Homeostatic Control of Body Systems
Unit 9 Learning aim B Joshua Moloney-Griffiths
Table of Contents
B. Introduction…………………………………………………...1
B. P2. Describe how homeostatic mechanisms maintain
normal function………………………………………………........
B. M2. Explain the role of hormones in homeostatic
mechanisms……………………………………………................
B. D2. Analyse the impact of homeostatic dysfunction on the
human body……………………………………………………....
B. Conclusion..........................................................................
, Homeostatic Control of Body Systems
Introduction
In this report I will discuss the homeostatic control of body systems. This will
include how physiological mechanisms involved in homeostasis maintain
normal function, the role of hormones and how they interact with body
systems for optimal bodily function.
Furthermore, I will explain, analyse and evaluate the regulation of the
physiological mechanisms:
Osmoregulation (Water concentration)
Thermoregulation (Temperature)
Blood glucose levels
Dysfunctions and interrelations of these homeostatic mechanisms will also be
covered.
Homeostasis:
Defined as the maintenance of a constant internal environment needed for
function and survival of an organism. Regulatory systems are actioned around
the body to resist against an imbalance of optimal internal conditions for
example, pH, temperature, water concentration or salt concentration all need
to be maintained to keep a steady internal state.
[Ref. 1]
This helps us understand the major role of homeostasis in organisms.
Glands and organs
The Endocrine System:
A network of glands which synthesize and secrete hormones directly into the
bloodstream, so they can reach all organs and tissues around the body.
Mainly promotes growth and development of the human body as the
hormones released aid the functions of almost all cells and organs. Generally,
is slow in its effect, but is long lasting until a concentration decreases.
The endocrine system is dependent on hormones. Hormones are chemical
messengers that transmit information from one cell to another via the blood.
This helps control and coordinate processes that occur around the body.
Another example of this in the body is the central nervous system and how
cells rely on neurotransmitters released by nerve synapses to send signals
from one cell to another. Electrical impulses are quick in effect but is very
brief.
[Ref. 2]
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, Homeostatic Control of Body Systems
The Exocrine System
Exocrine glands contain a ductal system which transports their secretions
along ducts to the duct surface – this is unlike the endocrine system which
only circulates its secretions internally through the bloodstream. An example
of this is the sweat glands, and it transporting sweat along its duct to the
surface in the skin. The main function of exocrine glands depends on exactly
what gland, but some such as the liver (which is also endocrine) help with
digestion by secreting digestive substances into the bile duct.
[Ref. 8, 25a.]
(Figure 1. The location of the major endocrine glands in the human body.
https://biologydictionary.net/endocrine-system/ )
Main glands with location, secretion(s) and functions:
Gland Location Secretion(s)
Exocrine Sweat glands. Dermis layer Sweat.
[Ref. 10] of the skin.
Brunner’s Duodenum. Alkaline mucus.
glands.
[Ref. a]
Salivary Lining of the Saliva.
glands. lips, tongue
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, Homeostatic Control of Body Systems
[Ref. 11] and roof of the
mouth.
Endocrin Hypothalamus. Centre of the hormones; anti-diuretic hormone
e [Ref. 12, 13] brain. (ADH), corticotrophin-releasing hormone
(CRH), gonadotropin-releasing hormone
(GnRH), oxytocin (OT), prolactin (PRL),
somatostatin (SS), growth hormone (GH),
growth hormone-releasing hormone (GHRH)
and thyrotropin-releasing hormone (TRH).
Pituitary. Base of brain, hormones; thyroid-stimulating hormone
[Ref. 14] above the (TSH), adrenocorticotropic hormone (ACTH),
hypothalamus. follicle-stimulating hormone (FSH), luteinizing
hormone (LH), growth hormone (GH),
prolactin (PRL), oxytocin (OT) and anti-
diuretic hormone (ADH).
Other; endorphins and polypeptides.
Pineal. Middle of the Melatonin.
[Ref. 15] brain at the
epithalamus.
Thyroid. Front of the Thyroxine.
[Ref. 16] neck, below
the larynx.
Parathyroid. Behind the Parathyroid hormone.
[Ref. 17] thyroid gland
in the neck.
Thymus. Between the Thymosin.
[Ref. 18] lungs behind
the breast
bone in the
chest.
Adrenal. On top of both Adrenaline, cortisol,
[Ref. 20, 21] kidneys. aldosterone, dehydroepiandrosterone (DHEA)
, testosterone, adrenocorticotropic hormone
(ACTH).
Ovaries Lie either side Oestrogen, progesterone.
(female). of the uterus.
[Ref. 21]
Testes (male). Scrotum. Testosterone, inhibin B, anti-Müllerian
[Ref. 22] hormone, oestradiol.
Exocrine Pancreas. Abdomen. Exocrine; pancreatic juice, alkaline mucus.
and [Ref. 23] Endocrine; Insulin and glucagon.
endocrine
Liver. Abdomen. Exocrine; Bile
[Ref. 24] Endocrine; insulin-like growth factor,
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