BIOM2010 (till mid sem)

Endocrinology

Endocrine system : a __________________________that acts by ________________________

directly into the ____________________ which then ____________ to other

parts of the body to act on ___________________ (cells, tissues, organs)

Endocrine gland : ___________________________ found ____________ at ______________

e.g. anterior pituitary gland, thyroid, adrenal

Major endocrine organs

Pineal Heart GI Female

Hypothalamus Adrenal gland Liver Ovaries

Pituitary Kidney Stomach Placenta (pregnant)

Thyroid Adipose tissue Duodenum Male

Parathyroid Skin Pancreas Testes

Hormones

Physiologic response

Hormone action on target cells

1. ___________________________________________________

↓ or no receptor present

2. ___________________________________________________

Modification to receptor so it doesn’t activate signalling cascade

3. ___________________________________________________

Downregulation of a component of signalling pathway

Upregulation of an inhibitor of signalling pathway

4. ___________________________________________________

Binding with receptor

1. Alters ____________________________________________by acting on

_________________________________________

/

2. Acts through _________________________________to alter activity of

________________________________

+/-

3. Activates ______________________to cause formation of ___________________________

Hormone bound to _______________________

____________, ____________ _____________ hormone

_______________

___________ response

_____________________ in liver or other tissues

Excretion in _______

Hormone action on target cells – intracellular signalling pathways (signal transduction)

1. ____________________________________________________

e.g. OT, GNRH, somatostatin, DA receptors

2. ____________________________________________________

e.g. insulin, IGF1 receptor

3. ____________________________________________________

e.g. EPO, leptin, prolactin & GH receptors

4. ____________________________________________________

e.g. oestrogen receptor

Homeostasis : the state of ___________________________________of the body that is

maintained by _______________________________________________of

_______________________________ & ____________________________.

Involves both the __________________ & ____________________ systems.

Negative feedback : ___________________________________________________________

Positive feedback : ___________________________________________________________

Endocrine Disorders

Hyposecretion Hypersecretion

Hormone activity

Clearance

Other

Pituitary Posterior pituitary Anterior pituitary

Neural Blood borne

Cell types 5

Hormones released 6

PVN

SON

Releasing & inhibiting

hormones

Posterior pituitary gland

1. _______________________ - VP (_______________________________________________)

2. _______________________ - OT

Neurons

- One neuron express ONLY _________ type of peptide (VP/OT)

- Project to the ___________________________________________________

1. ___________________________________________ (SON)

2. ___________________________________________ (PVN)

Hormones VP OT

Actions

Parturition:

Lactation:

Secretion Regulation

Stimulation

Inhibition

Target cells

Oxytocin

Synthesis

Secretion

MOA

Regulation

In males

Class Compound Receptor Pathway Effects

Oxytocics Oxytocin

Tocolytics Atosiban

Facilitates _________________________________________________________________________

Anterior pituitary gland

Cell type Hormone Grouping

Have direct effect in their own right

Trophic hormones

Function :

Regulation of other tissues

1. ___________________________________________________________________________

2. ___________________________________________________________________________

3. ___________________________________________________________________________

4. ___________________________________________________________________________

5. ___________________________________________________________________________

Hypothalamus Pituitary Axes

e.g. ______________________________________________________________________ (HPA axis)

activity of each cell type is regulated independently of the others

“Stalk Section” Hypothalamo-pituitary disconnection”

RF RIF

↑ Prolactin √

↓ GH √

↓ TSH √

↓ ACTH √

↓ FSH & LH √

RF RIF

↑ Prolactin ?

↓ GH

↓ TSH

↓ ACTH ?

↓ FSH & LH

Median eminence

Hypothalamic-hypophyseal portal system

Fenestra

Portal veins

Pituitary stalk

Secretion control

Response to neurohormones called

- ________________________________

- ________________________________

From hypothalamus

Releasing factors

Structure

Often __________________ ____________________

Secretion

From ________________________ into ________________________ at

specialised region of hypothalamus “_________________________________”

Transportation

In ________________________________ to a _________________________

____________________________ in the anterior pituitary gland.

Prolactin Growth hormone

Structure

Synthesis

&

secretion

__________________ -

Prolactin inhibiting factor (PIF)

Short term response –

_________________________________

Medium term response –

_________________________________

Long term response –

_________________________________

Receptor -

__________________________________

Expressed by

_________________________________

__________________- Signals via

multiple pathways to suppress PRL

_________________________ -

Inhibiting factor

Females Males

Amplitude

Frequency

Pulse

Peak in 24 hour:

_________________________________

__________________ -

Prolactin releasing factor (PRF)

__________________ - ↑ PRL synthesis

_____________________ -

Releasing factor

Action Reproductive role

Stimulates

__________________________________

________________________ to

_________________ &

_________________________of

__________________

e.g. milk proteins

Major determinant of growth

Generally ________________________

- ↑ no. & size in cells in

__________________________

e.g. skeletal muscles

- ↑ thickness & length of

__________________________

Non-reproductive role

e.g.

__________________________________

____, _____________________

_________________________________

distinct from effects of growth

Disorders

Hyposecretion Hypersecretion

PRL

______________________________________

Female - _______________________________

_______________________________

Male - _________________________________

_________________________________

GH

Adult

No major Sx

Adult

e.g. thyroid tumour ______________________

1. Enlarged ________________________

- Bones in ________________________,

______________ & ________________

2. Thickening _______________________

__________________________leads to

- ________________________________

- ________________________________

- ________________________________

- ________________________________

Children

_______________________________________

Body proportion:_________________________

Stature:__________________ max.________m

Muscle development:_____________________

Subcutaneous fat:________________________

_______________________________________

_______________________________________

- Diagnosed before puberty

- Gives near normal growth

Children

_______________________________________

Body proportion:_________________________

Abnormally tall: ________________________m

____________________________also affected

Somatomedin Hypothesis

Growth

Not weight gain alone

Involves ____________________________________________________________________

- Net synthesis ________________________________________________________________

- Lengthening of _______________________________________________________________

- ↑ cell _____________ (___________________) & ________________ (________________)

Growth curves : 2 major growth spurts

- ___________________________________

- ___________________________________

Control of growth & metabolism

Role of circulating IGF from liver

__________________________________________________________________________________

Relative contributions from tissues other than liver

Pit1 is necessary for __________________________________ & _____________________________

___________ GHRH +/- _________ somatostatin → ↑ GH

Growth Plate Closure

- Occurs after ________________________

- Due to _________________________________ action

- GH/IGF1 cannot cause further growth in _____________________________________ bones

(but can ↑ __________________________________________________________ of bones)

Growing person / child Adult

Epiphyses

GH action

1. ____________________________

2. ____________________________

- ____________________________

____________________________

(anti-insulin effect)

- ____________________________

____________________________

(anti-insulin effect)

- ____________________________

____________________________

1. _____________________

2. _____________________

Growth Drug

1. _______________________________________________________(GHRH agonist)

- Use test growth axis

2. _______________________________________________________(rhIGF1)

- For growth defects

3. _______________________________________________________(somatostatin analogue)

- Inhibit GH excess : for acromegaly & gigantism

- Inhibits other hormones producing tumours

4. _______________________________________________________

- Similar to octreotide

- Used for _____________________________________________________________ tumours

Endocrine pancreas

1. Carbohydrate

(4.1 kcal/g)

2. Lipid

(9.4 kcal/g)

3. Protein

(4.3 kcal/g)

Glucose

- Important _____________________________________ for all cells

- Main energy source for __________________________________

- Neurones cannot store __________________________________ (glia can)

- _________________________________________ are essentials for normal CNS function

Glucose homeostasis

↑ blood glucose ↓ blood glucose

GI tract

______________________________________

Transport of glucose into cells

- ______________________________

______________________________

- ______________________________

As _________ through _____________

As ______________________________

Liver – hepatic

- ________________________________

- ________________________________

Kidney

- _______________________________

- _______________________________

_______________________________

Facilitated diffusion

1. Carrier protein takes conformation in which solute binding site is exposed to region of high

concentration

2. Solute molecule binds to carrier protein

3. Carrier protein changes conformation so that binding site is exposed to region of lower

concentration

4. Transported solute is released & carrier protein returns to conformation in step 1

GLUT

Name Tissue Insulin sensitive Comments

1

2

3

4

5

Hyperglycaemia Hypoglycaemia

Signs of diabetes mellitus

e.g. osmotic diuresis

- ________________________________

- ________________________________

- ________________________________

Insulin & glucagon

Simple control system

Insulin Glucagon

Islet of

Langerhans

Homeostasis

Glucose, fatty

acids & a.a.

Impairment

Receptor

CHO

Fats

Proteins

Characteristics Type I Type II

Descriptions

Onset

Insulin dependency

Speed development Sx

Tx

Drugs

1. Insulin - __________________________________________________________________

Tx for

1. ________________________________

________________________________(sometimes)

2. Emergency tx for ____________________________________________________

3. ________________________________ diabetes

MOA: acts like ___________________________________________

Administration: ___________________________ (or ______________________________)

Duration action: different for different formulations

- ___________________________________

- ___________________________________

- ___________________________________

Oral

hypoglycaemics

Biguanides Sulfonylureas Thiazolidinediones

(glitazones)

e.g.

MOA

SE

1. Repaglinide

- Act like _____________________________________________________________

- Block _______________________________________________ _____________ cells

2. Acarbose

- Reduces ____________________________________________________________ in GIT

- Reduces _______________________________ increase _____________ during absorption