Introduction To Endo( Dr Femi) Flashcards
(33 cards)
What is a hormone
S E O Effect
Socete
This is a specific organic chemical produced by certain cells into the ECF which is directly transmitted into Target Organs for exertion of specific regulatory (physiological ) effect
2 broad types of hormones are
General
Local
________ hormones is not produced by specific glandular organ yet exert their action locally or at s distance from the area of production ( restricted area)
Mention 5 examples
- Local hormones
2.ACH SEROTONIN ERYTHROPOIETIN NORADRENALIN ADRENALINEa
General hormones are classified into _______
Namely
3
Protein
Peptide amino acid derivatives
Steriods
Name the glands that produce general hormones
Pituitary glands(ant+post) Thyroid Ovary Testis AdrenL cortex Parathyroid Pancreas
Most steroid hormones are derived from—–
Mention the glands that secrete steroids and the examples of what they secrete
Cholesterol
Placenta:oestrogen+progesterone
Ovaries: same
Testis: testosterone
Adrenal cortex: aldosterone and cortisol
What gland secrete Hormones derived from AA tyrosine
Hormones of thyroid gland: triiodothyronine and tyroxine
Adrenal medulla: Adrenaline and noreadrenaline
Hormones of the protein class are secreted by what glands and list the hormones secreted
Note: every hormone that is not steroid and AA derived
Ant pituitary:ACTH,TSH,,LH,GH,Prolactin Post pituitary:ADH,vasopressin,oxytocin Pancreatic:insulin, glucagon Paratyphoid: Parafollicular cells of thyroid gland:calcitonin
In formation of All protein hormones are
A.Synthesis is Initiated in the——
B.formed by—–
A. nucleus of the cell, the DNA of the nucleus initiates the formation of active MRNA and TRNA
TRNA acts on the cytoplasmic rough endoplasmic reticulum to produce the prohormones
B. Glandular endoplasmic reticulum
Hormones of Amino acid derivatives are formed by——
Enzymatic reactions in the cytoplasmic compartment of glandular cells
Receptors of hormones determines whether a cell will be sensitive or insensitive to a hormone
Receptors of protein , peptides, cathecholamines are located——
Receptors of steroids are located—-
Receptors of thyroid are located—–
In or on the surface of the cell membrane
Cell cytoplasm
Cell nucleus
What are the(mechanism) stages of hormones action
1.Recognition( binding of hormones to membrane receptors) ActionOF FIRST MESSENGERS
2.Formation of second messengers(CAMP)
: due to receptors action activating cytoplasmic system
i.e
Hormone/receptor complex activates adenyl cylase= conversion of ATP to CAMP
3. CAMP brings about all effects on the target organ
Examples of second messengers are
- CAMP
- Calcium ions/associated calmodulin
- products of membrane phospholipid breakdown e.g inositol triphosphate and diacyl gylcerol
- Cyclic GMP( cGMP)
What are the physiological responses to cAMP
- Alteration of membrane permeability
- Muscle contraction or relaxation
- activation of enzymes
- Protein synthesis
What is the action of calcium as a second messenger
Calcium ions binds with calmodulin which has 3-4 bind sites
Calmodulin is activated causing effects
It activates enzymes apart from CAMP activated enzymes leading to more effects
It finally activates myosin kinase which acts directly on myosin of smooth muscle leading to smooth muscle contraction
What is the mechanism of steroids hormones
- Hormones enters the cytoplasm and binds with the specific receptor
- Transport protein diffuses the hormone receptor protein complex into the nucleus
- The complex combines with DNA , activates specific genes to form MRNA
- the MRNA diffuses back into the cytoplasm to form new protein
- The protein forms enzymes, transport protein, structural protiens
What is the mechanism of hormone inactivation
There are 2 stages 1. Inactivation 2. Excretion of inactivated metabolite Inactivation occur in 3 sites Liver, kidney , target ogans Liver does more because of it conjugation property using glucoronide or sulphate . the conjugate is secreted into bile and excreted in feaces or it goes into the kidney through the bloodstream
Inactivation and excretion of oxytocin is by lactating mammary gland
Pituitary gland is also known as
Its diameter is
It weighs
Hypophysis
1cm
0.5-1g
Ant pituitary gland is also called——
Embryologically it originates from —
Its major role is
It has ——cell types
Adenohypophysis Rathke's pouch ,an invagination of pharyngeal epithelium Control of metabolic function 5 which are Somatotrophes= Corticotropes Thyropes Gonadotropes Lactotropes
Post pituitary gland is also called
Embryologically it originates from
2 peptide hormones are
Neurohypopysis
Neural tissue outgrowth from the hypothalamus
Adh and oxytocin
Secretory cells of PPG are—–
located in ——
They are magnocellular neurons
Outside the pituitary gland: in the supraoptic nuclei for ADH
and paraventicular nuclei for oxytocin which are both located in the hypothalamus
Neurophysis transport the hormones from the hypothalamus to the PPG for release and storage due to nerve impulse
Function of GH
- Its diabetogenic: it causes elevation of blood sugar by antagonizing insulin
- It increase milk production
- It increases bone growth length
- It has control over several metabolic activities
- It increases general body growth
Mechanism of action of GH
GH courses the liver to other tissues where it forms several small protein somatomadins which concentration is directly proportional to the rate of GH secretion . it has an effect on increasing all growth
Factors regulating GH secretion
GHRH
GHIH
Which are found in the ventromedial part of the hypothalamus
