Biology Assignment: Human Anatomy, Physiology and Disease

This biology assignment presents a comprehensive overview of human anatomy, physiology, and pathology. The assignment addresses a variety of topics, beginning with cellular biology, including cell types, their roles, and functions within the body. It then delves into physiological processes such as action potentials, immunity, and homeostasis, and discusses mechanisms of body temperature and blood pressure regulation. The assignment also includes urine analysis interpretation, genetics problems, and detailed explanations of respiratory and digestive systems. Additionally, it covers the structure and function of various tissues and organs, including the circulatory system and different types of blood vessels, alongside a discussion of infectious agents and epithelium types. Finally, it explores the effects of various diseases and disorders.

Students Name; Course code:
Date:
Question 1
Cell name Where would you usually
expect to find these types if
cells
Primary role
Parietal cell Gastric glands in the
stomach.
Secrete intrinsic factor and
HCl
Melanocytes Hair follicles and the
epidermis
Production of melanin to
protect underlying tissues
from harmful UV rays.
Pacemaker cells Sinoatrial node i.e within the
wall of the atrium near
opening of the superior
venacava
-Atrioventicular node i.e
between the right ventricles
and right atrium within the
atrial septum
-Along the interventricular
septum
-In the inner ventricular walls
of the heart , beneath the
endocardium
Spontaneous depolarise to
trigger contraction of cardiac
muscles.
Establishes the heart rate
Osteocyte Spaces of the vertebra bones -Bone remodelling and repair.
- Controlling mineral balance
or ion exchange.
Red blood cells/erythrocytes Haemoglobin Contains large quantities of
haemoglobin, enabling it to
bind plus transport
respiratory gases
Chief cells Deep mucosal layer of the
stomach lining
Responsible for secretion of
pepsinogen and chymosin in
ruminants

Question 2
The pressure driven movement of water and solutes from the glomerulus into the Bowman’s
capsule is best-described as tufts.
The movement of glucose into cells via glucose transporter
proteins is an example of facilitated diffusion.
Cells lining the small intestine continue to absorb glucose,
even when glucose concentrations are much higher in the
cells compared to the intestinal contents. This is because the
glucose is entering the cell via the process of facilitated
diffusion or active transport
When a micelle contacts the intestinal epithelium, the fatty
acids move into the cells via lymph.
In the thick ascending limb of the nephron loop, Na+ and Cl-
are removed from the tubular fluid via co-transporter
ADH facilitates the insertion of aquaporins into the apical
plasma membranes of the distal convoluted tubules and
collecting system. These channel proteins allow water to move
out of the tubular fluid via vasa recta
Question 3
The action potential spreads along the sarcolemma , until it reaches a T-tubule. The action
potential continues down the T-tubule where it triggers the release of Ca2+ from the sarcoplasmic
reticulum. This exposes binding sites myosin heads bind to the exposed sites on myofilament to
form cross-bridges.
Question 4
scenario Type of immunity
Bacterial septicaemia (bacterial
contamination in systemic circulation
Specific (cell-mediated immunity)
The pH of hydrochloric acid in the stomach Non-specific (first line defence)

act to destroy ingested bacteria
A liver cell mutates and becomes cancerous Specific (antibody-mediated)
A virus multiplies inside the epithelial cells in
your throat
Specific (cell mediated immunity)
Question 5
ADH Hormone Aldosterone
What is synthesised in this
hormone?
Neurones in the supraoptic
nucleus of hypothalamus
Zona glomerulosa in the
adrenal gland
Gland that secretes this
hormone
Posterior pituitary gland Adrenal gland
Facultative or obligatory re-
absorption?
Facultative re-absorption Obligatory
Mechanism of action Controls the concentration of
urine. Pituitary gland below
the skin produces ADH which
is released into the blood
stream and travels into the
blood to the kidneys
The hormones act in renal
collection ducts to strike re-
absorption of sodium ions and
secretion of potassium and
hydrogen ions
Question 6
Parameter Normal values Sample 1 Sample 2
Colour Yellow Dark yellow Reddish tinge
Glucose Negative Positive Negative
Bilirubin Negative Negative Positive
Ketones Negative ++ --
Specific gravity 1010-1030 1.039 1.010
Blood Negative -- ++
PH 5-6 5.5 6.0
Protein Negative or traces
(<30mg/dl)
++ ++
Nitrite Negative ++ ++
Leucocytes Negative ++ ++

a) What personal protective equipment should be worn when handling someone
else’s urine? Explain. (1 mark)
Gloves-when handling body fluids like urine or equipments containing body fluids
or touching someone else’s mucous membrane or broken skin as well as doing
invasive procedures it is advisable to wear protective gloves to prevent contraction
of the fluids that may lead to infections or diseases.
b) Compare the normal and sample values. List any abnormalities you observe in
the section below. Are they higher or lower than normal?
The colour change in sample 2 changes from yellow to reddish tinge
c) Give a situation in which you might expect to see these changes in an otherwise healthy
individual. A situation where a person uses drugs
d) What might have been happening in the nephron to cause these abnormal results?
Explain your observed abnormalities by linking them with the part of the nephron
involved and the process involved (ie filtration, secretion or reabsorption). Ensure that
any relationships between the abnormal readings are made clear in your response. (2 m
It compromises kidney function by promoting liver diseases
Question 7
Why is injury to the medulla oblongata frequently fatal? (2 marks)

The brain stem or medulla oblongata controls the autonomic functions of the brain such as
breathing, digestions and heart rate to mention just a few. However, damaging it will disrupt
these functions and since they are essential to living, the result will be death or life long
hospitalization with life support for the patent or victim
Question 8
Picture Name of phase Description of phase
a)
Vascular spasm phase
A cut blood vessel constricts
due to inherent vascular
response to injury as well as
induced vasoconstriction. The
constriction slows blood flow
via the defect and then
prevents blood loss. Since this
measure alone cannot prevent
further blood l, it minimizes
blood flow via a break in the
vessel until when the other
homeostatic measure is able to
plug up the defect.
b)
Platelet plug formation
Platelets join to form a plug at
the cut vessel. They(platelets )
don’t stick to smooth
endothelia surfaces of the
blood vessel , however when
the lining is damaged due to
vessel injury, platelets
becomes activated by the
exposed collagen and
immediately sticks to the
collagen to form a homeostatic
plug at the cut site.
c) Blood clotting
Blood clotting is due to a
chain reaction involving
plasma clotting factors.
Clotting is transformation of
blood from a liquid state into a
solid gel. The formation of
clot on the platelet plug makes

the plug stronger by
reinforcing a seal over a cut in
the vessel. Blood clotting in
this phase helps prevent
bleeding from any imminent
defect.
Question 9
Picture Vessel type? Identifying
cause
Layer of
vessel
Notable
because
Relates to vessel
a) Elastic artery Have thick
walls made of
three layers
Tunica
adventitia
Because it
contains
blood vessels
and nerves
Acts as a
supportive
vessel
b) Continuous
capillary
Are small in
size and the
walls are
single cell
thick
Media and
adventitia
muscles
Have a
continuous
basal laminae
They convey
blood between
venules and
arterioles
c) venule Narrow layer
of smooth
muscle cells
Three tunics Presence of
simple off-the
–shelf tube
Allows blood to
return from the
capillary beds to
drain into the
larger blood
vessels,
d) Muscular
artery
Has three
layers
tunica
externa.
Because it
contains
blood vessels
and nerves
Acts as a
supportive
vessel
Question 10

Mechanism Body temperature Blood pressure Mechanism: blood
clotting
Hormone: Thrombin
Role Maintaining body
temperature within
narrow, optimal
limits
Maintaining normal
blood pressure in the
body
Preventing excessive
bleeding
Receptor Thermoreceptor in
skin
Baroreceptors in the
heart
platelets
Control centre Brain (hypothalamus Brain Blood vessels
Effector Sweat glands and
arterioles near the
skin
Heart and blood
vessels
Platelets and proteins
in the plasma
Positive or negative
feedback?
Negative Negative Positive
Question 11
a)What is the mother’s genotype? Explain your reasoning. (1 mark)
Genotype is XDXd
Reason: Duchenne is carried on the x chromosome and since it is a recessive sex linked disorder.
b) What is the father’s genotype? Explain your reasoning. (1 mark)
Genotype is XD Y
Reason: since the father has no duchenne alleles which are denoted by d.
c) What is the likelihood of the male foetus having DMD? Use a punnet square to explain your
answer. (1 mark)
x
XD Xd
Xd X DXd Xd Xd
Y XD Y Xd Y
The likelihood of male foetus having DMD is 1:4
Question 12

Proteins are digested by pepsin at a neutral pH in the stomach. Further protein digestion is
achieved by pancreatic peptidase in the duodenum and completed at the microvilli by brush
border enzymes to liberate bile salts for absorption. Digestion in the small intestine requires a
pH that is alkaline. Intestinal pH is adjusted by secretion of bicarbonate produced by the liver
and insulin produced by the pancreas. Pancreatic enzymes show specificity for their
substrates. Pancreatic amylase digests carbohydrates to Disaccharides and disaccharides.
Brush border enzymes complete carbohydrate digestion to Monosaccharide’s for absorption.
Pancreatic lipase, together with bile salts acting as an emulsifying agent, digests fats to
monoglycerides and free fatty acids. Monosaccharides and amino acids are absorbed into the
intestinal capillaries. Monoglycerides and free fatty acids are absorbed into the Lymphatic
vessels.
Question 13
Describe the changes in volume and pressure inside the chest cavity during a normal
exhalation. Explain why these changes are occurring, and the effect upon airflow. (2 marks)
Exhalation increases internal volume of the lungs thus decreasing the volume in thoracic
cavity. This is because decreased volume in thoracic cavity increases pressure that pushes
lungs back to their normal shape hence allowing lungs to expel air during exhalation
Question 14
Question Answer
Contraction of which muscle/s produces the
movement labelled 1? Diaphragm muscles
Contraction of which muscle/s produces
movement labelled 2 Thoracic cavity
At label “3”, is pressure outside greater than or
less than pressure in the lungs The pressure is lower
Is the pressure in the space labelled "4", higher
or lower compared to atmospheric pressure The pressure is lower
At label “8”, is pressure outside greater than or
Less than pressure inside the lungs The pressure is greater
Name any ONE muscle that contracts to cause
the extra movement required when you need to External intercostals muscles

expire forcefully
Question 15
Regarding ventilation, which process is active - inhalation or exhalation? Explain your answer.
(1 mark)
Inspiration is the most active process regarding ventilation. It involves contraction of the
diaphragm where thoracic cavity increases in volume hence decreasing the intra-alveolar
pressure such that air flows into the lungs
16. Infectious agent: Salmonella typhi
Reservoir: contaminated food icy-slushie
Mode of transmission: contaminate food
Portal entry: mouth
Susceptible host: young child; immature immune system
Question 17
Location Type of epithelium Relate structure to function
Bladder
Transitional epithelium
Permits repeated cycles of
stretching and recoiling.
This allows the bladder to
cope with large changes in
volume (ie stretch as it fills
with urine, and recoil upon
micturition
Alveoli Squamous epithelium Facilitates transfer of gases
between the alveolar air as
well as the blood. They also
allow passage of materials
via filtration plus simple
diffusion in sites where
protection is not necessary
Trachea Presudostratified squamous
epithelium
Their mucous secretion and
cilia aids in collection of
foreign material so than they
can be coughed or sneezed
out

Jejunum Simple Columnar epithelium Lines organs of the digestive
tract such as the small
intestine , stomach and the
large intestine
Question 18
During resting membrane potential the inside of the cell is 70 mV more negative than the
outside of the cell. When a stimulus is applied, the membrane potential must reach peak
action potential in order for an Action Potential to be fired. At the start of an Action
Potential, Na+ channels open and Na+ ion enter the cell. This phase is called depolarization.
Which number indicates the point where a stimulus is applied 8? The action potential is the
period of time in which the nerve membrane can start another action potential only if a much
greater stimulus than usual is applied.