Biology Chapter 22 Chemical Coordination And Integration

Thymosin help in the production of antibodies which provide the humoral immunity. 

Vasopressin.

The follicular cells synthesize the following two hormones :
i. Tetraiodothyronine or thyroxine (T_4).
ii Triiodohyronine (T_3).

Parathyroid hormone (PTH)

Pars distalis produces six  hormones namely:
i. Growth hormone(GH)
ii. Prolactin (PRL)
iii. Thyroid stimulating hormone (TSH)
iv. Adenocortocotrophc hormone (ACTH)
v. Luteinizing hormone (LH)
vi. Follicle stimulating hormone (FSH)

Erythropoietin is produced by juxtaglomerular cells of kidney. 

The complex formed on binding of the hormone to its receptor are known as hormone receptors.

Aldosterone

Endocrine system : It consists of endocrine glands that secrete hormones directly into the circulatory system to be carried towards distant target organs.

Types of endocrine glands :

1. Pure endocrine glands : These glands only secrete hormones e.g. thyroid gland, pituitary gland etc.

2. Heterocrine glands : These glands secrete both enzymes and hormones. Thus, they act as endocrine and exocrine e.g. pancreas.

Androgens are hormones produced by the leydig cells or institial cells of testis. The androgens perform the following function :

1. It regulates the developement , maturationand functions of the male accessory sex organs like epidydimis, vas deferens etc. 

2. It regulates muscular growth, growth of facial hair.
3. It plays an important role in the stimulation of the process of spematogenesis. 

Endocrine glands : These are ductless glands which produce hormones. The hormones secreted by them are transported by the blood to the different parts of the body.

Hormones : The hormones are chemical informational regulatory molecules secreted by endocrine glands. They non-nutrient chemicals which act as intercellular messengers and are produced in trace amounts.  

On the basis of their chemical nature, hormones are divided into four groups  :

1. Amino acid derivatives : These hormones are formed from amino acids e.g. epinephrine, norepinephrine etc.

2. Peptide derivatives : These are of derived from peptide, polypeptide and proteins e.g. insulin, glucagon, pituitary, hypothalamic hormones etc

3. Iodothryonines derivatives : e.g. thyroid hormones.

4. Steroid hormones : These are derived from steroids just as cholesterol e.g. testosterone, progestrone etc.

i. Placenta : secretes a human chorionic gonadotrophin hormone (hCG). It stimulates the corpus luteum to secrete progesterone.

ii. Enteric epithelium of stomach : It secretes gastrin hormone when bolus comes into stomach. The gastrin hormone stimulates gastric glands to secrete the gastric juice.

Location : It is present in the neck. Thyroid gland is the largest endocrine gland. It is bilobed and both the lobes are connected by isthmus.

Structure: The thyroid gland is a lobular structure having two lobes. The lobes are connected by a thin flap like connective tissue called isthumus. The thyroid gland has two types of cells called follicular cells and stromal tissues. 
Hormones synthesized : The thyroid glands release two hormones which are tetraiodothyronine or thyroxine (T₄) and triiodothyronine (T₃) 

Functions of the hormones:

1. The thyroid hormones  play an important role in the regulation of metabolic rate.
2. they support the rate of red blood cell formation.
3. They control the metabolism of proteins, fats and carbohydrates. 
4. They maintain water and electrolyte balance in the body. 
5. They regulate the blood calcium levels.

Four major peptides hormone are secreted by the endocrine cells present in the gastro-intestinal tract :

It secretes the following hormones :

1. Gastrin : This hormone acts on the gastric gland and stimulate them to secrete hydrochloric acid and pepsinogen. 

2. Secretin : It acts on the exocrine pancreas and stimulates secretion of water and bicarbonates.
3. Cholecystokinin (CCK) : It stimulates gall bladder to release bile and stimulates pancreas to secrete pancreatic juice.

4. Gastric inhibitory peptide (GIP) - inhibts gastric secretion and motility.

Cause : It is caused due to the excessive secretion of thyroxine.

Symptoms :

The disease is characterised by increased rate of metabolism, bulging of eyeballs, increased blood pressure and excessive perspiration.

2. Iodine Deficiency Goitre :

Cause : It is caused due to the lack of iodine in food.

Symptoms : It causes enlargement of thyroid gland. It occurs mostly to the people of hilly areas.

 
3. Cretinism :

Cause : It is caused due to hyposecretion of thyroxine in children.

Symptoms :

The person suffering from cretinism shows
stunted growth, mental retardation and low blood pressure.

4. Myxoedema :

Cause : It is caused due to the hyposecretion of thyroxine in adults.

Symptoms :
The affected person shows low metabolic rate, body temperature, mental retardationand weakness. 

Hormones : These glands secrete parathyroid hormone (PTH) , which is a peptide hormone.
Functions of the hormones :

1. It increases the amount of calcium. It stimulates the resorption of Ca²⁺  from the digested food and and Ca²⁺ resorption in the renal tubules. It also the process of demineralization in bones. 

2. It decreases the amount of phosphorous in blood.
3. It plays a significant role in maintaining the calcium balance in the body. 

(a) Insulin is reponsible for lowering the blood sugar level by converting excess of glucose to gylcogen which is stored in muscles and liver. 

(b) The hormones released by the hypothalamus controls all the secretions of hormones of pituitary gland. The hypothalamus hormones regulate the secretion and production of the pituitart hormones.  Pituitary gland regulates the activities of other glands. Thus, pituitary gland and hypothalamus function as an integrated and coordinated system.

(c) At puberty there is an increase in the testosterone secretion by Leydig’s cells. The testosterone hormone plays a major role in body growthand accelerates body growth during puberty.  

(d) Adrenal medulla and the sympathetic nervous system are closely integrated systems as the emergency hormones like adrenaline and noradrenaline are secreted during danger when nerve impulse reaches adrenal medulla via sympathetic nerves.

(e) Gonadotrophic hormone secreted by pituitary gland controls the male and the female gonads. The gonadotrophins released by the pituitary regulates the reproductive system. 

Abnormalities of parathyroid gland :

1. Due to hyposecretion : Secretion of the PTH in lesser amount that the normal results in :

(a) Decrease of calcium of blood which causes cramps and convulsions.

(b) It also causes parathyroid tetani which is characterised by sustained contraction of muscles of face, larynx, limbs etc.

2. Due to hypersecretion : Secretion of the hormone in excess amount results in abnormal increase in the amount of calcium in blood. The increased calcium levels may results in easy fractures of bones.

Location : The thymus gland is a lobular structure located between the lungs and behind sternum on the ventral side of aorta.

Hormone : Secretes thymosin hormone. Thymosin is a peptide hormone. 

Functions of the hormones : 

1. It plays a major role in the differentiation of T-lymphocytes which provide cell-mediated immunity. 

2. It promotes the production of antibodies.

Adrenal gland :
The adrenal glands are present in pairs, one at the anterior part of each kidney. The adrenal gland is made of two kinds of tissues namely 
i. Adrenal medulla. 
ii Adrenal cortex. 

Parts of Adrenal gland :

1. Adrenal cortex : It is the outer part of the adrenal gland. It is further differentiated into three parts :

(a) Zona glomerulosa (Outer zone)

(b) Zona fasciculata (Middle zone)

(c) Zona reticulosa (Inner zone outer to adrenal medulla).

Hormones secreted - Adrenal cortex secretes the following three hormones derived from steroids :

(i) Aldosterone or mineralocorticoids.

(ii) Cortisol or glucocorticoids.

(iii) Sexcorticoids or androgens.

2. Adrenal medulla : It lies inner to cortex.
Hormones secreted- It secretes two hormones namely:

(a) Epinephrine

(b) Norepinephrine.

1. Aldosterone - 

Functions :

a. Regulates the balance of water in the body. 
b. It stimulates the reabsorption of Na⁺, water and excretion of K⁺.

b. It It helps in the maintenance of electrolytes, body fluid volume, osmotic pressure and blood pressure. 

2. Cortisol : 

Functions : 
a. Maintains the cardio-vascular system as well as kidney functions.
b. Produce anti-inflammatory reactions and suppresses the immune response.
c. It stimulates the producion of RBCs. 

Abnormalities caused by the hypo or hyper secretion of hormones of adrenal cortex:

i. Disease caused due to hyposecretion of hormones
(a) Addison’s disease : It is caused due to the deficiency of mineralo-corticoids and Cortisol.

Symptoms : It is characterised by low blood sugar level and low blood pressure.
ii. Disease caused due to hypersecretion of hormones

(b) Cushing’s syndrome : It is due to the excess of Cortisol.

Symptoms : It is characterised by high blood sugar level, diabetes, weakness and restlessness.

Adrenal medulla : It is the centrally located tissue that lies inner to cortex. It secretes following two hormones :

1. Norepinephrine : It controls heart beat, contraction of arteries, breathing etc. at normal time.

2. Epinephrine : It is released at the time of emergency. It has the following effects.

(a) It increases heart beat and breathing.

(b) It constricts the arteries so that more blood may go into muscles.

(c) It dilates pupil.

(d) It oxidises more food so that more energy is produced.

Hormones secreted by hypothalamus are:

1. Thyrotrophin-releasing hormone : It acts on the  anterior lobe of pituitary gland and stimulates it to release thyrotrophin or thyroid stimulating hormone.

2. Adrenocorticotrophin releasing-hormone : It acts on the anterior lobe of pituitary gland and stimulates it to release adrenocoticotrophin hormone.

3. Gonadotrophin releasing hormone : It acts anterior lobe of pituitary gland, resulting in the release gonadotrophin hormone.

4. Somatotrophin-releasing hormone : It stimulates anterior lobe of pituitary gland and directs it to release somatotrophin hormone or growth hormone.

5. Growth inhibiting hormone : It inhibits anterior lobe of pituitary gland not to release growth hormone. eg . Somatostatin

Gonadotrophin hormone : These are hormones which stimulate the gonadal activity. It is of two types :

(1) Follicle stimulating hormone (FSH) : It stimulates gonads to form gametes. It is present in both the sexes. In males it regulates spermatogenesis and in females it also stimulates ovary to produce oestrogens and stimulates the growth and development of the ovarial follicles.

(2) Luteinizing hormone : In males the LH results in thesynthesis and secretion of the androgens from the testis. 
In females LH induces the ovulation.

(1) Adrenocorticotrophin hormone (ACTH) : It stimulates the adrenal gland to release different hormones. It is synthesized and secreted by the anterior pituitary or the pars digitalis region of pancreas. 

(2) Thyroid stimulating hormone (TSH) : It stimulates thyroid gland to secrete various hormones. It is released by the anterior pituitary.

Somatotrophic or growth hormone : It stimulates growth and development of tissues by increased rate of cell division and protein synthesis. It is released by the anterior lobe of the pituitary or the pars digitalis region.

Abnormalities due to growth hormone :

1. Dwarfism : If GH is secreted in less amount ( hyposecretion), it may cause dwarfism.

2. Gigantism : When growth hormone is secreted in excess it brings abnormality in height. The person grows into a giant with long bones.

3. Acromegaly : If in adults it is secreted in more quantity then it brings enlargement of fingers, chin, toes, arms ,the proportion of the body and the limbs is disrupted. This condition is referred to as acromegaly.

Pancreas : The pancreas is a is a exocrine as well as endocrine gland. The pancreas has two types of cells :

(a) Pancreatic gland cells : These cells secrete enzymes.

(b) Islets of Langerhans : These are the endocrine part of the pancreas.  These cells are further of following types :

Fig. A part of the section of pancreas to show an islent of Langerhans.

(i) Alfa cells : These secrete glucagon. The glucagon converts glycogen into glucose. This process is called glycogenolysis.

(ii) Beta cells : These secrete insulin. It converts glucose to glycogen in liver. This process is called glycogenesis.

(iii) Delta cells : These secrete somatostanin hormone which controls the rate of absorption of food.

Diabetes mellitus : It is commonly called sugar disease. It is caused due to the lack of secretion of insulin.

Symptoms : The disease is characterised by the following:

1. Sugar in the urine.

2. Frequent urination.

3. Thirst increases.

5. Ketone bodies are formed and may be excreted with the urine.

6. Weakness.

7. Healing of the wound takes more time. 

The hormones produced are:

1. Thyroid stimulating hormone (TSH) : It is a proteinaceous hormone. It acts on the thyroid gland and regulates the secretion of the thyroid hormone. 

2. Adrenocorticotrophic hormone (ACTH or Corticotropin hormone) : It is a peptide hormone. It controls functioning of adrenal cortex, especially secretion of glucocorticoids & sex corticoids.

3. Growth hormone, somatotropin hormone (STH) : It is a proteinaceous hormone. It regulates the synthesis of growth of the body. 

4. Follicle stimulating hormone (FSH) : It is a glycoprotein gonadotrophic hormone. It controls spermatogenesis in testes, maturation of graafian follicles and secretion of estrogens in ovaries.

5. Luteinising hormone (LH) : It performs the following functions
(i) In females LH helps in growth and development of graafian follicles, ovulation, growth of ruptured follicle.

(ii) In females LH also helps in secretion of progestrone by corpus luteum.

(iii) IIn males it acts on Leydig’s or interstitial cells of testes to secrete testosterone and other androgens.

6. Prolactin (PRL) : It is a proteinaceous hormone. It stimulates development of mammary glands during pregnancy and lactation after child birth.

Ovaries : The ovaries secrete the following hormones :

(1) Estrogen : It is secreted by graafian follicles. Estrogen performs the following functions :
a. It brings ovulation.
b. It brings development of genital ducts.

(2) Progesterone : It is secreted by corpus luteum. The progesterone help in the implantation. The progesterone also maintains the enlargement of uterine wall during pregnancy.

(3) Relaxin : It is secreted by corpus luteum (part of graafian follicle after ovulation) at the end of gestation period. It enlarges the pelvic region during the childbirth.

The posterior pituitary gland or neurohypophysis or pars nervosa stores and release two hormones :

1. Vasopressin (ADH or Antidiuretic Hormone)

2. Oxytocin

1. Function of Vasopressin hormone. Vasopressin hormone controls urine output. When there is more water in the body then this hormone is secreted in less amount. When amount of water is less inside the body then it is secreted in more amount so the urine output is less. The ADH hormone reduces water loss. 

2. Function of Oxytocin :

(i) It acts on smooth muscles and results in their contraction .

(ii) It stimulates rigorous contraction in the uterine walls during the child birth.

(iii) It stimules ejection of milk from the mammary glands. 

Antagonistic hormones : These are the hormones which function in opposition to each other. Examples :

1. Insulin and glucagon are antagonistic to each other.
Insulin brings glycogenesis and lowers blood sugar level by changing glucose into glycogen.
Glucagon brings glycogenolysis and raises blood sugar level by changing glycogen into glucose.

Enteric epithelium of stomach : It secretes gastrin hormone into stomach. The gastrin hormone stimulates gastric glands to secrete gastric juice.

The adrenal medulla is the inner part of adrenal gland which lies above the kidney. 

Adrenal medulla produces following two hormones:

1. Adrenaline

2. Nor-adrenaline

1. Adrenaline : It is an emergency hormone because it is produced at the time of emergency or stress. Adrenaline instantly prepares our body for fight or flight. It increases breathing rate, heart rate, B.P. and also helps in releasing RBC from spleen.

2. Nor-adrenaline or Nor-epinephrine : This hormone regulates the heart rate, breathing rate, B.P. at normal time.

Steroid hormones are manufactured from cholesterol or cholesterol esters.

Examples of Steroid hormones :

I. Testosterone

II. Estrogen

(1) Insulin is reponsible for lowering the blood sugar level by converting excess of glucose to gylcogen which is stored in muscles and liver. 

(2) Adrenal medulla and the sympathetic nervous system are closely integrated systems as noradrenaline is secreted during danger when nerve impulse reaches adrenal medulla via the sympathetic nerves.

(3) Gonadotrophic hormone secreted by pituitary gland controls spermatogenesis in male and ovulation of mature follicles , growth and development of ovarian follicles and maintenance of corpur luteum in females. 

(4) Hormones maintain homeostasis. Hormones produced in body are under the control of hormones secreted by pituitary gland and hormones of pituitary gland are further controlled by hormones of hypothalamus. All this control of hormones is done by feed back mechanism. For example, if thyroxin amount is more in blood then it stimulates hypothalamus to secrete less thyrotropin releasing hormones which decreases thyroxine secretion. On decrease in amount of thyroxine below normal, thyrotrophin releasing hormone accelerates the release of thyroxine secretion. This is feed back control.

The steroid hormones bring changes in their target cells in the following manner :

1. Steroid hormones are lipid soluble hormones and can readily pass through the plasma membrane of a target cell.

2. After reaching the cytoplasm they bind to specific intracellular receptor proteins. They form a complex that enters the nucleus and binds to specific regulatory sites on chromosomes.

3. The binding alters the pattern of gene expression, initiating the tanscription of some genes (DNA), while repressing the transcription of others.

4. This results in the production of specific mRNA translation products such as proteins and usually enzymes, thus causing the required effects. 

Hormone released when blood glucose level falls : Glucagon hormone is released when blood glucose level falls. It converts glycogen into glucose in liver. The glucose is released into blood and raises blood glucose level.

Hormone released when blood glucose level elevated : Insulin is the hormone released when blood glucose level is elevated. It converts glucose into glycogen in liver and thus reduces level of glucose in the blood.

Diabetes : It is disease  which occurs due to the elevation of blood sugar level. It is characterized by the excretion of extra sugar in urine.

It is due to the deficiency of insulin hormone. The deficiency of insulin leads to increase in the glucose level in the blood as it does not convert excess of glucose in glucogen. This raises blood-glucose level. Somatostatin inhibits secretion of insulin and glucagon.

Treatment of diabetes :

1. Minimize intake of sugar and starch products.

2. Patients should take insulin tablets/ injections.

3. Daily walking for 5-6 km is good for diabetic patients.

Endocrine system is controlled by brain. Hypothalamus secretes releasing hormones which excite synthesis of various hormones from pituitary gland. The hormones of pituitary gland regulate hormonal release from thyroid, adrenal gland, gonads etc.

Hormonal response is selective but specific.

(1) Hyperglycemic hormone - Glucagon.

Hypoglycemic hormone - Insulin hormone.

(2) Hypercalcemic hormone - PTH or Parathyroid hormone.

(3) Gonadotrophic hormone - FSH (Follicular stimulating Hormone) or LH (Luteinizing hormone)
(4) Progestational hormone - Progesterone.

(5) Blood pressure lowering hormone - ANF (Atrial natriuretic factor ).

(6) Androgens : Testosterone in males
     Estrogens : Estrogen and progesterone.

The hormonal deficiency responsible of the following are:
(1) Diabetes mellitus : Deficiency of insulin .

(2) Goitre : Deficiency of Thyroid hormone.

(3) Cretinism : Deficiency of thyroxine. 

a

a

a

a

(b)  Thyroid hormones :
Thyroxine/ Tetraiodothyonine (T₄) and triiodothyronine (T₃) are collectively known as thyroid hoemones. They are secreted by the follicular cells of the thyroid gland and are peptide hormones.
Functions - They perform the following functions.

i. Regulate the basal metabolic rate
ii. Support the red blood cells formation. 
iii. Control the metabolism of carbohydrates, proteins and fats.
iv. Maintain the water and electrolyte balance.
v. Regulate the blood calcium levels.  

(c) Thymosins
Thymosins are released by the thymus gland. They are peptide hormones. 
Functions - They peform the following functions. 
i. Play a major role in the differentiation of T-lymphocytes.
ii. Promote the production of antibodies. 
(d) Androgens 
Androgens are the secreted by the Leydig cells or interstitial cells. Androgens are a group of hormones that consist mainly testosterone. 
Function - They perform the following functions.
i. Regulate the development, maturation and functions of the male accessor sex organs in males.
ii. Stimulate development of secondary sexual characters in males.
iii. Stimulate the process of spematogenesis.
iv. Produce anabolic effect on protein and carbohydrate metabolism.
(e) Estrogens  
Estrogen is secreted by ovary. It is a steroid hormone synthesied by ovarian follicles. 

Functions - They perform the following functions:
 Stimulate the growth and activity of female secondary sex organs. and regulate the female sexual behaviour
(f) Insulin and Glucagon
These are released by the pancreas. The insulin hormone is synthesized by the beta-cells and the glucagon is synthesized by the alpha-cells. 
Functions : They perform the following functions. 
i. They maintain the glucose homeostasis.
ii. The glucagon acts on the liver cells and result in glycogenolysis and thus in the increased glucose levels in the blood. It also reduces the glucose uptake and utilisation. 
iii. Insulin decreases the blood glucose level and enhaces cellular glucose uptake and utilisation. 

(1) Hypothalamus :
It secretes following hormones:

(a) Hypothalamus: Hormones secreted by the hypothalamus include:
(1) Releasing hormones: These hormones stimulate the secretions of the pituitary hormone. Examples of these hormones are:
(i) Gonadotrophin-releasing hormone
(ii) Thyrotrophin-releasing hormone
(iii) Somatotropin-releasing hormone
(iv) Adrenocorticotrophin-releasing hormone
(2) Inhibiting hormones: These hormones inhibit the secretions of the pituitary hormone. Examples of these hormones are:
(i) Somatostatin
(ii) Growth-inhibiting hormone
(iii) Melanocyte-inhibiting hormone

(2) Pituitary gland :
 Pituitary gland is divided into.

(i) Adeno hypophysis (ii) Neuro hypophysis 

Hormones secreted by the adenohypophysis are:
(i) Growth hormone (GH)
(ii) Prolactin
(iii) Thyroid-stimulating hormone (TSH)
(iv) Adrenocorticotrophic hormone (ACTH)
(v) Luteinizing hormone (LH)
(vi) Follicle-stimulating hormone (FSH)
(vii) Melanocyte-stimulating hormone (MSH)
Hormones secreted by the neurohypophysis are:
(i) Oxytocin
(ii) Vasopressin

(3) Thyroid gland :
Follicle cells of thyroid gland secrete two hormones.

Tetraidothyronine (T₄)

Tridothysonine (T₃)

C cells of thyroid also secrete thyrocalcitonin.

(4) Parathyroid gland : It secretes parathyroid hormone .

(5) Adrenal gland :
The adrenal gland has outer
(i) Adrenal cortex
(ii) Adrenal medulla.

(i) Adrenal cortex has three parts :

(a) Outer part or zona glomerulosa : It secretes mineral corticoids.

(b) Middle part or zona fasciculata : It secretes glucocorticoids,.

(c) Inner part or zona reticularis : Both middle and inner part secrete sex corticoids.

(ii) Adrenal medulla :
It secretes
i. epinephrine or adrenaline hormone
ii. noradrenaline or norepinephrine hormone.

(6) Pancreas : Its cells called Islets of Langerhans are of two types :

(a) α cells : These secrete glucagon hormone. (b) β cells : These secrete insulin.

(7) Testis: It has interstitial cells or cells of leydig which secrete androgens mainly testosterone.

(8) Ovary: The graafian follicle secretes estrogen hormone.

Corpus luteum secretes progesterone and relaxin hormone.

(9) Thymus :
It secretes thymosin hormone.

(10) Atrium : The atrial wall secretes atrial natiuretic factor (ANF)

(11) Kidney : The juxtaglomerular cells of kidney produce erythropoietrin hormone.

(12) G–1 Tract :
It secretes following hormones.
(i) secretin
(ii) cholecystokinin (CCK)
(iii) enterogastrone or gastric inhibitory peptide (GIP)
(iv) Villikinin
(v) Duocrinin
(vi) Enterocrinin.

Mechanism of FSH : 

(1) FSH is secreted by anterior lobe of pituitary gland.

(2) FSH binds to its receptor to form FSH -receptor complex.

(3) FSH receptor complex generates second messenger cAMP

(4) cAMP brings biochemical responses.

(5) The biochemical chages lead to the physiological responses. Due to biochemical responses graafian follicle are matured and they secrete estrogen while in case of male it brings formation of sperms.

Mechanism of FSH hormone

The endocrine glands and their locations in the body

The kidney release the hormone Erythropoietin 

C.

Relaxin relaxes pubic symphysis during parturition while inhibin decreases the secretion of FSH from anterior pituitary

A.

deficiency of iodine in diet

Hypothyroidism during pregnancy causes defective development and maturation of the growing foetus leading to stunted growth. Low secretion of GH results in stunted growth. Low secretion of GH result in stunted growth resulting in pituitary dwarfism. Paras distalis or anterior pituitary producers Growth hormone. prolactin (PRL), thyroid stimulation hormone (TSH), Adrenocorticotrophic Hormone (ACTH), Luteinising Hormone (LH) and Follicle Stimulating Hormone (FSH).

C.

Non-nutrient chemicals produced by the body in trace amount that acts as intercellular messengers are known as hormones.

Hormones are non-nutrient chemicals, which act as intracellular messengers and are produced in trace amounts. Endocrine cells are present in different parts of the gastrointestinal tract, e.g., gastrin, secretin, GIP. Atrial wall of our heart secretes a peptide hormone called ANF (Atrial Natriuretic Factor), RH/ IH are produced by the hypothalamus. Adenohypophysis is not directly under neural control, it is under the control of hypothalamic hormones, brought by portal system.

B.

Aldosterone

Aldosterone is not involved in sugar metabolism. It is a steroid hormone (mineralocorticoid) produced by the outer section(zona glomerulosa) of the adrenal cortex in the adrenal gland. It plays a central role in the adrenal gland. It plays a central role in the regulation of blood pressure mainly by acting on the distal tubules and collecting ducts of the nephron, increasing reabsorption of ions and water in the kidney, to cause the conservation of sodium, secretion of potassium, increase in water retention and decrease in blood pressure and blood volume. 

A.

Antidiuretic hormone

Antidiuretic Hormone (ADH) or vasopressin is a peptide hormone synthesised in the hypothalamus, but stored and released from the posterior pituitary lobe. 

A.

Sympathetic nervous system is activated releasing epinephrine and norepinephrine from adrenal medulla

Epinephrine and nor-epinephrine are secreted by adrenal medulla (under the control of sympathetic nervous system) in response to stress of any kind or during the emergency situations. These are also called emergency hormones or hormones of flight, fight and fright (triple F hormone).

D.

Cortisol and testosterone

Cortisol and testosterone are lipid soluble hormones, which can directly pass through the cell membrane of the target cell and bind with interacellular receptors. 

C.

In females, FSH first binds with specific receptors on ovarian cell membrane

FSH hormone is one of the gonadotropins secreted by anterior lobe of pituitary. It is a proteinaceous hormone, so binds with extra cellular or membrane bound receptors. 

B.

Melatonin - pineal gland, regulates the normal rhythm of sleep-wake cycle

Melatonin is a hormone present in animals, plants and microbes. In animals melatonin allowing the regulation of the circadian rhythms. Oxytocin is a neurohypophysial hormone which stimulates the muscle contraction (smooth muscle) in the wall uterus during childbirth. Progesterone is a female hormone produced by the ovaries during the release of a mature egg from an overly during ovulation.
ANF stimulates the secretion of Na and H₂O by the kidneys and helps in regulating blood pressure.

C.

the adrenal medulla, leading to increased secretion epinephrine and norepinephrine

Fight or flight reaction is a physiological reaction that occurs in response to an emergency. Emergency hormone are secreted by adrenal medulla of adrenal gland secretes adrenaline (epinephrine) and nor alternative (norepinephrine) hormones which stimulate sweating, heart beat and breathing rate. These also cause dilation of coronary artery ( for increasing inspiratory volume)and pupil (for better vision)

C.

Troponin and myosin - Complex proteins in striated muscles

Striated muscle consists of large number of muscle fibres called myofibrils. Myofibrils are made up of actin and myosin protein. The actin or secondary myofilaments also possess troponin and tropomyosin protein.
Thymosin hormone is secreted from thymus gland. Prolactin is a hormone secreted from anterior lobe of pituitary.
Rhodopsin is a pigment found in rod cells of eye.  

C.

spleen

The process of formation of erythrocytes is erythropoiesis, which is part of haemopoiesis (formation of blood).
The production of blood during different stages is as follows:
During few early weeks of embryonic life-yolk sac.
Some later stages (After 3-4 months) - liver (mainly) along with spleen and lymph nodes.
Later part of gestation and after birth (After 7 months) - red bone marrow  (till 5 yrs)
Bone marrow of long bones (20-25 yrs).
Membranous bones like vertebrae, etc.
 

C.

epinephrine

Epinephrine secreted from the medulla of adrenal gland acts as both, an endocrine hormone and as a neurotransmitter (produced at the ends of sympathetic never fibres).
Epinephrine as hormone accelerates metabolic rate for preparing us to face emergency situations.
As neurotransmitter, it transmits nerve impulse across a synaptic left. Calcitonin is released when Ca²⁺ level increases, melatonin causes concentration of pigment in melanocytes and cortisol is a glucocorticoid.

A.

The pituitary gland is located in a bony cavity called sella tursica and is attached to hypothalamus by a stalk. It is divided anatomically into an adenohypophysis and a neurohypophysis. The latter is also called pars nervosa or posterior pituitary. It stores and releases two hormone called oxytocin and vasopressin, which are actually synthesized by the hypothalamus and are transported axonally to neurohypophysis. Vasopressin acts mainly at the kidney and stimulates resorption of water and electrolytes by the distal tubules in the nephron and thereby reduces loss of water through urine (diuresis). Hence, it is also called as anti-diuretic hormone (ADH).

D.

melatonin

Melatonin, also know as chemically N-acetyl 5- methoxy tryptamine is a naturally occurring compound found in animals, plants and microbes. In animals, circulating levels of the hormone melatonin vary in a daily cycle, thereby allowing the entrainment of the circadian rhythms of several biological functions.

C.

Adrenalin

The adrenal medulla synthesises two hormones - adrenalin (epinephrine) and nor - adrenaline (non-epinephrine). These hormones are proteinaceous in nature and derived from amino acid tyrosine. Thus, injury to adrenal cortex will not affect the secretion of adrenaline.

A.

Glucagon - Beta cells (source)

In pancreatic islets, alpha or A -cells constitute about 15% of pancreatic islets cells and secrete glucagon. Its molecule consists of a single polypeptide chain of 29 amino acid residues. Glucagon intensifies glycogenolysis, deamination and gluconeogenesis, and inhibits glycogenesis in liver cells. It also intensifies lipolysis in adipose tissue. Thus, it is a promoter of catabolic metabolism.