BIOL121 Worksheet: Human Physiology, Immunity, and Blood Transfusion

This BIOL121 worksheet assesses understanding of human biology, covering various aspects of the immune system and human physiology. The assignment includes questions on different types of immunity (non-specific and specific), adaptive immunity properties, and bone cell function related to parathyroid hormone. Other questions explore hypertrophy in skeletal muscle, the renin-angiotensin-aldosterone system and its impact on blood pressure, the effects of alcohol on ADH secretion, and the genetic basis of haemophilia. Further questions delve into respiratory physiology (inhalation and gas exchange), blood transfusion reactions, baroreceptor function, and the Wigger's diagram of the cardiac cycle. The worksheet aims to evaluate the student's comprehension of these interconnected biological processes.

BIOL121 WORKSHEET
Submit: via Turnitin link on BIOL121 LEO page
QUESTION 1
Which type of immunity is expressed in the following scenarios? Choose between:
 Non-specific (first line defence)
 Non-specific (second line defence)
 Specific (antibody-mediated)
 Specific (cell-mediated immunity)
(0.5 mark each – total 2 marks)
Scenario Type of immunity
Bacterial septicaemia (bacterial
contamination in systemic circulation)
 Non-specific (second line defence)
Mucous-coated hairs within the nose trap
and filter microbes from inhaled air.
 Non-specific (first line defence)
Interferons are released by virus-infected
cells and interfere with viral replication.
 Specific (antibody-mediated)
A virus multiplies inside the epithelial
cells in your throat.
 Specific (cell-mediated immunity)
QUESTION 2
Choose TWO of the below scenarios and highlight these rows bold. State which general property of
adaptive immunity the scenario illustrates in the second column. Select ONE phrase (from the list below)
that BEST describes what is happening at a cellular level to result in this property of adaptive immunity.
Write the letter corresponding to this phrase in the third column. An example is included. (0.5 mark each –
total 2 marks)
Scenario General
property of
immunity
Explanation
Even though your body contains a relatively small number of
lymphocytes, your immune system can mount a response against
almost any antigen it encounters.
Versatility A
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Generally, after an initial infection, subsequent immune
responses to that antigen are faster, stronger and more sustained. Memory H
You can suffer from ‘the flu’ multiple times throughout your
lifetime. Specificity F
Your immune system can distinguish between antigens on your
own cells, and those of an invading pathogen. Tolerance G
Possible phrases are listed below. Not all phrases will need to be used and only ONE phrase is required per
row. If you record more than one, you will not be awarded any marks for your explanation.
A There are millions of different lymphocyte populations, each of which is sensitive to a different antigen.
Lymphocytes proliferate when activated by their specific antigen.
B Each T or B cell has receptors that respond to only one antigen and ignores all others.
C Activated lymphocytes produce two groups of cells: one group that attacks the invader immediately, and
another that remains inactive unless it is exposed to the same antigen at a later date.
D Each T and B cell can recognise many antigens and respond to a wide variety of possible threats.
E T cells are versatile because they produce copious quantities of antibodies that can respond to a wide
variety of threats.
F Phagocytes have a reduced ability to destroy pathogens during subsequent infections.
G The immune response ignores self-antigens and targets non-self antigens.
H B cells differentiate into T cells to create a long-lived immune response.
QUESTION 3
Which bone cells would be MOST affected by an absence of parathyroid hormone? In you answer; you
must explain the relationship between these cells and any subsequent effect upon blood calcium levels. (3
marks)
Parathyroid hormone works in the body by regulating the blood calcium level. Its absence in the body causes
complications. Insufficient production of parathyroid a condition referred to as hyperparathyroidism leads to
reduction of calcium concentration. The most affected bone cells in the absence of parathyroid hormone is
osteoblasts. This is because there will be no breaking of the bones where most of the calcium is stored. In
this effect there will be reduced calcium level in blood
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QUESTION 4
Define hypertrophy and use an example to explain how this term relates to skeletal muscle tissue. (3 marks)
Hypertrophy refers to an increase in muscular size and growth that is achieved via exercise. A good
example is skeletal muscle hypertrophy which occurs as a result of body’s response to resistance exercise.
Factors that contribute to hypertrophy may include myofibrillar hypertrophy and sarcoplasmic hypertrophy.
QUESTION 5
Think about how the renin-angiotensin-aldosterone system acts to maintain normal blood pressure. Susan
has sustained damage to her adrenal glands. Consequently, her circulating levels of aldosterone are
abnormally low. What do you expect the lack of aldosterone to do to Susan’s blood pressure? Explain your
answer. (3 marks)
Aldosterone hormone plays critical role in regulation of blood pressure by acting on kidney to increase the
amount of salt reabsorbed into the bloodstream. Lack of aldosterone will affect the kidney by making it
unable to regulate salt and water balance. This will then cause blood volume and blood pressure to drop.
QUESTION 6
Tasma is enjoying a night out at the pub with her friends. It is well established that alcohol inhibits the
secretion of ADH. Explain how this will affect her urine output. (3 marks)
Alcohol is a diuretic as it inhibits the secretion of antidiuretic hormone (ADH). AHD is a significant part in
the body as it acts in the kidney to control the volume and osmolality of urine. It specifically acts in the
distal convoluted tubule and collecting ducts cells. High levels of ADH make the kidney to retain water in
the body whereas low levels of it cause the kidney to excrete too much water. Since Alcohol inhibits the
ADH, there will be low levels of ADH will mean reduction in the permeability of DCT and CT cells to
water thus increasing the volume of urine output.
QUESTION 7
Haemophilia is the oldest known hereditary bleeding disorder. Explain why haemophilia is more commonly
seen in males. (3 marks)
Haemophilia is the rare inherited bleeding illness that occurs as a result of deficiency of clotting factor VIII.
The condition is as a result of an X-linked gene which is passed to offspring through the X-chromosome.
Haemophilia is very common in males than females because male (XY) inherit only one X chromosome
from their mother and Y chromosome from their father thus if an X chromosome contains haemophilic gene,
there is no another normal X chromosome to override it. On the other hand, females have two X
chromosomes (XX) thus there is one normal X chromosome that can protect her from having haemophilia.
QUESTION 8
Describe the changes in volume and pressure inside the chest cavity during a normal, quiet inhalation.
A. Explain why these changes are occurring, and the effect upon airflow. (4 marks)
Quiet breathing occurs when an individual is at rest with no active thought. During the process, the
diaphragm and the external intercostal muscles function at different extents. For quiet inhalation, the
diaphragm contracts, flattens and drops towards the abdominal cavity thus making the thoracic cavity to
expand. Besides, the external intercostal muscles contracts making the rib cage to expand and the sternum to
move outward thus leading into expansion of thoracic cavity. It is as a result of expansion of thoracic cavity
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which causes the lungs to expand. Expansion of the lungs and its adhesiveness of the pleural fluid cause the
pressure within the lungs to be lower than that of atmospheric thus making fresh air to rush into the lungs.
B. Is quiet inhalation an active process? Briefly explain your answer. (1 mark)
Quiet inhalation is an active process. This is because quiet inhalation requires muscular contraction to take
place.
QUESTION 9
A. Complete the below table of partial pressures in internal respiration. (2 marks)
pO2 (mmHg) pCO2 (mmHg)
Tissue 100mm Hg 40 mm Hg
Capillary 0.2 mm Hg 160 mm Hg
B. Use to the figures above to explain how differences in partial pressures drive the direction of gas
movement between the tissues and blood. (2 marks)
Gas movement between tissue and blood are driven by partial pressure differences. The partial pressure of
oxygen is lower in the blood in capillaries than in alveoli and the partial pressure of carbon dioxide in blood
in capillaries is higher than in the alveoli. This difference in pressure makes inhaled oxygen to move from
alveoli to the blood and in the capillaries and carbon dioxide to move from the blood in to the capillaries to
the air in the alveoli.
QUESTION 10
A person with type O blood has been involved in a car accident and excessive bleeding necessitates a blood
transfusion. Due to an error by a careless laboratory technician, the person is given type B blood. Explain
what will happen. (4 marks)
Blood transfusion is a significant process that is used to replace blood lost during an accident. Before blood
transfusion, blood typing is done to determine a person’s blood type. Blood typing is important as ensures
one receives blood type that is compatible. Blood agglutination will occur when a person with type group O
receives blood group B. This is because a person with blood group O can only receive blood from other
blood O individuals as people with type O have both anti A and anti B antibodies. Blood group B will be
seen as an antigen thus incompatibility. A person with type B blood is only able to donate blood to
individuals with blood type B and AB and not to a person with type O, otherwise blood agglutination will
occur leading into a severe reaction that may be life threatening.
QUESTION 11
Explain how baroreceptors are involved in a situation where a short period of widespread vasoconstriction
has been detected. How do these receptors then assist the body to respond to the situation? (4 marks)
Baroreceptors are pressure sensors within the circulatory system that constantly monitor the mean arterial
pressure. Any slight change in mean arterial pressure automatically mediates baroreceptor reflex that
influences the heart and blood vessels adjustment in attempt to restore the blood pressure to normal. When
blood pressure falls below normal, the baroreceptors react by reducing their activity. This induces the
cardiovascular centre to increase its sympathetic cardiac and vasoconstrictor nerve activity while minimizing
its parasympathetic output. This efferent pattern of activities leads to an increase in heart rate and stoke
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volume which is accompanied by venous and arteriolar vasoconstriction. These changes increase CO and
TPR thus raising the blood pressure to normal levels.
QUESTION 12
The Wigger’s diagram (below) represents pressure and volume relationships in the left side of the heart
during one cardiac cycle. To answer this question, you should focus on the changes in pressure in different
chambers of, or vessels leading from, the left side of the heart.
For TWO of the labelled points, state which valve is open/closed at that time. Highlight your chosen point
in bold. You must also explain WHY that valve opened/closed and where the blood is flowing immediately
after this point in time, due to the change in position of the valve. An example is provided. (4 marksl)
Label Valve (name and open/closed) Explanation
A Mitral valve passively closes The pressure in the right ventricle becomes higher
than that in the right atrium. Blood flows from the
right atrium to the right ventricle
B Aortic valve opens The pressure in the left ventricle becomes lower
than that in the left atrium. Blood flows from the
left atrium to the left ventricle.
C Atrioventricular valves closes The pressure in the right ventricle becomes higher
than that in the right atrium. Blood flows from the
right atrium to the right ventricle
D Left AV/bicuspid valve opens The pressure in the left ventricle becomes lower
than that in the left atrium. Blood flows from the
left atrium to the left ventricle.
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B
DA
C

QUESTION 13
The below pictures illustrate phases of haemostasis. Choose ONE of the pictures. State which phase of
haemostasis is depicted. You must also provide a brief description of your chosen phase. Highlight your
chosen row in bold. Note: it is not necessary to label parts of the diagrams, but you may do so if it will help
you explain the phases. (2 marks total)
Picture Name of phase Description of phase
Vascular spasm
Vascular spasm is the initial phase that is
triggered by endothelins chemicals. The
smooth muscle in the walls which consists
of both circular and longitudinal layers
contracts. The circular layer constricts the
flow of blood while a longitudinal layer
draws the vessel back into the surrounding
tissue.
Platelet plug
formation
Coagulation phase
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QUESTION 14
The following questions relate to the role and importance of a spinal reflex in the body.
A. Complete the table below to summarise the FIVE anatomical units of the reflex arc (column 1). Use
the patellar reflex to provide an example for the blank anatomical units (column 2). (3 marks)
Anatomical unit Example (patellar reflex)
1 Receptor
2 Sensory neurons Nerve cells
3 Integrating centre
4 Motor neurons Interneurons
5 Effector
B. Using the patellar reflex as an example, explain the purpose of a neural reflex. (2 marks)
The important of neural reflex is to protect the body from harm. The sensory neuron carries the stimulus to
the spinal column and into the brain thereby sending the message to the motor neuron the muscle attached to
the sense organ moves the organ thus protecting the body from danger by moving it from danger.
QUESTION 15
Name the region of the brain responsible for regulation of breathing and blood pressure. Would you expect
damage in this region to be fatal? Why? (1 mark)
Medulla oblongata is responsible for regulation of the blood pressure and breathing. Medulla controls vital
autonomic functions of the body such as heart rate and breathing thus its damage can be fatal. Its damage
can lead to paralysis, difficult in swallowing and acid reflux.
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QUESTION 16
Using the diagram provided as a prompt, outline the four steps involved in the transmission of an electrical
impulse from the presynaptic neurone to the post synaptic neurone. (4 marks)
Step Outline
1
Neurotransmitter Synthesis
2
Neurotransmitter packaging and release
3
Neurotransmitter binding
4
Stopping the chemical signal/Inactivation
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QUESTION 17
List two (2) differences between the external and internal urethral sphincters. The differences must relate to
structure, function or innervation of these sphincters. (1 mark/difference; 2 marks total)
Urethra sphincter is the structure that is involves in controlling the outflow of urine from the bladder into
urethra. There are two types of urethral sphincters, that is external and internal urethral sphincters. The
differences differences between the two is that internal urethral spincters are is composed of smooth muscle
and it sorrounds the opening of the bladder whereas external urethral sphincter is composed of skeletal
muscle and sorrounds the outside of urethra. The other difference is that internal urethral sphincter relaxes to
allow urine to pass and it is controlled involuntarily whereas external urethral sphincter relaxes for urination
to occur and it is controlled voluntarily.
QUESTION 18
Glucose and protein (e.g. albumin) are substances normally found in blood. For each of these molecules,
answer the following questions in the table below. Assume you are discussing what happens in a healthy
person. (1 mark per box; 6 marks total)
a) Describe what happens to each substance at the glomerulus. Explain why/why not the substance will
move into the tubule system.
b) If the substance moves into the tubule system, describe what happens to the substance along the
tubule system. Explain why.
c) Do you expect to find each substance in the urine? Explain why or why not.
Glucose Protein
a) Glomerulus Glucose is reabsorbed back into the
blood
Glucose does not move into the
tubule system because if it moves it
will disappear or be removed from
the body through urine.
Protein is reabsorbed back into the
blood.
Protein does not move into the tubule
system because if it moves it will
disappear or be removed from the
body through urine.
b) Tubule system
Glucose diffuses directly into the
blood
glucose
It diffuses because of concentration
gradient.
Protein diffuses directly into the
blood capillaries
It diffuses because of concentration
gradient.
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c) Urine Yes
The excess or extra glucose that is not
required by the body will be excreted
in urine as a waste product
Yes
The excess or extra protein that is not
required by the body will be excreted
in urine as a waste product
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