Histology Flashcards
1
Q
what is the maximum amount of shortening of a sarcomere?
A
30%
2
Q
how does skeletal muscle appear when cut transversely?
A
as a number of polygonal pink fibres arranged in clumps (fascicles). each pink staining block is a separate muscle fibre, on the periphery of each fibre are blue staining cell nuclei
3
Q
the banding of skeletal muscle is often difficult to see in H&E stained specimen, what stain can we used for better resolve?
A
staining with iron haematoxylin produces better contrast and make int possible to resolve all of the bands within a sarcomere.
4
Q
how are muscle attached to bones?
A
via tendons or mysium that surrounds the muscle fibres wither in the form of numerous small collagen bundles.
5
Q
discuss sharpey’s fibes
A
The collagen bundles of Sharpey’s fibres merge with the fibrous periosteum of the bone and merge with the collagenous matrix of the bone itself. This form of attachment spreads the force of the muscle over a wide area. Good examples are the origins of the rotator cuff muscles on the blade of the scapula
6
Q
describe the histology of seminiferous tubules
A
they are lined by stratified epithelium. they contain sertoli cells and spermatozoa. sertoli cells tightly joined to form the blood testis barrier . Each semniferous tubule is enclosed by a thin fibrous.
7
Q
what cells line the rete testis?
A
cuboidal epithelium
8
Q
what cells line the epididymis?
A
tall pseudo-stratified columnar epithelium, small rounded basal cell support ball columnar cells with very long microvilli (sterocilli). The tube is surrounded by a thin layer of smooth muscle, this becomes thicker and multilayered as it appraoches the vas deferens
9
Q
what cells line the vas deferens?
A
layers of smooth muscle. not as tall pseudo-stratified columnar epithelium and shorter microvilli
10
Q
which structures appear most prevalent in the renal cortex?
A
proximal convoluted tubules. the PCT are longer and becuase they are convoluted the same tubule appear many times in thesame section. Thus, the structure is most commonly found.
11
Q
what cells line the glomerular capillaries
A
The inside of the glomerular capillaries is lined by fenestrated vascular endothelial cells, and podocytes line the outside.
12
Q
What types of epithelium lines the renal pelvis?
A
urothelium
13
Q
what hormone does the Juxtaglomerular apparatus secrete?
A
renin
14
Q
what parts of the kidney are most sensitive to aldersterone?
A
cells of the distal tubule and collecting ducts are the most sensitive to aldosterone. this is where the hormone promotes the reabsoprtion of sodium ions and water, thereby concentrating the urine and conserves body fluid.
15
Q
what are lacis cells?
A
they are light staining pericytes in the kidney found outside the glomerulus, near the vascular pole. They resemble smooth muscle cells and play role in blood flow and pressure (RAS) regulation.
16
Q
does the ureter have a muscularis mucosa?
A
No, It is lined by urothelium beneath which is a lamina propria. Beneath this is a well developed muscularis propria.
17
Q
does the Bladder have a muscularis mucosa?
A
Yes, the bladder contains a poorly formed muscularis mucosa and a prominent muscularis propria, both are smooth muscle. Muscularis propria has three layers of muscle only apparent at the bladder neck. the lamina propria, muscularis mucosa and submucosa separates the muscularis propria from the urothelium.
18
Q
what does the macular densa do?
A
It may monitor sodium levels and may influence the initial filitration process of the glomerulus.
19
Q
Describe the histology of the Proximal convoluted tubule
A
Cuboidal epithelium, Round central/basal nuclei. brush border of microvilli at apical end. many mitochondria (for active transport) so appears eosinophillic
20
Q
what does bacterial enzyme hydrolysis in the gut produce, which is then excreted in faeces
A
stercobilinogen
21
Q
what structure is situated within the duodenal loop
A
pancreas
22
Q
which compound is returned to the liver by the enterohepatic circulation?
A
urobilinogen
23
Q
what structure is in the middle of the hepatic lobule?
A
Central vein
24
Q
What is the cause of physiological Jaundice of the newborn?
A
Excess breakdown of foetal haemoglobin
25
obstructive jaundice is commonly caused by the gall stone within what structure?
the common bile duct
26
what do Stellate cells store?
vitamin A
27
what do Kupffer cells do?
they are macrophages that break down haeme to bilirubin using an enzyme
28
What are the three main components of bile?
bile salts 70%
phospholipids
bilirubin
29
Describe a classic lobule
Area drained by one central hepatic venule. Some hepatocytes are more richly oxygenated than others. Hepatocytes near central vein are more deprived.
30
Describe hepatocytes
Polyhedral epithelial cells. Abundant mitochondria, which cannot be seen easily. Large central spherical nuclei. There is a prominent nuclei, few are binucleate. Numerous peroxisomes.
31
What are the three important surfaces of hepatocytes.
| .
Most (70%) are in contact with permits exchange of material with blood space of Disse. 15% canalicular permits excretion of bile. 15% of intercellular
32
What are contained in space of disse?
Reticulin fibres and stem cells
33
What are sinusoid
Are highly specialised blood vessels. Thin discontinuous fenestrated endothelium. No basement membrane between vascular endothelial cells and hepatocytes. Contains scattered Kupffer cells.
34
What cells line the intrahepatic biliary tree? What cells line extrahepatic bile ducts
Lined by simple cuboidal to columnar epithelium, or simple columnar epithelium.
35
Describe the histology of the gallbladder
The gallbladder concentrates and store bile, expels bile via the common bile duct into the duodenum. Lined by simple columnar epithelium, specialised mucosa and loose fibrous connective tissue. It does not have a muscularis mucosa, has a thick layer of smooth muscle muscularis propria and a layer of loose fibrous connective tissue
36
What cells line the mouth?
Stratified squamous non keratinising epithelium
37
what protects the outlet of the oropharynx?
A ring of lymphoid tissue
38
what are the three pairs of saliva re glands that secrete into the oral cavity?
Parotid, sublingual, and submandibular
39
Describe the Histology of the tone.
The tongue is covered by a stratified squamous epithelium come out non carrot and eyes on its ventral surface but heavily character dies on its dorsal surface due to constant abrasion on this surface.
40
Describe the Histology of parotid salivary glands.
They are secretory cells, which are pyramidal in shape. The basal Cytoplasm is filled with rough endoplasmic reticulum and the apex of the cell contains prominent secretion granules.
41
Discuss the structure of the epiglottis.
The epiglottis lies posterior to the tongue and it is directly attached to it. Most of its surface is covered by stratified squamous epithelium although the lower part of its posterior surface has a pseudostratified columnar ciliated epithelium. Internally it contains a plate of elastic cartilage and its submucosal often contains lymph nodules and Salivary glands.
42
What's roughens the surface of the tongue?
Filiform papilliae
43
Where are the circumvallate papillae?
between the anterior 2/3 and posterior third of the tongue
44
What feature confirms the site of origin of the oesophagus?
Squamous lined ducts. Oesophageal mucosa is lined by a nonkeratinizing stratified squamous epithelium also found in the mouth. The ducts are unique to the oesophagus.
45
What do parietal cells secrete?
Gastric parietal cells secrete hydrochloric acid and intrinsic factor. Intrinsic factor plays a role in the absorption of vitamin B12. Vitamin B12 is absorbed in the terminal ileum.
46
In the duodenum what is the purpose of Brunner’s glands?
They secrete an alkaline mucus that helps neutralise gastric acid.
47
Which autonomic nerve plexus innervates the gastrointestinal tract?
Meissner’s plexus lies in them submit mucosa, Auchbahs plexus lies between the layers of the muscularis propria.
48
Do you find lymphoid aggregates in the jejunum?
No, prominent lymphoid aggregates also known as Peyer’s patches are found in the ileum but they are not present in the judging him or duodenum.
49
What Artery supplies the colon ?
The superior mesenteric artery and the inferior mesenteric artery.
50
What tissue bridges the gap between the free ends of C- shaped cartilage in the trachea ?
smooth muscle
51
What is present within the walls of bronchi but not Bronchioles’?
Cartilage
52
what type of tissue holds open the larynx and the trachea?
Hyaline cartilage
53
do you find microvilli in respiratory epithelium?
No
54
where are the pores of kohn?
Alveolar walls
55
how thick is the air blood barrier?
600 nanometres
56
How many cell layers are there in their air blood barrier?
2, we have surfactant, type one pneumocytes, basement membrane, and vascular endothelial cells
57
Which cells secrete surfactant?
Type 2 pneumocytes
58
where is Reinke’s space?
In the vocal cords
59
What is the purpose of neuro-endocrine cells?
They are numerous in the smaller bronchi, they monitor the air inspired for allergens and harmful elements
60
What lines the bronchial tree?
Ciliated columnar epithelial, which is pseudostratifies in the larger bronchi
61
What is the function of paranasal sinus is?
They lower the weight of the skull, they add resonance to the voice, they humidify in warm inspired air and they aligned with respiratory epithelium.
62
What are the names of the nasal sinus is?
Maxillary, ethmoid, sphenoid and frontal sinus.
63
What is the difference between mucosa associated lymphoid tissue and lymph node?
MA Lt samples inhaled antigenic material and prepares defence mechanisms against it. A lymph node is a discrete encapsulated collection of lymphoid tissue, whereas MALT is less discrete, lacks a capsule and is present in a mucosa often related to the epithelium.
64
What are the essential components of the larynx?
The larynx includes the true and false folds and the vestibule of the larynx. The uppermost set of the force chords lined by respiratory epithelium (ciliated columnar), while the lowermost are the true vocal cords lined by a stratified squamous epithelium. The vestibule lies between these two sets of folds.
65
What is reinke’s space?
It's in the vocal cords , it is a Overlying loose irregular fibrous connective tissue. There are almost no lymphatic so it is difficult for cancer to spread into the lymphatic space.
66
Describe the cartilaginous rings in the trachea.
They are C shaped cartilage and its rings . It is held open by 12 -15 incomplete rings of hyline cartilage . The end of the ‘C’ lie posteriorly towards the Suffolk as and are joined by an involuntary smooth muscle called the trachea less muscle.
67
Which of the following lacks lymphatics: Brain. Cartilage. Hearts. Lung. Small intestine?
The answer is cartilage
68
where do you find pericytes?
Around capillaries and venues
69
what yellow / Brown pigment accumulates in cardiac myocytes with increasing age?
Lipofuscin
70
Where in the heart will you find the nodules of Arantius?
The aortic valve cusps
71
what cell type lines the mitral valve?
endothelial cells
72
how do the Maya sites of the sinoatrial node differ from normal cardiac myocytes?
They have no intercalated discs
73
what type of epithelium is in the pericardium?
Simple squamous
74
Purkinji Cells are found in the epicardium what colour do they stain in Histology?
Deep magenta
75
What is the outer most layer of the heart?
The visceral pericardium
76
What is endocardium?
The endocardium is the innermost layer of tissue that lines the chambers of the heart. The endocardium also provides protection to the valves and heart chambers.
77
What is epicardium?
a serous membrane that forms the innermost layer of the pericardium, attached to the muscles of the wall of the heart.
78
What is myocardium? t
he muscular tissue of the heart.
79
what is the predominant leukocyte?
Neutrophils are the most abundant white blood cell, constituting 60-70% of the circulating leukocytes
80
what proportion of the blood is made up of white blood cells?
White blood cells protect the body from infection. They are much fewer in number than red blood cells, accounting for about 1 percent of your blood.
81
In a heamatocrit what percentage are blood cells?
45%
82
what is the function of blood?
It transports gases, nutrients and hormones. It maintains acid base homeostasis. Maintains a constant body temperature. And platelets are derived from megakaryocytes
83
Where are Erythrocytes destroyed?
In the liver and spleen
84
the neutrophil contains three types of cytoplasmic granules, primary surgery and touch re granules. What is the purpose of tertiary granules?
They are adhesion molecules that facilitate the insertion of proteins into the membrane of the cell surface.
85
What is the function of T cytotoxic cells?
They kill previously marked target cells
86
what is the function of T suppressor cells?
They suppressed T H cells and hence suppressed immune response
87
what is the purpose of natural killer cells?
They mainly kill virus infected cells
88
Which cells produced Myelin?
Swann cells
89
name an elastic artery.
The aorta, pulmonary trunk, common carotid , subclavian , vertebral and common iliac arteries
90
Name the three distinct layers forming the walls of arteries and veins:
the innermost layer is the tunica intima, the middle muscular layer of the blood vessel is the tunica media, the outer most layer of the blood vessel is the tunica adventitia.
91
Discuss fenestrated capillaries:
found in the kidney and liver they drain into the venous system. There are no surrounding muscles or connective tissue
92
Describe peripheral nerve:
they are composed of axons, supported by Schwann cells, most are myelinated. Comprised of connective tissue that binds individuals nerves together
93
Endoneurium:
Peroneurium:
Epineurium:
present between individual axons
surrounds the groups of axons to form fascicles
binds fascicles together to form nerve fibres.
94
What are the three major types of blood vessels?
Thick walled arteries which carry blood away from the heart under relatively high pressure.
Thin walled capillaries which permeate through tissues and organs.
Thicker walled veins which carry blood back to the heart under relatively low pressure.
95
What are the two major circulatory systems?
Largest systemic circulation where blood is transported from the heart to other tissues of the body. The smaller pulmonary circulation between the hearts to the lungs for the re oxygenation of the blood.
96
Why are silver stains good for neurons?
Silver stains have an affinity for elements of the cytoskeleton of cells, neurons have well developed cytoskeletons, they stain heavily with silver stains.
97
What limits the speed of conduction along nerves?
It is limited by the electrical capacity and resistance of the Axon. Wide Axon's have a lower capacity than narrow ones, increasing their diameter therefore increases the speed of nerve conduction . However giant axon's require high metabolic upkeep so they are inefficient. The speed of conduction can also be increased if leakage is minimalised.
98
What is the difference between a Swan cell and a oligodendrocyte?
Schwann cells myelinate only one Axon. Oligodendrocytes made Myelinate ate several adjacent axon's.
99
What develops from mesenchymal cells?
fibroblast, fat cells, chondroblast, mast sell, osteoblast, adipocyte , and most cartilage and bone cells.
100
what develops from the haemopoietic stem cell line?
monocytes, macrophage, Lymphocytes, mast cells and blood cells
101
```
Type I collagen is found in ... _________________
Type II: _________________
Type III: ___________________
Types IV: _________________
Types V: _________________
```
```
Type I: prevalent in skin
Type II: cartilage
Type III: liver, bone marrow, spleen
Types IV: basement membranes
Types V: placenta
```
102
What is loose connective tissue?
Why do you space Finn collagen fibres. With fibroblast.
103
What is dense connective tissue?
Collagen fibres are densely packed together . Closely spaced thick collagen fibres. Fibroblast. Maybe irregular or regular depending on the arrangement of fibroblast.
104
Describe the structure of ligaments.
Ligaments are composed of thick ribbons of parallel collagen fibres, which lie between the fibroblast that synthesise them. The fibres become very compact and regular Commerce quashing the fibroblast full stops such fibres cannot be stretched. Collagen fibres are not elastic or contractile.
105
Describe Reticulum:
It is a type 3 collagen, fibula collagen, formed supporting scaffold in many organs such as bone marrow, liver, kidney, lymph node and spleen . It is not visible on H&E so you need a silver stain.
106
Describe elastin:
elastin protein in connective tissue. It consists of microfibres of fibrillin set in an amorphous matric of elastin. May be branched. Produced by fibroblasts. Stain pink on H&E. easily confused with muscle cells. Stains more strongly than collagen
107
Where is elastic cartilage made?
Found In the pinna and the epiglottis.
108
list visible extracellular fibre:
the visible fibres and extracellular material are collagen, elastin and reticulin. Fibronectin and laminin are invisible fibres.
109
Compare Brown adipose tissue in neonates to adults:
It is abundant in neonates but scanty in adults. In neonates it is found in the neck, back, around the aorta and around the kidneys. In adults it is found between the shoulder blades. Brown adipose tissue plays a role in thermo-regulation by producing heat through the metabolism of fat.
110
What is different about the connective tissue in the penile fascia compared to ligament and tendons?
dense regular connective tissue is found in ligaments and tendons. The penile fascia comprises dense irregular connective tissue.
111
Describe the histology of elastic cartilage when stained:
pale basophilic extracellular matrix containing eosinophilic elastin fibres with entrapped chondrocytes. Hyaline is glassy, greyish blue, and smooth looking and no visible EC fibres.
112
Describe the histology of the uterine wall:
it is smooth muscle. Spindle shaped cells. Cells are jammed together- not fibres. No EC collagen.
113
What structure has pseudostratified epithelium with goblet cells and pale cilia?
Nasopharynx
114
What type of collagen is the basement membrane made of?
Type 4
115
What are the epithelial cell junctions?
Occluding junctions (impermeable barrier), anchoring junctions (mechanical strength) and communicating junctions (movement of molecules)
116
What are the main functions of occluding junctions?
Prevention of diffusion of molecules between adjacent cells. Prevention of lateral migration of specialized cell membrane proteins.
117
What are desmosomes?
They are plaques that form physical joints between cells and connect the cytoskeletons of adjacent cells
118
What is The Michaelis-Menten equation?
Vmax is the maximal rate of the reaction. The Michaelis-Menten equation can then be rewritten as V= Kcat [Enzyme] [S] / (Km + [S]). ... Km is the concentration of substrates when the reaction reaches half of Vmax.
119
Why is light microscope using wax embedded section the main technique in Histology?
tissue is immersed in preservation solution and then embedded in paraffin wax for cutting into thin sections. paraffin is cheap and simple come out the wax is a physical support. Once the slices are made the wax is removed using an organic solvent, the section is rehydrated using dilutions of alcohol in water.
120
Name the main types of tissue staining:
empirical using Van Gieson’s And trichrome methods,
history chemical,
enzyme history chemical,
immunohistochemical.
121
What are some commonly used histological stains?
H&E because it is simple, reliable, inexpensive and informative. Van Gieson method stains the College in pinkish red and muscle yellow. Trichrome methods using a mixture of three dyes. And periodic acid shift stains.
122
Compare transmission electron microscope to scanning electron microscope:
in transmission electron microscope the electrons in a vacuum chamber passed through a very thin section of tissue , some components absorb the electron -electron dense Others electron lucent. The electron that pass through hit a phosphorescent screen.
Scanning electron microscope he allowed resolutions are three dimensional subcellular structures. It uses solid pieces of tissue rather than ultra-thin tissue sections and allows perception of three dimensional views of the surface of cells. A small piece of tissue is dried and coated in gold
123
What are the five classes body tissue?
Epithelial tissues, supporting tissues, muscle cells, nerve cells and germ cells.
