endocrine-glands.pdf anatomy and physiology

This ppt is related to endocrine system which is related to glands and their secretions

2. EndocrineSystem
IntroductionConsideredtobepartofanimalscommunicationsystem
1.Nervoussystemusesphysicalstructuresforcommunication
2.Endocrinesystemusesbodyfluidstotransportmessages(hormones)
Hormones
A.
Classically,hormonesaredefinedaschemicalsubstancesproduced
byductlessglandsandsecretedintothebloodsupplytoaffectatissue
distantfromthegland,butnowitisunderstoodthathormonescanbe
producedbysinglecellsaswell.
1.Epicrine
Hormonespassthroughgapjunctionsofadjacentcellswithoutentering
extracellularfluid
2.Paracrine
Hormonesdiffusethroughinterstitialfluid (e.g.Prostaglandins)
3.Endocrine
Hormonesaredeliveredviathebloodstream(e.g.growthhormone)

8. Principal functions of the endocrine system
•
Maintenance of the internal environment in the body
(maintaining the optimum biochemical environment).
• Integration and regulation of growth and development.
• Control, maintenance and instigation of sexual reproduction,
including gametogenesis, coitus, fertilization, fetal growth and
development and nourishment of the newborn.

9. Endocrine System
•Helps to maintain homeostasis by Integration & control.
•Secretion of chemical signals called hormones
•That travel through the bloodstream to act on target
cells.

12. Endocrine versus Nervous system
Nervous System
• Performs short term crisis
management
• sends electrical messages to
control and coordinate the body
• nerve impulse is delivered by
the axon of a nerve cell called
neuron
Endocrine System
•Regulates long term ongoing metabolic
activity uses chemicals messenger
called hormones to “communicate”.
•Hormones alter metabolic activities of
tissues
•Hormone is secreted by a group of
specialized cells called gland and
transported by the blood vessels
•Paracrine communication involves
chemical messengers between cells
within one tissue

13. Endocrine system
Includes all cells and endocrine tissues that produce
hormones or paracrine factors
Following are important endocrine glands
•Hypothalamus
•Pituitary gland
•Pineal Gland
•Thyroid gland
•Parathyroid gland
•Thymus
•Adrenal Gland
•Gonads (testes/ovaries)
•Pancreatic Islet
•Heart
•Kidney
•Digestive Tract

14. Differentendocrineglandswithcell
Organ
Division
Cellarrangement/morphology
Hormone
Hypophysis
Adenohypophysis
Parsdistalis
Cellsincordsaroundlarge-bore
capillaries:
Acidophils Growthhormone,
prolactin
Basophils ACTH,TSH,FSH,
LH
Parsintermedia
Mostlybasophiliccellsaround
cysticcavities
ACTH,POMCParstuberalis
Narrowsleeveofbasophilccells around
infundibulum
LH
Neurohypophysis
Parsnervosa
Nervefibersandsupportingcells
(pituicytes)
Oxytocinand
vasopressin
(producedin
hypothalamus)
Infundibulum
Nervefibers(travelingfrom
hypothalamustoparsnervosa)
PancreasIsletofLangerhans
Irregularlyarrangedcellswith
manycapillaries
Insulin,glucagon

15. Thyroid
Follicles:Simplecuboidal tocolumnar
epitheliuminsphericalshellsaround
colloid
Principal
cells:T3andT4
Parafollicularcell:
Thyrocalcitonin
Parathyroid Denselypackedcordsofpolygonalcells
(chiefcellsandoxyphiliccells)
PTH
Adrenal
Cortex
Zonaglomerulosa Columnarcellsinrounded
clusters
Aldosterone
Zonafasiculata
Large,pale-stainingpolygonal cellsin
columns
Glucocorticoids
(Cortisone)
ZonareticularisRoundcellsinirregularcords Gonadocorticoids
(DHEA)
Medulla Chromaffincells=largeroundcellswith
centrallylocatednucleuswithprominent
nucleus,oftencytoplasmicgranules.Note
largeveinsincenterofmedulla.
Norepinephrine and
epinephrine

16. Hypothalamus and Pituitary
Hypothalamus
Located in the brain, the hypothalamus
releases hormones which stimulate or
suppress the production of other
hormones throughout the body.
Pituitary
The pituitary is a small body that
hangs in the central area of the brain.
It produces hormones which help
control the body’s water and
electrolyte levels, help with childbirth,
trigger the production of sex
hormones, and promote body growth.

17. Control by Hormonal Stimuli
•Hormonal stimuli –stimulation received from other hormones
• The hypothalamic hormones stimulate the anterior pituitary
• In turn, pituitary hormones stimulate targets to secrete still
more hormones

18. PituitaryGland(hypophysiscerebri)
Hastwodistinctparts
1.anteriorlobe(adenohypophysis)
2.posteriorlobe(neurohypophysis)
Locatedinabonyrecess(sellaturcica)atthebaseof thebrain
Connectedtothebrainbythehypothalamusandaportalbloodsupply
1.veindrainingthehypothalamusbreaksupintoacapillarybedwithinthe anterior
pituitary
2.routebywhichreleasingfactorsfromthehypothalamustraveltocause
releaseofhormonesfromtheanteriorpituitary

19. Thyroid and Parathyroid
Thyroid
The thyroid is located around
the esophagus. It creates
hormones which control
metabolic processes in all
cells and control blood
calcium levels.
Parathyroid
The parathyroid is a group of
small glands that are found
on the thyroid and emit
hormones which help
regulate calcium throughout
the body. If levels get too low
the bones will be instructed
to release more; if the levels
get too high the bones are
told to absorb the extra
calcium.

20. Adrenal Gland
Kidneys
The adrenal gland is really two glands,
which are situated on top of either
kidney. The adrenal gland makes
hormones which regulate the body’s
water and electrolyte levels as well as
hormones which control the metabolism
of proteins, lipids, and carbohydrates.
The most noticeable thing it does is
protect the body from…

21. THYROID
I.GrossAnatomy
Thethyroidglandislocateddorsolateraltothetrachea,closetothelarynx.Ithastwo lobesthatareconnectedbyanarrow
isthmus.
II.Histology
Thethyroidgland iscomposedoffolliclesandinterfollicularconnectivetissue.The capsule,classifiedas
looseareolarconnectivetissue,surroundsthemassofthyroidfollicles andsendssmallerpiecesof
connectivetissueintotheglandtosurroundtheindividual thyroidfollicles.Nearthethyroidglandand
embeddedinthesameconnectivetissue capsuleistheparathyroid gland.
Sometimespatchesoflymphocytescanbeobservedinthethyroid/parathyroidglands.
Thyroid folliclesconsistofalayerofsimpleepitheliumsurroundingagel-likepinkish materialcalledcolloid.
Theprincipalcellisthemostnumerouscellpresentinthesimple epitheliallayerandisresponsiblefor
secretingthethyroidhormonesaswellas thyroglobulin,aglycoprotein.
Thyroidhormonesarestoredextracellularlyaspartofthethyroglobulinwhichisthemain
componentofthecolloid.
Thesizeoffolliclesandtheheightofprincipalcellsvariesevenwithinonesectionofthegland.
Thisistheparafollicularcellwhichmaybefoundassinglecellsintheepithelial liningofthefollicle
Parafollicularcellssecretecalcitonin,ahormonethatlowersthelevelofcalciuminthe
blood.

23. Pancreas
The pancreas is located
between the two kidneys.
Produces hormones which
adjust carbohydrate
metabolism. When blood
sugar levels rise (after you
eat) insulin lowers the
levels; when blood sugar
levels are low (if you
haven’t eaten all day)
glucagon's raises the blood
levels.

24. Ovaries and TesTes
Testes
Testes are found in the scrotum
of males. They generate
hormones which facilitate the
development of male reproductive
organs and produce sperm.
Ovaries
Ovaries are found in the abdomen of
women. They produce hormones which
assist with the development of the
female reproductive organs and
prepare the uterus for pregnancy.

25. LeT’s BuiLd a MOdeL

By building a model of the endocrine system, you can
show how the hormones travel through the body and
different areas are affected.

26. Supplies

One piece of butcher paper, longer than you are tall

Markers, pencils, or pens

Play-Doh or modeling clay

String

27. Procedure

Working in partners, have one student lie down on
the butcher paper. Outline their body with markers,
pens or crayons.

28. Procedure

Shape the organs of the
endocrine system in Play-
Doh or modeling clay.

Place the organs in the
correct places on the
drawing you have made .

29. ThankYou