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Transcript of Function Regulates mood Responsible for growth and development Tissue function Metabolism Sexual...
FunctionRegulates moodResponsible for growth and development Tissue functionMetabolismSexual function and reproductive processes
in the body
Foundations of the Endocrine SystemHormones
Transfers information and instructions from one set of cells to another
GlandsGroup of cells that produces and secretes, or
gives off, chemicals. A gland selects and removes materials from the blood, processes them, and secretes the finished chemical product for use somewhere in the body
Types of GlandsGlands can be divided into two groups:
Endocrine glands - glands that secrete their product directly onto a surface rather than through a duct.
Exocrine glands - secrete their products via a duct, the glands in this group can be divided into three groups:
- Apocrine glands - a portion of the secreting cell's body is lost during secretion - Holocrine glands - the entire cell disintegrates and secrete its substances - Merocrine glands - cells secrete their substances by exocytosis
Major Glands of the Endocrine SystemHypothalamusPituitary glandThyroidThymus glandParathyroidsAdrenal glandsPineal bodyReproductive glands (which include the
ovaries and testes)
HypothalamusCollection of specialized cells that is located in
the lower central part of the brainMaintains homeostasis
(examples: heart rate, body temperature, water balance, and the secretions of the pituitary gland)
Main link between the endocrine and nervous systems
Nerve cells in the hypothalamus control the pituitary gland by producing chemicals that either stimulate or suppress hormone secretions from the pituitary
Pituitary GlandLocated at the base of the
brain just beneath the hypothalamus
Often called the "master gland" because it makes hormones that control several other endocrine glands
The production and secretion of pituitary hormones can be influenced by factors such as emotions and changes in the seasons
Pituitary GlandThe pituitary is divided into two parts:
anterior lobe- regulates the activity of the thyroid, adrenals, and reproductive glands. The anterior lobe produces hormones such as: Growth hormone- stimulates the growth of bone and
other body tissues and plays a role in the body's handling of nutrients and minerals
Prolactin- activates milk production in women who are breastfeeding
Thyrotropin- stimulates the thyroid gland to produce thyroid hormones
Corticotropin- stimulates the adrenal gland to produce certain hormones
Pituitary Glandposterior lobe
helps control the balance of water in the body Produces oxyton: triggers the contractions of the
uterus in a woman having a baby
Secretes endorphins:chemicals that act on the nervous system and
reduce feelings of pain
ThyroidLocated in the front part of the lower neckShaped like a bow tie or butterfly Produces the thyroid hormones thyroxine and
triiodothyronine control the rate at which cells burn fuels from
food to produce energy.Help kids' and teens' bones grow and develop
Parathyroids
Four tiny glands that function together
Release parathyroid hormone: which regulates the
level of calcium in the blood
Adrenal GlandsTriangular shapedLocated above each kidneyEach gland has two parts:
Adrenal cortex, the outer part, produces hormones called corticosteroids that influence or regulate salt and water balance in the body, the body's response to stress, metabolism, the immune system, and sexual development and function.
Adrenal medulla, the inner part produces catecholamines such as epinephrine, also known as adrenaline. This increases blood pressure and heart rate when the body experiences stress.
Pineal GlandsLocated in the middle
of the brainSecretes melatonin:
hormone that may help regulate when you sleep at night and when you wake in the morning.
Reproductive GlandsMain source of sex hormones are the gonads:
sex gland in which gametes are producedMales
Male gonads, or testes are located in the scrotum
Secrete the hormone testosterone: Which affect many of the male characteristics such
as penis and height growth, deepening in the voice and growth in facial and pubic hair and sperm production.
Reproductive GlandsFemales
Female gonads, or ovaries are located on both sides of the uterus, below the opening of the fallopian tubes
Produce the hormones estrogen and progesterone Involved when a girl begins to experience breast
growth, accumulate body fat around the hips and thighs, a growth spurt. Estrogen and progesterone are also involved in the regulation of a girl's menstrual cycle and pregnancy
Thymus GlandLocated in the upper part of the chest cavity,
directly behind the sternumProcesses a type of white blood cell known as
a T-lymphocyte. They help cells recognize and destroy invading
bacteria, virus, and abnormal cell growth such as cancer, and foreign tissue.
PancreasAlso part of the digestive systemProduces two hormones:
Insulin and glucagon- work together to maintain a steady level of glucose in the blood and keep the body supplied with fuel to produce and maintain stores of energy
Negative Feedback MechanismsMain way to regulate blood levels of hormones.Rising hormone levels inhibit further hormone
release.
Example: The thyroid gland has secreted the right amount of thyroid hormones into the blood. The pituitary gland senses the normal levels of thyroid hormone in the bloodstream. Then the pituitary gland adjusts its release of thyrotropin, the hormone that stimulates the thyroid gland to produce thyroid hormones.
Gland Hormone Action Regulated byPineal Melatonin Sleep cycles Light and dark
Pituitary ADH Retention of water by kidneys Hypothalamus reponse to water/salt imbalance
oxytocin Uterine contractions Response to uterine stretching or baby suckling.
GH growth hypothalamus
Prolactin Milk production hypothalamus
FSH Production of ova and sperm hypothalamus
LH Stimulates ovaries and testes hypothalamus
TSH Stimulates thyroid Thyroxine in blood
ACTH Stimulates adrenals glucocorticoids
Thyroid T4 and T3 Stimulates metabolism TSH
Calcitonin Reduces blood Ca levels. Ca levels in blood.
Parathyroid PTH Raises blood Ca levels Ca levels in blood
Adrenal Epinephrine/norepinephrine Increase blood glucose, rate of metabolism; constrict blood vessels.
Nervous; sympathetic division
Steroids Promote reabsorption of Na and excretion of K in kidneys
Change in blood volume or pressure.
Pancreas Insulin Reduces glucose High glucose levels
Glucagon Raises glucose Low glucose levels
Testes Androgens Support sperm; male sex characteristics FSH and LH
Ovaries Estrogens Female sex characteristics; stimulate uterine lining growth
FSH and LH
Progesterone Growth of uterine lining FSH and LH
Homeostasis:Menopause
Late middle age, ovary function declines.Diabetes mellitusHypothyroidismHyperthyroidismAddison’s
Hyposecretion of all adrenal cortex hormonesCushing’s disease
Excessive output of glucocorticoids
http://www.becomehealthynow.com/article/bodynervousadvanced/956/
http://kidshealth.org/teen/your_body/body_basics/endocrine.html#
http://www.innvista.com/health/anatomy/thymus.htmhttp://www.umm.edu/endocrin/reproduct.htmwww.endocrineweb.com/endocrinology/your-adrenal-glands http://parathyroid.com/parathyroid-function.htmhttp://www2.estrellamountain.edu/faculty/farabee/biobk/
biobookendocr.htmlAn Ingegrated Approach to Health Science-BookEssentials of Human Anatomy and Physiology
References