hour5 20.3 human
TRANSCRIPT
-
7/30/2019 Hour5 20.3 Human
1/39
CHAPTER 20
COORDINATION
20.3 HORMONES IN MAMMALS
-
7/30/2019 Hour5 20.3 Human
2/39
OBJECTIVES
List the types and characteristics of
hormones
Explain the mechanism of hormone
action
Gene activation: steroid hormone
Second messenger (cAMP): non steroid
hormone (adrenaline and glucagon)
-
7/30/2019 Hour5 20.3 Human
3/39
ENDOCRINE SYSTEM
is a collection of glands that produce chemicalmessenger called hormones.
-
7/30/2019 Hour5 20.3 Human
4/39
-
7/30/2019 Hour5 20.3 Human
5/39
Endocrine glands characteristics :
Secretes hormones
Has no duct Secreted directly into the bloodstream
Has a rich supply of blood with a
relatively large number of bloodvessels
-
7/30/2019 Hour5 20.3 Human
6/39
HORMONES
is a chemicalmessenger secreted
by cells in theendocrine glands toregulate bodysgrowth, metabolism,sexual developmentand function
-
7/30/2019 Hour5 20.3 Human
7/39
HORMONE PROPERTIES.
Small soluble organic molecule
Travels in the blood
Effective in low concentrations Specific for a particular target cells
Produces response only when they reach
target cells
-
7/30/2019 Hour5 20.3 Human
8/39
T t ti P i i l ti
-
7/30/2019 Hour5 20.3 Human
9/39
Endocrine gland and hormone Target tissue Principal actions
HypothalamusReleasing and inhibiting
hormones
Anterior lobe of anterior Regulate secretion ofhormones by the anteriorpituitary
Hypothalamus (production)
Posterior lobe of pituitary(storage and release)Oxytocin
Antidiuretic hormone(ADH)
UterusMammary glands
Kidneys (collecting ducts)
Stimulates contractionStimulate ejection of milk into
ductsStimulates reabsorption ofwater; conserves water
Anterior lobe of pituitaryGrowth hormone
ProlactinThyroid stimulating hormone
(TSH)
General
Mamary glandsThyroid gland
Stimulates production ofinsulin-like growth factors;stimulates growth bypromoting protein synthesisStimulates milk productionStimulates secretion ofthyroid hormones; stimulates
increase in size of thyroidland
E d i l d d h T t ti P i i l ti
-
7/30/2019 Hour5 20.3 Human
10/39
Endocrine gland and hormone Target tissue Principal actions
Adrenocorticotropic hormone(ACTH)
Adrenal cortex Stimulates secretion ofadrenal corticol hormones
Gonadotropic hormones(follicle-stimulatinghormones[FSH]; luteinizinghormone[LH]
Gonads Stimulates gonad functionand growth
Thyroid glandThyroxine
General Stimulate metabolic rate;essential to normal growthand development
Islets of Langerhans of
PancreasInsulin
Glucagon
General
Liver; adipose tissue
Regulate sglucoseconcentration in blood;stimulates glycogenproduction;stimulates fatstorage and protein synthesisRegulates glucoseconcentration in blood;
stimulates glycogenbreakdown; mobilizes fat
E d i l d d h T t ti P i i l ti
-
7/30/2019 Hour5 20.3 Human
11/39
Endocrine gland and hormone Target tissue Principal actions
Adrenal cortexAldosterone
Cortisol
Kidney tubules
General
Maintain sodium andpotassium balance; increasesodium reabsorption;increase potassium excretionHelp body cope with longterm stress ; raise bloodglucose level; mobilize fat
OvaryEstrogens (estradiol)
Progestrone
General; uterus
Uterus; breast
Develop and maintain sexcharacteristics in female;stimulate growth of uterinelining
Stimulates development ofuterine lining
TestisTestosterone
Inhibin
General; reproductivestructures
Pituitary (anterior)
Develop and maintain sexcharacteristics in male;promotes spermatogenesisInhibits FSH release in male
-
7/30/2019 Hour5 20.3 Human
12/39
TYPES OF HORMONES
Can be divided into 2 groups:
1) Steroids
- large,
- Lipid soluble molecules
- Enable to permeate the cell membrane easily
- Synthesized from cholesterol
- Cortisol, aldosterone
- Testosterone
- Progesterone and estrogen
-
7/30/2019 Hour5 20.3 Human
13/39
2) Non-steroid
- Small
- Water soluble
- Unable to permeate the cell membrane.
-
7/30/2019 Hour5 20.3 Human
14/39
There are 2 groups of non steroid hormones:
a) Amine
The simplest hormonesEpinephrine, norepinephrineThyroxine (can enter cell)FSH,LH, prolactin
b) Peptide/proteinThe largest hormone groupOxytocin, ADH, insulin, GH, Glucagon
-
7/30/2019 Hour5 20.3 Human
15/39
Secreting cellTarget cell
receptor
Not a target cell (no receptor)
MECHANISM OF HORMONE
ACTION
-
7/30/2019 Hour5 20.3 Human
16/39
ormones are very specific
nly target cells that possess the particular protein receptor
that recognise the hormone will show the response
on target cells which lack the particular protein
eceptor do not respond to the hormones
MECHANISM OF HORMONE
ACTION
-
7/30/2019 Hour5 20.3 Human
17/39
The two most important effects are by:
GENE ACTIVATION
CYCLIC AMP ACTIVATION
-
7/30/2019 Hour5 20.3 Human
18/39
Involved the steroid hormones such as sexhormones
Secreted by an endocrine gland and transportedto the target cell via the blood circulation
Small, lipid soluble molecules Can pass freely through the plasma membrane
GENE ACTIVATION
-
7/30/2019 Hour5 20.3 Human
19/39
Hormones then bind with a receptor in the
cytoplasm
Certain receptor can be found in the nucleoplasm
Steroid hormone-receptor complex combines with
spesific site on the DNA
Activates or represses specific genes
Leading to mRNA transcription
-
7/30/2019 Hour5 20.3 Human
20/39
mRNA enters the cytoplasm
Translated into new proteins such as enzyme
Produce the changes in structure or metabolic
activity
-
7/30/2019 Hour5 20.3 Human
21/39
-
7/30/2019 Hour5 20.3 Human
22/39
-
7/30/2019 Hour5 20.3 Human
23/39
Involved peptide hormones such as adrenaline,
glucagon
Secreted by an endocrine gland and transported to
the target cell via the blood circulation
Insoluble in lipid
Cannot pass through the plasma membrane.
Hormone diffuses through the blood, into theinterstitial fluid, and then reaches the target cell .
Binds to the receptors present on the surface of the cell
CYCLIC AMP ACTIVATION
-
7/30/2019 Hour5 20.3 Human
24/39
This binding activates G protein which in turn activate
adenyl cyclase
-
7/30/2019 Hour5 20.3 Human
25/39
Adenylate cyclase converts ATP into cAMP cAMP then activates a variety of protein kinases in the
cell
-
7/30/2019 Hour5 20.3 Human
26/39
Each type of protein kinase phosphorylates a specific
protein
These phosphorylated proteins will alter the activity of thecells
-
7/30/2019 Hour5 20.3 Human
27/39
In this mechanism,
The hormone acts as the first messenger
Brings information to the plasma membraneonly
A second messenger, cAMP then relays the
message of the hormone inside the cell.
-
7/30/2019 Hour5 20.3 Human
28/39
-
7/30/2019 Hour5 20.3 Human
29/39
-
7/30/2019 Hour5 20.3 Human
30/39
Adrenaline/Glucagon
Receptor
G Protein
Adenyl cyclase
ATP cAMP
Activate protein kinase
Activate phosphorylase
Glycogen Glucose
-
7/30/2019 Hour5 20.3 Human
31/39
-
7/30/2019 Hour5 20.3 Human
32/39
Cascade Effect
The action of one enzyme will activates another
enzymatic reaction resulting in many product of
molecules
At each stage in the process, amplification occurs
Each receptor can affect a number of G proteins
In turn can activate a number of molecules ofadenylate
cyclase
Then produce thousands of molecules of cAMP per second
-
7/30/2019 Hour5 20.3 Human
33/39
-
7/30/2019 Hour5 20.3 Human
34/39
COMPARISON BETWEEN GENE
-
7/30/2019 Hour5 20.3 Human
35/39
COMPARISON BETWEEN GENE
ACTIVATION AND CYCLIC-AMP
MECHANISMS
Gene Activation cAMP Activation
Hormones are permeable to cellmembrane
Hormones are impermeable tocell membrane
Hormones bind to internalreceptor
Hormones bind to receptor onthe cell membrane
No second messenger Involves cAMP as the secondmessenger
The effects are caused by theprotein produced by the genes
The effects are caused by thesecond messenger
No cascade effect involved Cascade effect involved
-
7/30/2019 Hour5 20.3 Human
36/39
QUESTION:
Describe the different types of hormones
-
7/30/2019 Hour5 20.3 Human
37/39
Steroid hormones:
- lipid soluble
- permeable to cell membrane- pass into the cell, bind to an
internal receptor and turn on the
genes
- proteins produced by the genesare responsible for the effects
- E.g: male and female sex
hormones
Peptide hormones
- water soluble
- impermeable to cell membrane
- cannot pass through the cellmembrane, therefore, bind to thereceptors on the cell membrane.This causes the release of secondmessenger, cAMP inside the cell
- the second messengers areresponsible for the hormoneeffects
E.g: GH, ACTH, FSH
-
7/30/2019 Hour5 20.3 Human
38/39
ary Morgan has just been brought into the emergency
room of Ipoh Hospital. She is perspiring profusely and is
breathing rapidly and irregularly. Her breath smells likeacetone (sweet and fruity), and her blood glucose tests out
at 650mg/100ml of blood. She is in acidosis. What hormone
drug should be administered, and why?
Critical Thinking.
NEXT
-
7/30/2019 Hour5 20.3 Human
39/39
PLANT
HORMONES
AUXI N
GI BBERELLI N
CYTOKI NI NS
ETHYLENEABSI SI C
ACI D
NEXTLECTURE