Endocrine Tissues & Glands Flashcards

1
Q

Pituitary Gland - (Hypophysis)

Anterior - (Adenophypophysis)

Posterior - (Neurohypophysis)

  • Location
  • What Hormones does it secrete
A

Location - Base of the Brain

Secretes -
TSH - Thyroid-Stimulating hormone
ACTH - Adrenocorticotropic hormone
Gonadotrophins
(FSH) - Follice-Stimulating hormone
(LH) - Luteinizing hormone
(GH) growth hormone
Prolactin
(MSH) - Melanocyte-Stimulating hormone
(ADH) - Antidiuretic Hormone
Vasopressin
Oxytocin’s

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2
Q

Thyroid Gland
- Location
- What does it secrete

A

Location - Anterior to the trachea (two lobes)

Secretes -
Thyroxine (T4)
Triodothyroinine (T3)

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3
Q

Parathyroid Gland
- Location
- What does it secrete

A

Location -
Lie on the dorsal surface of the thyroid gland (4 glands - 2 pairs)

Secretes -
Parathormone (PTH)

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4
Q

Adrenal Gland
- Location
- What does It secrete

A

Location -
Top of the each Kidney
(2 sections - medulla is inner and 2 cortex surrounds medulla)

Secretes -
Cortex - Corticosteriods (glucosteriods and mineralcorticiods)

Small amounts of androgen, estrogen, and progestin.

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5
Q

Pancreas
- location
- what does it secrete

A

Location -
Left of and behind the stomach (Exocrine and Endocrine Gland)

Secretes -
Exocrine secretes digestive enzymes into the duodenum
Endocrine has cell clusters called islets of langerhans, Alpha islet cells produce glucagons,
Beta cells secrete insulin

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6
Q

Glycoproteins and peptide hormones
- Synthesis and storage
- Transport in blood
- Location of receptor
- Response to receptor Ligand binding
- Examples

A
  • Made in advance; stored in secretory vesicles
  • Dissolved in plasma
  • Cell membrane
  • Activation of second messenger systems; may activate gene expression
  • Insulin, Glucagon, Prolactin, ACTH, PTH, Gastrin
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7
Q

Steroid Hormones
- Synthesis and storage
- Transport in blood
- Location of receptor
- Response to receptor Ligand binding
- Examples

A
  • Synthesis on demand from precursors
  • Bound to carrier protein
  • Cytoplasm or nucleus; Some have membrane receptors to
  • Activation of genes for transcription and translation; may have non-genomic actions
  • Oestrogen, androgens, progesterone, cortisol, glucocorticoids
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8
Q

Amino acid Derived hormones - Catecholamines
- Synthesis and storage
- Transport in blood
- Location of receptor
- Response to receptor Ligand binding
- Examples

A
  • Made in advance; stored in secretory vesicles
  • Dissolved in plasma
  • Cell membrane
  • Activation of second messenger system
  • Adrenalin, Noradrenalin, Dopamine
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9
Q

Amino acid Derived hormones - Thyroid hormone
- Synthesis and storage
- Transport in blood
- Location of receptor
- Response to receptor Ligand binding
- Examples

A
  • Made in advance; stored in secretory vesicles
  • Bound to carrier proteins
  • Nucleus
  • Activation of genes for transcription and translation
  • Thyroxine (T4), Triiodothyronine (T3)
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10
Q

Lipid Hormone
- Synthesis and storage
- Transport in blood
- Location of receptor
- Response to receptor Ligand binding
- Examples

A
  • Synthesis on demand from precursors
  • Dissolved in plasma and bound to carrier proteins
  • Cell Membrane
  • Activation of second messenger system
  • Thromboxanes, Prostaglandins, Endocannabinoids
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11
Q

Was do Endocannaboids do, how were they used to treat obesity

A

Endocannabinoids, Creates the hunger symptoms
- Drug used to inhibit Endocannabinoids
- patients lost 50 % of body weight
- How ever there is a side effect that makes you suicidal

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12
Q

What does the Hypothalamus deal with

A

Hypothalamus deals with:
– Thermoregulation, panting, sweating, shivering, etc.
– Plasma osmolality via osmoreceptors
– Heart rate, blood pressure
– Feeding, satiety, regulation of the gastrointestinal tract
– Circadian rhythms, wakefulness, sleep (nerves from retina)/ hormones (melatonin from pineal gland)
– Stimuli from the autonomic nervous system (both sympathetic and parasympathetic)
– Emotion, sexual behaviour, mood
– Lactation (suckling/baby crying)

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13
Q

What does the Hypothalamus produce, and what do they travel through

A

Hypothalamusproduces
– Vasopressin (ADH) and oxytocin that travel to posterior pituitary through nerves
– Six hormones that travel via the hypothalamo-hypophyseal portal system (blood) to the anterior pituitary.

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14
Q

What are the two lobes of the pituitary

A

The Anterior Pituitary
The Posterior Pituitary

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15
Q

What is the difference between a typical circulatory group and a portal circulatory group

A

Portal circulatory system differ from there typical circulatory route in that the blood passes through two steps of smaller vessels before returning to the heart.
Blood from the first sets of capillaries collects in portal vessels (sometimes calls portal veins) which then begins to branch again to supply a capillary network to a second location before entering a series of veins which lead to the heart.

In the Typical Circulatory Route when blood branches out into capillaries it becomes de-oxygenated

In Portal Circulatory Route, After first branch out blood becomes deoxygenated, after second branch out blood becomes Anoxic, no oxygen.

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16
Q

Hypothalamo-hypophyseal portal system, Brief overview

A

Oxygenated blood goes into the hypothalamus, picks up releasing factors and travels through the portal system in to the anterior pituitary, where it then acts in different trophic cells to release hormones

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17
Q

Development of the Endocrine System

A

At 4 weeks gestation, no endocrine glands have formed

From weeks 5 onwards:

  1. Pituitary develops from neurohypophyseal bud and
    hypophyseal pouch
  2. Thyroid develops from floor of pharynx – 2nd pouch
  3. Parathyroid and thymus develop from 3rd and 4th
    pharyngeal pouches
  4. Pancreas develops from the foregut
  5. Adrenals develops from intermediate mesoderm and
    neural crest
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18
Q

Where do you get development of the Endocrine System

A

Pharyngeal pouches

19
Q

Which Hormones does the Posterior Lobe of the pituitary gland release

What do they do

A
  • ADH - Effects kidneys
  • Cytosin - Males; Smooth muscle in ductus deferens and prostate gland
20
Q

Which Hormones does the Posterior Lobe of the pituitary gland release

What do they do

A
  • ADH
    • Effects kidneys
  • Oxytocin
    • Males; Smooth muscle in ductus deferens (sperm release) and prostate gland
    • Females; Uterine smooth muscle and mammary glands
21
Q

How are pituitary hormones secreted

A

All of these pituitary hormones are all subject to constitutive and regulated merocrine secretion
This is why there is always a small concentration of these hormones in the blood

22
Q

Where is the thyroid Gland

A

Base of the neck
Sits above the second Tracheal cartilage

23
Q

When are thyroid hormones produced

A

Under the actions of TSH and TSAbs produce T4 and T3 (thyroid hormones)

24
Q

What is hyperthyroidism and hypothyroidism,
What controls TSH levels

A

High T3 or T4 = hyperthyroidism
Low T3 or T4 = hypothyroidism

TSH levels are due to negative feedback loop on TRH production and release at the hypothalamus

25
Q

What is the role of the Parafollicular cells
What is it major and minor effects

A
  • Role to monitor plasma calcium concentrations and decreases Ca2+ levels (counteracts the function of PTH)
  • Major effect:
    inhibits osteoclast activity in bone
  • Minor effect:
    inhibits renal calcium and phosphate re-absorption in the tubular cells —> more calcium and phosphate excreted
26
Q

What is the role of Parathyroid gland

A
  1. Constantly monitor plasma calcium concentrations
  2. Plasma calcium is low, then parathyroids make parathyroid hormone (PTH)
  3. PTH causes the bones to release calcium into the blood (Activates osteoclasts, this breaks down bone releasing calcium) and prevents
    calcium loss by the kidneys; absorb more calcium from the GI Tract
  4. Classical negative feedback loop (calcium reaches set point; parathyroid glands STOP making PTH)
27
Q

Why is calcium important

A

Calcium is the most important element for the nervous system, the muscular system, and the skeletal system

  • Calcium provides the electrical system for our nerves, and muscles, allowing the nerves to conduct electricity and the muscles to contract*
28
Q

Hyperparathyroidism, symtoms
How common is it

A

A fairly common condition

Digestive System
- Loss of appetite
- Nausea
- Vomiting
- Constipation

Nervous System
- Fatigue
- Depression
- Confusion

Urinary System
- Kidney stones
- Increased thirst
- Increased Urination

Musculoskeletal System
- Muscle weakness
- Aches and Pains in bones and joints

29
Q

Hypoparathyroidism, symptoms
how common is it

A

A rare health condition
- Tingling sensation in finertips, toes and lips
- Muscle cramps
- Fatigue
- Coarse Hair
- Brittle nails
- Dry & Rough skin
- Twitching facial muscles

30
Q

What is Hyperparathyroidism

A

Hyperparathyroidism is where the parathyroid glands (in the neck, near the thyroid gland) produce too much parathyroid hormone.

31
Q

What is Hypoparathyroidism

A

Hypoparathyroidism is a rare condition where the parathyroid glands, which are in the neck near the thyroid gland, produce too little parathyroid hormone.

32
Q

What is an adrenal gland a mix off

A

Adrenal gland
– a mixed endocrine and neuroendocrine tissue

33
Q

What is the structure of the Adrenal gland

A

Inside is the Medulla and outside is the Cortex

34
Q

What is the Adrenal Medulla

What does it do

A

The medulla, is composed of a parenchyma of large, pale-staining epithelioid cells called chromaffin cells. The chromaffin cells are, in effect, modified neurons

  • Numerous myelinated, pre-synaptic sympathetic nerve fibres pass directly to the chromaffin cells
  • When nerve impulses reach the catecholamine-secreting chromaffin cells, they release their secretory products adrenaline and noradrenaline
  • Therefore, chromaffin cells are considered the equivalent of post-synaptic neurons
35
Q

Adrenal Cortex Structure and function

A

Three Layers:
Outer – Zona glomerulosa Aldosterone regulates BP

Middle – Zona fasciculata
Glucocorticoids (cortisone/cortisol)
mobilises fats, proteins and carbohydrates

Inner –
Zona reticularis
Androgen precursors i.e.
androstenedione, DHEA, etc…
These will go on to make Testosterone, Eostrogen and Progesterone.

36
Q

What is the definition of Stress Response

A
  • Stress is commonly defined as “…a state of real or perceived threat to homeostasis…”.
  • “Maintenance of homeostasis in the presence of aversive stimuli (stressors) [that] requires activation of a complex range of responses involving the endocrine, nervous and immune systems, is collectively known as the stress response”
  • Activation of the stress response initiates a number of behavioral and physiological changes that improve an individual’s chance of survival when faced with homeostatic challenges
37
Q

What are the behavioural and Physiological changes that occur to stress response

A

Behavioural changes
* increased awareness
* improved cognition
* euphoria
* enhanced analgesia

Physiological adaptations
* Increased cardiovascular tone
* Increased respiratory rate
* Increased intermediate metabolism

38
Q

Where are the principle effectors of the stress response

A

The principal effectors of the stress response are localised in the hypothalamus, the anterior lobe of the pituitary gland, and the adrenal gland

39
Q

What Is the Flight or Fight Response

A

Ramping up your blood pressure, dumping your glucose into your blood stream and shutting down non emergency services.

40
Q

How does the hypothalamus prepare for flight or fight

A

in the portal system
- CRH produced by the neurons
- Dumped out by blood vessels
- Passes it down into Anterior pituitary
- In the Anterior Pituitary ACTH is stored
- When it gets Signal (CRH) it is released
- ACTH binds to ACTH receptors in the adrenal cortex
- This releases needed molecules

41
Q

Structure of Pancreases

A
  • Acinar glands
  • Grouped into lobules
  • Contain numerous zymogen
    granules
  • Connect through numerous intercalated ducts to pancreatic duct
  • Which joins with bile duct to make common bile duct
  • Intercalated duct lined with cuboidal epithelial cells
42
Q

Pancreas - Exocrine function (acini)

A

Produces:
* Trypsinogen (converted to trypsin)
* Chymotrypsinogen (converted to chymotrypsin)
* Lipase
* Amylase
* Ribonuclease
* Deoxyribonuclease
* Gelatinase
* Elastase

43
Q

Pancreas - Endocrine function (islet of Langerhans)

A

α cell – Glucagon (catabolises glycogen to glucose)
β cell - Insulin (uptake and storage of glucose)
δ cell – Somatostatin (inhibits insulin and glucagon secretion)
PP cell - Pancreatic polypeptide (inhibits bile, pancreatic enzyme and bicarbonate secretion)
D-1 cell – Vasoactive intestinal peptide (similar to glucagon, stimulates enzymatic secretion and gut motility)
EC cell – Secretin (stimulates bicarbonate production), motilin (increases gastric and intestinal motility), substance P (analgesia, i.e. pain relief)
Ε cell – Ghrelin (increases feeding behaviour)
G cells – Gastrin (stimulates HCl production by the stomach)

44
Q
A