Endocrine system Flashcards
(183 cards)
1
Q
Which organs are included in the endocrine system (6)?
A
Gonads
Pancreas
Pituritary gland
Thyroid gland
Parathyroid glands
Adrenal glands
2
Q
Are peptide hormones soluble in water?
A
Yes
3
Q
Do peptide hormones need a transporter?
A
No because they are soluble in water and can travel through the membrane
They need a receptor
4
Q
What do endocrine organ secrete?
A
Signals in form of hormones
5
Q
Do steroid hormones need a receptor?
A
Yes
6
Q
Are steroid hormones soluble in water?
A
No
7
Q
What does the hypothalamus-hypophyseal system target?
A
Other endocrine glands
8
Q
What does the hormones from the hypothalamus stimulate?
A
The pituitary gland
9
Q
2 parts of the pituitary gland
A
Adenohypohysis
Neurophypohysis
10
Q
Different name for pituitary gland
A
Hypophisis
11
Q
What is the part of the CNS that includes the hypothalamus called?
A
Diencephalon
12
Q
Which 7 structures forms the border of the hypothalamus?
A
Superior: Hypothalamic sulcus
Inferior: Optic chiasm, tuber cinereum, mammillary body and infundibulum
Anterior: Lamina terminalis
Posterior: Midbrain
13
Q
What is the small swelling in the tuber cinereum called (located behind the infundibulum)?
A
Median eminence
14
Q
What is the connection between the pituitary gland and thalamus called?
A
Infundibulum
15
Q
Functions of the hypothalamus
A
Regulation of food and water intake
Sleep-wake cycle
Sexual behaviour patterns
Defence mechanisms against attack
16
Q
What kind of tissue is the neurohypophysis?
A
Nervous tissue
17
Q
What cells are the adenohypophysis made of?
A
Endocrine cells
18
Q
Origin of neurohypophysis
A
Diencephalic downgrowth
19
Q
Origin of adenohypophysis
A
Ectodermal derivative
20
Q
Which is anterior, neurohypophysis or adenohypophysis?
A
Adenohypophysis
21
Q
What forms the infundibular stem?
A
Axons of neurons which body is located in the hypothalamus
22
Q
What forms the neural stalk (connection of hypothalamus and pituitary gland)?
A
Median eminence
Infundibular stem
23
Q
3 regions of the hypothalamus
A
Anterior (supraoptic)
Middle (tuberal)
Posterior (mammillary)
24
Q
Where is the body of the parvocellular neurosecretory cells located?
A
Inside the middle part of the hypothalamus
25
Where is the axons of the parvocellular neurosecretory cells located?
Infundibular
26
Is there a portal system in the pituitary gland?
Yes
27
What are the 2 magnocellular nuclei called?
Paraventricular nucleus
Supraoptic nucleus
28
What supplies the primary capillary plexus in the upper infundibulum?
Superior hypophysial artery
29
How many capillary beds in the hypothalamohypophysial portal system?
2
30
Which hormones do the basophils contain?
Glycoprotein hormones
31
Which hormones do the acidophils contain?
Polypeptide hormones
32
What do lactotrope cells produce?
Prolactin
33
What do somatotrope cells produce?
Growth hormone
34
What do thyrotropes cells produce?
Thyroid stimulating hormones
35
What do gonadotropes cells produce?
Luteinising hormone or follicle stimulating hormone
36
What do corticotropes cells produce?
Adrenocorticotrophic hormone
37
Where is the thyroid gland located?
Lower neck, C5-T1
38
When does the thyroid gland enlarge in women?
During menstruation and pregnancy
39
What connects the 2 lobes of the thyroid?
The isthmus
40
What muscles protect the thyroid gland?
The infra hyoid muscles
-> Omohyoid, sternohyoid muscle, sternothyroid and thyrohyoid muscle
41
Where are the parathyroid gland attached?
Thyroid
42
What is the thin capsule of the thyroid gland made of?
Connective tissue
43
What is the functional unit of the thyroid gland?
Follicles
44
What shape does the follicles have?
Spherical and cyst like
45
What is the core of the follicles made up of?
Central colloid core
46
What is the colloid?
Storage form of thyroid hormone
47
What is iodothyroglobulin?
The inactive stored form of the active thyroid hormones
48
What produced T3 and T4?
The follicular epithelial cells
49
Which follicles are large? resting or active?
Resting
50
Why are resting follicles large and lined by squamous or low cuboidal epithelium?
Because they store a lot of hormones
51
Why are active follicles small and lined by cuboidal cells?
Because they are secreting hormone via endocytosis
52
What 2 types of cells in the thyroid gland?
Follicular cells
C cells
53
Where are C cells found in the thyroid gland?
Inbetween follicular cells
54
What does C stand for in C cells?
Clear
Calcitonin
Calcium
55
What do C cells produce?
Calcitonin (thyrocalcitonin)
56
Where are the arteries that supply the thyroid gland from?
External carotid artery
Thyreocervical trunk (branch of subclavian artery)
57
3 veins of the thyroid gland
Superior thyroid vein
Inferior thyroid vein
Superficial branch
58
What is the color of the parathyroid glands?
Yellow-brownish
59
Embrylogical origin of the parathyroid glands?
Endodermic origin
60
What does it mean that parathyroid glands are ectopic?
That they are in an unusual place
61
2 cell types in the parathyroid
Chief cells
Oxyphil (eosinophil) cells
62
Where are the suprarenal (adrenal) glands located?
Above the adipose of each kidney
63
What is the position of the adrenal glands?
Retriperotoneal
64
Which adrenal gland is longer?
The left
65
Does the renal fascia also contain the adrenal glands?
Yes
66
What are the renal fascia surrounded by?
Renal fascia and peri renal adipose tissue (fat)
67
Shape of the left adrenal gland
Semilunar
68
Shape of the right adrenal gland
Pyramidal
69
3 superrenal arteries for each adrenal gland
Superior, middle and inferior suprarenal arteries
70
Where does the superior suprarenal arteries branch from?
Inferior phrenic arteries
71
Where does the middle suprarenal arteries branch from?
Directly from the aorta
72
Where does the inferior suprarenal arteries branch from?
Renal arteries
73
What does the vein from the right adrenal gland drain into?
Directly into the inferior vena cava
74
What does the vein from the left adrenal gland drain into?
Left renal vein
75
Does the renal glands have their own capsule?
Yes
76
What does the cortex of the adrenal glands synthesise?
Steroid hormones
77
What does the medulla of the adrenal glands synthesise?
Catecholamines (adrenalin and noradrenalin)
78
3 different part of the cortex of the adrenal gland
Zona glomerulosa
Zona fasciculata
Zona reticularis
79
What is the endocrine system?
Communication between different parts of the body
80
What is the endocrine system vital for maintaining?
Homeostasis
81
What does angiotensin and renin regulate?
Blood pressure and renal filtration
82
What are hormones transported via?
The bloodstream
83
Why are endocrine glands vascularised with a dense microvascular network?
Because hormone transport take place via the bloodstream
84
What does the microenvironment of the microvasculature of endocrine glands harbour?
Stem and progenitor cells
85
Via what does the hypothalamus control the production and secretion of numerous hormones in the pituitary gland?
Neuroendocrine signals
86
What do the hormones released into the bloodstream from the hypothalamus trigger?
The release of hormones from their target glands which in turn affect organ function
87
What regulates the hormone level?
Feedback mechanisms
88
What creates a negative feedback loop?
When hormones from target glands reach a certain concentration in the blood
89
What does the negative feedback loop do?
Inhibits further hormone release in the hypothalamus and pituitary gland
90
Where is the pituitary gland contained?
In the hypophyseal fossa
91
Different name for adenohypohysis of the pituitary gland
Anterior lobe
92
Different name for Neurohypophisis of the pituitary gland
Posterior lobe
Neural lobe
93
What kind of structure is the hypothalamus?
Bilateral, paired structure
94
In what 2 areas does the hypothalamus have major functions?
Homeostasis and survival
95
What does the homeostatic functions by the hypothalamus include?
Control of body temperature and circulation of blood
96
What is the pituitary gland continuos with?
Infundibulum
97
In which bone is the pituitary fossa found?
Sphenoid bone
98
What is the pituitary gland covered by superiorly?
A circular diaphragma sellae of dura mater
99
What does the dura mater that covers the pituitary gland superiorly form?
A bridge pierced by the sellae dorsal
100
When during development does the pituitary gland loose contact with the primitive oral cavity?
When rathe's pouch is pinched off
101
What does the central infundibular stem contain?
Neural hypophyseal connections
102
What is the central infundibular stem continuous with?
The median eminence of the tuber cinereum
103
What is the infundibular stem formed by?
Axons of neurons whos body is in the hypothalamus
104
What part of the adenohypophysis surrounds the infundibular stem?
The pars tuberalis
105
What part of the adenohypophysis is the largest?
Pars distalis
106
What is in-between neurohypophysis and adenohypophyis?
The pars intermedia
107
3 parts of the adenohypophyis
Pars tuberalis
Pars intermedia
Pars distalis
108
How are the endocrine cells of the adenophysis classified?
According to their staining
109
What does the staining of the endocrine cells of the adenophysis reflect?
Their hormone production which reflects their function
110
Which part of the hypothalamus is above the infundibulum?
The middle (tuberal)
111
What does the parvocellular neurons reach?
The infundibular capillary bed
112
What does the action potentials of pravocellular neurons result in?
Calcium-dependent exocytosis of releasing hormones or inhibiting hormones into the capillary bed
113
What are the pravocellular neurons transport to?
Adenohypophysis
114
What does magnocellular neurons give rise to?
The hypothalamohypophyseal tract
115
What does the hypothalamohypophyseal tract descend to?
The neurohypophysis
116
2 hormones secreted directly to the capillary bed by magnocellular nuclei
Antidiuretic hormone (vasopressin)
Oxytocin
117
What makes up nearly half the volume of the neurophypophysis?
Axon swellings containing the secretory granules for antidiuretic hormone and oxytocin
118
Which nuclei does the neurons which secrete antidiuretic hormone and oxytocin belong to?
Supraoptic
Paraventricular nuclei
119
Which artery does the superior hypophyseal artery anastomoses with?
Inferior hypophyseal artery
120
Which vein connects to the inferior hypophyseal artery capillary bed?
Hypophysial vein
121
Which lobe of the pituitary gland is the secondary capillary plexus located in?
Anterior lobe
122
What tissue is the adenophypophysis composed of?
Winding cords of epithelial cells flanked by vascular sinusoids
123
3 types of cells seen in adenophypophysis when staining
Acidophils
Basophils
Chromophobes
124
How does acidophils stain?
Their cytoplasm stains red or orange
125
How does basophils stain?
Their cytoplasm stains blueish
126
How does chromophobes stain?
They cytoplasm stains very poorly
127
What kind of hormones does the acidophil cells contain?
Polypeptide hormones
128
What kind of hormones does basophil cells contain?
Glycoprotein hormones
129
How much hormone content is found in chromophobes?
Little to none
130
What kind of cells can chromphobes in adenohypophysis be?
Acidophils or basophils that have granulated and are depleted of hormones
Stem cell that haven't differentiated into hormone producing cells
131
What is the posteromedial aspects of the lobes of the thyroid gland attached to?
The side of the cricoid cartilage
132
What connects the lower part of the lobes of the thyroid gland?
The isthmus
133
Where is the isthmus typically?
Anterior to the 2nd and 3rd tracheal cartilage.
However the site greatly varies
134
Is the conical pyramidal lobe always present?
No, often absent or small
135
Where does the conical pyramidal lob ascend towards?
The hyoid bone
136
What is the convex lateral surface of the thyroid gland covered by?
Sternothyroid
137
What prevents the upper pole of the gland from extending o to thyrohyoid?
Attachments of the sternothyroid muscle
138
From lateral to medial how is the neurovascular bundle of the neck organised
Jugular vein
Vagus nerve
Common carotid artery
139
Name of fascia in the neck
Pretracheal (visceral)
140
What is the thyroid gland developed from?
Endocermal cells
141
Where in the embryo is the thyrogloassal duct?
Posterior to the tongue
142
What is the central collie core of follicles surrounded dby?
A single-layered epithelium
143
What does the central colloid core rest on?
Basal lamina
144
What does colloid consist of?
Iodinated glycoprotein
Iodothyroglobulin
145
What is iodothyroglobulin?
The inactive stored form of the active thyroid hormones
146
What is iodothyroglobulin produced by?
The follicular epithelial cells
147
What does the follicular cell type depend on?
Their level of activity
148
What controls the follicular cells' level of activity?
Hypophysial thyroid-stimulating hormone (TSH, thyrotropin)
149
Wha does the peptide hormone calcitonin do?
Lowers blood calcium
150
What is the venous drainage of the thyroid gland usually via?
Superior, middle and inferior thyroid vein
151
Where do the parathyroid glands usually lie?
Between the posterior lobar borders of the thyroid gland and its capsule
152
How many parathyroid glands are there typically?
2 on each side
153
What are the parathyroid glands usually supplied by?
The inferior thyroid arteries
154
What is the endodermic origin of the parathyroid glands?
3rd and 4th pharyngeal pouch
155
What is the capsule of the parathyroids made up of?
Connective tissue
156
Does the parathyroid glands have distinct lobules?
No
157
What do the parathyroid glands synthesize and secrete?
Parathyroid hormone (PTH)
158
What makes the number of oxyphil cells in the parathyroid increase?
Age
159
When are chief cells dominant in the parathyroid glands?
In childhood
160
When does adipose tissue accumulate in the stroma?
After puberty
161
Where does the right adrenal gland lie in relations to the inferior vena cava?
Posterior
162
What separates the right adrenal gland and the inferior vena cava?
A thin layer of fascia and connective tissue
163
What does the left adrenal gland lie closely to?
Left crus of the diaphragm
164
What separates the left adrenal gland and the crus of the diaphragm?
A thin layer of fascia and connective tissue
165
Where does the medullary veins emerge from?
The hilum
166
Wheat does the medullary veins form?
A suprarenal vein
167
What does the right suprarenal vein pass into?
Directly into the inferior vena cava
168
What does the left suprarenal vein pass into?
Left renal vein
169
What is the adrenal glands capsule like?
Thick collagenous
170
What forms the main mass of the adrenal glands?
An outer cortex
171
Do the zones of the suprarenal cortex synthesize the same hormones?
No they each synthesise a specific hormone
172
Is the function of androgen the same in both genders?
Yes
173
What makes up 70% of the cortex of the adrenal glands?
The zona fasciculata
174
What is the suprarenal medulla composed of?
Groups and columns of chromatin cells separated by wide venous sinusoids and supported by a network of reticular fibers
175
What are chromaffin cells functionally equivalent to?
Postganglionic sympathetic neurons
176
What are chromaffin cells dericatives of?
Neural crest
177
What do chromaffin cells do?
Synthesise, store and release noradrenaline and adrenaline
178
What is 80% of what is produced by the chromaffin cells in the suprarenal medulla?
Adrenaline
179
What mediates the release of adrenaline and noradrenaline into the venous sinusoids?
Sympathetic neurones
180
How is adrenaline stored?
In small granules
181
How is noradrenaline stored?
In large granules
182
Do some cells of the suprarenal medulla synthesize both noradrenaline and adrenalin?
Yes
183
What does a double plexus of the adrenal glands show?
That it may have function in productions of the other hormones
