Endocrine System Flashcards
1
Q
In order for all cells in our body to survive, we maintain …
A
…a constant internal environment
2
Q
Examples of homeostasis?
A
Glucose for energy
Gas exchange (oxygen / carbon dioxide)
Growth rate
Removal of waste
Temperature
3
Q
Homeostasis is the process by which…
A
…we maintain this constant internal environment, irrespective of the changing environment around us.
4
Q
Homeostasis is accomplished by carefully balancing…
A
…excretion, losses, and intake of nutrients and internal production and metabolic consumption.
5
Q
Homeostasis involves…
A
…the interaction between our many body systems
6
Q
The endocrine system is closely linked with the…
A
…reproductive system
7
Q
Whats a hormone?
A
a chemical released by one part of the body, but regulates the activity of a cell in another part of the body
8
Q
Hormones are usually dispersed by…
A
…the blood circulation
9
Q
What are glands?
A
synthesises substances (such as hormones) for release
10
Q
Whats a neurotransmitter?
A
chemical released by nerve impulse; usually released locally at a synapse
11
Q
Whats a receptor?
A
- Target for hormone
- Target for neurotransmitter
12
Q
The endocrine system releases hormones into …
A
…the circulation or into interstitial fluid.
13
Q
Hormones released by the endocrine system travel in the…
A
…bloodstream
14
Q
Hormones target distant cells/organs in the…
A
…body
15
Q
ENdocrine system regulates…
A
…homeostasis
16
Q
Glands of the Endocrine System:
A
Pituitary / Hypothalamus
Thyroid
Thymus (Immune System lecture)
Adrenal
Pancreas
Ovaries / Testes
17
Q
In contrast, glands of the exocrine system…
A
…release fluids into the lumen or outside of the body, typically by way of a duct
18
Q
the pancreas has both …
A
…endocrine and exocrine functions
Endocrine = insulin and glucagon into the bloodstream
Exocrine = digestive enzymes into the duodenum
19
Q
Hormones released by endocrine glands travel around …
A
…the body, but only exert their effect on target cells
20
Q
target cells have specific ________ for specific _________
A
target cells have specific receptors for specific hormones
21
Q
adrenaline released by the …
A
…adrenal glands travels around the bloodstream and binds to adrenoceptors (adrenergic receptors)
22
Q
when adrenaline meets β1 adrenoceptors in the heart
A
increases inotropy (force of contraction)
increases chronotropy (rate of contraction)
23
Q
Whats intropy?
A
force of contraction
24
Q
Whats chronotropy?
A
rate of contraction
25
Some hormones have many different ...
...receptors
26
adrenaline has ___ different receptors
adrenaline has 5 different receptors
27
Adrenalines 5 receptors:
a1, a2, B1, B2, B3
28
Adrenalines different receptors...
...all exert different effects and are found in different tissues
29
Adrenalines different receptors are activated by...
....different concentrations of adrenaline
30
There are two types of hormones:
- Water soluble
- Lipid soluble
31
Water soluble examples:
- Adrenaline
- Noradrenaline
32
Water soluble hormones include...
...Include amine containing hormones
33
Lipid soluble hormones include...
...steroid hormones
34
Examples of lipid soluble hormones:
- Cortisol
- Aldosterone
- Androgens
- Oestrogens and progestogens
35
Lipid-Soluble Hormones are found...
...inside cells.
36
as the hormones are lipid soluble, they can ...
...diffuse across cell membranes
37
Lipid soluble hrmones are known as...
...intracellular receptors and are insdie the target cell
38
Lipid soluble hormones usually in...
...the cytoplasm or nucleus
39
Lipid-Soluble Hormones forms a ...
...a receptor/hormone complex
40
Lipid-Soluble Hormones alters...
...gene expression
- turns things on/off
41
Lipid-Soluble Hormones alter gene expression, turns things on/off, and affects...
...the target cells’ activity
42
Water soluble hormones bind to ...
...target receptors outside cells
43
water soluble hormones cannot...
...diffuse across cell membranes
44
Water soluble hormones are known as...
...extracellular receptors (G protein-coupled receptor)
45
Water-Soluble Hormones are the...
...1st messenger
- binds to the receptor
46
What do 2nd messenger systems do?
1) cyclic adenosine monophosphate (cAMP)
2) cAMP activates protein kinases
3) protein kinases phosphroylate proteins
4) this either turns the protein on/off
5) affects the target cells’ activity
47
The Hypothalamus is the...
...master controller of the endocrine system
48
The hypothalamus is located...
...just below the thalamus of the brain.
49
Hypo means...
...under or below in greek
50
The hypothalamus is a major link between the ...
...nervous and endocrine systems
51
The Hypothalamus is linked to the pituitry gland by the...
...infundibulum
52
Hormones from the Hypothalamus made by ...
...the neurosecretory cells
53
Hormones from hypothalamus are packaged into...
...vesicles, which are released and diffuse into the plexus of the hypophyseal portal system
54
Hypothalamus produces...
...a variety of releasing / inhibiting hormones
55
Releasing hormones of the hypothalamus ?
CRH – Corticotropin Releasing Hormone
GHRH – Growth Hormone Releasing Hormone (Somatocrinin)
GnRH – Gonadotrophin Releasing Hormone
PRH – Prolactin Releasing Hormone (*thought to exist)
TRH – Thyrotrophin Releasing Hormone
56
Inhibiting hormones of the hypothalamus?
GHIH – Growth Hormone Inhibiting Hormone (Somatostatin)
57
Releasing and Inhibiting Hormones cause the anterior pituitary...
....to start/stop secreting hormones.
58
The Pituitary Gland is split into two parts:
1) Posterior Pituitary
2) Anterior Pituitary
59
Posterior Pituitary does not...
...synthesise hormones
60
Posterior Pituitary function?
Stores and releases two hormones made by the hypothalamus
61
What hormone does the posterior pituitary secrete?
- Vasopressin (Antidiuretic Hormone (ADH)) – urinary system
- Oxytocin -- effects uterus and breasts
62
Anterior Pituitary gland Synthesises and secretes ...
...a wide range of hormones
63
Anterior Pituitary Gland synthesises...
...releasing hormones.
64
Anterior Pituitary Gland five different...
...tropic cell types (1 – 5)
65
Anterior Pituitary Gland Secretes how many different hormones...
seven different hormones (I – VII)
66
The hormones released by Anterior Pituitary Gland?
1) Somatotrophs
- Secrete human Growth Hormone (hGH)
- cause cells to produce Insulin-like Growth Factors (IGF’s)
2) Thyrotrophs
- Secrete Thyroid Stimulating Hormone (TSH)
- controls the Thyroid Gland
3) Gonadotrophs
- Secrete Follicle Stimulating Hormone (FSH)
- Secrete Luteinising Hormone (LH)
4) Lactotrophs
- Secrete Prolactin
5) Corticotrophs
- Secrete Adrenocorticotrophic Hormone (ACTH)
- Secrete Melanocyte Stimulating Hormone (MSH)
67
How many adrenal glands?
2
68
Where are adrenal glands found?
Found on top of each kidney
69
Size of adrenal glands?
3-5 cm high
2-3 cm x 1 cm width
70
The Adrenal Glands differentiated into ___ regions?
Two regions
71
What are the two regions of the adrenal glands?
1) Cortex
2) Medulla
72
adrenal glands produces...
...hormones
73
Adrenal glands are under...
...central control
74
Adrenal hormones produced by hypothalamus ?
Hypothalamus - Corticotropin Releasing Hormone (CRH)
75
Adrenal hormones produced by pituitary ?
Pituitary - secretes Adrenocorticotrophic Hormone (ACTH)
76
Adrenal glands surrounded by a...
...capsule
77
Capsule made up of...
...connective tissue
78
Connective tissue / capsule of adrenal glands is highly...
...vascularised (blood supply)
79
The cortex and medulla of the adrenal gland secrete...
...hormones
80
The cortex of the adrenal gland comprises...
...80-90% of the gland
81
Medulla of adrenal glands comprises...
...10-20% of the gland.
82
Are adrenal glands essential for life?
Yes
83
Loss of the adrenal hormones leads to ...
...death by dehydration/electrolyte imbalance
84
The cortex of the andrenal glands is subdivided into...
....3 zones
85
3 zones of the adrenal glands cortex?
1) Zona glomerulosa
2) Zona fasciculata
3) Zona reticularis
86
Zona glomerulosa:
- Outer zone
- Makes mineralocorticoids (Aldosterone)
87
Zona fasciculata:
- Middle zone
- Makes glucocorticoids (Cortisol)
88
Zona reticularis:
- Inner zone
- Weak androgens (dehydroepiandrosterone (DHEA))
89
Adrenal medulla contains...
...chromaffin cells.
90
Adrenal medulla are able to secrete...
- Adrenaline (A)
- Noradrenaline (NA)
91
Aldosterone is the major...
...mineralocorticoid
92
Aldosterone is produced by...
...the zona glomerulosa
93
Mineralocorticoid Hormones involved in...
...the excretion of H+ ions into the urine
94
Mineralocorticoid regulates...
...the acid / base balance of the blood
95
mineralocorticoid prevents ...
...acidosis (blood pH < 7.35)
96
97
Main function of mineralcorticoids?
homeostasis of two mineral ions
- sodium (Na+)
- potassium (K+)
98
Mineralocorticoids regulate homeostasis of potassium and sodium which regulate...
- regulate blood volume
- regulate blood pressure
99
Homeostasis of sodium and potassium by mineralocorticoids is done through the...
...Renin-angiotensin-aldosterone (RAA) pathway
100
WHats ACE stand for?
Angiotensin Converting Enzyme (ACE)
101
Angiotensin Converting Enzyme (ACE) prevents...
...the conversion of Angiotensin I to Angiotensin II
102
What are Angiotensin Converting Enzyme (ACE) taken for?
hypertension
103
Examples of ACE drug?
Lisinopril / Enalapril
104
Lisinopril / Enalapril reduces...
...vasoconstriction of arterioles
105
Lisinopril / Enalapril treat...
...high blood pressure (hypertension)
106
Lisinopril / Enalapril reduce...
... death rate following myocardial infarction / heart failure
107
Lisinopril / Enalapril reduce load on...
... the heart and kidneys (in chronic kidney disease)
108
There are three glucocorticoids:
1) Cortisol (hydrocortisone) – 95%
2) Cortisone
3) Corticosterone
109
Glucocorticoids are produced by...
...zona fasiculata
110
glucocorticoids are very similar in structure to ...
...aldosterone
- differ only in C=O and OH groups
111
Glucocorticoid function:
Regulate metabolism
Resistance to stress
112
Slide 28
113
What do glucocorticoids do?
114
Glucocorticoids are ____ hormones
Glucocorticoids are stress hormones
115
WHen are glucocorticoids released?
Released by the body to deal with ‘challenging’ situations
116
glucocorticoids promote...
...protein breakdown.
117
Glucocorticoids increase the rate of ...
...protein breakdown in the body
- Usually in muscle fibres
118
Glucocorticoids liberate ___ into the bloodstream
Glucocorticoids liberate amino acids into the bloodstream
119
Amino acids may be used by body cells to ...
- synthesise new proteins
- ATP production during prolonged hypoglycaemia (low blood sugar)
120
Slide 30
121
Slide 31
122
The additional glucose helps alleviate stress by ...
...providing ATP to combat stresses
123
The additional glucose helps alleviate stress by providing ATP to combat stresses caused by:
Exercise
Fasting
Fright
Extremes of temperature
High altitude
Bleeding and Trauma
Infection
Disease
Surgery
124
slide 33
125
Glucocorticoid Drugs are used on ...
...Psoriasis
126
Positive affect of Glucocorticoid Drugs on Psoriasis?
Topical corticosteroids reduce local inflammation
Hydrocortisone cream
Lessens the redness
Prevents itching
This is good
127
Negative affect of Glucocorticoid Drugs on Psoriasis?
They suppress the immune system
They can enable an infection to develop
Hide the signs of infection
This is bad
128
Positive affect of Glucocorticoid Drugs on Organ transplantation / autoimmune disease?
If you have a transplant, you must take drugs to prevent tissue rejection forever
Or suppress immune system in autoimmune disease
This will keep you alive
This is good
129
Negative affect of Glucocorticoid Drugs on Organ transplantation / autoimmune disease?
Getting the right balance between suppression / infection is very difficult
If the dose is not quite perfect
Very high risk of opportunistic infection
Kaposi sarcoma (tumour caused by Herpes virus)
This is bad
130
Cushing syndrome is caused by...
...high levels of exposure to cortisol
131
Causes of Cushing Syndrome:
1) Overstimulation of the adrenal cortex by excessive hormone release
- Corticotrophin releasing hormone (CRH)
- Adrenocorticotropic hormone (ACTH) - corticotrophin
2) Adrenalcorticol adenoma secreting cortisol
- Very common benign tumour (up to 30% of us have it at death)
- But only 15% actually secrete hormones
3) ACTH secreting tumours
- These are not pituitary tumours as you would expect
- Called small cell carcinomas
- Highly malignant cancer most commonly found in the lung
- Produce hormones including ACTH (or ADH)
4) Exposure to glucocorticoid drugs (iatrogenic or preventable)
- Usually through certain asthma / rheumatoid arthritis / immunosuppression medications
132
Symptoms of Cushing Syndrome:
- Excessive gluconeogenesis
- Elevated blood glucose
- Glucose gets deposited as fat
- Moon face
- Buffalo hump
- Loss of lean muscle
- Weakness
133
What does treatment of Cushing Syndrome depend on?
- Treatment depends on the cause
134
What is DHEA?
Dehydroepiandrosterone
135
DHEA produced by...
...zona reticularis
136
Prior to puberty ____ is the major androgen in males
Prior to puberty Dehydroepiandrosterone (DHEA) is the major androgen in males
- Then, testosterone takes over.
137
Functions of Adrenal Androgens in males?
Pubic hair development, but insignificant after puberty
138
Functions of Adrenal Androgens in females?
- Sex drive (libido)
- Converted to oestrogen (female sex hormone) by other tissue in the body
- After menopause, they will be the only source of oestrogen
139
Slide 39
140
The adrenal medulla is a modified what?
a modified sympathetic ganglion
141
What does the adrenal medulla lack?
Axons
142
How do cells grow in blood vessels?
The cells grow in clusters around blood vessels (chromaffin cells)
143
Adrenaline is released as...
... a hormone
144
The medulla is innervated by the...
...ANS
145
The medulla is innervated by the ANS and can quickly ...
...stimulate catecholamine secretion
146
The adrenal medulla is the innermost part of the...
...adrenal glands
147
What does the adrenal medulla produce?
Catechoolamines (epinephrine and norepinephrine / adrenaline and noradrenaline)
148
Percentage amounts of catecholamines produced?
Adrenaline (epinephrine) - (80%)
Noradrenaline (Norepinephrine) – (20%)
149
In the adrenal glands catecholamines are ...
... hormones
150
In the adrenal glands catecholamines are hormones.
However in the CNS they function as...
... neurotransmitters.
151
Function of Catecholamine hormones?
– Produce the ‘Fight or Flight’ response
– Stressful situations
– Exercise
152
Effects of catecholamines?
- Increase force and rate of heart contraction
- Increase blood pressure
- Dilate airways – B2 adrenoceptor
- Increase blood sugar by breaking down glycogen
- Increase blood flow to the muscles / liver.
153
Why are catecholamines important?
- Heart is primed for activity
- Extra glucose for muscles and lots of air to the lungs
154
Examples of catecholamine drugs?
1) Ventolin
2) Beta blockers
155
What is ventolin?
Asthma inhaler
156
What does ventolin contain?
salbutamol
157
What kind of agonist in ventolin?
B2 adrenoceptor agonist
158
Ventolin specifically affects receptors in...
...the airways
159
How does ventolin make it easier to breathe?
Dilates airways making it easier to breathe
160
How are catecholamines used in cardiac arrest?
- Administer adrenaline / noradrenaline
- CPR
- Defibrillation
- Increases heart rate
- Increases force of contraction
- Helps restart the heart
161
Examples of catecholamine drugs?
- Propranolol (b1 and b2 antagonist)
- Atenolol (b1 antagonist)
162
What are catecholamine drugs used to treat?
- High blood pressure
- Tachycardia
- Angina
- Glaucoma
163
What can beta blockers also be used to help calm?
Performance anxiety
164
How do beta blockers help with performance anxiety?
Prevents:
- Dry mouth
- Increased heart rate
- Butterflies in the stomach
- Tremor
- Banned in sports (not useful in all sports)
165
How many Gonads do males and females have?
Males have two and females have two
166
What are the Gonads in males?
Testes
167
What are the Gonads in females?
Ovaries
168
Like many other glands, the gonads are under...
... central control by the hypothalamus.
169
What does the hypothalamus release which helps to control the gonads?
Secretes Gonadotrophin Releasing Hormone (GnRH)
170
What does the pituitary gland release which helps to control the gonads?
Secretes Luteinising Hormone (LH) and Follicle Stimulate Hormone (FSH)
171
Whats LH?
Luteinising Hormone
172
Whats FSH?
Follicle Stimulating Hormone
173
What is the primary trigger of puberty?
Gonadotrophin Releasing Hormone (GnRH)
174
Gonadotrophin Releasing Hormone (GnRH) is produced by...
...Hypothalamus gland
175
Gonadotrophin Releasing Hormone (GnRH) has a [...] release
Gonadotrophin Releasing Hormone (GnRH) has a pulsatile release
176
Gonadotrophin Releasing Hormone (GnRH) causes the release of ...
.... Gonadotrophins
177
Gonadotrophins have a [...] release.
Gonadotrophins have a pulsatile release.
178
In females, Luteinising Hormone (LH) acts on...
... Theca cells
179
Theca cells surround the ...
...follicles
180
What do theca cells synthesise?
androgens
181
Oestrogens are synthesised
from ...
... androgens
182
In females, FSH stimulates...
... immature ovarian follicles to develop
183
n females, FSH stimulates immature ovarian follicles to develop.
Then the follicles...
.... mature.
184
Follicle means what in latin?
means nest in latin
185
The process of egg development is known as?
Oogenesis
186
Whats Oogenesis?
Egg development
187
Whats oestrogen responsible for in females?
- Growth of breasts
- Growth of pubic hair
- Bone growth (growth spurts, widening of the hips)
- More subcutaneous fat (hips, thighs, and buttocks)
- Growth of the uterus
- Proliferation of the endometrium (menstrual cycle, monthly development and release of 1 egg, place for implantation (endometrium))
188
Whats endometrium?
place for implantation
189
In males, LH acts on...
...Leydig cells
190
In males, LH acts of the Leydig cells which synthesises what?
synthesises testosterone (increases testosterone levels)
191
In males, FSH stimulates...
... follicles
192
In males, FSH stimulates follicles and acts on the...
...Sertoli cells
193
In males, FSH acts on the Sertoli cells which stimulates...
... primary spermatocytes to undergo
the first division of meiosis, forming secondary spermatocytes.
194
FSH is a key hormone in the process of...
...spermatogenesis (sperm production)
195
Whats spermatogenesis?
sperm production
196
Effects of testosterone in males?
- Enlargement of the larynx & laryngeal muscle
- Enlargement of the genitalia
- Growth of pubic hair
- Growth of facial hair
- Bone growth (growth spurt, become broader in the shoulders)
- Fusing of epiphyseal plates
197
What are epiphyseal plates?
- hyaline cartilage plate in the metaphysis
- found at each end of the long bones
198
