It's been a while since this blog is updated with a new post. This could be due to the hectic schedule post holiday, with all the buzz of the short and fast midterm.
Anyway this blog's topic is a summary of rare diseases of Endocrine System and different hormones produced by glands, particularly from the gonads or sex organs. Sound interesting? well just keep scrolling.... and maybe like Archimedes you'll find something that will make you shout EUREKA!!
Hormone stimulated by Sunlight
Melanocyte-stimulating Hormone - MSH
What is MSH?
• Melanocyte-stimulating hormone (MSH) isone of
the several hormones secreted primarily by the anterior pituitary gland.
• This hormone regulates the synthesis and
production of pigment granules called melanin in specialized cells and thereby
influences changes in skin pigmentation.
What does it do to Humans?
• To mammals are to suppress appetite.
• Its most major effect in humans is to
increase the total amount of pigment in the skin and therefore control the skin
tone.
• In humans exposure to sunlight stimulates the production and secretion of
MSH, which causes the skin to darken.
• This darkening results from a change in the
total amount of melanin present in the melanocytes.
How does it produce melanin?
 |
Figure 1. Mechanism of Action of alpha MSH from UV exposure
|
Ultraviolet radiation (UVR) induces DNA
damage in epidermal cells, and evidence supports DNA damage is a key signalling
event in UVR-induced tanning, triggering increased α-MSH
synthesis by keratinocytes. The secreted α-MSH binds to the melanocortin 1 receptor
(MC1R) on nearby melanocytes, increasing cAMP and cAMP-dependent protein kinase
production and ultimately the activity of the melanogenic enzymes, including
tyrosinase (Fig. 1). Increased cutaneous eumelanin production results in skin
pigmentation, providing a partial barrier to penetration of UVR and visible
light. In particular it forms a protective 'nuclear cap' of melanin over the
nuclei of basal keratinocytes. Eumelanin also scavenges UVR-induced reactive
oxygen species that can damage DNA, proteins and lipids.
Gonads
- a sex organ that can be able to produce sperm or egg cells.
- Either a male’s testicle or a female’s ovary
Ovarian hormones & their actions
Its Hormones
First off.. what is a hormone? These are natural substances produced by our body. They also influence the way we grow and develop!
What hormones can be found the male and female gonads?
As a component of the endocrine system, both the male and female gonads produce sex hormones or steroid hormones which can pass through cell walls to influence some cell’s genes and express them.
FEMALE HORMONES
- ESTROGEN: also known as Estradiol, this hormone is important for the development of a female’s characteristics. It does not only bring changes to a woman’s menstrual cycle, but also to her physical feature. Some examples would be breast development, widening of the pelvis (hip bone), greater fat distribution in the hips and increased growth of body hair.
- PROGESTERONE: this hormone prepares the uterus for birth, regulates changes during the menstrual cycle, increases sexual desire, and stimulates the development of other glands needed for the production of milk during pregnancy.
- ACTIVIN: this hormone assists in the regulation of the menstrual cycle.
MALE HORMONES
- ANDROGEN: this hormone influences the development of the male reproductive system. NOTE that this hormone can also be found in women, but with much higher levels in med.
- TESTOSTERONE: this sex hormone is important for the development of the male’s sex organs and sex characteristics. It is also responsible for increased muscle and bone mass, increased growth of body hair, development of broad shoulders, deepening of the voice and penis growth.
- INHIBIN: this hormone is involved with the production and regulation of sperm cells.
SECONDARY Sexual CHARACTERISTICS
When we say secondary sex characteristics, these are indicators of sexual maturity that develops during puberty. For males, the sex hormone testosterone is responsible for the increase in larynx size (thereby deepening one’s voice), penile growth, emergence of pubic, facial, and armpit hairs, development of the skeletal muscles, as well as elevated production of sebum and sweat. In females, estrogens account for the enlargement of the breast and nipples, development of pubic hair, vaginal growth, broadening of the hips and waist, as well as the initiation of menstruation as a response of the endometrium. Both sexes may have an increase in the levels of growth hormone and related hormones in order to promote growth and development.
SECONDARY Sexual CHARACTERISTICS
When we say secondary sex characteristics, these are indicators of sexual maturity that develops during puberty. For males, the sex hormone testosterone is responsible for the increase in larynx size (thereby deepening one’s voice), penile growth, emergence of pubic, facial, and armpit hairs, development of the skeletal muscles, as well as elevated production of sebum and sweat. In females, estrogens account for the enlargement of the breast and nipples, development of pubic hair, vaginal growth, broadening of the hips and waist, as well as the initiation of menstruation as a response of the endometrium. Both sexes may have an increase in the levels of growth hormone and related hormones in order to promote growth and development.
Ovarian hormones & their actions
Hormones
secreted by the ovary is triggered by the release of two hormones coming from
the Anterior Pituitary Gland which are the Luteinizing Hormone (LH) and
Follicle Stimulating Hormone (FSH). These two hormones are then controlled by
another releasing hormone which is the GnRH or Gonadotropin Releasing Hormone
coming from the Hypothalamus. The release of LH and FSH can then be triggered
if a woman is preparing to ovulate, to have her monthly period, or prior to
being pregnant.
The
ovary secretes the following hormones:
1.
Progesterone
2.
Estrogen
3.
Inhibin
4.
Relaxin
Progesterone.
This functions mainly to regulate the
condition of the inner lining (endometrium) of the uterus. In the
ovaries the site of progesterone production is the corpus luteum.Progesterone is secreted after ovulation prior to being
pregnant because of the Luteinizing hormone. If no fertilization (meeting of
egg and sperm) occurs in the female, the corpus luteum will gradually
degenerate and the endometrium will shed causing Menstruation.
Estrogen.
This mainlyaffects the uterus,andmammary glands. In the ovaries, the site of estrogen production are the developing follicular cells and
the corpus luteum. Estrogen help to stimulate the growth of the egg
follicle. They also build and maintain the endometriumincreasing the
endometrium’s size and weight, cell number, cell types, blood flow,
protein content, and enzyme activity. Estrogens also stimulate the muscles in
the uterus to develop and contract and responsible for growth of the breasts
during adolescence, pigmentation of the nipples, and the eventual cessation of
the flow of milk.
Relaxin
and Inhibin.
Inhibin,
hormone secreted by the granulosa cells in the ovaries acts primarily to inhibit the secretion of follicle-stimulating
hormone (FSH) by the anterior pituitary gland. Since the major action of
follicle-stimulating hormone is to stimulate the formation and function of
granulosa cells, the relationship between inhibin and follicle-stimulating
hormone represents a typical negative feedback servomechanism.
Relaxin
is produced in the corpus luteum. Relaxin promotes the development of the nipples and mammary glands in pregnant mammals. Because of
these effects, relaxin was initially thought to serve only as a pregnancy
hormone.
Endocrine Disorders
Acromegaly is a hormonal disorder that most commonly occurs in middle-aged men and women.
Acromegaly comes from Greek words “acro” (extremities) and “megaly” great
because one of the most common symptoms is abnormal growth of hands and feet.
Causes and Symptoms
Cause: Pituitary gland produces too much growth hormone during
adulthood. When Growth Hormone is secreted into your bloodstream, it triggers
your liver to produce a hormone called insulin-like growth factor-I (IGF-I). Too
much IGF-I can cause abnormal growth of your soft tissues and skeleton.
Symptoms:
·
Enlarged
hands and feet
·
Coarsened,
enlarged facial features
·
Coarse,
oily, thickened skin
·
Excessive
sweating and body odor
·
Small
outgrowths of skin tissue (skin tags)
·
Fatigue
and muscle weakness
·
A
deepened, husky voice due to enlarged vocal cords and sinuses
·
Severe
snoring due to obstruction of the upper airway
·
Impaired
vision
·
Headaches
·
Enlarged
tongue
·
Pain
and limited joint mobility
·
Menstrual
cycle irregularities in women
·
Erectile
dysfunction in men
·
Enlarged
liver, heart, kidneys, spleen and other organs
·
Increased
chest size (barrel chest)
Gigantism
It is a rare
condition that causes abnormal growth in
children because of too much production of growth hormone while epiphyseal
growth plates are open during childhood.
Causes: Pituitary gland tumor is
almost always the cause of gigantism. When a tumor grows on the pituitary
gland, the gland makes more growth hormone than the body needs.
Symptoms:
·
Delayed puberty
·
Double vision or difficulty with side
(peripheral) vision
·
Frontal bossing and a prominent jaw
·
Headache
·
Increased sweating
·
Irregular periods (menstruation)
·
Large hands and feet with thick fingers and
toes
·
Abnormal growth in height
·
Release of breast milk
·
Thickening of the facial features
·
Weakness
How do Gigantism and Acromegaly differ?
Acromegaly commonly occurs in middle-aged individuals while Gigantism occurs at puberty. Both are due to pituitary gland tumors but they differ on manifestation and symptoms.
Dwarfism
WHAT IS DWARFISM?
Dwarfism or restricted growth, is
a condition that is typically characterized by a short stature and various
other symptoms, depending on the cause of the condition. Technically, that
means an adult height of 4 feet 10 inches or under.
Dwarfism generally refers to a
group of genetic disorders characterized by shorter than normal skeletal
growth. Achondroplasia is the most common type of dwarfism. The majority of
children born with this condition have average-sized parents. Abnormal skeletal
growth is known as skeletal dysplasia.
Causes
· can be caused by any one of
more than 300 conditions, most of which are genetic. The most common type,
accounting for 70% of all cases of short stature, is called achondroplasia.
· can and most often does occur
in families where both parents are of average height. In fact, 4 out of 5 of
children with achondroplasia are born to average-size parents.
Diagnosis and treatment
A diagnosis of dwarfism is based primarily on
measurements of the child’s height, weight and head circumference. Other
factors taken into consideration include genetics, family medical history and
the results of hormone tests and imaging studies.
Treatment cannot improve stature but is aimed at
improving complications of the condition.
Video
The
Science of Dwarfism
FUN FACTS
Midget. The term
midget is considered very offensive by many people with dwarfism. Although
dwarf and little person are acceptable, it is preferable that a person with
dwarfism be addressed by his/her name.
Lower IQ. People
with achondroplasia have "normal" intelligence. Achondroplasia
affects the growth of the long bones in the body. It greatly decreases the
growth in areas that have more cartilage. Since the nose is formed with
cartilage, it is another body part that usually remains small.
People with achondroplasia usually produce
adequate growth hormone. The change on the FGFR-3 gene, which causes
achondroplasia, does not allow growth hormone to work properly. At this time,
extended limb lengthening is the only procedure that would allow a person with
achondroplasia to achieve average or close to average height. This procedure is
controversial among some people with dwarfism.
the same as people of
average height. People with achondroplasia are at the same risk for
illness as that of the general population. Doctors encourage people with
dwarfism to watch their weight. Extra stress on the smaller joints can cause
orthopedic damage.
REFERENCE
http://www.britannica.com/EBchecked/topic/478202/progesterone
http://www.britannica.com/EBchecked/topic/193679/estrogen
http://www.britannica.com/EBchecked/topic/496940/relaxin
http://www.britannica.com/EBchecked/topic/288233/inhibin
Contributors
Cacho,Joyce Angelica
De Guzman, Trisha Mariah
Delfin, Nathaniel
Denolo, Maria Nicole
Hipe, Alyanna
Okafor, Vera Marie
Sarines, Johnathan
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| End. |
REFERENCE
http://www.britannica.com/EBchecked/topic/478202/progesterone
http://www.britannica.com/EBchecked/topic/193679/estrogen
http://www.britannica.com/EBchecked/topic/496940/relaxin
http://www.britannica.com/EBchecked/topic/288233/inhibin
Contributors
Cacho,Joyce Angelica
De Guzman, Trisha Mariah
Delfin, Nathaniel
Denolo, Maria Nicole
Hipe, Alyanna
Okafor, Vera Marie
Sarines, Johnathan
