external respiration) and movement of O2 from blood to the tissues and
CO2 from tissues to the blood (referred to as internal respiration).
60
What does the diffusion of Oxygen and CO2 require during the respiration?
It requires partial pressure gradients between the alveolar air in
the lungs and blood (during external respiration) and blood and tissues (during internal
respiration).
61
What takes place during the inhalation process? (at internal respiration level)
During inhalation, fresh air mixes with the stale air in the lungs.
This mixture in the lungs has a higher partial pressure of oxygen (PO2) and a lower partial pressure
of carbon dioxide (PCO2) than the blood in the alveolar capillaries.
There is thus a concentration gradient favoring the diffusion of these two gases in opposite directions.
Net diffusion of O2 takes place from the air in the alveoli to the blood and net diffusion of CO2 takes place from the blood into the alveoli.
62
What happens the O2 diffuses into the blood capillaries?
When O2 molecules diffuses into blood capillaries they bind to heamoglobin in the red blood cells. Four molecules of O2 bind reversibly with one molecule of haemoglobin and form oxyhemoglobin
63
What happens when blood leaves the alveolar capillaries the oxygen and carbon dioxide partial pressures?
They will be in equilibrium
64
What happens when blood leaves the alveolar capillaries the oxygen and carbon dioxide partial pressures?
They will be in equilibrium
65
What happens during the loading and unloading O2 and CO2?
* Blood reaching the tissues in the systemic capillaries have a higher PO2 and a lower PCO2 than in the tissues.
* These partial pressure gradients result in the net diffusion from the blood stream into the tissue and CO2 diffusion from the cells into the blood stream across the extracellular fluid/interstitial fluid.
* This is called unloading of O2 and loading of CO2
* Then the blood returns to heart and pumped to lungs again.
66
What is breathing regulated by?
Involuntary mechanisms
67
What do the involuntary mechanisms of breathing help coordinate?
help coordinate gas exchange with blood circulation and metabolic demands
68
What is the main breathing regulator center in the brain?
Medulla oblongata, at the base of the brain
69
Where are the pair of breathing control centers found in homeostatic control of breathing?
There are a pair of breathing control centers found in medulla and they are responsible for regulating the breathing rhythm.
70
What process control homeostatic control of breathing?
A negative-feedback mechanism
71
What do the sensors found in the lungs detect?
Sensors which detect stretching of the lung tissues are found in the lungs.
72
What do the sensors in the lungs do in inhalation?
During inhalation, these sensors send nerve impulses to the neurons that act as control
circuits in the medulla and further inhalation is inhibited and this prevents the
lungs from over expanding.
73
To regulate breathing, what does the medulla depends on?
pH changes in tissue fluids.
74
What is the indicator for CO2 concentration?
The pH of tissue fluid
75
What happens in blood when the CO2 concentration increases?
when metabolic activities increase, the concentration of CO2 in the blood increases.
Because CO2 diffuse into the cerebrospinal fluid, this results in an increase of CO2 concentration in the cerebrospinal fluid as well.
There CO2 reacts with water and form carbonic acid (H2CO3). H2CO3 dissociate into HCO3-
and H+
Hence, a high CO2 concentration results in an increase in H+ concentration, thereby a lower pH.
76
How is the low Ph is detected in the blood?
This pH change is detected by the sensors in the medulla and in major blood
vessels called arteries and aorta.
77
How is the low blood Ph controlled?
Sensors in the medulla and major blood vessels detect this decrease in pH.
In response, the control circuits in medulla increase the depth and rate of breathing until the excess CO2 is removed in exhaled air and the pH of blood comes to its normal value which is 7.4
78
How is the Ph change detected by the blood?
Sensors in the medulla and major blood vessels detect this decrease in pH. In
response, the control circuits in medulla increase the depth and rate of breathing
until the excess CO2 is removed in exhaled air and the pH of blood comes to its
normal value which is 7.4
79
Describe the influence of Oxygen in the breathing control centers
The O2 level has little influences on the breathing control centers. But, when O2
concentration becomes very low, O2 sensors found in the aorta and the carotid
arteries send impulses to the medulla to increase the breathing rate
80
What are the additional systems in which breathing modulated by?
The regulation of breathing is also modulated by additional neural circuits in the
pons, a part of the brain stem found above the medulla.
81
Why is cigarette smoke bad for the body?
Cigarette smoke harms nearly every organ in the body including the organs of the respiratory system and increase the risk of illness, disability and death.
82
What is an addictive drug in the smoke?
Nicotine
83
What are the adversities of nicotine?
It temporarily increases the rate of heart beat
constriction of peripheral blood vessels causing a temporary increase in blood pressure.
84
What does cigarette smoke stimulate?
* The secretion of mucus by the goblet cells
* Inhibits the action of cilia in the respiratory tract
85
What does cigarette smoke cause?
Causing accumulation of mucus in bronchioles and blocking them
Leading to bronchial inflammation or bronchitis.
As a result, breathing may become difficult.
86
What are the adversities of HCN?
* It stops the cilia from working properly.
* Due to loss of action of cilia, dust and other particulate matter get collected in the lung, resulting in an increase in phagocytic cells in the lung tissue.
* Due to release of large amounts of lytic enzymes by these cells, the alveolar tissue is destroyed thus reducing the effective area available for gas exchange.
87
What does CO in tobacco smoke do?
Smoke is absorbed into the blood and is able to bind to hemoglobin better than oxygen and combines irreversibly
with hemoglobin.
Thus it decreases the amount of oxyhaemoglobin produced.
Therefore, oxygen transport through blood is decreased.
88
What is the cause for nearly 90% of lung cancer?
due to smoking
89
What does tobacco smoke contain?
large number of cancer-causing substances/ (carcinogens)
90
What does tobacco smoke contain?
large number of cancer-causing substances/ (carcinogens)
91
With the long term exposure to cigarette smoke, explain the formation of a cancer
Long term exposure to such chemicals in cigarette smoke results in the proliferation of cells in the bronchial epithelium, forming a mass of abnormal cells.
92
How would a cancer spread among the body?
93
Does Passive or second hand smoking will also result in the mentioned ill effects of smoking?
Yes
94
What is silicosis?
This may be caused by long-term exposure to dust containing silica compounds
95
What are the causes for silicosis?
96
What are the high risk industries for silicosis?
1. Quarrying granite, slate, sandstone
2. Glass and pottery work
3. Mining hard coal, cu, Au, Sn
4. stone masonry and sand blasting
97
What happens when silica particles are inhaled?
When silica particles are inhaled they accumulate in the alveoli.
These particles are ingested by macrophages, some of which remain in the alveoli and come out in to the
connective tissue around bronchioles and blood vessels close to the pleura
98
What does progressive fibrosis result in when it comes to silicosis?
Progressive fibrosis is stimulated during silicosis.
It eventually obliterates the blood vessels and respiratory bronchioles.
99
What does gradual destruction of the lung tissue lead to?
Gradual destruction of lung tissue eventually leads to pulmonary hypertension and heart failure.
100
What is asbestosis?
This occurs when asbestos fibers are inhaled with dust.
(Those who are involved in making or using products containing asbestos are at risk. )
101
What penetrates the level of respiratory bronchioles and alveoli during asbestosis?
In spite of their large size the particles (asbestos)
This includes shorter and larger asbestos fibers
101
What penetrates the level of respiratory bronchioles and alveoli during asbestosis?
In spite of their large size the particles (asbestos)
This includes shorter and larger asbestos fibers
102
What happens to the larger asbestos fibers?
The larger fibers are surrounded by macrophages, protein materials and iron deposits.
The macrophages that have engulfed fibers move out of the alveoli and accumulate around respiratory bronchioles and blood (RB) vessels, stimulating the formation of fibrous tissue
103
What happens to the shorter asbestos fibers in asbestosis?
Macrophages accumulate in the alveoli and the shorter asbestos fibers are ingested.
104
What does asbestosis result in?
progressive destruction of lung tissue
pulmonary hypertension.
105
90% of lung cancer is due to what reason?
smoking
106
What happens when one smokes?
When one smokes, the nasal hairs, mucus and cilia in the respiratory tract become overwhelmed.
107
What is the function of the nasal hairs, mucus and cilia in the respiratory tract?
protect the lung from chemical and biological irritants
108
What accumulate in lungs when the nasal hairs, mucus and cilia in the respiratory tract become overwhelmed?
Irritants, free radicals, carcinogens and pathogens accumulate in the lungs (pic f)
This eventually leads to lung cancer.
109
What is Tuberculosis caused as a result of?
by the bacterium Mycobacterium tuberculosis.
110
How does the bacterium Mycobacterium tuberculosis spread through out the body?
The bacterium spreads when an infected person coughs and the bacterium enters the body of an uninfected person through inhaled air.
111
What is the most common form of bacteria that affects the lungs?
Pulmonary TB
112
What are the adverse affects of pulmonary TB in tuberculosis?
It affects the lungs.
Other organs may also be affected.
113
What affects the lungs the most during tuberculosis? (and other orans too)
The most common form of pulmonary TB
114
How does pulmonary TB start to transmit through out the body in tuberculosis?
by inhaling the bacterium into the lungs
115
Where does the bacteria Mycobacterium tuberculosis survive in?
in the air and in the house dust for long periods.
116
What reduces the resistance to TB?
Malnutrition and other infectious can reduce resistance to the disease.
117
What are the symptoms of TB?
Loss of appetite,
loss of weight,
excessive sweating,
fever,
a racking cough
spitting
up blood.
118
What is asthma characterized by?
characterized by wheezing and chest tightness
119
How is asthma caused by?
Sudden contractions of smooth muscles in the walls of the bronchioles which causes the bronchioles to narrow or even close.
120
What happens during breathing in asthma?
During this time breathing causes whistling or wheezing sound
121
What is the cause of asthma?
The cause of asthma is an over reaction of an immune response to stimuli like
*pollen
*dust
*mites
*spores
*particular food
*cold
*air
*exercise
*smoking gases.
122
What helps control asthma?
Anti-inflammatory drugs help control asthma
123
What does the amount of air that flows in and out of the lungs depend on?
conditions of inspiration and expiration
123
What does the amount of air that flows in and out of the lungs depend on?
conditions of inspiration and expiration
124
What us the formula for inspiratory capacity (IC)?
IC = TV + IRV
125
What is the formula for functional residual capacity (FRC)?
FRC = RV + ERV
126
What is the FRC important for (functional residual capacity)?
For continuous exchange of gas in the alveoli and to prevent the collapse of the alveoli during expiration.
127
What is the equation for vital capacity (VC)?
VC = TV + IRV + ERV
128
What are examples for pathogens?
* Bacteria
*fungi
*virus
129
What are examples for foreign substances?
chemical components of pollen grains
incompatible blood cells
transplanted tissues
130
What are the features of the immune system
Immune system of animals should be able to distinguish own body cells (self) from foreign cells/particles within the body (non-self) for initiating defensive immune responses for destruction of the foreign agents such as pathogens
131
Why does the immune system defend against pathogens?
Special cell types in the body fluid and tissues of most animals can interact with these foreign invasions and destroy them.
Immune cells produce receptor molecules that bind specifically to molecules from foreign cells and agents and activate defense responses.
132
What are the two types of immunity of humans?
* Innate immunity
* Acquired immunity
133
what are the features of innate immunity?
In innate immunity, recognition and defense responses will depend on characters common to groups of pathogens.
Innate immunity lacks specific responses to specific invaders and its protective mechanisms functions the same way
regardless of the type of the invader.
Hence innate immunity is also known as non-specific defense.
Innate immune responses include defense mechanisms that provide immediate but general protection against foreign invasion.
Innate immunity is found in both invertebrates and vertebrates.
134
What are the two types of innate immunity
External barriers (External defenses/ barrier defense)
Internal nonspecific defenses (Internal defenses).
135
What is the first line defense of the human body
External defense
136
What are examples for innate immunity, external defense?
*skin
*mucus membranes
*secretions of various organs
They act as physical and chemical barriers.
137
What speeds up the mucus movement in external defense system?
Coughing and sneezing speed up the mucus movement and its entrapped pathogens out of the body preventing their entry to the lungs.
138
What are examples of secretions?
tears, saliva, mucus
139
What is the function of tears in external defense?
Tears in the eyes provide continuous washing action that
1. helps to dilute microbes
2. prevent settling on the surface of eyes.
140
What is the function of saliva in external defense?
Saliva washes microbes from the mouth surface and the flow of saliva reduces the colonization of microbes in the mouth.
141
What is the function of mucus secretions in external defense?
Mucus secretions which bathe various exposed epithelia provide a continual washing action to dilute and inhibit colonization microbes such as bacteria and fungi
142
Where can we find lysozyme?
tears, saliva, perspiration and mucous secretions
143
What is the function of gastric juice?
Gastric juice which provides an acidic environment in the stomach can destroy many bacteria and bacterial
toxins ingested with food.
144
What is the function of Secretions of the sweat and sebaceous glands of the skin?
give acidity of the skin which helps to prevent growth of bacteria
145
What are the two types of phagocytic cells?
Neutrophils
Macrophages
146
Explain the activity of the neutrophils and macrophages
While circulating in the blood, neutrophils are attracted first to the infected site by signals from affected tissues. Then neutrophils can ingest and destroy infected pathogens. (Macrophages are larger and more potent phagocytic cells. )
147
What is the activity of natural killer cells
They can detect the cells with abnormal surface molecules (e.g. virus- infected body cells and some cancerous cells) and kill them. Natural killer cells do not engulf these abnormal cells but upon binding they can release chemicals to kill the virus-infected cells and cancerous cells which could inhibit further spread of the virus or cancer.
148
What are the two types of antimicrobial proteins?
Interferons
Complement proteins
149
What is the activity of the interferons?
Once released by virus-infected cells, interferons diffuse to uninfected neighboring cells where they are stimulated to
produce “anti-viral proteins” which inhibit viral replication.
Some interferons activate macrophages which enhance the phagocytic activity
150
What is the activity of complement proteins?
Complement proteins are a group of normally inactive proteins in the blood plasma and plasma membranes.
When they are activated by different substances present on the surfaces of microbes, a cascade of biochemical reaction occurs which lead to lysis of invaded cells.
They also promote phagocytosis and inflammatory response.
151
What are the steps involved in the process of inflammatory resonse?
promote increased permeability
dilation of blood vessels,
enhance migration of phagocytes
destruction of invading pathogens and aid in tissue repair
152
What is the function of inflammation?
Inflammation attempts to destroy the microbes at the site of the injury preventing the spread to other tissues and promote tissue repair.
Activated complement proteins can cause further histamine release which attracts more phagocyte cells to enter injured tissue and carry out additional phagocytosis.
This process can digest the microbes and cell debris at the site of injury.
153
What is the function of histamine?
increased permeability and dilation of nearby blood vessels (blood capillaries).
154
What takes place after the permeability of the blood vessels is increased, by histamine?
Increased permeability of the blood vessels enhance the infiltration of white blood cells, antimicrobial proteins and clotting elements to enter the injured area from the blood that aid in destruction of invading pathogens and tissue repair
155
How is cytokines are released?
Activated phagocytes (macrophages and neutrophils) moved from the blood to the damaged tissue area can also discharge signaling molecules (cytokines).
156
What is the function of cytokines in the immune system?
* promotes blood flow to the injured or infected site
157
What are the signs and symptoms of inflammation?
redness
heat
swelling
pain
158
How are signs and symptoms of inflammation caused?
1. Redness: Dilation of blood vessels causes redness.
2. Heat production: heat production due to high metabolism in the area
3. Swelling: Increased permeability of blood vessels triggers localized swelling, due to leaking of tissue fluid into neighboring tissues
4. Pain: Pain results from injury to neurons and microbial toxins.
159
What is the result of most inflammatory response?
pus may be accumulated.
It is a fluid rich in dead phagocytes, dead pathogens and cell debris from the damaged tissue.
160
What is the difference between a minor injury and a systemic response?
Minor Injury
Minor injury or infection causes a localized inflammatory response.
Systemic response
If the injury or infection is severe it may lead to a systemic response (throughout the body) leading
to fever. Elevated body temperature within limits may enhance the phagocytosis and
accelerate tissue repair by speeding up the chemical reaction
161
Where can acquired immunity be found in?
In Vertebrates
162
What are the two lymphocytes involved in acquired immunity?
T lymphocytes
B lymphocytes
163
What does the acquired immunity show?
i) specificity for particular foreign molecules
(ii) recognition of animals own molecules (self-molecules) from non-self-molecules and
(iii) memory for most previously encountered pathogens such that the subsequent encounter causes a stronger and more rapid response (immunological memory).
164
Where are T and B lymphocytes originated in the man?
are originated from stem cells in the bone marrow.
165
What lymphocytes migrate to the thymus for maturation?
T lymphocytes (T cells)
166
What are the lymphocytes that remain in the bone marrow for completion of development?
B lymphocytes (B cells).
167
What do B lymphocytes require before leaving to secondary lymphatic tissues?
their plasma membranes acquire diverse specific protein receptors (antigen receptors) which have the ability to recognize specific
foreign invasions (There can be over 100,000 antigen receptors on the surface of a ingle B lymphocyte or T lymphocyte)
168
What are examples for antigens
*Viral proteins
*bacterial toxins
*chemical components of bacterial structures such as flagella and cell walls can be antigenic.
*Structural components of incompatible blood cells
*transplanted tissues
*Antigens are usually large foreign molecules such as proteins and polysaccharides
*but certain parts of a large antigen molecule
169
What is an epitope?
The small accessible portion of the antigen that binds to a specific antigen receptor of a T lymphocyte or
B lymphocyte is called an epitope (for exp a group of amino acids in a large protein).
170
What is the function of the epitope?
for exp a group of amino acids in a large protein and can serve as an epitope.
171
How many epitopes does an antigen usually have?
Usually a single antigen has several epitopes, each can bind with a specific antigenic receptor of the single T or B lymphocyte.
172
In acquired immunity, two types of immune responses are mediated by...
T lymphocytes
B lymphocytes
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What are the two types of immune responses in acquired immunity?
*Cell mediated immune responses
*Humoral immune responses
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What is humoral immune response also known as?
Antibody mediated immune response
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What are immune responses triggered by?
Both immune responses are triggered by antigens. A given pathogen may provoke both types of immune responses.
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What takes place during cell mediated immune response?
*Sensitized T lymphocytes attach to the antigen undergo proliferation and eventually differentiate into “Cytotoxic T cells” that can directly kill the cells with the invading antigen .
*In addition “Memory T cells” are formed that can cause stronger and more rapid response at the subsequent encounter of the same antigen to the body.
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What is cell mediated immune response effective against?
fungi, parasites, virus that are present within host cells, some cancer cells and foreign transplanted cells
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What does cell mediated immunity always involve?
Cell mediated immunity always involves cells attacking cells.
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What takes place during humoral immune response?
* Humoral immune response is a type of acquired immunity in which specifically sensitized B lymphocytes attach to a particular antigen undergo proliferation and eventually differentiate into “Plasma cells” that secrete circulating antibodies that can
neutralize and inactivate the specific toxins and pathogens in the blood and lymph.
* In addition “Memory B cells” are formed that can cause stronger and more rapid response
at subsequent encounter of the same antigen.
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What can humoral immune response work against antigens?
Humoral immune response works mainly against antigens present in body fluids and extracellular pathogens (mainly bacteria)
that multiply in the body fluids.
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What is the function of antibodies?
Antibodies can neutralize and inactivate the specific toxins and pathogens in the body fluids.
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What is the function of antibodies?
The antibodies do not directly kill the pathogens but can interfere with activity of the pathogen or mark the pathogen for inactivation and destruction.
Antibody-antigen complexes can activate complement system and phagocytosis to destroy the pathogen.
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What is another name for antibodies?
immunoglobulins
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Explain the structure of immunoglobin
Immunoglobulin has the same Y shaped structure as B lymphocyte antigen receptors but are secreted
than membrane bound.
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What is the Role of T lymphocytes and B lymphocytes in acquired immunity?
Recognition of the antigen, binding to the antigen and sensitization
Proliferation and differentiation into Effector cells
Elimination of invaders
Provide immunological memory
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What is active immunity a result of ?
Active immunity can be developed as a result of natural infection of a pathogen or artificial immunization.
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What is an example for naturally acquired active immunity?
Virus of Chickenpox
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Give an example for artificially acquired active immunity
vaccines like Polio and BCG vaccines
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Give an example for naturally acquired active immunity
Short term antibody mediated immunity for some infectious diseases can be developed within the body of the fetus or nursing infant due to the natural transfer of antibodies produced by the mother.
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Give an example for artificially acquired passive immunity
*Readymade human serum antibodies for hepatitis A virus
*readymade human anti-tetanus immunoglobin for acute conditions of tetanus)
*antivenin, serum prepared from horses that have been immunized against snake venom
Immunity derived from artificially acquired passive immunization lasts for few weeks to four months
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Give examples for allergens
pollens
dust
some food (e.g. shellfish)
some antibiotics, (e.g. penicillin)
venom from honey bees and wasps.
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What happens when an allergic reaction take place?
Whenever an allergic reaction takes place the tissue injury occurs. The most allergens stimulate production of plasma
cells which secrete antibodies specific for the antigen. When the same allergen enter the body later, it become attach to the antibodies specific to the allergen which induce the mast cells to release histamine and other inflammatory chemicals. Acting on a variety of cell types these signals bring about typical allergy symptoms
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What are allergy symptoms
sneezing,
runny nose,
teary eyes
smooth muscle contractions in the airways of the lungs that can result in breathing difficulties
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What does an acute allergy reaction may lead to?
n acute allergic conditions sometimes lead to death of the person due to breathing difficulties and low blood pressure with a few
seconds of exposure to an allergen.
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What are examples for autoimmune diseases?
Type 1 Diabetes mellitus, Multiple sclerosis and Rheumatoid arthritis
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What are immunodeficiency diseases?
HIV aids
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What organisms use contractile vacuoles for osmoregulation?
Amoeba, Paramecium
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What are the metabolic substrates in the body?+
carbohydrates, fats, proteins and nucleic acids
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What do the excretory products of the substrates depend on?
chemical structure and the composition,
availability of enzymes,
oxygen availability
the habitat in which they live.
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When the carbohydrates are metabolized within the body cells, What are the end products? (in presence of O2)
when oxygen is available final excretory end products are CO2 and water
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If carbohydrates are metabolized anaerobically, what is the end product?
lactic acid
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What are the products if fats are subjected to anaerobic respiration?
lactic acid
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When fats are subjected to aerobic metabolism, what are the products?
CO2 and
water.
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During protein metabolism, what are produced?
Since proteins contain amine groups in their structure, during metabolism of
excess amino acids ammonia is produced
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What are the excretory products of the nucleic acids?
Since nucleic acids contain nitrogenous bases ammonia is produced as an excretory product during their metabolism.
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Depending on the habitat and the availability of enzymes ammonia will be further converted...
other nitrogenous waste products such as urea and uric acid.
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What are the Nitrogenous excretory products of animals?
ammonia, uric acid and urea.
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How do the excretory products vary?
vary significantly in their toxicity and the energy costs of producing
them.
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What is the advantage and the disadvantage of NH3?
Since ammonia is highly toxic, a large volume of water is needed to excrete ammonia.
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What is the advantage of NH3?
Energy cost for producing ammonia for excretion is comparatively low.
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What organisms use NH3 as an excretory product?
Therefore typically the organisms that live in water such as bony fi shes, many aquatic
invertebrates and aquatic amphibians specially tadpoles excrete ammonia since they
have ready access to water.
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What organisms use urea as the excretory product and why?
Instead most terrestrial animals such as mammals and adult
amphibians mainly excrete urea as the main nitrogenous excretory product.
REASON: Terrestrial animals do not have access to sufficient water to excrete ammonia as the
main excretory product
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What are the advantages and disadvantages of urea?
ADVANTAGE: Urea is less toxic than NH3
DISADVANTAGE: However animals must expend more energy to produce urea from ammonia.
Some marine fishes such as sharks also excrete urea (which they use for osmoregulation)
as the main nitrogenous waste.
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What animals excrete uric acid as the main excretory product?
birds, many reptiles, land snails and insects excrete
uric acid as the main excretory product
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What are the advantages of uric acid?
ADVANTAGE: Uric acid is relatively non-toxic and generally insoluble in water Therefore it is excreted as a semisolid with trace amount of water.
DISADVANTAGE: However uric acid production from ammonia requires more energy than urea production
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How do organisms excrete through the body surface? What organisms excrete through the body surface?
The cells of some animals which are in direct contact with the
environment and eliminate excretory products by diffusion. e.g. cnidarians
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How do organisms excrete by flame cells? What are the examples?
These are specialized excretory cells connected to a network of tubule
which opens to the outside of the animal. E.g. flatworms.
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How do organisms excrete by nephridia? What are the examples?
They are multi cellular, tubular structures. One end of the tubule is open
to the coelom while the other end opens to the outside. e.g. Annelids
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Explain about the Malpighian tubules and examples?
These are extensive blind end tubules immersed in hemolymph
and opens in to the digestive tract. e.g.: Insects and other terrestrial arthropods
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Explain about green glands and examples?
Green glands / Antennal glands –Two large glands found ventrally in the head and
anterior to the oesophagus. e.g. Crustaceans
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Explain about the sweat glands? Give some examples
There are coiled tubular glands situated in the dermis and connected to
a sweat duct which open as a pore on the surface of the skin. E.g. human skin.
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Explain about the salt glands and give an example?
They are paired glands found near the eyes to excrete excess salts. e.g.
Marine birds and marine reptiles.
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Explain about the kidney and give examples?
These are the major excretory and osmoregulatory organs of all vertebrates.
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Role of kidney in homeostasis?
• Maintaining electrolyte and water balance in the body fl uids (osmoregulation).
• Excretion of toxic waste products from the body.
• Regulating blood pH through acid base balance.
• Controlling blood volume and blood pressure.
• Secretion of erythropoeitein hormone that stimulates red blood cell production.
• Production and Secretion of renin an enzyme important in control of blood
pressure.
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What involves in bladder and kidney stones?
These are formed due to precipitation of urinary constituents (usually oxalates and
phosphates) normally in urine. They are also called renal calculi.
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What are the causes of bladder and kidney stones?
• Dehydration due to not drinking suffi cient amount of fl uids.
• Alkaline nature of urine.
• Infections that can alter pH of urine
• Metabolic condition.
• Family history
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How can we prevent bladder and kidney stones?
• Drinking plenty of water
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What involves in kidney failure?
This is due to the inability of the kidneys to function properly. Therefore waste products
and excess fluid will be accumulated in the blood.
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Reasons for kidney failure?
• Diabetes
• High blood pressure
• Having family history
• Getting older
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Describe the CKD condition?
It is a condition of gradual loss of kidney function over time. There are many reasons
for Kidney failure:
• Diabetes
• High blood pressure
• Having family history
• Getting older
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How to prevent CKD?
Follow a low salt, low fat diet
Doing proper exercise
Having regular check ups
Prevent smoking
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Describe about dialysis
Dialysis is done for the patients with kidney failure. It is a process of removing
excretory products, excess solutes and toxins from the blood by an artifi cial method.
