أحياء لغات Hormonal Coordination للصف الثالث الثانوى 2016

أحياء لغات Hormonal Coordination للصف الثالث الثانوى 2016

Hormonal Coordination in living organisms

-:The endocrine system

.All Body functions are under the nervous & Hormonal Control

The endocrine glands

Have the followings characteristics

.They are ductless glands -

.They secrete hormones directly to the blood stream -

The amount of hormone secreted should be in proper amount according tothe requirement of the body because Any increase or decrease in the amount of secretion of any hormone leads to disturbances in the functions and results in pathological changes and symptoms characteristic for this hormone

Hormones

The hormone is defined as a chemical substance synthesized and secreted by an endocrine gland and transported by the blood to another organ where it affects the function and the growth of this organ

(NB

Most of the effects of hormones are in the form of stimulation of other glands or organs

But in plants there is no special glands secreting Hormones , but they secret auxins from the buds & growing points which they affect the functional processes in places other than where they are secreted as indol acetic acid

Discovery of plant hormones

:Boysen Jensen

He was able to explain phototropism of a growing point in view of auxins (plant hormones

He proved that the connection between the receptor and the region of curvature occurs due to the auxins which are secreted by the tip of the coleoptile

Other researches followed concerning auxins

:The importance of auxins

.Regulate plant growth

.Organize the development of different tissues

.Formation of flowers , leaf fall ,fruit formation

.Affect the functions of all tissues

:Discovery of animal hormones

1- Claude Bernard in 1855

2- Starling in 1905,found that

1-He studied the liver functions and considered the stored sugar in the liver as an internal secretion

2- The bile as an external secretion.

1- He found that the pancreas starts to secrete the pancreatic juice directly after the arrival of food to the duodenum even after the nerve supply was cut.

2-He concluded that there must be a non nervous stimulation.

3-He discovered the presence of certain chemical substances secreted from the mucus membrane lining the duodenum which pass to the blood to stimulate the pancreas to secrete the pancreatic juice.

4-He named these substances (Hormones), a Greek word which means activators.

:Hormonal regulation in Man

:The scientists were able to know the functions of hormones through

The study of symptoms resulted from enlargement or removal of one of the endocrine glands (in Man and animals

The study of the chemical structure of the extract of endocrine glands, and their effect in different vital activities

:Characteristics of Animal Hormones

1. Hormones are organic substances. Some hormones are proteins, others are amino acids, or steroids (lipid derivatives

Hormones are secreted in very small amounts in micrograms (1/1000 milligram

Hormones are secreted by endocrine gland & transported by the blood

:Hormones perform the following functions

a. Keep the balance of the internal environment of the body (homestasis

b. Body growth

c. Sexual maturity

d. Metabolism (utilization of food

e. Human behavior and his emotional and intellectual development

Glands in Man

:Three types of glands are present in the Human body

1- Endocrine gland	2- Mixed gland	3- Exocrine gland
Ductless glands and secrete hormones directly in blood.	Consists of an exocrine and an endocrine part, such as the pancreas	Each exocrine gland consists of a secretary part in addition to a duct or a system of ducts which carries the secretion either to a cavity inside the body as salivary glands, and digestive glands, or to outside the body as the sweat glands

:Endocrine glands

Endocrine gland	Place
1- Pituitary gland	Beneath the brain
2- Thyroid gland	In the neck in front of the trachea
3- Parathyroid gland	4 glands on two on each side of the thyroid gland (trachea)
4-Adrenal(suprarenal)	Two each one above one kidney
5-Pancrease(islets of Langerhans)	Group of cells in the pancreas called Iselts of Langerhans
6-Gonads	Testes in males & Ovaries in females
7-Mucous membrane of alimentary canal	Mucous lining of stomach & small intestine

First: Pituitary gland

Place	It lies beneath (below the brain & in connection with the hypothalamus)
Structure(description	Consists of two parts vAdenohypophysis ;- Consists of the anterior & middle lobe. vNeurohypophysis:- Consists of the posterior lobe &a part of the brain called infundibulum (a stalk connecting the gland to the brain).
Importance	It is considered as the master gland, WHY? as it controls the function and the secretion of most of the endocrine glands, WHY?? As the pituitary gland secretes hormones which affect the secretion of hormones secreted from other endocrine glands .

:(Hormones of the Adenohypophysis (the anterior lobe

:(Growth Hormone (GH

.Function :-it controls metabolism especially protein synthesis, accordingly it controls the physical growth of the body

Hypo- secretion of G.H	Hyper-secretion of G.H
During Childhood causes Dwarfism	During the childhood causes Gigantism	In adults causes Acromegaly

Acromegaly

:Causes

.Hyper-secretion (increase in secretion )of growth hormone in adults

:Symptoms

Increased bone growth at the extremities leading enlarged hands , feet ,fingers

Enlarged bones of the face

Pituitary Trophins

,A group of hormones that affect the activity and secretion of other glands

Thyrotrophins Hormone

Adrenocorticotrophic (A.C.T.H)

Gonadotrophic hormones

Thyroid stimulating hormone (T.S.H)

That stimulate the thyroid gland

Which affects the function of cortex of adrenal (suprarenal) glands

Follicle stimulating hormones

(F.S.H)

Lutenizing

Hormones

(LH)

Prolactin

(NB) Gonadotrophic hormones Affects the function of gonads (ovaries in females&testes in males

Hormones	FSH	LH
Male	Affects the formation of seminiferous tubules, spermatozoa, and prostate	The formation and secretion of the interstitial cells in the testes of males
Female	Which affects the growth of the ovarian follicles and formation of Graafian follicles in females	Which stimulates the formation of corpus luteum in females.
NB)	These two hormones are important for sexual maturity as they are responsible for secretion of male (Testosterone) and female sex hormones (Progestrone & Estrogen).

Prolactin

:(Hormones of the Neurohypophysis (the posterior lobe

.(Neurohypophysis:- consists of the posterior lobe & a part of the brain called Infundibulum (a stalk connecting the gland to the brain

Neurohypophysis:- secretes Two hormones are secreted from the nerve cells in the hypothalamus and reach the neurohypophysis posterior lobe of pituitary gland) through the infundibulum after which they are secreted to the blood stream

1- Antidiuretic hormone (A.D.H)

2- Oxytocine hormone

vThis hormone increases the re-absorption of water from the kidney tubules.

vDecreasing the volume of urine excreted.

vIn addition, it increases blood pressure.

vThis hormone affects the uterine contraction and increases it during delivery (labour).

vGynacologests use this hormone to accelerate the birth of a baby by stimulating strong contractions of uterine muscles.

vIn addition, Oxytocin stimulates the release of milk from mammary glands with the beginning of lactation (milk letting hormone).

رااائع

» أحياء لغات – The Thyroid Gland للصف الثالث الثانوى 2016
» أحياء لغات – Reproduction in livings للصف الثالث الثانوى 2016
» أحياء لغات – Alternation of generations للصف الثالث الثانوى 2016
» أحياء لغات -Reproduction in Human1 للصف الثالث الثانوى 2016
» أحياء لغات -Reproduction in Human2 للصف الثالث الثانوى 2016

أحياء لغات Hormonal Coordination للصف الثالث الثانوى 2016

Hormonal Coordination in living organisms

-:The endocrine system

.All Body functions are under the nervous & Hormonal Control

The endocrine glands

Have the followings characteristics

.They are ductless glands -

.They secrete hormones directly to the blood stream -

The amount of hormone secreted should be in proper amount according tothe requirement of the body because Any increase or decrease in the amount of secretion of any hormone leads to disturbances in the functions and results in pathological changes and symptoms characteristic for this hormone

Hormones

The hormone is defined as a chemical substance synthesized and secreted by an endocrine gland and transported by the blood to another organ where it affects the function and the growth of this organ

(NB

Most of the effects of hormones are in the form of stimulation of other glands or organs

But in plants there is no special glands secreting Hormones , but they secret auxins from the buds & growing points which they affect the functional processes in places other than where they are secreted as indol acetic acid

Discovery of plant hormones

:Boysen Jensen

He was able to explain phototropism of a growing point in view of auxins (plant hormones

He proved that the connection between the receptor and the region of curvature occurs due to the auxins which are secreted by the tip of the coleoptile

Other researches followed concerning auxins

:The importance of auxins

.Regulate plant growth

.Organize the development of different tissues

.Formation of flowers , leaf fall ,fruit formation

.Affect the functions of all tissues

:Discovery of animal hormones

1- Claude Bernard in 1855

2- Starling in 1905,found that

1-He studied the liver functions and considered the stored sugar in the liver as an internal secretion

2- The bile as an external secretion.

1- He found that the pancreas starts to secrete the pancreatic juice directly after the arrival of food to the duodenum even after the nerve supply was cut.

2-He concluded that there must be a non nervous stimulation.

3-He discovered the presence of certain chemical substances secreted from the mucus membrane lining the duodenum which pass to the blood to stimulate the pancreas to secrete the pancreatic juice.

4-He named these substances (Hormones), a Greek word which means activators.

:Hormonal regulation in Man

:The scientists were able to know the functions of hormones through

The study of symptoms resulted from enlargement or removal of one of the endocrine glands (in Man and animals

The study of the chemical structure of the extract of endocrine glands, and their effect in different vital activities

:Characteristics of Animal Hormones

1. Hormones are organic substances. Some hormones are proteins, others are amino acids, or steroids (lipid derivatives

Hormones are secreted in very small amounts in micrograms (1/1000 milligram

Hormones are secreted by endocrine gland & transported by the blood

:Hormones perform the following functions

a. Keep the balance of the internal environment of the body (homestasis

b. Body growth

c. Sexual maturity

d. Metabolism (utilization of food

e. Human behavior and his emotional and intellectual development

Glands in Man

:Three types of glands are present in the Human body

1- Endocrine gland

2- Mixed gland

3- Exocrine gland

Ductless glands and secrete hormones directly in blood.

Consists of an exocrine and an endocrine part, such as the pancreas

Each exocrine gland consists of a secretary part in addition to a duct or a system of ducts which carries the secretion either to a cavity inside the body as salivary glands, and digestive glands, or to outside the body as the sweat glands

:Endocrine glands

Endocrine gland

Place

1- Pituitary gland

Beneath the brain

2- Thyroid gland

In the neck in front of the trachea

3- Parathyroid gland

4 glands on two on each side of the thyroid gland (trachea)

4-Adrenal(suprarenal)

Two each one above one kidney

5-Pancrease(islets of Langerhans)

Group of cells in the pancreas called Iselts of Langerhans

6-Gonads

Testes in males & Ovaries in females

7-Mucous membrane of alimentary canal

Mucous lining of stomach & small intestine

First: Pituitary gland

Place

It lies beneath (below the brain & in connection with the hypothalamus)

Structure(description

Consists of two parts

vAdenohypophysis ;- Consists of the anterior & middle lobe.

vNeurohypophysis:- Consists of the posterior lobe &a part of the brain called infundibulum (a stalk connecting the gland to the brain).

Importance