Regulates 2000). Regulates the amount of sugar in our





Regulates blood pressure – Blood
pressure needs to stay within the range of 120/80 outside of theses ranges it
can cause us to have a stroke, become ill quickly or even die (Clegg, 2000).


Regulates the amount of sugar in our blood – The acceptable
blood glucose levels are between 4-10 m.mol/litre.
If your blood sugars drop lower than 3.5m.mol/litre hypos can
occur.In the same way if your blood sugars raise above 10.1 m.mol/litre it can
cause hypers both these can cause serious fatalities such as comas or even

We Will Write a Custom Essay Specifically
For You For Only $13.90/page!

order now


Body temperature – Normal body temperature is 37 degrees,
Temperatures way above or below these normal levels cause serious
complications. At 28 degrees Muscle failure occurs and loss of consciousness
occurs from 33 degrees. the central nervous system starts to break down at 44
degrees and sadly even death occurs at a temperature of 44 degrees.



Q3 List three things in the human body that are controlled by
homeostasis and state their acceptable range of parameters.





6/ The enzymes that control every
chemical response in our body work best at their optimum temperature of 37
degrees Centigrade. If our body cells get excessively hot or excessively cold
they would die (Clegg,


5/ Seventy percent of our weight is water. Without keeping
the appropriate measure of water we would die. The kidney is the key methods
for this control.


4/Having enough glucose for respiration
plus acceptable supplies of glycogen
is vital. If the blood glucose level falls too low we will die.











3/If the right balance of ions
is not kept, our cells can become shriveled, swollen or even burst. Sodium, Potassium,
Hydrogen and Phosphate are Important ions. These are controlled by our urine
and the volume of water we drink. We also lose some, like sodium ions, through
our faeces and our sweat.


2/Urea is the waste chemical produced when we digest
amino acids in the liver. It is poisonous and so must be removed. This is done
mainly through the urine, but an amount is lost through our sweat.


1/Extra carbon dioxide must be removed, because the body
turns too acidic. It is lost mainly in the air we breathe out, but a small
amount is lost in the urine.


All our cells are contained in
a watery solution, which is made by some of our blood plasma this is allowed to
leak out of our blood, meaning it carries away any waste materials back into
the blood. The balancing act of these things within the tissue fluid it is
vital for the cells and the whole body. There
are six things that are essential for health and that must be controlled.


Homeostasis is a vital characteristic of living things.
Keeping a stable internal environment requires constant adjustments as
conditions change inside and outside the cell. The adjusting of systems within
a cell is called homeostatic regulation. Because the internal and external
environments of a cell are constantly changing, adjustments must be made
continuously to stay at or near the set point (the normal level or range).
Homeostasis can be thought of as a dynamic equilibrium rather than a constant,
unchanging state (Clegg,


Q2 What is the point of homeostasis? Is it useful?


It means maintaining a constant environment. The nervous and endocrine systems control
homeostasis in the body through feedback mechanisms involving various organs
and organ systems Homeostasis
is the regulation of conditions in the body such as temperature, water content
and carbon dioxide levels. It is through the homeostatic system that body
temperature is kept to normal range, the osmotic pressure of the blood and its
hydrogen ion concentration (pH) is kept within strict limits, nutrients are
provided to cells as required, and waste products are removed before they
accumulate and reach toxic levels of concentration. These are but a few
examples of the thousands of homeostatic control systems within the body (, 2017). The organs
that take part in homeostasis are: hypothalamus, pituitary gland, Liver, lungs, pancreas, muscles, Kidney, Skin.


Q1 What is homeostasis?


Based on the knowledge you have gained in class and from this video
resource please answer the questions below.


Watch this video:


Part C (assessment criterion 4.3)









sympathetic nerves increase your heart rate while you exercise, while the parasympathetic
nerves slow the heart rate after you are done. The accelerans, or sympathetic
nerves, carry nerve impulses from the medulla oblongata in the brain to the
heart. The heart reacts by increasing both the rate of contraction and the
strength of the contractions. You can increase your heart rate to up to 180
beats per minute by exercise this is one way that pathway is activated. This
will increase the amount of blood pumped by the heart and sent out to
exercising muscles. As the atrium stretches to
accommodate the extra blood, the stretch receptors in the heart muscle relay
the information to the medulla oblongata.The harder the muscle pump works, the
more blood gets sent to the right atrium of the heart. The increased
concentration of carbon dioxide is recorded by special receptors in the aorta
and carotid arteries, and this information is passed to the medulla
oblongata.The muscle pump is the contraction of muscles surrounding your veins,
which pushes blood back to the heart. When you are
cooling down and no longer require the increased cardiac output needed during
exercise, pressure receptors in the carotid arteries and the aorta signal the
vagus nerves of the parasympathetic nervous system. They then send the message
from the medulla oblongata to the heart that slows your heart rate down. Noradrenaline is a hormone secreted by some sympathetic nerves. It has the
capability to cause your arteries to contract, forcing blood through at a
quicker rate. This hormone plays a role in increasing your heart rate and the
strength of the beats. Acetylcholine on the other hand, is a hormone secreted
by the vagus nerve this helps in the reduction of your heart rate. The
sympathetic and parasympathetic nervous systems work together to dictate your
heart rate (UC Davis Health,


Describe how the autonomic nervous system controls a human’s heart rate.



the thyroid hormone level is too high, this increases the basal metabolic
rate, speeds up the chemical reactions in the body, causes the release of
more heat, and the person often feels too hot. If the thyroid hormone level is
too low, this decreases the basal metabolic rate, slows down the
chemical reactions in the body, causes the release of less heat, and the person
often feels too cold (, 2017).


These hormones Instructs every cell in the body when
to consume oxygen and nutrients this
controls the body’s metabolism; these reactions are cells perform to provide us
with energy. This hormonal notification from the thyroid gets the heart pumping
more efficiently and makes our cells breaks down nutrient faster when you need
more energy the thyroid helps by sending out hormones to increase metabolism’s
thyroid helps our cells to use energy, grow and reproduce.


The thyroid gland secretes two main thyroid hormones
which are triiodothyronine (T3) and thyroxine (T4). T3 and T4 regulate your
body’s temperature, metabolism and heart rate.

The 2 main thyroid hormones are T3
(triiodothyronine) and T4 (thyroxine). T3 and T4 regulate your body’s
temperature, metabolism and heart rate.

the thyroid gland secrete?


The 2 main thyroid hormones are T3
(triiodothyronine) and T4 (thyroxine). T3 and T4 regulate your body’s
temperature, metabolism and heart rate.

thyroid gland secrete?

The 2 main thyroid hormones are T3
(triiodothyronine) and T4 (thyroxine). T3 and T4 regulate your body’s
temperature, metabolism and heart rate.

thyroid gland secrete?

The 2
main thyroid hormones are T3 (triiodothyronine) and T4 (thyroxine). T3 and T4
regulate your body’s temperature, metabolism and heart rate.

the thyroid gland secrete?

The 2 main thyroid hormones are T3
(triiodothyronine) and T4 (thyroxine). T3 and T4 regulate your body’s
temperature, metabolism and heart rate.

thyroid gland secrete?


Hormones are secreted by organs in the endocrine system. Describes how
hormones produced by the thyroid hormone regulate at least three processes in
the body.


Part B (assessment criterion 4.2)










Figure 3. The function and process of the
neuromuscular junction (, 2017)





The larger influx of sodium ions in comparison to the
outwards flux of potassium ions this makes the membrane the potential to be
less negative. When the membrane potential is at its threshold value an action
potential transmits along the cyrcolema. Removal of the acetylcholine from the
synaptic cleft happens, the neurotransmission to muscle fibres stops. This can
take place in one of two ways. Acetylcholine diffuses away from the synapse
alternatively acetylcholine with the assistance of acetylcholinesterase is
broken down into acidic acid along with Choline Following this resynthesise of
the choline then happens when it is transported into the axel terminal (Clegg, 2000).



arrival of an action potential travels down a motor neuron to an
axel terminal. Next voltage gated calcium channels open and calcium ions
diffuse into the terminal. Through the process of exocytosis calcium entry
enables synaptic vesical to release acetylcholine this then diffuses across the
synaptic cleft and fuse to acetylcholine receptors that comprise of ligand-gated
cat ion channels. This channels then opens allowing sodium ions to endocytose
the muscle fibre whilst potassium ion fibres exocytose the muscle fibres.












Figure 2. Synapse with receptor
physiology (Receptor,


The Synaptic
cleft is the space between the motor end plate muscle fiber part and synaptic
end bulb on the motor neuron part of the neuromuscular junction. This cleft
makes a gap between the motor neuron and the muscle fiber break resulting in
the action potential not being able to cross. Transmission across the synaptic
cleft isn’t electrical its chemical, in which carry the impulse from one side
of the cleft to the other using small diffusible molecules. Acetylcholine and
Noradrenaline are frequent transmitter substances.

piece of the sarcolemma of muscle cell, which is in closest proximity to the
synaptic end bulb is called the motor end plate. It demonstrations certain
specific features different to those of the other regions of muscle cell
sarcolemma. One being the Synaptic
Gutter which is the invaginated membrane, which creates space
for the synaptic end bulbs to get close to the muscle fiber sarcolemma. Another
is the Subneural Clefts,
they are small folds of the muscle membrane located at the bottom of the
synaptic gutter. They majorly increase the surface area at which the
neurotransmitter can perform. The final one being the Increased number of mitochondria. The
area in which the muscle fiber surrounds the motor end plate demonstrate a significant
increase in the number of mitochondria. The obvious explanation for this is the
energy by form of Adenosine Trisphosphate demand of the neuromuscular junction (Clegg, 2000).











axon of the motor neuron enters the skeletal muscle, it makes numerous branches
called axon terminals. At the end of each axon terminal, is a bulbous swelling
called “synaptic end bulb”. Every synaptic end bulb comprises of many synaptic
vesicles. These vesicles consist of the vital neurotransmitter substances such
as acetylcholine. These neurotransmitter substances are in charge of
transmission of impulse from axon to muscle fiber using the synapse.


neuromuscular junction is composed of three parts Synaptic end bulbs, Motor end
plate and the Synaptic cleft.


The soma is the cell body which contains the nucleus
and a significant number of the organelles found in different sorts of cells
like ribosomes, chromosomes, Golgi apparatus, and so on, yet no centrioles. The
axon consists of a solitary long tube that stretches out from the soma with
various branching’s at the end of it. The
fundamental job role of the axon is to convey a message from the soma to the
terminal buttons, that are the structures at the end of the axon that discharge
the neurotransmitters into the synaptic cleft. The dendrites are the smaller
tree-like branching’s that project from the soma. Their main job is to get the
signs from the axons of different neurons (Clegg, 2000).



Figure 1. A basic structure of a motor
neuron (O’Reilly | Safari, 2017)





Neuromuscular junctions are the place
and means by which the motor neurones of the nervous system instruct the muscle
cells of the muscular system to take actions leading onto muscle