Human biology

TABLE OF CONTENTS
TASK 1............................................................................................................................................3
Features of alveoli........................................................................................................................3
Structure of trachea supporting its function.................................................................................4
TASK 2............................................................................................................................................4
TASK 3............................................................................................................................................4
TASK 4............................................................................................................................................6
TASK 5............................................................................................................................................6
REFERENCES................................................................................................................................9

TASK 1
Nostril: Filters, warms and moistens air, detects smell.
Oral cavity:
Larynx: Sound or voice box, sound production, links pharynx with trachea allowing passage of
air.
Right lung: Responsible for providing oxygen to capillaries and exhaling carbon dioxide.
Right main bronchus: It helps in delivering oxygen to the right lung’s three lobes. Connects
trachea to lungs (Aleksanyants, Pogodina and Yuferev, 2018).
Diaphragm: Major muscle of respiration which performs the function of contracting continually
and rhythmically and even involuntarily. Upon the process of inhalation, the contraction and
flattening of diaphragm takes place along with the enlarging of chest cavity. Muscle performs the
function of helping the lungs so that air can be pulled in and pushed out.
Pharynx: Organs which are responsible for digestion and respiration which gives passage to the
air to move from nose to the trachea.
Trachea: This is present in the neck and its positioned in front of the oesophagus. It carries out
various functions such as helping in cough reflex, supporting head and neck. Also, the mucus
performs the function of lubricating the passage and the organ cilia helps in filtering out the dust
(El-Hashash, 2018).
Left main bronchus: It helps in delivering the oxygen (air) to the left lung’s two lobes.
Bronchioles: The airways of branching which represents the conducting system so that the air
can travel from trachea to the ducts of alveoli and the alveoli itself where the gas exchange
occurs.
Alveoli: The exchange of the gases like oxygen and carbon dioxide takes place in the tiny air
sacs which are present in the lungs.
Alveoli’s Features
Main feature of alveoli is that it gives much bigger surface area to the lungs. They consist
of thin and moist walls along with having capillaries which are tiny blood vessels which are large
in number. These are tiny structures which is in the shape of a balloon and also which is
considered as the passageway which is very small in the respiratory system (Kiyokawa and
Morimoto, 2020). These is only one thick cell present through which the gases like CO2 and O2
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can easily be transferred between the capillaries which are the blood vessels and the alveoli. Its
adaption takes place so that the exchange of gases can occur efficiently (Li and et.al., 2020). As
there is a movement of blood where the capillaries become the medium which are present in the
alveoli, there is diffusion of oxygen into it and diffusion of carbon dioxide out of it.
Structure of trachea supporting its function
It is considered as the passage of air, provides moist and warmth while passing in the
lungs and protecting the surface of respiration so that particles from outside do not accumulate.
This is also lined with a membrane layer of mucus which is moist and which consists of cells
which also contains tiny hairlike projections referred as cilia (Kocjan and et.al., 2017). It is
hollow whose structure is like a tube which runs from the larynx which is also considered as the
voice box to the two passageways which is responsible for connecting the trachea to the lungs
and is known as bronchi. Along with transporting air, it also helps in defending against the
diseases as the mucus which is present in the trachea helps in capturing the microorganisms like
virus and harmful bacteria prior to entering the lungs (Law and et.al., 2016).
TASK 2
a. Diaphragm: When the lungs inhale, there is a contraction in diaphragm and its is pulled
downwards (Palkar and et.al., 2018).
b. External intercostal muscle: At the same time, the external intercostal muscle i.e., the
muscle which is present between the ribs contract and is pulled upward.
c. Ribs: These protects the organs assisting in respiration and provide support for upper
extremities. In one breathing, ribs are elevated and are depressed at the time of
expiration.
d. Thoracic cavity: Its size is increased which decreases the inside pressure. Due to this,
there is rushing of air and helps in filling lungs.
TASK 3
Breathing is a rhythmic activity which is performed automatically which is produced by
neuron’s network which takes place in the hindbrain. The network of neurons play role of
directing muscles that form walls of thorax as well as abdomen and also helps by producing the
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pressure gradients that contributes in movement of air in the lungs and out as well. The rhythm
of respiration and the respiration’s each phase’s length are completely set by the reciprocal
stimulatory and interconnection of inventories of the neurons whose stem is the brain. The main
characteristic of the respiratory system in humans is the ability for adjusting the patterns of
breathing at both times of internal milieu as well as the external environment. There are changes
in the ventilation also whether increase or decrease which is in proportion of the production of
carbon dioxide and also the consumption of oxygen which is caused by the changes in metabolic
rate.
The rhythm of respiration is developed in the pons and the medulla oblongata. There are
three groups of neurons which are responsible for different functions such as a group which
consists of neurons which are inspiratory residing in the dorsomedial medulla, another of both
the inspiratory and expiratory neurons which are present in the ventrolateral medulla and also an
another one in rostral pons which consists of the neurons that is to be discharged in both
expiration and inspiration. This is considered that the inspiration and expiration respiratory cycle
is developed by the synaptic interactions within certain neuron groups.
When body is at rest, breathing takes place which is known as quiet breathing also referred as
Eupnea which do not need psychological thoughts of the person. During this, diaphragm as well
as the external which is intercostal muscles contract which is required by the deep breath called
diaphragmatic breathing. There is no control of the individual but the neurons play their role.
On the other hand, the costal breathing which is usually the shallow breathe needs the intercostal
muscles to contract. As there is relaxation in these muscles, there is passive movement of the air
to leave the lungs (Bordoni and et.al., 2018).
Contradiction to the above, the forced breathing which is also known as hypernea is occurred
during the exercise or can be considered as actions which needs the breathing’s active
manipulation like singing. During this, both the processes inspiration and expiration are occurred
due to contraction in muscles. The diaphragm and the intercostal muscles do not only contract
but the other accessory muscles also contract.
Tidal breathing describes the inhaling and exhaling of gases during the restful breathing. Its
range is defined by inspiration’s depth and passive exhalation’s end point at FRC, the
interconnection at which balance between the outward and inward elastic recoil of lungs is made.
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It is often maintained in a small range in a person who is quietly breathing and also who does not
have any sort of lung disease (Jerath, Beveridge and Barnes, 2019).
During the inspiration which is forced, neck’s muscles which includes the scaling, contracting
and lifting the thoracic wall thereby enhancing the volume of lung. During the forced expiration,
accessory muscles of abdomen, including obliques, contract that forces the abdominal organs
upward against the diaphragm. This also helps in pushing the diaphragm into the thorax which
contributes in pushing more air out.
TASK 4
a. Red blood cells are referred as erythrocyte which is cellular part of blood, mainly
responsible for the colour of blood and performs the function of carrying oxygen from
lungs to tissues. The red blood cell in humans when mature is tiny, biconcave as well as
round which has a profile shape of dumbbell. It is also flexible and imagines the shape of
bell as it passes through blood vessels which are small (Nombela and Ortega-Villaizan,
2018). A liquid and protein composed membrane covers it in which the nucleus lacks and
consists the haemoglobin which is red protein which is iron-rich that helps in binding the
oxygen.
b. The red cell and the haemoglobin composed in it performs the responsibility of carrying
O2 from lungs or gills to all the tissues of the body and carries C02, which is
metabolism’s waste product to the lungs where excretion takes place. In invertebrates, the
plasma carries the pigment which is oxygen carrying, the concentration of red cells in
vertebrates for exchange of O2 and CO2 takes place as gases which are much efficient
and also is considered as an important development in terms of evolution. The red cells of
mammals are adapted by lacking a nucleus (Karsten, Breen and Herbert, 2018).
Therefore, the amount of oxygen which a cell requires is very low for its own metabolism
and the carried oxygen can be excreted into tissues. The shape of the cell which is
biconcave is allowing the exchange of oxygen at a suitable rate over the possible area but
largest.
The exchange of gas takes place in alveoli which is in lungs as well as in the capillaries
which helps in enveloping them. The oxygen which is inhaled moves from the alveoli to
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the blood which is in the capillaries and there is movement of carbon dioxide from blood
to air in alveoli.
TASK 5
Causes Symptoms Treatments
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Asthma Cold Air, air
pollutants and irritants
such as smoke,
physical activity,
respiratory infections
such as common cold,
airborne allergens
such as dust mites,
mold spores, pollen,
pet dander or
cockroach waste
particles (Qian and
et.al., 2017).
Coughing (especially at
night or in morning),
wheezing which is
whistling sound when
breathing, shortness of
breath, tightness, pain or
pressure in chest, trouble
sleeping due to breathing
problems.
Serious symptoms such
as fast breathing, skin
around the ribs pulls
inward when breathing,
pale or blue face.
Some treatments can
be done at home by
avoiding the asthma
triggers. Exercising
regularly, keeping
healthy weight,
taking care of
conditions that can
help in triggering
the symptoms such
as GERD. Breathing
exercises for easing
the symptoms which
does not need
medication. Other
treatments can be
acupuncture, yoga,
biofeedback or
supplements like
Vitamin C.
Medications can be
leukotriene
modifiers, inhaled
corticosteroids,
long-acting beta-
agonists,
theophylline,
anticholinergics etc.
Pneumonia Bacteria, Fungi and
viruses (including
COVID-19), germs
Chest pain when
breathing or coughing,
changes in mental
It can be treated at
home by controlling
the fever with
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empowering the
immune system and
infects the lungs,
bacteria-like
organisms (Zaidi and
Blakey, 2019).
awareness, cough which
can result in phlegm,
fatigue, fever, shaking
chills and sweating, body
temperature low,
shortness of breath,
nausea, diarrhoea or
vomiting (Pneumonia
treatment and recovery,
2020.).
aspirin, drugs which
are nonsteroidal
anti-inflammatory
drugs such as
ibuprofen or
acetaminophen.
Aspirin cannot be
given to children.
Drinking plenty of
fluids, warm
beverages, taking
steamy baths,
staying away from
smoke, taking lot of
rest.
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REFERENCES
Books and Journals
Aleksanyants, G.D., Pogodina, S.V. and Yuferev, V.S., 2018. Signal indicators of regulatory
changes in the respiratory system under physiological deviation conditions. Bulletin of
the Georgian national academy of sciences. 12(4). pp.100-107.
Bordoni, B. and et.al., 2018. The influence of breathing on the central nervous
system. Cureus. 10(6).
El-Hashash, A., 2018. Brief overview of the human respiratory system structure and
development. In Lung Stem Cell Behavior (pp. 1-3). Springer, Cham.
Jerath, R., Beveridge, C. and Barnes, V.A., 2019. Self-regulation of breathing as an adjunctive
treatment of insomnia. Frontiers in psychiatry. 9. p.780.
Karsten, E., Breen, E. and Herbert, B.R., 2018. Red blood cells are dynamic reservoirs of
cytokines. Scientific reports. 8(1). pp.1-12.
Kiyokawa, H. and Morimoto, M., 2020. Notch signaling in the mammalian respiratory system,
specifically the trachea and lungs, in development, homeostasis, regeneration, and
disease. Development, growth & differentiation. 62(1). pp.67-79.
Kocjan, J. and et.al., 2017. Network of breathing. Multifunctional role of the diaphragm: a
review. Advances in respiratory medicine. 85(4). pp.224-232.
Law, J.X. and et.al., 2016. Tissue-engineered trachea: a review. International journal of pediatric
otorhinolaryngology. 91. pp.55-63.
Li, K. and et.al., 2020. The clinical and chest CT features associated with severe and critical
COVID-19 pneumonia. Investigative radiology.
Nombela, I. and Ortega-Villaizan, M.D.M., 2018. Nucleated red blood cells: Immune cell
mediators of the antiviral response. PLoS pathogens. 14(4). p.e1006910.
Palkar, A. and et.al., 2018. Diaphragm excursion-time index: a new parameter using
ultrasonography to predict extubation outcome. Chest. 153(5). pp.1213-1220.
Qian, C.J. and et.al., 2017. Pneumonia risk in asthma patients using inhaled corticosteroids: a
quasi‐cohort study. British journal of clinical pharmacology. 83(9). pp.2077-2086.
Zaidi, S.R. and Blakey, J.D., 2019. Why are people with asthma susceptible to pneumonia? A
review of factors related to upper airway bacteria. Respirology. 24(5). pp.423-430.
Online
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Pneumonia treatment and recovery, 2020. [ONLINE] Available through :<
https://www.lung.org/lung-health-diseases/lung-disease-lookup/pneumonia/treatment-
and-recovery>
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