Topic 9: Endocrine System Flashcards
What are the major endocrine glands in cats
Pituitary gland
Tyroid hormone
Parathoyroid gland
Pancreas
Ovaries
Testes
Adrenal glands
What are the mechanism controlling hormone secretion
Nerve Impulses
Srimularing or release hormone
Level of certain chemicals in the blood
Negative feed system
Explain how nerve impulses control hormone secretion and example
Eg adrenaline released from adrenal gland in response to nerve impulses fro, sympathetic nervous system (nerve impulses from sympthayelic system cause release of adrenaline from adrenal gland)
Explain how stimulating or releasing hormone control release of hormone example
Secretion of thyroid hormone is controlled by thyroid stimulating hormone from pituitary hormone
How does levels of certain chemicals control hormone secretions eg
Raised blood glucose level stimulate the release of insulin from pancreas
How does negative feedback system control hormone secretion example
This mechanism prevent over secretion
Eg. estrogen from ovaries prevents the further secretion of follicle stimulating from pituitary gland
What are the two different glands in the pituitary gland and their function
Anterior pituitary glands: produce hormones (rostral)
Posterior pituitary gland: sotors and release hormones produced in the hypothalamus (caudal)
What are the hormones produced by the anterior pituitary gland
-growth hormone
- -prolactin
Follicle stimulations hormone
Luteinizintg hormone
Interstitial cell stimulating hormone
Thyroid stimulating hormones
Adrenocorticotropic hormone
What is the function of growth hormones
Promote body growth in young animals
Helps regulate the metabolism of protein, carbohydrates and lipids
What is the function of prolactin
- helps to trigger and maintain.Lactation (secretion of milk by mammary glands)
Prolactin production and release continues as long as nipple continues to be stimulated by nursing or milking
When prolactin stimulates stops, milk production stops and mammary gland shrinks to its non-lactating size
What is the function of thyroid stimulating hormone
Stimulates the developememt of thyroid gland and it’s production of thyroid hormone
What is the function of adrenocorticotropic hormone
Stimulate the growth and developement of adrenal gland and its release of its hormones In times of sudden stress, ACTH can also be released very quickly as a result of stimulation of the hormones
Function of follicle stimulating hormone
Stimulates growth and developement of ovarian follicles
Stimulates follicular cells to secrete estrogen
In males, FSH acts on tubules of testis to aid in sperm production.
Function of luteinising hormone
Secretion is stimulates in the presence of oestrogen in the blood
LH stimulates the ripe follicles to rupture and release their ova (ovulation)
The remaining empty follicle becomes
‘luteinised’ to form the corpus luteum
(yellow body)
Function of interstitial hormone
Stimulates the interstitial cells in testis to release testosterone
What are the hormones produced in the hypothalamus that is stored in the posterior pituitary gland
ADH and oxytocin
How does adh and oxytocin get released from posteror pituitary gland
Released into the bloodstream in response to the nerve impulses from the hypothalamus
Function of ADH
Reabsorption of water from urine to return to blood stream (ADH is released when receptors in the hypothalamus detect a change in osmotic pressure ion blood from dehydration)
Function of oxytocin.
Acts on mammary glands during late pregnancy and causes milk to be released in response to suckling by neonate
At the end of gestation, oxytocin causes the contraction of the smooth muscles of the uterus resulting in parturition and deliver of fetus
What hormones does the thyroid gland secrete
T3
T4
Calcitonin
Function of T3 and T4
Regulates the metabolic rate of all the body cells which is the rate the body burns the nutrients to produce energy
Essential for normal growth
Function of calcitonin
Regulates blood calcium level in conjunction with parathyroid hormone
It’s lowers calcium level by inhibiting the rate of decalcification of bone and by stimulate it bone growth (take in more calcium)
What is hypothyroidism and what do affected animals show
Hypothyroidism: a condition of under secretion of thyroid hormone
Signs: stunted (dwarfism) growth in young animals
Older animals: hair loss, slow heart rate
Dog may become fat and sluggish
What is hyperthyroidism and what doe affacted animals show
Hyperactive, aggressive activities
Increased appetite
Increased heart rate
What hormones does parathyroid gland produce
Parathyroid hormone/ parathormone
Function of parathyroid hormone
Helps to maintain blood calcium levels
If calcium levels are low, calcium is reabsorbed form the bones and absorption of calcium from the intestine is increased
Hormones produced by the pancreas
Insulin (b cells)
Glucagon (a cells)
Stomatostatin (d cells)
Function of insulin
Produced by d cells. Insulin decrease blood glucose levels by increasing intake of glucose into body cells and used as energ and storing excess glucose as glycogen in the liver (glycogen is is)
What is the condition when there is insufficient insulin production
Diabetes mellitus
Function of glucagon
Produced by a cells in response to low glucose levels
Glycogen increase blood glucose levels by breaking down stores of glycogen in the liver
Function of statostain
By d cells, Inhibits the secretion of insulin and glucagon
Which smooths out the daily fluctuation in blood glucose levels
What are the two parts the adrenal gland is made up of
Adrenal cortex and adrenal medulla
What are the two parts the adrenal gland is made up of
Adrenal cortex and adrenal medulla
Which part refers to the inner portion of the adrenal gland
Medulla
What is the classification of hormones produced by the adrenal cortex
Aldosterone
Glucocorticoids
Sex hormones
What is the classification of hormones produced by the adrenal cortex
Aldosterone
Glucocorticoids
Sex hormones
Function of aldosterone
Acts on kidney ( at DCT) to regulate the acid/ base balance
By increasing absorption of sodium ions in exchange for potassium ions and hydrogen ions
Function of glucocorticoids
Cortisone and corticosterone are typical glucocorticoids
In normal animals they are present in low levels but increase due to stress
Their two main actions: increase glucose levels
When present in large quantities they depress inflammatory reaction which delays repair and healing
Function of sex hormones
Estrogen (females) androgen (male): important for maintain secondary sexual characteristics
Hormones produced by adrenal medulla
Epinephrine and norepinephrine
Function of epinephrine and norepinephrine
Raise blood glucose levels by the breakdown of glycogen in liver (energy level increase)
• Increase the heart rate and respiration (to meet the high demand of the body for oxygen)
• Dilate the blood vessels of the skeletal muscles (to meet the increased the supply of glucose and oxygen)
• Decrease the activity of the GI tract and the bladder (in an emergency their functions are less important)
Hormones produced by ovaries
Estrogen
Progesterone
Relaxin
Hormones produced by ovaries
Estrogen
Progesterone
Relaxin
Function of estrogen
Produced by ovarian follicles
Causes the behaviour associated with the extrusion cycle in female animals
Prepares the reproductive tract and external genitalia for mating
Function of progesterone
Secreted by corpus luteum
Prepared the reproductive organs for pregnancy and maintain pregnancy
Causes the developement of the mammary glands during pregnancy
Function of relaxin
Produced by ovaries in later stage of pregnancy
Sold ten and relax ligaments around the birth canal and prepare them for parturition
Function of testosterone
In response to the secretion of ICSH (interstitial cell-stimulating hormone, male version of LH ) from anterior pituitary gland.
• Testosterone leads to the development of male characteristics
• such as muscle development,
• male behavioural patterns e.g. territorial
behaviour, mating display and aggression,
• development of sperm
