Histology Flashcards
(815 cards)
1
Q
What colour does PAS stain sugars?
A
Deep magenta
2
Q
What colour does alcian blue stain mucins?
A
Blue
3
Q
What colour does H&E stain nuclei and cytoplasm?
A
Nuclei - Blue
Cytoplasm - Pink
4
Q
What shape are smooth muscle cells?
A
Fusiform
5
Q
What are columnar cells?
A
Epithelial cells which are taller than they are wide
6
Q
What are squamous cells?
A
Flattened plate-like cells
7
Q
Where does DNA transcription occur?
A
The nucleolus
8
Q
What 2 things happen in the outer membrane of the mitochondria?
A
- Lipid synthesis
- Fatty acid metabolism
9
Q
What happens in the inner membrane of the mitochondria?
A
Respiratory chain ATP production
10
Q
What happens in the matrix of the mitochondria?
A
TCA (Kreb’s) cycle
11
Q
What happens in the inter membranous space of the mitochondria?
A
Nucleotide phosphorylation (ADP to ATP)
12
Q
What is the lifespan of erythrocytes?
A
120 days
13
Q
What is chromatin?
A
Nuclear DNA and proteins
14
Q
What happens in the RER?
A
Protein synthesis
15
Q
What happens in the SER?
A
Membrane lipid is formed
16
Q
What happens in the Golgi apparatus?
A
Formation of complex oligosaccharides, protein phosphorylation and proteolysis
17
Q
What is the filament with the smallest diameter?
A
Actin
18
Q
Name a microfilament
A
Actin
19
Q
Name a microtubule
A
Tubulin
20
Q
Name 3 intermediate filaments
A
Desmin, nuclear laminin and vimentin
21
Q
Name the three filaments in increasing size
A
Microfilament, intermediate filament, microtubules
22
Q
What is the intermediate filament mainly found in muscle?
A
Desmin
23
Q
Where are cytokeratins (intermediate filaments) found?
A
Epithelial cells
24
Q
Where are desmin (intermediate filaments) found?
A
Myocytes
25
Where are Glial fibrillary acidic protein (intermediate filaments) found?
Astrocytic glial cells
26
Where are Neurofilament protein (intermediate filaments) found?
Neurons
27
Where are nuclear laminin (intermediate filaments) found?
Nuclei of all cells
28
Where are vimentin (intermediate filaments) found?
Mesodermal cells
29
What is lipofuscin?
A wear and tear pigment formed by per oxidation of membrane lipids
30
What is haemosiderin?
An iron-containing brown pigment
31
What is melanin?
A brown pigment produced by melanocytes in skin (and elsewhere)
32
What is rhodopsin?
A pigment found in the retina
33
How is simple squamous epithelium formed?
By flattened epithelial cells resting on a basement membrane
34
What is endothelium?
An epithelium which lines the inside of blood vessels?
35
What is mesothelium?
An epithelium which lines the outside of the lungs
36
What is peritoneum?
An epithelium which lines the abdominal organs
37
What are the two features of columnar epithelium?
- Cells are taller than they are wide
| - May have projections such as cilia/microvilli
38
Do all epithelial compromise of nucleated cells?
Yes
39
What is a possible feature of simple columnar epithelium?
Microvilli on luminal surface
40
What is the epithelium of the Fallopian tube?
Columnar ciliated epithelium
41
What does respiratory epithelium consist of?
Pseudostratified columnar ciliated epithelium containing admixed goblet cells
42
Where is respiratory epithelium found?
The conducting airways:
- Nasopharynx
- Nasal sinuses
- Trachea
- Bronchi
- Bronchioles
43
What are the two proteins which are involved in ciliary movement?
- Tubulin
| - Dynein
44
Name two non-contractile proteins
- Collagen
| - Elastin
45
Name two contractile proteins which are found in muscle cells
- Actin
| - Myosin
46
Name one feature of urothelium
It is waterproof
47
What type of epithelium is urothelium?
Complex stratified epithelium with a pseudo stratified component beneath a surface layer of umbrella cells that aren't in contact with the basement membrane
48
What is the purpose of umbrella cells in urothelium?
Make the epithelium waterproof
49
Name 4 places where the urothelium lines
- Renal pelvis
- Ureters
- Urinary bladder
- Urethra
50
What does PAS help highlight?
Basement membranes
51
Name things which basement membranes consist of
Type IV collagen and fibronectin
52
What is the function of desmosomes?
Help spread mechanical forces across cells and their neighbours, and anchor cells together
53
What is the function of hemidesmosomes?
Bind the basal cell layer to the basement membrane
54
What is holocrine secretion?
When a gland secretes by shedding individual cells
55
Where is merocrine secretion?
Release of cell products by exocytosis from apical cell surface
56
What is apocrine secretion?
Involves pinching off part of the apex of the cell
57
Name 3 types of exocrine secretion
- Holocrine
- Merocrine
- Apocrine
58
What is endocrine secretion?
Release of products from the cell base into the bloodstream
59
What are monocytes derived from?
Haematopoietic stem cells
60
What cells are derived from mesenchymal cells?
Fibroblasts, fat cells and most cartilage/bone cells
61
What cells are from the haemopoietic stem cell line?
Monocytes, macrophages, lymphocytes, mast cells and blood cells
62
What substance is found in the walls of elastic arteries?
Elastin
63
What do fibroblasts produce?
Elastin and collagen
64
Name 3 visible extracellular fibres
- Reticulin
- Collagen
- Elastin
65
Name 2 invisible fibres
- Fibronectin
| - Laminin
66
What is tropocollagen?
A triple helix of peptides
67
What secretes tropocollagen subunits?
Fibroblasts
68
Where is type I collagen found?
Skin
69
Where is type II collagen found?
Cartilage
70
Where is type III collagen found?
Liver, bone marrow and spleen (reticulin)
71
Where is type IV collagen found?
Basement membranes
72
Where is type V collagen found?
Placenta
73
What kind of cartilage is found in the epiglottis?
Elastic
74
Name 2 places where fibrous cartilage can be found?
- Symphysis pubis
| - Intervertebral discs
75
Name 2 places where hyaline cartilage can be found?
- Part of the nasal septum
| - The knee joint
76
What is the structure of fat inside the white adipose tissue?
- Single, large non membrane-bound globules of lipid in each cell
- Pushes the nuclei to the edges of cells
77
What is one of the differences between brown and white adipocytes?
- White has one big globule
| - Brown has multiple fat globules
78
What is the primary function of brown adipose tissue?
Heat generation
79
Where is brown adipose mainly found in adults?
Between shoulder blades
80
Where is brown adipose mainly found in neonates?
Neck, back, around the aorta and the kidneys
81
What is the structure of the tendons or ligaments?
Dense regular fibrous connective tissue
82
Which connective tissue has collagen fibres running in the same direction?
Dense regular connective tissue
83
What is the connective tissue in the penile fascia?
Dense irregular connective tissue
84
What is the connective tissue in the adventitia of arteries?
Loose irregular connective tissue
85
What is the connective tissue in the dermis?
Dense and loose irregular connective tissue
86
What is the muscular layer of the uterus and what muscle type is it?
Myometrium - smooth muscle
87
Name two elastic arteries in the body
Aorta and pulmonary artery
88
Name two muscular arteries in the body
Radial and splenic
89
What is the feature of muscular arteries?
The media compromises of smooth muscle with very little elastin
90
Name one component which veins lack
External elastic lamina
91
What are the layers of the arteries, from inside out?
- Endothelium
- Intima
- Internal elastic lamina
- Media
- External elastic lamina
- Outer adventitia
92
How is the diameter of capillaries regulated?
By pericytes
93
What are pericytes?
Contractile cells which wrap around the outside of capillaries and regulate capillary diameter
94
What is the structure of capillaries?
Compromise of endothelial cells resting on a basement membrane. They don't have an intima, media or adventitia
95
Where may capillaries be fenestrated?
The kidney or liver
96
What are fenestrations?
Gaps in the endothelial layer
97
Give 3 characteristics of lymphatic vessels
- Contain valves
- Poorly developed elastic laminae
- Thin media, making them similar to veins
98
Name two things which cartilage lacks
Blood vessels and lymphatics
99
Where is endometrium present?
Between individual axons
100
Where is perineurium present?
Surrounds the groups of axons to form fascicles
101
Where is epineurium present?
Binds fascicles together to form nerve fibres
102
Which cells produce myelin?
Schwann cells
103
How do Schwann cells produce myelin?
By repeatedly wrapping itself around part of an axon
104
What does myelin compromise of?
Multiple layers of Schwann cell membrane
105
What is a Node of Ravier?
A gap between two Schwann cells on a single axon. The axon is in tact but there is no myelin at this site
106
What are Schmidt-Lanterman incisures?
Small pockets of cytoplasm left behind during the Schwann cell myelination process
107
How many axons are myelinated by a single Schwann cell?
1
108
In unmyelinated axons, how many axons are supported by a single Schwann cell?
Many
109
Define motor neuron
Cell bodies in grey matter of spinal cord
110
Define sensory neuron
Cell bodies in dorsal root ganglion
111
Define sympathetic neuron
Cell bodies in grey matter of cord and in adjacent sympathetic ganglia
112
Define parasympathetic neuron
Cell bodies in brain and basal ganglia
113
What percent of the blood is made up of white blood cells?
1%
114
What is the fluid in blood?
Plasma (or serum if the clotting factors have been removed)
115
What percentage of the blood is the plasma?
56%
116
What percentage of the blood consists of the red blood cells?
43%
117
What percentage of the blood does the white cells and platelets consist of?
1%
118
What is plasma?
Serum + clotting factors
119
What is the pattern of formation of erythrocytes?
- First formed in the yolk sac
- Then formed in the liver
- The formed in the bone marrow
120
Where is haematopoiesis confined to?
- Marrow of flat bones
| - Proximal ends of the humeri/femurs
121
Where are erythrocytes destroyed?
Liver and spleen
122
What are the predominant leukocytes?
Neutrophils
123
What is the function of eosinophils?
Help defend against parasitic infections. There numbers increase when there is a parasitic infection
124
Where do B lymphocytes mature in adults?
Bone marrow
125
Name two cells which have receptors to IgE and the significance of this
- Basophils and Eosinophils
| - They are antagonistic in function
126
Which cell produces histamines?
Basophils
127
Which cells counter the action of histamine?
Eosinophils
128
Name 3 cells in the immune system which are phagocytic
- Eosinophils
- Neutrophils
- Monocytes
129
Which cells secrete antibodies?
Plasma cells
130
What is the most abundant leucocyte?
Neutrophils
131
Name 1 cell of the immune system which doesn't have IgE receptors
Neutrophils
132
Which cells become mast cells?
Basophils
133
Which cells neutralise histamine?
Eosinophils
134
What cells do monocytes develop into in the liver?
Kupffer cells
135
What cells do monocytes develop everywhere?
Tissue macrophages and antigen presenting cells
136
What cells do monocytes develop into in bone?
Osteoclasts
137
What cells do monocytes develop into in the lungs?
Alveolar macrophages
138
What are haemocytoblasts?
Multipotential haemopoietic stem cells
139
What do megakaryocytic give rise to?
Platelets
140
What are platelets?
Membrane-bound fragments of the cytoplasm of megakaryotes
141
Where does erythropoiesis occur?
Away from bony trabeculae
142
What is the basic process of erythropoiesis?
- Cells start basophilic and become eosinophilic
- They gradually lose organelles (as they gain haemoglobin)
- The nucleus stays round and is eventually extruded
- The cells get smaller as they mature
143
What is the outermost layer of the heart?
Visceral pericardium
144
What are the layers of the heart (outside in)?
Visceral pericardium, epicardium, myocardium, endocardium
145
What is the parietal pericardium?
A fibrous sac that contains the heart
146
Name two layers of the heart which have the same cells
Visceral pericardium and parietal pericardium
147
What cell type is the pericardium of the heart?
Simple squamous epithelium
148
What cell type is the pleura and peritoneum of the heart?
Simple squamous epithelium
149
What is a feature of ventricular cardiac myocyte?
Myofibrils in register (they appear striated)
150
Name 3 visible extracellular fibres
Reticulin, collagen and elastin
151
Name 2 invisible extracellular fibres
Fibronectin and laminin
152
Which collagen type is prevalent in the placenta?
Type V
153
What is the structure of tropocollagen?
A triple helix of peptides
154
Where are tropocollagen subunits secreted from?
Fibroblasts
155
Which collagen type is prevalent in the skin?
Type I
156
Which collagen type is prevalent in cartilage?
Type II
157
Which collagen type is prevalent in liver?
Type III
158
Which collagen type is prevalent in bone marrow?
Type III
159
Which collagen type is prevalent in the spleen?
Type III (reticulin)
160
Which collagen type is prevalent in basement membranes?
Type IV
161
What kind of cartilage does the epiglottis have?
Elastic cartilage
162
What type of cartilage is found in the symphis pubis and intervertebral discs/
Fibrous cartilage
163
What type of cartilage does part of the nasal septum and the knee joint have?
Hyaline cartilage
164
What is the most commonly used dye combination?
H&E
165
What colour does H&E stain certain cell parts?
Cell nuclei - Blue
| Cytoplasm - Pink
166
Name something other than cytoplasm that stains pink with H&E
Extra-Cellular fibres
167
What does PAS stain?
Sugars
168
What does Van Gieson stain?
Elastic
169
What does alcian blue stain?
Mucins
170
Name 6 shapes of cells
- Rounded
- Polygonal
- Fusiform
- Squamous (flattened)
- Cuboidal
- Columnar
171
What type of cells tend to be smaller?
Ones which are less metabolically active
172
Name 1 cell type which has a lifespan of days
Lining of the gut
173
Name 3 cell types which have a lifespan of days
Blood, skin and connective tissues
174
Name 2 cell types which have a lifespan of years
Bones and tendons
175
Name a cell type which lasts nearly a whole life
Skeletal muscle (limited regeneration)
176
Name 3 cell types which last a whole life
Nerves/brain, Cardiac muscle and germ cells
177
Give 3 features of the nucleus
- Brain of the cell
- Double nuclear membrane
- Houses DNA
178
Give 2 features of the nucleolus
- 1-3 microns in diameter
| - Site of rRNA formation
179
Give 4 features of the mitochondria
- Powerhouses of the cell
- Site of oxidative phosphorylation
- Have their own DNA
- Double membrane
180
What is the function of the outer membrane of the mitochondria?
Lipid synthesis and fatty acid metabolism
181
What is the function of the inner membrane of the mitochondria?
Respiratory chain and ATP production
182
What is the function of the matrix of the mitochondria?
TCA (Krebs' cycle)
183
What is the function of the inter membranous space of the mitochondria?
Nucleotide phosphorylation (ADP to ATP)
184
What is the function and structure of RER?
- Site of protein synthesis
| - Highly folded flattened membrane sheets
185
What is the function and structure of the Golgi apparatus?
- Processes macromolecules synthesised in the ER
| - Parallel stacks of membrane
186
Where is the Golgi apparatus usually prominent?
Plasma cells
187
What are vesicles and what are they used for?
- Small spherical membrane-bound organelles
| - Used for transport, storage and exchanging cell membrane between compartments
188
What are the function of lysosomes?
Contain acid hydrolyses that degree proteins
189
What are the function of peroxisomes?
Contain enzymes which oxidise long-chain fatty acids
190
What is a typical diameter of a microfilament?
5nm
191
What is a typical diameter of a microtubule?
25nm
192
What is a typical diameter of a intermediate filament?
10nm
193
Where can cytokeratins be located?
Epithelial cells
194
Where can desmin be located?
Myocytes
195
Where can glial fibrillary acidic protein be located?
Astrocytic glial cells
196
Where can neurofilament protein be located?
Neurons
197
Where can nuclear laminin be located?
Nuclei of all cells
198
Where can vimentin be located?
Mesodermal cells
199
What is lipofuscin and where is it commonly found?
- Membrane-bound orange-brown pigment
| - Common in heart/liver
200
What are the 3 functions of epithelia?
Protection, absorption and secretion
201
What are the 3 types of muscle?
Smooth, skeletal and heart
202
Name 4 supporting tissues
Cartilage, bone, tendons and blood
203
What does epithelial compromise of?
A cohesive sheet of cells, with one or more layers, resting on a basement membrane
204
How is epithelia categorised?
According to the shape of the cells and the number of layers of cells
205
What is simple epithelia?
A single layer of cells on a basement membrane
206
What is stratified (compound) epithelia?
Two or more layers of cells on a basement membrane
207
What is simple squamous epithelium?
A single layer of flattened plate-like cells on a basement membrane with parallel oval nuclei
208
What is endothelium?
The simple squamous epithelium which lines the inside of blood vessels
209
What is mesothelium?
The simple squamous epithelium which lines the outside of the lungs
210
What is peritoneum?
The simple squamous epithelium which lines the abdominal organs
211
What is simple cuboidal epithelium?
A single layer of cells with similar height and width on a basement membrane, central spherical nuclei
212
Name 2 places where the simple cuboidal epithelium lines
- Kidney tubules
| - Small ducts
213
What is simple columnar epithelium?
A single layer of cells taller than they are wide, on a basement membrane. They may have cilia or microvilli
214
Name 3 places where the simple columnar epithelium lines
- Stomach
- Intestines
- Uterus
215
What are microvilli?
- Microscopic projections on luminal surface of absorptive cells
- Increase SA
216
Where may microvilli be found?
Intestinal brush border
217
What is cilia?
Microscopic motile projections on luminal surface of cells
218
Where may cilia be found?
Respiratory or reproductive tracts
219
Give 2 features of stratified epithelia
- Protective function
| - Many layers of cells
220
Where is stratified epithelia usually found?
At sites subject to abrasive forces
221
What is stratified squamous non-keratinising epithelium?
- Multiple layer of cells on a basement membrane
| - Mature surface layers are plate-like squames
222
Name 3 places which stratified squamous non-keratinising epithelium lies
- Mouth
- Oropharynx
- Vagina
223
What is stratified squamous keratinising epithelium?
- Multiple layer of cells on a basement membrane
- Mature surface layers are plate-like squares
- Waterproof layer of keratin
224
Where is stratified squamous keratinising epithelium found?
Skin
225
What is pseudostratified epithelium?
A single layer of cells of variable height, mimicking multiple layers on a basement membrane
226
Where is pseudo stratified epithelium found?
Lines the conducting airways
227
What is urothelium?
A specialised stratified epithelium
228
What is the structure of urothelium?
- Surface layer of umbrella cells
| - Cells between umbrella cells appear 3-7 layers thick
229
Where is urothelium found?
The collecting part of the urinary tract
230
What is the basement membrane made of?
Several extra-cellular proteins including collagen IV and fibronectin
231
What is the function of the basement membrane?
Essential for the proper functioning and survival of the epithelium
232
What is an occluding (tight) junction?
Band-like fusions between cells that are impervious to most molecules, prevents diffusion between cells
233
What are desmosomes (anchoring/adherent junctions)?
- Plaques that form physical joins between cells and connect the cytoskeletons of adjacent cells
- Spread forces across several cells
234
What are gap junctions (aka communicating junctions)?
Electrical junctions that permit the transfer of small molecules, electrically couple adjacent cells
235
What is the origin of connective tissue cells?
Mainly derived from undifferentiated mesenchymal cells, but may also be from the haemopoietic stem cell line
236
Name the 5 cell types which are derived from mesenchymal cells
- Mast cells
- Fibroblasts
- Chondroblast
- Osteoblast
- Adipocytes
237
What do fibroblasts later derive into?
Fibrocytes
238
What do chondroblasts later derive into?
Chondrocytes
239
What do osteoblasts later derive into?
Osteocyte
240
What are the 3 constituents of connective tissues?
- Cells
- Visible fibres
- Ground substance (a hydrophilic jelly and invisible fibres)
241
What are the 3 types of connective tissues?
- Fibrous (loose/dense)
- Hard (cartilage/bone)
- Fatty (white/brown)
242
What is tropocollagen?
A triple helix of peptides
243
Where is tropocollagen secreted from?
Fibroblasts
244
Where is type I collagen found?
Skin
245
Where is type II collagen found?
Cartilage
246
Where is type III collagen found?
Liver, bone marrow, spleen (reticulin)
247
Where is type IV collagen found?
Basement membranes
248
Where is type V collagen found?
Placenta
249
What colour do collagen fibres stain with H&E?
Pink
250
Give 3 features of loose connective tissue
- Widely spaced thin collagen fibres
- Fibroblasts/fibrocytes
- Unstained ground substance
251
Give 4 features of dense connective tissue
- Closely spaced thick collagen fibres
- Fibroblasts/fibrocytes
- Unstained ground substance
- May be irregular or regular
252
Give 4 features of reticulin
- Type III collagen
- Fibrillar collagen
- Forms a supporting scaffold in many organs
- Not visible with H&E - need a silver stain
253
What does elastic tissue compromise of?
Fine fibres and sheets of elastin
254
Give 3 features of elastin
- May be branched
- Produced by fibroblasts
- Stain pink on H&E
255
What is the structure of white adipose (fatty) tissue?
Large cells with a single fat globule in each cell
256
What is the structure of brown adipose (fatty) tissue?
Cells with many globules of fat
257
Where is brown adipose tissue found in a newborn?
Across the shoulders and down the back
258
What is the importance of brown adipose tissue in a newborn?
Important in neonatal thermos-regulation
259
What are the 4 constituents of cartilage?
Cells, extracellular matrix, proteoglycans and extracellular fibres
260
Is cartilage vascular or avascular?
Avascular
261
Where is hyaline cartilage usually found?
In synovial joints
262
What is the structure of hyaline cartilage?
Chondrocytes in lacunae surrounded by a amorphous matrix. has no visible fibres
263
What is perichondrium?
Fibroblasts and collagen
264
Name 2 places where elastic cartilage can be found
- Pinna
| - Epiglottis
265
What is the structure of elastic cartilage?
Visible elastic fibres in matrix and perichondrium
266
Where can fibrocartilage be found?
In the annulus fibrosus pubic symphysis
267
What is the structure of fibrocartilage?
Visible collagen fibres matrix and perichondrium
268
Where is synovium usually found?
Lines the inside of the joint capsule
269
What is the structure of the synovium?
- 1-4 layers of synovial cells
- Type A (phagocytes) and Type B (rich in RER)
- Variable shapes (squamous to cuboidal)
- Richly vascular
- Highly innervated
270
Where is visceral (smooth) muscle found?
- Arterial wall
- Wall of intestine
- Airways of lungs
271
Where is voluntary (skeletal) muscle found?
- Skeletal muscle
- Larynx
- Diaphragm
272
Where is cardiac muscle found?
- Heart
| - Base of great vessels
273
Name 3 other contractile cells
- Pericytes
- Myo-Fibroblasts
- Myo-epithelial cells
274
Give 5 properties of smooth muscle?
- Involuntary muscle
- Fusiform cells
- Central nucleus
- No striations
- Non-branching
275
What is the general structure of arteries (inside to outside)?
- Lumen
- Intima
- Basement membrane
- Internal elastic lamina
- Media
- External elastic lamina
- Adventitia
276
Where are the elastic arteries found?
Near the heart e.g. aorta and pulmonary arteries
277
What are the features of the elastic arteries?
Media contains abundant concentric sheets of elastin
278
What are the features of muscular arteries?
The media compromises of layers of smooth muscle. Little elastin is in the media
279
Which vessels are 'resistance vessels'?
Arterioles
280
What are arterioles arbitrarily described as?
As having 3 or fewer muscle layers in their media. The elastic laminae is poorly defined
281
What is the structure of a capillary (from inside to outside)?
Lumen, endothelium and a basement membrane
282
What are capillaries composed entirely of?
Thin-walled endothelial cells with no surrounding muscle or connective tissue
283
Which tissues tend to have fenestrated capillaries?
Kidney and liver
284
What is the structure of veins (from inside to outside)?
- Lumen
- Intima
- Basement membrane
- Internal elastic lamina
- Media
- Adventitia
285
What is the structure of venues?
Thin walled, contractile pericytes wrap around outside of endothelial cells and form a complete layer as venues get larger
286
What gets replaced as venues become veins?
Pericytes get replaced by smooth muscle
287
What is the structure of lymphatics?
- Thin walled
- Similar to capillaries and veins
- Have valves
- Don't contain blood
- Contains eosinophilic lymph
- May contain lymphocytes
288
What is the structure of peripheral nerves?
- Composed of axons supported by Schwann cells
- Most are myelinated
- Myelin is produced by Schwann cells
289
What are the myelinated peripheral nerve components?
Endoneurium, perineurium and epineurium
290
Where is endoneurium present?
Between individual axons
291
Where is perineurium present?
Surrounds the groups of axons to form fascicles
292
Where is epineurium present?
Binds fascicles together to form nerve fibres
293
What is the structure of a small peripheral nerve fibre?
Bundle of axons interspersed with endometrium and surrounded by perineurium and epineurium
294
What is myelin and what is its function?
It is a spiral of apposed Schwann cell membranes. It insulates axons
295
How many Schwann cells are there per myelinated axon?
Multiple
296
How many axons are there per Schwann cells?
One
297
What are the gaps between myelin?
Nodes of Ranvier
298
What is significant about myelinated axons?
- Larger
| - Transmit impulses faster than unmyelinated ones
299
Name 4 peripheral nerves
Motor neurones, sensory neurones, sympathetic neurones and parasympathetic neurones
300
What is the structure of motor neurones?
Cell bodies in grey matter of spinal cord
301
What is the structure of sensory neurones?
Cell bodies in dorsal root ganglion
302
What is the structure of sympathetic neurones?
Cell bodies in grey matter or cord and in adjacent sympathetic ganglia
303
What is the structure of parasympathetic neurones?
Cell bodies in brain and local ganglia
304
What is the pericardium?
Outermost layer of the heart
305
What are the two types of pericardium?
Visceral and parietal
306
What is the structure of the pericardium?
Layer of mesothelial cells resting on thin layer of fibrous connective tissue
307
What is the epicardium and where is it situated?
The underlying adipose tissue, vessels and nerves. it is between the pericardium and myocardium
308
What is the structure of specialised cardiac muscle?
- Striated
- Central nuclei
- Branching
- Intercalated discs
309
What is endomysium?
Loose fibrous connective tissue between the muscle fibres in the myocardium
310
What is the myocardium?
The thickest layer of the heart
311
Which type of myocytes are larger?
Ventricular. Atrial are smaller
312
What do atrial myocytes contain?
Perinuclear neuroendocrine granules (for atrial natriuretic peptide)
313
What is the conducting system of the heart?
- SAN
- AVN
- Bundle of His
- Purkinje fibres (subendocardial and large vacuolated muscle cells)
314
What is the endocardium and what is it compromised of?
- Innermost layer of the heart
- Thin layer of fibrous connective tissue
- Endothelial cells
315
Where are heart valves found and what are they covered by?
Covered by endothelium and attach to central fibrous body
316
What do heart valves consist of?
Fibrosa (dense fibrous CT), spongiosa (loose fibrous CT) and ventricularis (collagen dn elastin)
317
What is the structure of cardiac myocytes?
Branching cells with a single nucleus. Their myofibrils are in register, so they appear striated
318
What hormone do atrial myocytes secrete?
Atrial natriuretic peptide
319
Where can Purkinje fibres be found?
Beneath the endocardium
320
What is the function of Purkinje fibres?
To transmit electrical impulses
321
What is the structure of the Purkinje fibres?
Large specialised cardiac muscle cells with a cytoplasm rich in glycogen
322
Which is smaller: myocytes of the SAN or regular?
Those of the SAN
323
What is the difference between SAN myocytes and regular myocytes?
The myocytes of the SAN have no intercalated discs and are joined by desmosomes . They are embedded in fibrous tissue
324
Name two things which all cardiac myocytes have.
A nucleus and mitochondria
325
What cell type lines the mitral valve?
Endothelial cells
326
What cell type lines the inner surface of the heart, including the surface of the cardiac valves?
Vascular endothelial cells
327
Where are the nodules of Arantius found?
In the aortic valve cusps
328
What are the nodules of Arantius?
Nodules of fibroelastic tissue on the centre of each free edge of each of the valve cusps in the aortic and pulmonary valve
329
Where are the nodules of Arantius more prominent?
The aortic valve, due to increased pressure in that side of the circulation
330
What is the yellow pigment which accumulates in cardiac myocytes with increasing age?
Lipofuscin
331
How is lipofuscin formed?
By periodisation of membrane lipids
332
Where do the coronary arteries run?
In the epicardium
333
What is the structure of the coronary arteries?
Medium-sized muscular arteries with external elastic lamina
334
Where are Weibel-Palade bodies found?
The endothelial cells in the heart
335
What is the function of Weibel-Palade bodies?
Storage granules found in the cytoplasm which contain vo Willebrand factor and other vascular mediators
336
Name 4 places which lacks lymphatics
- Cartilage
- Eye
- Bone marrow
- Spinal cord
337
What is the structure of respiratory epithelium?
- Pseudostratified
- Ciliated epithelial cells
- Interspersed goblet cells
338
Where does respiratory epithelium line?
The tubular portion of the respiratory tract (Nasopharynx, bronchi, conducting airways and sinuses)
339
What cells are the alveoli lined by?
Pneumocytes
340
What are the nares lined by?
Stratified squamous keratinising epithelium
341
What are the vocal cords lined by?
Non-keratinising stratified squamous epithelium
342
What is the apex of the nasopharynx lined by?
Olfactory epithelium
343
What holds open the larynx and trachea?
Hyaline cartilage. Holds the airways open against negative pressure during inspiration
344
What bridges the gap between the free ends of the C-shaped cartilages in the trachea?
Smooth muscle (trachealis
345
What is present in the walls of the bronchi but not in the bronchioles?
Cartilage
346
Where is Reinke's space?
In the vocal cords
347
What is Reinke's space occupied by and where does it lie?
- Occupied by the loose irregular fibrous tissue
| - Lies between vocal epithelium. Beneath that is the vocalis muscle
348
What does type II pneumocytes secrete?
Surfactant
349
What do goblet cells produce?
Mucus
350
What do Clara cells do?
Secrete lipoproteins that prevent luminal adhesion
351
What do type I pneumocytes do?
Form the air/blood barrier
352
What do alveolar macrophages do?
Act as phagocytes
353
What are the layers of the air-blood barrier?
- Surfactant
- Type I pneumocyte
- Basement membrane
- Vascular endothelial cell
354
How thick is the air-blood barrier?
600nm
355
Where are the pores of Kohn found?
In the alveolar walls
356
What is the function of the pores of Kohn?
They connect adjacent alveoli to each other. They allow for rapid even distribution of air through the lung on inhalation
357
What is a disadvantage of the pores of Kohn?
They allow for the passage of microbes, which may result in lobar pneumonia
358
What is the histological structure of the posterior third of the tongue?
Stratified squamous non-keratinising epithelium over a loose fibrous connective tissue
359
What does the epithelium overlie in the posterior third of the tongue?
A lymphoid infiltrate (part of Waldeyer's ring)
360
Where is the circumvallate papillae?
Between the anterior 2/3 and posterior 1/3 of the tongue. It forms a V shaped line
361
What is the function of the filiform papillae?
To roughen the surface of the tongue, to help aid in mastication
362
What is the most numerous papillae on the tongue?
The filiform papillae
363
Where is the filiform papillae found?
The dorsal surface of the tongue
364
What is the colour of the cytoplasm in mucous glands?
Clear
365
What kind of gland is the submandibular gland?
Mixed mucous/serous
366
What kind of gland is the sublingual gland?
Mostly mucous
367
What kind of gland is the buccal gland?
Mostly mucous
368
What kind of gland is the lingual gland?
Mostly mucous
369
What are the features of oesophageal mucosa?
- Non-keratinising stratified squamous epithelium
- Lymphocytes in the submucosa
- Mucinous glands in the submucosa which have squamous-lined ducts
370
What epithelium lines gland ducts?
Squamous or epithelium
371
What is the structure of gastric antrum?
- Has long branching crypts
- Lined by mucous-secreting cells
- Lack of parietal cells
372
Which cells secrete intrinsic factors?
Parietal cells
373
What do gastric parietal cells secrete?
Hydrochloric acid and intrinsic factor
374
What do the surface mucous cells secrete?
A bicarbonate rich mucous
375
What is one role of intrinsic factor?
Helps with absorption of vitamin B12, which enters via the diet
376
What do chief cells secrete?
Pepsinogen, which is later cleaved to activate pepsin in the gastric lumen
377
What are the common presentations of the duodenum?
Broad leaf-like villi and the submucosal Brunner's glands
378
What is the role of Brunner's glands?
Secrete an alkaline mucus that helps neutralise gastric acid
379
What is chyme?
Digested food that leaves the stomach
380
What does ileum look like histologically?
- Villous appearance
| - Prominent lymphoid aggregates (Peyer's patches) in the submucosa and mucosa
381
Name a histological difference between the ileum and the jejunum & duodenum
The jejunum & duodenum don't have Peyer's patches
382
Name a histological difference between the ileum and the appendix & colon
The appendix and colon don't have a villous architecture
383
Where does Auerbach's plexus lie in the colon?
Muscular propria
384
What are the two autonomic nerve plexuses which innervate the GI tract?
Meissner's plexus and Auerbach's plexus
385
Where does Meissner's plexus lie?
In the submucosa
386
Where does Auerbach's plexus lie?
Between the layers of the muscularies propria
387
What is significant about the muscular propria in the colon?
It is double layered. The layers are the inner circular and outer longitudinal
388
What is the structure of the epithelium in the colon?
A simple columnar layer of mucus-secreting enterocytes
389
What is something which is featured in the small intestine, but not the colon?
A prominent brush border
390
Where are the epithelial stem cells of the colonic mucosa found?
At the base of the crypts of the Lieberkhun
391
Where is the muscular mucosa of the colon found?
Immediately below the lamina propria
392
What arteries supply the colon?
The superior mesenteric artery and inferior mesenteric artery
393
Where is vitamin B12 absorbed?
In the terminal ileum
394
What is the structure of a classic lobule of the liver?
- Roughly hexagonal
- A portal vein, hepatic artery and bile duct at each corner
- Central vein in the middle of the hexagon
395
Where is bile synthesised?
Hepatocytes
396
What are the phagocytes of the liver?
Kuppfer cells
397
What are the antigen presenting cells of the liver?
Ito cells
398
Where are Ito cells found?
Space of Disse
399
Where is angiotensinogen synthesised?
The liver
400
Where does haematopiesis take place in the foetus?
Hepatic sinusoids
401
What is the structure of hepatocytes?
Large polygonal epithelial cells that are arranged in plates compromising thin cords of hepatocytes, supported by a meshwork of type 3 collagen (reticulin). They have a microvillous brush border and abundant mitochondria
402
What is the function of the SER in hepatocytes?
Inactivates drugs and toxins
403
What is the function of the RER in hepatocytes?
A role of synthesis of plasma proteins
404
What is a function of the Ito cells?
Store fat in the liver
405
Where can Kuppfer cells be found?
Lie in the sinusoids of the liver
406
What cells are Kuppfer cells derived from?
Monocytes
407
What will happen to Kuppfer cells in a patient with haemochromatosis?
The cells will accumulate the pigment haemosiderin, which contains iron
408
What can hepatocytes store?
Fat soluble vitamins
409
What can the gall bladder absorb?
Water
410
What is the structure of the gallbladder epithelium?
Columnar, with a prominent microvillous brush border
411
Why do the cells of the gall bladder absorb water?
To concentrate the bile that was secreted by hepatocytes
412
Where are acinar cell found?
Exocrine pancreas
413
What is the function of acinar cells?
Secrete a wide variety of enzymes (all of which are in precursor form)
414
Where is secretin secreted from?
The endocrine cells of the GI tract
415
Where is albumin made?
The hepatocytes
416
Where are centriacinar cells found?
Exocrine pancreas
417
What is the function of centriacinar cells?
- First part of the ductal system of the pancreas
- Secrete a bicarbonate-rich alkaline solution when stimulated by secretin
- Secretes mucin
418
What is the function of cholecystokinin?
Causes acinar cells to release digestive enzymes by exocytosis
419
Where is insulin and pancreatic polypeptide secreted from?
Islets of Langerhans
420
Which structure appears to most prevalent in the renal cortex?
The proximal convoluted tubule
421
Which structure lines the outside of the basement membrane of the glomerular capillaries?
Podocytes
422
Which arteries directly gives rise to the afferent arterioles in the kidney?
Interlobular arteries
423
What is the name given to the epithelium which lines the renal pelvis?
Urothelium
424
Where can pseudo stratified columnar ciliated epithelium be found?
Trachea of the lungs
425
What epithelium lines the ducts and convoluted tubules of the kidney?
Simple cuboidal
426
Where is renin secreted from?
The macula densa of the kidneys
427
Where is aldosterone made?
In the adrenal gland in the adrenal cortex
428
Where is vasopressin made?
In the hypothalamus but secreted by the posterior pituitary
429
What is the juxtaglomerular apparatus?
Macula densa + afferent arteriole
430
Where in the kidney is very responsive to aldosterone?
The collecting ducts
431
What are Lacis cells?
Lightly staining pericytes in the kidney
432
What does the ureter lack?
Muscular mucosa
433
What is the most easily discerned at the bladder neck?
Muscular propria
434
What is the structure of the male urethra?
A membranous urethra lined by urothelium
435
Where does the external sphincter lie in the male urethra?
Surrounds the membranous urethra
436
What is the outermost layer of the epidermis?
Stratum corneum
437
What is the layer of the epidermis which contains the melanocytes?
Stratum basale
438
What is the layer of the epidermis which contains visible desmosomes?
Stratum spinosum
439
Where is keratin synthesised?
In the stratum granulosum of the epidermis
440
What is the function of melanocytes?
To synthesise melanin from tyrosine
441
What is a hair follicle?
A down-growth of the epidermis into the dermis
442
What is a hair bulb?
A downward extension of the epidermis into the dermis
443
What is a hair papilla?
A specialised part of the dermis that is richly innervated and richly vascular
444
Where are apocrine sweat glands usually found and what cytoplasm type do they have?
- Found in skin around anus/genitals
| - Eosinophilic cytoplasm
445
Which glands open directly onto the surface of the labia?
Sebaceous glands
446
What do Pacinian Corpuscles do?
Sense changes in pressure. They have a part which is compromised of Schwann cells
447
What do B cells do?
Become plasma cells and secrete antibodies
448
What do T cells do?
Involved in cell mediated immunity
449
What do T helper cells do?
Helps B cells and activates macrophages
450
What do T cytotoxic cells do?
Kill previously marked target cells
451
What do T suppressor cells do?
Suppress TH cells and hence suppress the immune response
452
What do natural killer cells do?
Mainly kill virus infected cells
453
What do monocytes do?
- Immature cells
- Circulate briefly in the blood
- Readily differentiate into other cells
454
Where do monocytes differentiate into tissue macrophages?
Everywhere
455
Where do monocytes differentiate into Kupffer cells?
Liver
456
Where do monocytes differentiate into osteoclasts?
Bone
457
Where do monocytes differentiate into antigen presenting cells?
Everywhere
458
Where do monocytes differentiate into alveolar macrophages?
Lung
459
What are the functions of platelets?
Responsible for clotting blood, notably when the endothelium lining all blood vessels is breached
460
What is the structure of respiratory epithelium?
Pseudostratified, ciliated epithelial cells with interspersed goblet cells
461
Where does respiratory epithelium line?
The tubular portion of the respiratory system
462
Name 4 functions of the nose
Filtration, humidification, warming and olfaction
463
What is the cell structure of the nose?
- Both keratinising and non-keratinising squamous epithelium
- Respiratory epithelium
- Richly vascular lamina propria containign seromucinous glands
464
How does olfaction happen in the nose?
Olfactory receptor cells and bipolar neurones in the pseudo stratified columnar epithelium
465
Name 4 functions of the nasopharynx
Gas transport, humidification, warming and olfaction
466
What cell type is the nasopharynx lined by?
Respiratory epithelium
467
Give 3 functions of the nasal sinuses
- Lower the weight of the skull
- Add resonance to the voice
- Humidify and warm inspired air
468
What are the nasal sinuses lined by?
Respiratory epithelium
469
What is the function of the larynx?
Voice production
470
What is the structure of the larynx?
- Cartilaginous box
- Respiratory epithelium
- Loose fibrocollagenous storm with seromucinous glands
- Lymphatics and blood vessels common
471
What is the function of the vocal cords?
Voice production
472
What is the structure of the vocal cords?
Stratified squamous epithelium overlying loose irregular fibrous tissue (Reinke's space), almost no lymphatics
473
What is the function of the trachea?
Conducts air to and from the lungs
474
What is the structure of the trachea?
- Respiratory epithelium
- Seromucinous glands in submucosa
- Trachealis muscle posteriorly
- C-shaped cartilaginous rings
475
What are the functions of Clara cells?
- Most numerous in terminal bronchioles
- Oxidise inhaled toxins
- Antiprotease function
- Surfactant production/elimination
- Stem cell
476
What are the functions of respiratory bronchioles?
- First part of distal respiratory tract
- Gas exchange as well as transport
- Link terminal bronchioles and alveolar ducts
477
What is the structure of respiratory bronchioles?
- Cuboidal ciliated epithelium
- Spirally-arranged smooth muscle
- No cartilage
478
What is the function of the alveoli?
Gas exchange
479
What is the function of Type I pneumocytes?
Allow for gas exchange
480
What is the function of Type II pnuemocytes?
Produce surfactant
481
What is the function of alveolar macrophages?
Phagocytose particulates including dusts and bacteria
482
What is the order of the blood-air barrier of the alveoli?
Type I pneumocytes, fused basement membrane of pneumocyte and capillary, vascular endothelial cell
483
What is the interstitium in the lung?
Where endothelial cells aren't in direct contact with pneumocytes
484
What is the visceral pleura?
Flat mesothelial cells in the lungs
485
What type of cells are Sertoli cells?
Phagocytes
486
Where is testosterone secreted from?
Leydig cells
487
Which cells contain Reinke's crystalloids?
Leydig cells
488
How much does the normal human test weigh?
15-19g
489
Where do the rete testes lie?
Between the straight tubule and epididymis
490
Where is the site of acid phosphatase storage?
The prostate
491
Where does sperm mature?
The epididymis
492
Give 2 features of the corpus spongiosum
- Highly vascular
| - Urothelium lining duct
493
Where is the spiral mitochondria kept in the spermatozoa?
The body/midpiece
494
Where is there abundant lipofuscin in males?
The seminal vesicles
495
What is the function of PSA?
Liquidises semen after ejaculation
496
What is the basic function of FSH?
Causes proliferation of ovarian follicles
497
How many primordial follicles are present at birth?
400,000
498
What is the usual cite of fertilisation?
The Fallopian tube
499
What function is a prominent brush border usually linked to?
Absorption
500
Name the two parts of the body with ciliated epithelium
Fallopian tube and respiratory tract
501
Which part of the female reproductive tract is hormonally sensitive?
All of it
502
What does the endocervix do to act as barrier against sperm?
Secretes mucus to act as a barrier
503
What is proliferative endometrium characterised by?
The presence of stroll mitotic figures
504
What is significant about the cervical transformation zone?
It is a prominent site for cervical cancer to form
505
Give 2 features of secretory endometrium
- Prominent spiral arteries
| - Subnuclear glycogen vacuoles
506
Give 3 features of early secretory phase of the endometrium
- Growth occurring in the glands
- Pale vacuoles (subnuclear)
- Lack of luminal secretions
507
What epithelium does the labia majora have?
Stratified squamous keratinising epithelium with hairs
508
What is the structure of the gut from inside to outside?
- Lumen
- Epithelium
- Basement membrane
- Lamina propria
- Muscularis mucosae
- Submucosa
- Inner circular layer
- Outer longitudinal layer
- Adventitia/serosa
- Muscularis propria
509
What is the structure of the stomach from inside to outside?
- Lumen
- Epithelium
- Basement membrane
- Lamina propria
- Muscularis mucosae
- Submucosa
- Innermost oblique layer
- Middle circular layer
- Outermost longitudinal layer
- Adventitia/serosa
- Muscularis propria
510
What is the purpose of the oral cavity?
Receives food, chews food and starts digestion
511
What kind of cancer is oral cancer?
Squamous cancer
512
What are the 3 salivary glands?
- Parotid gland
- Submandibular gland
- Sublingual gland
513
What is the purpose of salivary glands?
Produce saliva and enzymes
514
What is Sjorgen's syndrome?
No saliva production
515
What is the purpose of the oesophagus?
Swallow food
516
What is the cellular structure of the oesophagus?
- Squamous epithelium
| - Has sub mucous glands
517
What is the purpose of the stomach?
Digests food
518
What do parietal cells of the stomach do?
Secrete HCl
519
Name 2 substances what chief cells secrete
Pepsinogen and lipase
520
Give 4 purposes of the intestines
- Digest food
- Absorb food
- Absorb water
- Resist bugs
521
What is the function of the interstitial cells of Cajal?
'Pacemaker' which creates the potential which leads to the contraction of smooth muscle
522
Give the basic anatomy of the GI tract in order
Stomach, duodenum, jejunum, ileum, large intestine (colon)
523
What is the purpose of the duodenum?
- Digests food
- Absorbs food
- Resist bugs
524
What is the purpose of the jejunum and ileum?
Digests food, absorbs food and resists bugs
525
What is the purpose of the appendix?
The 'safe house'
526
What is the anatomy of the large colon?
- Ascending colon
- Transverse colon
- Descending colon
- Sigmoid colon
- Rectum
- Anus
527
What is the purpose of the colon?
- Absorbs food
- Absorbs water
- Resists bugs
528
What do the portal tracts in the liver contain?
Portal veins, arteries and bile ducts
529
How are hepatocytes arranged in the liver?
Arranged into cords with intervening sinusoids and central veins
530
What is the conventional design of the cells in the liver?
- Divided into classic lobules
| - Bile duct, portal vein and hepatic artery at each 'corner' of the hexagon with a central vein in the middle
531
What is the drainage of the classic lobule in the liver?
An area drained by one central hepatic lobule
532
What is the acinus structure of hepatocytes in the liver based around?
Blood supply rather than drainage
533
What is the structure of the acinus in the liver?
Links the central vein in two different hexagons by 2 sets of bile ducts, portal veins and hepatic arteries
534
Why is there some variation in the size of different hepatocytes?
Some are more richly oxygenated
535
Give 10 features of hepatocytes
- Principle functional cells of the liver
- Polyhedral epithelial cells
- Abundant mitochondria
- Large central spherical nuclei
- Prominent nucleoli
- Active Golgi
- Prominent ER
- Lots of mitochondria
- Numerous perioxisomes
- May be binucleate
536
What are the 3 important surfaces of the liver and what are their proportions?
Sinusoidal (70%), canalicular (15%) and intercellular (15%)
537
What is the function of the sinusoidal surface in the liver?
Permits exchange of material with blood (Space of Disse)
538
What is the function of the canalicular surface in the liver?
Permits the excretion of bile
539
Give 4 features of sinusoids
- Highly specialised blood vessels
- Thin discontinuous fenestrated epithelium
- No basement membrane
- Contains scattered Kupffer cells
540
What is the structure of the intrahepatic biliary tree and what is the change in epithelium?
- Goes from simple cuboidal to columnar epithelium
| - Canaliculi to Bile ductules to Trabecular ducts to Bile ducts
541
Give 2 functions of the gallbladder
- Concentrates and stores bile
| - Expels bile via common bile duct into duodenum
542
What is the structure of the specialised mucosa of the gallbladder?
- Simple columnar epithelium
- Microvilli
- Thrown into folds
- Adapted for water and salt absorption
- Connective tissue (lamina propria)
543
What is the function of the exocrine pancreas?
To synthesise and secrete enzymes and a bicarbonate-rich fluid into the duodenum
544
What is the structure of the exocrine pancreas?
- Poorly defined fibrous capsule with septum dividing gland into lobules
- Epithelial cells arranged into acini
545
Give the structure of acinar cells
- Epithelial
- Pyramidal shape
- Basally rich in RER
- Apically, has zymogen granules (enzyme precursors)
546
Name the 4 ducts of the exocrine pancreas
- Centroacinar cells
- Intercalated ducts
- Interlobular ducts
- Main pancreatic duct
547
How can the nephron's loop of Henle be further divided?
Into a thick and thin limb
548
Give 7 features of the glomerulus of the nephron
- Tuft of convoluted fenestrated capillaries
- Glomerular basement membrane
- Lined by podocytes
- Supported by mesangial cells
- Encased in Bowman's capsule
- Has capillary epithelial cells
- Mesenglial cells lie between capillaries
549
What is the juxtaglomerular apparatus compromised of?
Afferent arteriole and distal convoluted tubule
550
What does the afferent arteriole contribute?
Granular cells
551
What is the function of renin?
Secreted in response to low blood pressure, to increase blood pressure
552
What is the macula densa?
A patch of closely packed endothelial cells along the distal convoluted tubule
553
What is the function of the macula densa?
Senses NaCl concentration and regulates tubuloglomerular feedback
554
What is the structure of the proximal convoluted tubule?
- Cuboidal epithelium
- Round central/basal nuclei
- Brush border of microvilli at apical end
- Many mitochondria so appear eosinophilic
555
What is the function of the proximal convoluted tubule?
Reabsorption of NaCl, proteins, polypeptides, amino acids and glucose
556
What is the cell type in the thin segment of the loop of Henle?
Simple squamous
557
What is the cell type in the thick segment of the loop of Henle?
Low cuboidal
558
What is the blood supply to the loop of Henle?
The rich vasa recta
559
What is the epithelium in the distal convoluted tubule?
Low cuboidal epithelium
560
Give 2 significances in structure of the distal convoluted tubule
- Scanty microvilli
| - Numerous mitochondria
561
What are the 2 functions of the distal convoluted tubule?
- Regulates acid-base by secreting hydrogen ions and absorbing bicarbonate via cellular carbonic anhydrase
- Regulates Na level by exchanging Na for K
562
What is the epithelium in the collecting duct?
Cuboidal epithelium
563
What is the function of principle cells in the collecting duct?
Respond to aldosterone and ADH
564
What is the function of intercalated cells in the collecting duct?
Exchange hydrogen ions for bicarbonate ions
565
Name 5 arteries which supply the kidneys
- Abdominal aorta
- Renal artery (at L1)
- Interlobular artery
- Interlobar artery
- Arcuate artery
566
Name 3 veins which drain the kidneys
- Vasa recta
- Renal veins
- Inferior vena cava
567
What endothelium does the renal pelvis have?
Urothelium
568
What is the function of the renal pelvis?
Transmits filtrate from nephron to ureter
569
What is urothelium?
- Specialised epithelium found in the collection/drainage parts of the urinary tract
- Complex stratified epithelium
- Layer of umbrella cells overlies a pseudostratified layer of polygonal cells
570
What is the epithelium in the ureters?
Transitional epithelium
571
What is the structure of the ureters?
- Spiral muscular tube (inner - longitudinal & outer - circular)
- No serosa
- Loose adventitia
572
What is the epithelium in the bladder?
Urothelium
573
What are the cell layers in the bladder?
- Urothelium
- Lamina propria
- Muscularis mucosa
- Submucosa
- Muscularis propria
- Subserosa and serosa
574
How is reflux into the ureter from the bladder prevented?
By a functional valve
575
How long is the female urethra?
4-5cm
576
What is the structure of the female urethra?
- Proximally transitional epithelium
- Distally squamous epithelium
- Paraurethral and periurethral glands open into the urethra
577
How long is the male urethra?
20cm
578
What is the structure of the male urethra?
- Prostatic urethra
- Membranous urethra lined by urothelium
- Penile urethra pseudostratified epithelia proximally
- Stratified squamous epithelium distally
579
Which parts of the body have urothelium?
Renal pelvis, ureter, bladder and urethra
580
Name the glands which are present in the epidermis
Eccrine, apocrine and sebaceous glands
581
What is the structure of the basement membrane in the epidermis?
- Not usually visible with H&E
| - Made of type IV collagen
582
What is the structure of the stratum basale in the epidermis?
- Sits on the basement membrane
- Basal epithelial cells (stem cells)
- Melanocytes
583
What are the function of melanocytes in the stratum basale of the epidermis?
Synthesise melanin and transfer it to surrounding keratinocytes in melansomes in response to MSH and ACTH stimulation
584
What is the function of melanin?
Absorbs UV light, protecting us from non-ionising radiation damage
585
What other two cell types are present in the stratum spinosum?
Langerhans cells and Merkel cells
586
What is the structure of stratum spinosum cells?
- Plump polygonal keratinocytes
| - Prominent intercellular adhesions
587
What are the functions of the Langerhans cells in the stratum spinsoum?
For antigen recognition
588
What are the functions of the Merkel cells in the stratum spinsoum?
For sensory functions
589
What is the structure of the stratum granulosum in the skin?
- Flattened squames
- Eosinophilic cytoplasm
- Haematoxophilic keratosis-hyaline granules
590
What's the structure of stratum corneum in the skin?
- Acellular
- Plates of keratin
- Prominent in certain sites
591
What is epidermal adnexae?
Downgrowths of the epidermis into the dermis
592
Give 4 examples of epidermal adnexae
- Hair follicles
- Sebaceous glands
- Eccrine sweat glands
- Apocrine sweat glands
593
What is the function of sebaceous glands in the skin?
- Accompany hair follicles
| - Produce sebaceous secretions which lubricate and waterproof hairs
594
What kind of secretion do the sebaceous glands do?
Holocrine secretion
595
What is the function of apocrine glands in the skin?
- Accompany hair follicles
| - Axillae and groins ceruminous glands in the ear
596
What is the function of eccrine glands?
Give a thin watery secretion
597
What is the space in the derma-epidermal junction?
The papillary dermis
598
What is the general structure of the dermis?
- Irregular loose connective tissue
- Fibroblasts
- Collagen
- GAG matrix
- Blood vessels + lymphatics
- Nerves
- Sensory cells
- Scattered inflammatory cells
599
What are the sensory structures of the dermis?
- Meissner's corpuscle
| - Pacinian corpuscle
600
What is the structure of Meissner's corpuscle?
Encapsulated unmyelinated nerve endings, dermal papillae, especially in hairless skin
601
What is the function of Meissner's corpuscle?
For fine touch
602
What is the structure of Pacinian corpuscle?
Large encapsulated sensory receptors, central non-myelinated nerve and surrounding lamellae
603
What is the function of Pacinian corpuscle?
For vibration and tickle
604
What is the structure of the subcutis?
Adipose tissue and fibrovascular septa
605
What are the functions of the subcutis?
- Insulation
- Shock-absorber
- Food store
606
What is the structure of the breast tissue?
Myoepithelial system of ducts and lobules set in fibroadipose tissue, ducts all empty at the nipple
607
When is breast tissue present from?
Birth
608
What is the structure of terminal duct lobular units in the breast?
Lobules are arranged around a terminal duct and are set in loose fibrous connective tissue
609
What are the ducts and lobules of the breast lined by?
- Two layers of cells
| - Outer myoepithelial and inner columnar epithelial
610
What is the process regarding lactation?
Ducts and an inner layer of secretory cells which become vacuolated
611
What are the three histological layers of the skin?
Epidermis, dermis and subcutis. The epidermis and dermis can be further subdivided
612
What two features of skin are downgrowths of the epidermis?
- Sweat glands
| - Hair follicles
613
What are the testis and how much do they weigh?
- Paired organ in the scrotum
| - Average weight 15-19g
614
What are the 4 layers of the testis?
- Capsule
- Tunica vaginalis
- Tunica albuginea
- Tunica vasculosa
615
What is the cellular structure of the tunica vaginalis?
Flattened layer of mesothelial cells
616
What is the cellular structure of the tunica vasculosa?
Loose connective tissue containing blood vessels and lymphatics
617
How is testicular parenchyma divided?
Into lobules by septa originating from the capsule
618
How many lobules are there in the testicular parenchyma?
Around 250
619
What do the lobules of the testicular parenchyma contain?
1-4 seminiferous tubules
620
What do seminiferous tubules contain?
Germ cells in varying stages of maturation and Sertoli cells
621
What do Type A spermatogonia look like?
Darkly stained stem cells and pale stained cells
622
What do Type B spermatogonia look like?
Differentiating progenitor cells which have spherical nuclei with densely stained masses of chromatin
623
What is the pattern of development for spermatogonia?
Spermatogonia - primary spermatocyte - secondary spermatocyte - spermatid - spermatozoon
624
What is the cellular structure of Sertoli cells?
Columnar cells on the basement membrane of the tubules
625
What is the function of Sertoli cells?
- Send cytoplasmic projections around the germ cells
| - Supportive, phagocytic and secretory functions
626
What is the structure of the nuclei of the Sertoli cells?
Irregularly shaped, folded and have a prominent nucleolus
627
What is present in the head of spermatozoa?
Acrosomal cap and nucleus
628
What is present in the midpiece of spermatozoa?
Spiral mitochondria
629
What is present in the tail of spermatozoa?
Neck (centrioles), axoneme and plasma membrane
630
Where are Leydig cells found?
Singly and in clusters in the interstitial between tubules
631
Name two features of Leydig cells
- Abundant cytoplasm containing lipid
| - Has Reinke's crystalloids
632
What is the function of Leydig cells?
Produce testosterone
633
What is the rete testes?
An network of tubules at the hilium of the testis
634
What is the function of the rete testis?
Receive luminal contents from seminiferous tubules. Acts as a mixing chamber
635
What is the cellular structure of the rete testis?
Lined by simple squamous or low columnar epithelium on a relatively thick basement membrane
636
What is the structure of the efferent ducts of the male reproductive system?
12-15 convoluted tubules which empty into epididymis
637
What is the cellular structure of the efferent ducts?
Lined by ciliated and non-ciliated simple columnar epithelium with interspersed cuboidal cels (basal cells) giving a pseudostratified appearance
638
What is the structure of the epididymis?
A tubular structure 4-5cm long containing a highly convoluted epididymal duct
639
What is the cellular structure of the epididymis?
- Lined by tall columnar cells with long typical cilia
| - Epithelium supported by a thick basement membrane surrounding which is a well-defined muscular coat
640
What is the structure of the vas deferens?
- 30-40 cm tubular structure arising from the caudal portion of the epididymis
- Distal part enlarged to form the ampulla which joins the excretory duct of the seminal vesicle to form the ejaculatory duct
641
What is the cellular structure of the vas deferens?
- Lined by pseudostratified columnar epithelium comprising columnar and basal cells
- Has thick muscular wall of 3 layers
642
What is the prostate?
- A pear shaped glandular organ
| - Weighs up to 20g in young adult
643
Where does the prostate surround?
The bladder neck and prostatic urethra
644
What are the lobes of the prostate?
Anterior, middle, posterior and two lateral lobes
645
What are the gland regions of the prostate?
Peripheral, central, transitional and peri-urethral
646
What is the prostate covered by?
An ill-defined fibro-connective tissue capsule
647
Name the two main components of the prostate
Glandular and non-glandular components
648
What are the ducts of the prostate?
Large primary and small secondary
649
What are the acini of the prostate?
30-50 tubuloalveolar glands with convoluted edges
650
What are the acini of the pancreas lined by?
Secretory cells, basal cells and neuroendocrine cells
651
What do the secretory cells located on the luminal side of the prostate do?
Secrete PSA and PAP into the seminal fluid
652
What is the structure of the stroma of the prostate?
- Smooth muscle
- Fibroelastic fibres
- Blood vessels
- Nerves
653
What happens the the stroma and glands of the prostate with age?
Hyperplasia (enlargement)
654
What are the seminal vesicles?
Paired highly coiled tubular structure which are posterolateral to the bladder
655
Where does the duct of the seminal vesicle empty?
Into the ejaculatory duct
656
What are the seminal vesicles lined by?
Tall non-ciliated columnar epithelium
657
Name 2 features of the seminal vesicles
- Has vacuoles and lipofuscin
| - Mucosa is folded
658
What is the broad structure of the seminal vesicles?
Has 2 layers of smooth muscle and an adventitia
659
What is the general structure of the penis?
- Erectile tissue arranged into 3 components
- Left and right corpora cavernous on the dorsal side
- Corpus spongiosum on the inferior side (surrounds urethra)
660
What does the erectile tissue compromise of?
- Irregular vascular spaces separated by fibroelastic tissue and smooth muscle
- Rich nerve supply
661
What do the testis contain?
Seminiferous tubules that produce spermatozoa
662
What 3 structure produce the bulk of the seminal fluid?
Prostate, seminal vesicles and Cowper's glands
663
What is the ovary?
A paired organ lying on either side of the uterus close to the lateral pelvis wall
664
What are the three attachments of the ovary?
- The mesovary by the broad ligament
- The uterus by the utero-ovarian ligament
- The pelvic wall by the suspensory ligament
665
What joins the mesovary and the ovary?
The broad ligament
666
What joins the uterus and the ovary?
The utero-ovarian ligament
667
What joins the pelvic wall and the ovary?
The suspensory ligament
668
What is the histological structure of the ovary?
- Covered by a single layer of modified mesothelium
- A poorly defined connective tissue layer (tunica albugnia)
- Stroma is divided into cortex and medulla with indistinct boundaries
669
What is the structure of the ovarian cortex (top portion)?
Spindle stroma cells arranged in whorls/storiform pattern, ovarian follicles, some leutinised cells
670
What is the structure of the ovarian medulla (bottom portion)?
Loose fibroelastic tissue with blood vessels, lymphatics and nerves
671
What is the rete ovarii?
An analogue of the rete testis - present at the hilium
672
Where are primordial follicles found?
The periphery of the ovarian cortex
673
Give 2 features of primordial follicles
- Contains primary oocyte in a resting state
| - Surrounded by a single layer of epithelial cells (granulosa cells)
674
What is the mechanism of development into primary follicles from primordial follicles?
- Cyclic FSH secretion from anterior pituitary stimulates follicular development
- Follicular epithelial cells proliferate (granulosa cells)
- Oocyte enlarges
- Stromal cells become organised into connective tissue sheath
- Zona pellucida forms directly around oocyte
675
What is the mechanism of development into secondary follicles from primary follicles?
- Formation of antrum (space filled with follicular fluid)
| - CT differentiate into inner theca interna and outer theca externa (Cumulus oophorus)
676
What is the structure of mature (Graafian) follicles?
- Ovum surrounded by a thick Zona pellucida
- A layer of granulosa cells surround the oocyte (corona radiata)
- Basal lamina, theca interna and theca externa
677
What is the process of the conversion from a follicle to a corpus luteum?
- Luteinisation of granulosa and theca cells occurs (they become polygonal, larger in size, have abundant cytoplasm containing lipid)
- Secrete progesterone and oestrogen
678
What is the process of regression of a corpus luteum if fertilisation doesn't take place?
- Starts 8-9 days after ovulation
- Granulosa cells decrease in size and develop pyknotic nuclei
- Accumulate abnormal lipid, cells undergo dissolution and are phagocytosed
679
What forms after the corpus luteum degenerates?
The corpus albicans
680
What is the structure of the corpus albicans?
Mainly composed of dense collagen fibres, it is an ovarian scar
681
Give two functions of the Fallopian tube
- Transports ovum to the uterus
| - Fertilisation occurs here
682
What are the four segements of the Fallopian tube?
Intramural, isthmus, ampulla and infundibulum
683
Where is the intramural found?
Inside the uterine wall
684
Give two features of the infundibulum
- Trumpet-shaped opening to peritoneum
| - Has fimbriae
685
How thick is the isthmus?
2-3cm (it is thick walled)
686
What is significant about the ampulla?
It is the expanded area of the Fallopian tubes
687
What is significant about the mucosa of the Fallopian tube?
Thrown into branching folds
688
What are the two cell types of the Fallopian tubes?
Secretory and ciliated
689
What are the two layers of the muscularis of the Fallopian tube?
Inner circular and outer longitudinal
690
What is serosa?
Connective tissue covered by mesothelium
691
What are the three layers of the uterus?
Endometrium, myometrium and serosa
692
What are the layers of the endometrium?
- Deep basal layer (stratum basalis)
| - Superficial functional layer (further divided into stratum compactum (towards surface) and stratum spongiosum)
693
What happens in the proliferative phase of endometrium?
- Oestrogen stimulation
- Straightedges proliferating glands with mitotic activity
- No luminal secretions
- Stromal cells are spindled and compact and show mitotic activity
694
What happens in the secretory phase of the endometrium?
- Progesterone stimulation
- Early (sub-nuclear glycogen vacuoles)
- Mid (vacuoles above and below the nucleus and layer intraluminal secretions, glands more rounded, stroma-oedema)
- Late (elongated and saw-toothed glands with more intraluminal secretions, stroma - spiral arterioles, decimal change)
695
What happens in the menstrual phase of the endometrium?
- Progesterone stimulation withdraws
- Stromal haemorrhage and granulocytes
- Stromal and glandualr fragmentation
696
What is the structure of the myometrium?
Thick muscular wall with 3 ill-defined layers of smooth muscle: inner longitudinal, middle circular and outer longitudinal
697
What is the structure of the endocervix?
Loose fibromuscular stroma lined by simple columnar ciliated epithelium, thrown into crypts
698
What is the structure of ectocervix?
Dense smooth muscle stroma lined by non-keratinising stratified squamous epithelium
699
What is the structure of the mucosa of the vagina?
Lined by non-keratinising stratified squamous epithelium..
700
What is the structure of the stroma of the vagina?
Elastic fibres and a rich vascular network
701
What is the structure of the muscular wall of the vagina?
Smooth muscle cells, inner circular and outer longitudinal structure
702
What is the structure of the adventitia of the vagina?
Loose connective tissue
703
What is the histology of the labia majora?
Lined by keratinising stratified squamous epithelium and has skin adnexae
704
What is the histology of the labia minora?
Mostly non-keratinising stratified squamous epithelium
705
What is a Bartholin's gland?
Tubuloalveolar glands. Acini lined by mucus-secreting epithelium
706
What are minor vestibular glands?
Simple tubular glands lined by mucus-secreting epithelium
707
What are Skein's glands (periurethral glands)?
Analogous to prostate, lined by pseudostratified columnar epithelium
708
What is the histology of the hymen?
Lined by non-keratinising squamous epithelium
709
What is the structure of the clitoris?
Erectile tissue rich in blood vessels and nerves
710
Give 4 common features of the endocrine system
- Glandular epithelium
- Richly vascularised
- Secrete a variety of hormones
- Controlled by positive and negative feedback loops
711
What is the function of the pituitary?
Coordinates the endocrine organs through feedback loops
712
What are the two functional components of the pituitary?
Posterior and anterior
713
What is the structure of the posterior pituitary?
- Downwards extension of hypothalamus
| - Neural tissue (axons/glial cells)
714
What does the posterior pituitary store/secrete?
Oxytocin and vasopressin (ADH)
715
What is the structure of the anterior pituitary?
- Nested epithelial pituicytes
- Richly vascular fibrous stroma
- Several different types of pituicytes
716
Name 6 hormones which are produced in the anterior pituitary
- Growth hormones
- Prolactin
- ACTH
- FSH
- LH
- Thyroid stimulating hormone
717
What hormone is produced by somatotrophs?
Growth hormone in the anterior pituitary
718
What hormone is produced by lactotrophs?
Prolactin in the anterior pituitary
719
What hormone is produced by corticotrophs?
ACTH in the anterior pituitary
720
What hormones is produced by the gonadotrophs?
FSH and LH in the anterior pituitary
721
What hormone is produced by thyrotrophs?
Thyroid stimulating hormone in the pituitary
722
What is the function and structure of somatotrophs?
- Diffuse cytoplasmic growth hormones
- Lateral wings of anterior pituitary
- Present throughout gland
723
What is the function and structure of lactotrophs?
- Polygonal cells
- Cytoplasmic processes wrap around other cells
- Variable prolactin staining
724
What is the structure of thyrotrophs?
- Angular chromophobes
- Elongated processes
- Variable TSH staining
725
What is the structure of gonadotrophs?
- Scattered round/oval cells
726
What is the function and structure of corticotrophs?
- Round basophilic cells
- Median of gland
- Large cytoplasmic vacuoles
727
What is the function and structure of supporting cells in the anterior pituitary?
- Sustenacular cells
| - Surround the normal follicles
728
What is the structure of the pineal gland?
Pinealocytes in rosettes
729
Where is melatonin secreted from?
Pineal gland
730
Where is thyroxine produced?
Thyroid gland
731
Where is calcitonin produced?
Thyroid gland
732
What is the structure of the thyroid gland?
- A combination of follicular cells and colloid
| - Richly vascular
733
How many parathyroid glands are there?
4
734
Where are the parathyroid glands located?
Variably in the neck
735
What do the parathyroid glands do?
Produce parathyroid hormone
736
What are the 3 cell types in the parathyroids?
Chief cells, oxyphils and adipocytes
737
What is the structure of the chief cells of the parathyroid?
- Polygonal cells
- Scant cytoplasm
- No calcium oxalate crystals
- Strong immunoreactivity for PTH
738
What is the function of the chief cells of the parathyroid?
- Secretes PTH
| - Raises serum calcium ions
739
What is the structure of the oxyphil cells of the parathyroid?
- Large polygonal cells
- Increase with age
- Abundant eosinophilic cytoplasm
740
What is the structure of the Islets of Langerhans?
- Balls of cells
- Thin fibrous capsule
- Mostly in pancreatic tail
741
What are the 4 components of the Islets of Langerhans?
Beta cells, alpha cells, delta cells and PP cells
742
What do beta cells of the pancreas produce?
Insulin
743
What do alpha cells of the pancreas produce?
Glucagon
744
What do the delta cells of the pancreas produce?
Somatostatin
745
What do the PP cells of the pancreas produce?
Pancreatic polypeptide
746
What are the three layers of the adrenal cortex?
Zona glomerulosa, zona fasciculata and zona reticularis
747
What is released from the zona glomerulosa?
Mineralcorticosteroids (aldosterone)
748
What is released from the zona fasciculata?
Glucocorticosteroids (cortisol)
749
What is released from the zona reticularis?
Androgenic steroids
750
What is the structure of the zona glomerulosa?
Thin & incomplete, small cells, vacuolated cytoplasm
751
What is the structure of the zona fasiculata?
Most prominent layer, large polygonal cells, almost clear cytoplasm
752
What is the structure of the zona reticularis?
Innermost cortical layer, androgenic steroids, anatomising columns of small polygonal cells
753
What is secreted from the adrenal medulla?
Adrenaline and noradrenaline
754
What is the structure of the adrenal medulla?
Centre of adrenal gland, chromaffin cells, large and polyhedral
755
Name two features of the endocrine system
- All epithelial (except posterior pituitary)
| - All have a rich blood supply
756
Name 3 places where visceral (smooth muscle) can be found
Arterial wall, wall of intestine and airways of lungs
757
Name 3 places where voluntary (skeletal) muscle can be found
Skeletal muscles, larynx, diaphragm
758
Name 2 places where cardiac muscle can be found
Heart & base of great vessels
759
Name 3 contractile cells
Pericytes, myo-fibroblasts, myo-epithelial cells
760
What is the structure of myoblasts in skeletal muscle?
Fused to form multi-celled syncytium
761
How are myofibrils formed?
By sarcomeres joined end to end
762
How are fascicles formed?
By the clumping of muscle fibres
763
Name 3 structures which are held together by connective tissue
Endomycium, perimycium and epimycium
764
What is significant about the cytoplasm of skeletal muscle?
It is rich in glycogen
765
Is skeletal muscle voluntary or non-voluntary?
Voluntary
766
Give 5 histological features of skeletal muscle
- Elongated fibres
- Striated cytoplasm
- Multinucleate
- Nuclei at edges
- Non-branching
767
Why is striated muscle striated?
Due to myofibrils being in register
768
What are the different types of muscle fibre?
Type 1 and 2
769
What is significant about type 1 muscle fibre?
Rich in fibrillar ATPase and is slow twitch
770
What is significant about type 2 muscle fibre?
Rich in fibrillar ATPase, fast twitch. Stains paler
771
What is the structure of muscle spindles?
- Intrafusal muscle fibres wrapped around by gamma efferent nerve fibres
- Fibrocollagenous capsule
772
What is the function of muscle fibres?
Detect stretch and tension
773
What is the function of Sharpey's fibres?
- Connect muscle to bone (and penetrate bone)
| - Attach muscle to bone over a wide area
774
What is the structure of Sharpey's fibres?
Bundles of collagen linking epimysium to periosteum
775
What is the function of tendons?
- Connect muscle to bone
| - Attach muscle to bone over a small area
776
What is the structure of tendons?
Parallel bundles of collagen with intervening fibroblasts
777
What is a specialised form of connective tissue?
Skeletal muscles
778
Name 4 cells of the bone
- Osteoprogenitor cells
- Osteoblasts
- Osteocytes
- Osteoclasts
779
What forms the extracellular matrix of the bone?
Collagen and calcium hydroxyapatite
780
Which cells of the bone are derived from embryonic mesenchyme?
Osteoprogenitor cells
781
Where is osteoid secreted from?
Unmineralised bone
782
Which bone cells become trapped in their own matrix?
Osteocytes
783
Which cells of the bone connect to surrounding cells via canaliculi?
Osteoblasts and osteocytes
784
Which cells of the bone are derived from monocytes?
Osteoclasts
785
Give 3 features of osteoclasts
- Multinucleate cells
- Absorb bone - sit in Howship's lacunae
- Activity is linked to that of osteoblasts
786
How can bone be differentiated by origin?
Primary (woven) and secondary (lamellar)
787
How can bone be differentiated by mode of formation?
Membranous and endochondrial
788
How can bone be differentiated by gross appearance?
Spongy/cancellous & compact or osteons & appositional
789
How does secondary bone form?
As osteons
790
What is the structure of secondary bone?
- Central Haversian canal containing blood vessel
| - Surrounding concentric rings of lamellar bone with osteocytes
791
Which bones have intramembranous formation?
Flat bones of the skull and some cortical bone shafts
792
Which bones have endochondrial formation?
All bones except flat bones of the skull
793
Where is synovial usually found?
Inside of the joint capsule (1-4 layers of synovial cells)
794
What is the function of type A synovial cells?
Phagocytic
795
What is a feature of type B synovial cells?
Rich in rER
796
How do exocrine glands secrete their products?
Via ducts
797
How do endocrine glands secrete their products?
Via the blood
798
What is the only endocrine organ which isn't epithelial?
The pituitary
799
Name two hormones which are made in the same tissue
Prolactin and growth hormone
800
Name two hormones which are made by neural tissue
- Oxytocin and vasopressin
| - Made in posterior pituitary
801
Where is prolactin found?
In lactotrophs, in the anterior pituitary
802
What is the least common pituicyte?
Thyrotrophs
803
Give 3 properties of the pineal gland
- Has meninges lying over the top
- Has calcium spread throughout
- Secretes melatonin
804
Where is calcitonin made?
By the C cells of the thyroid
805
Where is pepsinogen synthesised?
By the chief cells of the stomach
806
What do parathyroid chief cells make?
Parathyroid hormone
807
Where is calcium oxalate found?
In thyroid tissue
808
Give 4 functions of somatostatin
- Delayed gastric emptying
- Hepatic glycogenesis
- Lowered blood glucose concentration
- Suppression of gastric acid secretion
809
How is serum calcium concentration regulated?
By parathyroid hormone
810
Where is ANP made?
In the atrial myocardium of the heart
811
What does the adrenal zona fasciculate principally secrete?
Cortisol
812
What is the thickest layer of the adrenal cortex?
The zona fasciculata
813
Where does the adrenal gland synthesize hormones and with what substance?
- From cholesterol
| - Done in the layers of cells near to the surface (adrenal cortex)
814
Where is the adrenal gland are hormones synthesised from tyrosine?
In the adrenal medulla
815
What is the endocrine organ which receives its blood supply through a portal circulation?
The anterior pituitary
