Biology Homework: Human Body Systems - Homeostasis, Nervous, Excretory

This biology assignment comprehensively covers three key human body systems: homeostasis, the nervous system, and the excretory system. It begins by defining homeostasis and then explains the mechanisms of body temperature regulation and water balance, including the roles of the hypothalamus, sweat glands, blood vessels, osmoreceptors, and the kidneys. The assignment also explores the regulation of blood glucose levels by the endocrine system, focusing on insulin and glucagon. It then delves into the structure and functions of the nervous system, differentiating between the central and peripheral nervous systems and detailing the roles of the brain, spinal cord, and autonomic nervous system. The assignment further examines the similarities and differences between the endocrine and central nervous systems. Finally, it outlines the organs of the excretory system, including the kidneys, skin, lungs, liver, and urinary bladder, and describes their functions in waste removal and maintaining the body's internal environment. The assignment includes illustrations and tables to enhance understanding.

ASSIGNMENT

Table of Contents
Q1. DEFINE HOMOEOSTASIS?...................................................................................................1
Q2.....................................................................................................................................................1
Part 1. Procedure of maintaining body temperature and its importance................................1
Part 2. Maintenance procedure of water level inside the body and its importance................2
Part 3. Regulation of blood glucose level by endocrine system.............................................3
Q3. ...................................................................................................................................................3
Part 1. Major parts of Nervous system...................................................................................3
Part 2. Functions of each part of nervous system...................................................................4
Q4. SIMILARITIES AND DIFFERENCES BETWEEN ENDOCRINE AND CENTRAL
NERVOUS SYSTEM......................................................................................................................5
Q5. ORGANS OF EXCRETORY SYSTEM AND THEIR FUNCTIONS....................................6
REFERENCES................................................................................................................................8

Illustration Index
Illustration 1: Parts of Nervous System...........................................................................................3
Illustration 2: Illustration 1: Detailed structural Diagram of Excretory Organs .............................7

Index of Tables
Table 1: Similarities and differences between Endocrine and Central Nervous system ................5

Q1. DEFINE HOMOEOSTASIS?
Ans. Homoeostasis, is derived from Greek word that means “same” and “steady”. It is defined as
a biological process that is used to maintain a stable condition necessary for survival. It performs
the functions like regulation of body temperature, maintaining pH of extracellular fluid along
with concentration of potassium, sodium, calcium ions and glucose in blood plasma (Kajimura
and Saito, 2014).
Q2.
Part 1. Procedure of maintaining body temperature and its importance.
Ans. The body temperature in human beings is maintained by the process of neural feedback
mechanism that is operated through the hypothalamus. It is a region of fore-brain which contain
the control mechanism of body along with temperature controlling sensors.
In case when it is too hot outside:
Due to this control mechanism when the temperature of skin rises above 37 degree Celsius then
process of sweating is initiated from the sweat glands. It increases with the rise in temperature of
skin to regulate the inside body temperature (Raccuglia and et.al., 2016). Vasodilation of blood
vessels increases the flow of blood towards the skin to lose more heat.
In case when it is too cold outside:
When temperature of skin drops below 37 degrees then following responses are generated to the
conserve heat within the body:
 Cessation of sweating.
 Body starts shivering to produce more heat in muscles.
 Hormones like thyroxine, norepinephrine and epinephrine are released to generate more
heat.
 Constriction of blood vessels to lower the flow of heat towards skin.
It is necessary for our body to regulate the optimum temperature for the proper functioning of the
enzymes in our body. In case of high temperature the enzymes denature and become inactive and
in condition of low temperature, enzyme become less effective as their functioning slows down
(Liu and et.al., 2014).

Part 2. Maintenance procedure of water level inside the body and its importance.
Ans. Osmoregulation is the process that is used for regulating water concentration in
bloodstream and effectively manage the amount of water absorbed by cells. The procedure of
homoeostatic control of water is given below:
 Change in water concentration leads to activation of this mechanism through the process
of negative feedback control.
 This change in water level concentration is detected by Osmoreceptors that are situated
on hypothalamus following the circulatory system.
 Then hypothalamus forward these chemical messages to the pituitary gland present next
to it.
 This activated pituitary gland secretes the anti diuretic hormones (ADH) that in turn
trigger kidney (Fonseca and et.al., 2013). In human kidney plays a major role in process
of osmoregulation.
 After reaching to the target organ hormones like aldosterone, antidiuretic hormone and
angiotensin II alter the permeability of tubules of kidney to water.
 In case if more amount of water required in blood stream the concentration of anti
diuretic hormone rises to increase the permeability of kidney tubules.
 If, less amount of water is required then accordingly the concentration of the anti diuretic
hormone reduced to decrease the permeability of tubules.
Kidney also plays major role maintaining the water balance by generating urine of various
concentration. In condition when water level is low in blood plasma then urine become more
concentrated due to reabsorption of more water. In case when water level is too high in blood
plasma our urine become more diluted (Mikkelson and et.al., 2013).
It is important to maintain the optimum balance of water in body as: when our body is
short of water then it leads to dehydration. It can cause headache, tiredness, fatigue and loss of
concentration. In case of high concretion of water in body, the mechanism of organs is hindered
and can even lead to hyponatremia. It causes confusion, lung congestion, vomiting, brain
swelling and in severe case it leads to coma.
Part 3. Regulation of blood glucose level by endocrine system
Ans. It is important to maintain the blood glucose level in an appropriate range in body. Insulin
and glucagon plays the major role in maintaining the optimum level of blood sugar. They are
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secreted from pancreas and endocrine system is responsible for regulating the function of
pancreas. This is why insulin and glucagon are also known as pancreatic endocrine hormone
(Francis and Stevenson, 2013).
Insulin is secreted from beta islets cells present in pancreas. It is secreted in response to
stimulus of presence of high level of glucose in blood. It causes liver to transform more glucose
into the glycogen by taking up glucose from the blood through GLUT 4 transporters and result in
decrease level of blood sugar.
Similarly, glucagon is secreted from alpha islet cells of pancreas. It is secreted when the
level of blood glucose lower down. It causes liver to secrete more amount of glucose stored in
the cells into the blood vessels.
The blood glucose level in our body should be maintained in between the range of 70
mg/dl to 110 mg/dl. In case if it is below 70 mg/dl then person is suffering from hypoglycaemia
and if it is higher than 180 mg/dl than it is called hyperglycaemia. The person having blood sugar
measurement above 200 mg/dl is diagnosed with diabetes.
Q3.
Part 1. Major parts of Nervous system.
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Illustration 1: Parts of Nervous System

Part 2. Functions of each part of nervous system.
Ans. Central Nervous system (CNS): It controls all the functions of body and mind. It is also
responsible for receiving all the sensory information and respond to them accordingly. It mainly
consists of two part: brain and spinal cord.
 Brain: It is the main controlling centre of various functions of body like walking, talking,
breathing, smelling, taste, swallowing and so on. It is consists of three parts:
 Fore-brain: It is the largest part of brain having two divisions: the diencephalon and
telencephalon. Diencephalon consists of thalamus and hypothalamus that performs
various functions like controlling autonomic functions, motor control and transferring
sensory information. Telencephalon contains cerebrum which is the largest part of
brain. It performs the function of processing information in brain (Ciccarelli and
et.al., 2013).
 Mid-brain: It performs various functions that are involved in brainstem mechanism
like: controlling vocal cords, controlling function of pharyngeal and respiratory
muscles. It also controls the function of tongue, lips, palate and mandible. The
Periqueductal Gray controls facial tissue and laryngeal which is responsible for laugh
and cry.
 Hind-brain: It consists of brain stem and cerebellum. It helps in controlling the vital
automated system of body.
 Spinal cord: It helps in the transferring the nerve signals from motor cortex to the body
and from sensory neuron to sensory cortex (Zhang, Chen and Xu, 2014).
Peripheral Nervous system (PNS): The major function of PNS is connecting CNS to particular
limbs and organs and establishing the contact between brain, spinal cord and whole body.
 Autonomic Nervous system: It helps in regulating the body functions like heart rate,
respiratory rate, urination, digestion, pupillary response and sexual arousal. It consists of
two parts:
 Sympathetic Nervous system: It helps in preparing body for performing physical
activities by activating body's fight to flight response.
 Parasympathetic nervous system: It performs the opposite function of sympathetic
nervous system and helps in relaxing the body (Mathias and Bannister, 2013).
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 Somatic Nervous system: It performs the voluntary movement of muscles and organs and
second major function is process of the reflex arc. It consists of two parts:
 Spinal nerves: It helps in transfer of sensory, autonomic and motor information
among brain, spinal cord and whole body.
 Cranial nerves: There are various types of cranial nerves like olfactory nerves for
smell, optic for vision, oculomotor for movement of eyeball and eyelids and many
more (Dibona, 2013).
Q4. SIMILARITIES AND DIFFERENCES BETWEEN ENDOCRINE AND
CENTRAL NERVOUS SYSTEM.
Ans.
Table 1: Similarities and differences between Endocrine and Central Nervous system
Endocrine system Nervous System
Similarities  Regulation of many physiological processes involves the functional
overlap between two systems.
 In process of regulation they both use same positive and negative
feedback mechanisms (Morton and et.al., 2017).
Differences  Works through hormones that
are transmitted in the blood.
 It travels slowly and take long
time.
 Response generated is long
lasting.
 Works through nerve
impulses.
 It travels faster and have
instant effect.
 Response generated is for
short term.
Q5. ORGANS OF EXCRETORY SYSTEM AND THEIR FUNCTIONS
Ans. The organs involved in excretory system are as follows:
 Primary Excretory Organs.
 Kidneys: It filters out the waste that includes salt, urea and excess water in the form
of urine.
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 Skin: It performs the function of excretion through sweat glands and produce sweat
that contains excess salts, oils and other unnecessary substance (Bradley, 2013).
 Lungs: Lungs perform important excretory function of expelling carbon dioxide out
from body through the process of exhalation.
 Accessory Excretory Organs.
 Liver: Harmful chemicals and poisons that are either consumed or produced in body
are detoxified by liver.
 Gallbladder: A liquid juice produced in liver named Bile juice is stored in gall
bladder. It is discharged into the small intestine to break down the fats and acidic
waste.
 Urinary Bladder: Urinary bladder provides the storage area for urine until it is
discharged from the body.
 Ureters: Ureters perform the function of transferring liquid waste from kidney to
urinary bladder.
 Urethra: It is a tube that carry urine for its discharge out from the body (Verkhratsky
and et.al., 2016).
 Large Intestine: Undigested food particle that are not absorbed through small intestine
are transferred to large intestines for storage. This waste product is excreted from
body through anal canal.
Structure of Excretory system
The excretory system mainly consists of kidneys, ureters, urethra, bladder, skin and
lungs. Kidney is 10-13 cm long and 2.5-4 cm wide dark bean shaped organ. The kidney is
divided into two parts outer renal cortex and inner renal medulla. Within each kidney there are
millions of nephrons and each nephron consists of several capillaries that are known as
glomerulus. Each glomerulus is surrounded by cup shaped sac known as Bowman capsule.
Through the glomerulus the water, glucose and urea enters the bowman capsule leaving RBC
and WBC in the blood. Kidney help in controlling the liquid present in our body. At the end only
waste is left behind in the nephron and this waste is known as urine that consists of urea, water
and many other inorganic salts. Ureter consists of two narrow tube that carry urine from kidney
to urinary bladder. Urinary bladder is pear shaped hollow bag that helps our body to store urine
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for a small duration of time. At the end is urethra that is a muscle tube that help in passing out
urine from the body.
Structure Of Excretory Human Torso Labelled Structure Of Excretory System – Human
Anatomy. 2017.
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Illustration 2: Detailed structural Diagram of Excretory Organs

REFERENCES
Books and journals
Kajimura, S. and Saito, M., 2014. A new era in brown adipose tissue biology: molecular control
of brown fat development and energy homeostasis. Annual review of physiology,. 76.
pp.225-249.
Raccuglia, M. and et.al., 2016. Post-warm-up muscle temperature maintenance: blood flow
contribution and external heating optimisation. European journal of applied
physiology,. 116(2). pp.395-404.
Liu, L. and et.al., 2014. Cavin-3 knockout mice show that cavin-3 is not essential for caveolae
formation, for maintenance of body composition, or for glucose tolerance. PloS
one,. 9(7). p.e102935.
Fonseca, C. and et.al., 2013. Financing capital maintenance of rural water supply systems:
current practices and future options. The Hague: IRC International Water and Sanitation
Centre, pp.90-94.
Mikkelson, K. M. and et.al., 2013. Mountain pine beetle infestation impacts: modeling water and
energy budgets at the hill‐slope scale. Ecohydrology,. 6(1). pp.64-72.
Francis, H. and Stevenson, R., 2013. The longer-term impacts of Western diet on human
cognition and the brain. Appetite,. 63. pp.119-128.
Zhang, J., Chen, B. and Xu, X., 2014. Impact of rituximab on incidence of and risk factors for
central nervous system relapse in patients with diffuse large B-cell lymphoma: a
systematic review and meta-analysis. Leukemia & lymphoma,. 55(3). pp.509-514.
Ciccarelli, N. and et.al., 2013. Revised central nervous system neuropenetration-effectiveness
score is associated with cognitive disorders in HIV-infected patients with controlled
plasma viraemia. Antivir Ther,. 18(2). pp.153-160.
Mathias, C. J. and Bannister, R. eds., 2013. Autonomic failure: a textbook of clinical disorders of
the autonomic nervous system. OUP Oxford.
Dibona, G. F., 2013. Sympathetic nervous system and hypertension. Hypertension,. 61(3).
pp.556-560.
Morton, P. G. and et.al., 2017. Critical care nursing: a holistic approach. Lippincott Williams &
Wilkins.
BRADLEY, T. J., 2013. 10 The EXCretory System. Structure and Physiology. Regulation:
Digestion, Nutrition, Excretion, p.421.
Verkhratsky, A. and et.al., 2016. Astrocytes as secretory cells of the central nervous system:
idiosyncrasies of vesicular secretion. The EMBO journal,. 35(3). pp.239-257.
Online
Structure Of Excretory Human Torso Labeled Structure Of Excretory System – Human Anatomy.
2017. [Online]. Available through <https://anatomyclass123.com/structure-of-excretory-
human-torso-labeled/structure-of-excretory-human-torso-labeled-structure-of-excretory-
system-human-anatomy/>. [Accesesd on 8th September 2017].