LABS Flashcards
1
Q
description of first microscope with “high” magnification and good image quality
A
- beads of molten glass were used as lenses which were mounted in a metal late that had an adjustable stage on which the specimen to be examined was mounted
- natural light or light from candle flame was used to illuminate the specimen
2
Q
what are the important parts of the compound microscope
A
- objective lenses of different magnifications
- stage
- illuminator
- coarse focus knob
- fine focus knob
3
Q
what is the cell theory
A
all plant and animal tissues are composed of cells, the ultimate units of living organisms
4
Q
cells are the smallest potentially independent unit of a living organism. however, cells contain even smaller structures ____ which are potentially independent
A
organelles
5
Q
which are the 4 types of tissues?
A
- epithelial tissue
- connective tissue
- muscle tissue
- nervous tissue
6
Q
endocrine organs are made up of _____
A
epithelial tissue
7
Q
what is used during fixation
A
formaldehyde, alcohol or Bouin’s fluid
8
Q
what are the steps involved in making paraffin sections
A
- sampling
- fixation
- dehydration
- clearing
- infiltration (impregnation)
- sectioning
- staining
- dehydration and clearing
- mounting
9
Q
what is used during clearing
A
removal of alcohol with xylem
10
Q
what is used for infiltration (impregnation)
A
paraffin
11
Q
which divide is used for sectioning?
A
microtome
12
Q
what are the steps involved in staining paraffin sections
A
- remove wax(paraffin)w with xylem
- hydrate with decreasing concentration of alcohol
- staining
- dehydration
- clearing
- mounting
13
Q
which are the most common dyes used in staining/histology
A
Hematoxylin and eosin
14
Q
hematoxylin with mordants [metallic ion which helps dye to stick to what it’s staining] stains _____
A
acidic structure (nucleic acids, nuclei, RER) blue
15
Q
Eosin stains ____
A
basic structures (proteins and membranes) pink
16
Q
advantage and disadvantage of frozen sectioning
A
can see real anatomy but very short half-life due to faster degradation
17
Q
why do we want to measure hormones
A
- to understand hormone dynamics and function
- to diagnose hyper or hypofunction
- to determine efficacy of hormonal treatment
- to determine abuse
18
Q
what are the current methods of hormone assays
A
- antibody based assays
- liquid-chromatography mass-spectrometry based assays
19
Q
what are the two types of antibody based assays
A
- competitive binding assays
- immunometric assays
20
Q
relationship between proportion of antigen attaching to antibody and original concentration
A
directly proportional
ie. the amount of a given antigen that ends up binding on antibody depends on its proportion in the first place
21
Q
what gives the signal in ELISA
A
the detection antibody that has tagged enzyme which, when given its substrate, will give a color/fluorescence
22
Q
what is the advantage of ELISA compared to RIA
A
the danger of radioactivity is removed
23
Q
what are the advantages of immunoassays
A
- widely used, trusted, and relatively easy to troubleshoot
- relatively inexpensive, flexible and scalable
- good sensitivity and specificity
- works in complex samples containing multiple antigens [don’t have to purify medium ie. serum]
- dynamic range depending on analyze
24
Q
disadvantages of immunoassays
A
- poor antibody specificity can lead to over estimations
- range is somewhat limited
- very difficult to identify any post-translational modification
- multi-step process and time consuming
- intra- and inter-lab variation
- running costs can be high due to reagent usage
- sample volumes can be high
25
what is the principle behind liquid-chromatography mass-spectrometry based assays
HPLC separation of analyze involves the interaction between mobile phase (analyze) with solid phase. Separation is based on polarity, charge or size of the analyte
26
principle of MS
adds charge to hormone we are looking at -> ionization
once the hormone is ionized, they can be passed through a magnetic field where their mass analysis can be done based on their mass to charge ratio => each macromolecule has a characteristic mass to charge ratio
27
does post-translational modification affect peaks appearing on MS?
yes, post-translational modification changes ionizability and mass to charge ratio and time point in which their peak will shift
28
what are the advantages of LC-MS?
- did not need antibodies
| - measure multiple things at the same time in given matrix
29
what are some precautions that must be taken into account during hormone assays?
- circadian and ultradian rhythms
- lab-specific/technique-specific range
- need for correlation with symptoms/history during interpretation
30
where are the neurons producing the hormones found?
found in the hypothalamus
31
which stain is used for the brain?
Cresyl Violet
32
what does a nucleus in the brain refer to?
are where there is a higher density of neurons, potentially part of a particular process (sleep, memory)
33
which are the most common nuclei found in the hypothalamus
1. PVN- paraventricular nucleus
2. VMH- ventromedial hypothalamus
3. Arc- Arcuate nucleus
34
which neurons are found in the PVN nucleus? and where do they terminate
Somatostatin, CRH, TRH neurons which terminate in the median eminence
Vasopressin and Oxytocin neurons that terminate in posterior pituitary
35
which neurons does the Arc nucleus have
GHRH and GnRH neurons
36
which neurons are found in the VMH nucleus
estrogen and progesterone receptor expressing neurons and neurons that regulate feeding behaviour and metabolism
37
what kind of cells are found in the anterior pituitary?
- acidophils [PINK]: somatotrophs (GH) and lactotrophs (prolactin)
- basophils [BLUE/PURPLE]: Corticotrophs, thyrotrophs, gonadotrophs
- chromophobes (not endocrine, weak staining)
38
the anterior pituitary is vascularized, true or false?
true, we can see blood vessels/capillaries containing RBCs (no nuclei therefore no blue spots)
39
can you differentiate somatotrophs from lactotrophs?
no, they both stain pink and are referred to as acidophils
40
what color do acidophils stain?
PINK
41
what color do basophils stain?
Bluish-purple
42
what can be found in the small area between the anterior and posterior pituitary?
Rathke's cyst
43
do we find endocrine cells in the posterior pituitary?
no, we mainly find glial cells called Pituicytes and herring bodies which are cross-sections of axons coming from hypothalamic neurons
44
what are herring bodies found in the posterior pituitary?
enlarged axonal regions from hypothalamic neurons that contain vesicles that ave posterior pituitary hormones
45
why does the anterior pituitary stain dark and the posterior pituitary stain light?
anterior is made up of various endocrine cells which stain dark and the posterior stains light because it is mostly nervous tissue (axons terminating)
46
how many lobes of thyroid glands does each person have
2 lobes
47
what type of tissue connects the two lobes of the thyroid gland?
connective tissue
48
what is the capsule of the an endocrine organ
the capsule is the thin layer of connective tissue that surrounds the organ, giving it a shape
49
what are trabecular found in the thyroid gland
connective tissue that extends inwards from the capsule to partially outline irregular lobules
50
what is the functional unit of the thyroid gland
thyroid follicle [circular structure]
51
what is a follicle in the thyroid gland
it is a round structure surrounded by follicular cells creating a fluid filled cavity containing proteins
52
can we see blood vessels in the thyroid gland?
yes, we can observe some capillaries
53
_____ produce thyroid hormones
follicular cells
54
what is the liquid found inside the follicle cavity called
colloid
55
____ production calcitonin
parafollicular cells
56
what are parafollicular cells
cells that are outside follicle - they appear slightly larger compared to follicular cells
involved in calcium metabolism
57
where are the parathyroid glands located?
located on the food poles backside of the thyroid
58
thyroid and parathyroid glands are dependent endocrine organs. true or false?
false, they are undefended endocrine organs although you always find parathyroid gland on thyroid gland
59
the parathyroid gland also contains a capsule and trabecular, similar to that of thyroid gland. true or false
true
60
which cells are the most abundant in the parathyroid gland
chief cells
61
chief cells produce _____
parathyroid hormone
62
what is the second type of cell found in the parathyroid gland?
oxyphil cells
63
oxyphil cells have an endocrine fucntion. true or flase
false
64
what are the three cells found in the parathyroid gland?
- chief cells
- oxyphil cells
- adipose cells
65
what are the two parts making up the adrenal gland?
the medulla (most inner part) and the cortex
66
the adrenal gland has a _____ giving it its shape
capsule of connective tissue
67
the blood vessels appearing in the periphery penetrate the capsule of the adrenal gland and branch into ______ supplying the cortex and medulla
sinusoid capillaries
68
the cortex of the adrenal gland appears ___ whereas the medulla appears ___
cortex: pink
medulla: purple
69
the cortex si made up of 3 zones which are:
1. zona glomerulosa (outer most zone)
2. zona fasciculata (middle zone)
3. zona reticularis (inner most zone, closest to medulla)
70
what type of cell structure makes up the zona glomerulosa?
glomerular-like clusters of cells that have a central small dark nucleus and that appear foamy due to lipid vacuoles
71
why are the cells in zona glomerulosa foamy?
they contain lipid vacuoles because they produce steroids => ALDOSTERONE
72
which zone makes up 80% of the cortex of the adrenal gland?
zona fasciculata
73
what type of cell structure is found in the zona fasciculata
two cell wide vertical cords [columns in pairs] that also have a central nucleus and lipid filled cytoplasm -> foamy
74
cells found in the zona fasciculata secrete ___
cortisol
75
in the zona fasciculata you can see _____ between any of these columns
sinusoidal capillaries
76
what differentiates the zona glomerulosa to the zona fasciculata?
columns with sinusoidal capillaries in between
77
what type of cell structure is found in the zona reticularis
cells are no longer foamy but appear eosinophilic, they are present in rows perpendicular to the columns of fasciculata
78
what do the cells present in the zona reticularis secrete?
they secrete androgens mainly DHEA and androstenedione which are precursors that can ultimately be converted to testosterone
79
the different zones of the adrenal cortex are separated by clear boundaries. true or false
false, there are no clear boundaries, they are determined by the varying cell types
80
you always see _____ in medulla
medullary vessels
81
the medulla is made up of _____
chromaffin cells
82
what are chromaffin cells
modified postganglionic sympathetic neurons that secrete catecholamines epinephrine and norepinephrine
83
the medulla is a _____ tissue
nervous
84
in addition to chromaffin cells, you can also see _____ cells in the medulla
ganglion cells
85
what are ganglion cells
rare postganglionic neurons that may secrete norepinephrine only
86
what are the white channels that we can observe on a pancreas H&E stain
interlobular ducts or pancreatic ducts
87
the pancreas contains islets of lanterns that contain 5 types of endocrine cels which are?
- beta cells
- alpha cells
- delta cells
- gamma (PP) cells)
- epsilon cells
88
which part of the pancreas has an endocrine functions
islets of Langerhans
89
___ and ___ are the 2 endocrine organs that have multiple cell types secreting multiple different hormones
islets and pituitary gland
90
which cell type is the most abundant in the islets and what do they secrete?
beta cells and secrete insulin
91
alpha cells in the pancreas secrete ____
glucagon
92
the different cell types present in the islet cannot be distinguished by H&E. true or false?
true
93
which stain is used to distinguish beta and alpha cells in islets
Gomori's stain
94
what is Gomori's stain
it is a specific stain made up of hematoxylin and phloxin
95
how do the beta and alpha cells stain with Gomori's stain
beta cells stain blue
| alpha cells stain pink
96
which special stains are used for the pancreas
Gomori's stain and Aldehyde fuchsin
97
how does the pancreas stain with Aldehyde fuchsin
beta cells stain dark purple and exocrine pancreas stains a reddish-orange
98
why is the surface epithelium layer of the ovary important?
these cells are not endocrine but contribute to the majority of ovarian cancers
99
structures making up the ovarian cortex
it contains follicles and corpora lutea at different developmental stages
100
structure of primordial follicle
each primordial follicle contains one oocyte surrounded by single layer of flattened epithelial granulosa cells
101
structure of primary follcile
oocyte + single layer of cuboidal epithelial cells
102
structure of antral follicle
```
outer most layer to inner most layer:
- theca cells
- granulosa cells
=> these two departed by membrane
- oocyte
- zona pellucida
- cumulus cells
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