Download presentation
Presentation is loading. Please wait.
1
Micro Image Review #3 Labs 7-9
2
Reticular connective tissue
Will stain with PAS or silver Are glycosylated, that’s why they stain with PAS Can’t see with LM alone 9/23/2018
3
Reticular connective tissue
9/23/2018
4
Adipose tissue Fat is usually dissolved by reagents used to section the material Unilocular fat cells have one large vacuole of fat Nuclei are pressed off to margins of the cell because of the large fat vacuole Reticular cells are found surrounding where the cells were Supportive 9/23/2018
5
Unilocular fat 9/23/2018
6
Multilocular fat More than one fat vacuole per cell
Adipose tissue that is developing multilocular unilocular 9/23/2018
7
Brown fat More mitochondria, thus, they are browner Brown fat
White fat 9/23/2018
8
Brown fat Notice many vacuoles of fat per cell and also notice how red the cells are – due to the mitochondria 9/23/2018
9
In EM Remember – adipose will usually stain clear in EM because it is melted out Also remember that brown fat has shitloads of mito, So if you see an EM cell with tons of them do not forget about brown fat 9/23/2018
10
mesenchyme Only one type of cell (mesenchymal cells)in ground substance 9/23/2018
11
mesenchyme There are usually too many nuclei for it to be dense irreg CT, plus NO COLLAGEN FIBERS 9/23/2018
12
Cartilage What is cartilage? How do chondrocytes get nutrients?
9/23/2018
13
cartilage What is cartilage? How do chondrocytes get nutrients?
Living cells (chondrocytes) in avascular matrix. How do chondrocytes get nutrients? Diffusion through the gel matrix 9/23/2018
14
cartilage What are the three classes of cartilage?
How does cartilage develop? What are the two mechanisms of growth? 9/23/2018
15
cartilage What are the three classes of cartilage?
Hyaline, elastic, and fibrocartilage How does cartilage develop? From centers of chondrification Formation of aggregates (mesenchymal cells) which produce ECM What are the two mechanisms of growth? Interstitial and appositional 9/23/2018
16
What happens in interstitial growth?
9/23/2018
17
What happens in interstitial growth?
Growth from within Division of chondrocytes Each daughter cell produces ECM which forces cells apart. 9/23/2018
18
What happens in appositional growth?
9/23/2018
19
What happens in appositional growth?
Occurs from the perichondrium What is the perichondrium? Lines the surface of hyaline and elastic cartilage ***note that fibrocartilage has NO PERICHONDRIUM! Gives rise to chondroblastschondrocytesmatrix secretion 9/23/2018
20
Hyaline translucent blue/white
Articular cartilage is a special kind lining surfaces of long bones and joints (no perichondrium) Elastic Cartilage like hyaline but contains elastic fibers pink in H&E Fibrocartilage no perichondrium, looks a lot like dense irregular CT 9/23/2018
21
Notice the pink fibers in the elastic cartilage between lacunae
Notice the pink fibers in the elastic cartilage between lacunae... Major distinguishing feature 9/23/2018
22
cartilage Hyaline Smooth and shiny looking
Look for lacunae – these are KEY Chondrocytes live in them – they may label these so be aware Has perichondrium, like elastic but unlike fibro PS. you need to know isogenous nests too – lots of chondrocytes bunched together having a nice time Will most likely show you in hyaline 9/23/2018
23
Hyaline cartilage 9/23/2018
24
Elastic cartilage Sometimes stained purpley so you can see elastic fibers Looks fibrous, while the hyaline looks smooth and sleek, but both have perichondrium 9/23/2018
25
Elastic vs. hyaline smooth Not smooth 9/23/2018
26
Fibrous cartilage NO PERICHONDRIUM
Can be confused for connective tissue so you MUST look for lacuna 9/23/2018
27
Fibrous cartilage 9/23/2018
28
Top is fibrocartilage you know because of the presence of lacunae… bottom is dense irregular CT
9/23/2018
29
Bone Be able to label: Haversian systems aka osteons – the round units
Haversian canals – canal in middle of round unit Lacunae – where osteocytes live, the dark spots around osteons Canaliculi – lines connecting lacunae, thin Interstitial lamellae (between osteons) Osteocytes – in lacunae found around osteons Trabeculae – spongy bone extensions Bone marrow – if you see spicules of spongy bone it is everything that is around it – contains fat, your new friend Volkmann’s canal – shaped like a filled in number 8 – contain blood vessles – right angle to osteons 9/23/2018
30
Cells of bone Osteoblasts? Osteocytes? Osteoclasts? 9/23/2018
31
Osteoblasts? Osteocytes? Osteoclasts? Cuboidal
Synthesize and secrete bone components Since they make proteins… they have what? Cytoplasmic basophilia! Osteocytes? Osteoblasts that have been enveloped by bone Connected to other osteocytes by cannaliculi Osteoclasts? Large multi-nucleated cells Bone reabsorption Produce Howships lacunae 9/23/2018
32
Osteoblastsosteoid bone Intramembranous bone formation What happens?
What bones form this way? What happens? 9/23/2018
33
Osteoblastsosteoid bone Intramembranous bone formation
What bones form this way? Flat bones (skull) What happens? Mesnchymal cells form aggregates osteoblasts secrete osteoidcalcification surround osteoblasts making them osteocytesspicules trap mesenchymal cells which differentiate to bone marrow remodeling to secondary bone lamellar ordering of collagen 9/23/2018
34
Bone reabsorption What happens? 9/23/2018
35
Bone reabsorption What happens?
Attachment to bone (mediated by integrins) this region of cytoplasm lacks organelles=clear zone Ruffled border is region directly involved in bone reabsorption= invaginated memb. Vesicular zone- contains many endocytic vesicles Basal zonelocated furthest from Howships lacunae contain cellular organelles 9/23/2018
36
__1__ __2__ __3__ __4__ 9/23/2018
37
1) zone of resting cartilage
2) zone of proliferation (increases length) 3) zone of hypertrophy 4) zone of calcification 9/23/2018
38
What are some factors affecting bone development?
9/23/2018
39
What are some factors affecting bone development?
Parathyroid hormone and calcitonin PTH signals bone resorption (inc. serum calcium) Calcitonin inhibits bone resorption 9/23/2018
40
Joints Synarthroses—joints that allow restricted movement—skull, ribs
Diarthroses—synovial joints… allow movement 9/23/2018
41
Where to begin…… 9/23/2018
42
Compact bone Interstitial lamellae 9/23/2018
43
LM view Osteocytes in little lacunae holes 9/23/2018
44
Bone cells Osteoclasts have all sorts of nice little nuclei, and they are large to quite large in size Osteoblasts on the surface of bone, only one nuclei and elongated shape – they form osteoid so they have CYTOPLASMIC BASOPHILIA…. Remember that?? 9/23/2018
45
Bone cells cont’d Nice little multinucleated osteoclast
Osteocyte in their lacuna 9/23/2018
46
Osteoblasts on surface of bone- have irregular shape and ONE nuclei and cyto baso – more purple than bone around them 9/23/2018
47
Spongy bone Trabecula, bone marrow with FAT 9/23/2018
48
If they showed you this you would say…..
Intramembranous bone formation!! Why? Looks like its forming randomly in multiple spots – nice little spicules help you to see this 9/23/2018
49
Endochondral bone formation
Resting = normal cartilage Proliferation – lines of cells in a row Hypertrophy – cells large now and in large holes Calcification – the part that looks way different from the part before it 9/23/2018
50
Endochondral 9/23/2018
51
Don’t forget about howships lacuna!!
Multinucleated osteoclasts sit in them, nice clue Howships have scalloped edges 9/23/2018
52
Bone diagram Periosteum goes with outer circum. lamellae
Fewer layers in outer as compared to inner Inner circum lamellae goes with endosteum So 3 types lamellae total = interstitial, inner circum, outer circum 9/23/2018
53
Endosteum and inner circumferential lamellae
Multiple osteons and interstitial lamellae Inner circumferential lamellae Endosteum 9/23/2018
54
Periosteum vs. endosteum
Endosteum faces medullary cavity Look for marrow on the inside Periosteum faces outside of bone Hi. Marrow here. 9/23/2018
55
QUIZ TIME What is A and B 9/23/2018
56
A is chondrocyte in lacuna B is hyaline cartilage – has perichondrium
9/23/2018
57
Name A, C, and D 9/23/2018
58
A = central canal/Haversian Canal
Not to be confused with haversian system (same thing as osteon) C = osteocyte D = canaliculi 9/23/2018
59
What is this tissue What cells are present 9/23/2018
60
Fibrocartilage – herringbone pattern
This makes the nuclei chondrocyte nuclei 9/23/2018
61
What process is going on here What is the arrow pointing to
9/23/2018
62
Intramembranous bone formation Osteoblast – cyto baso
9/23/2018
63
What is E? 9/23/2018
64
Zone of hypertrophy Huge nuclei in endochondral bone formation
9/23/2018
65
What tissue is this 9/23/2018
66
Spongy/cancellous bone
You can see the spicules and marrow What does marrow often contain? Fat! 9/23/2018
67
What are these? 9/23/2018
68
Reticular fibers – black and scraggley looking
9/23/2018
69
What are these 9/23/2018
70
Elastic fibers – wavy Also found around arteries – this is a VERY GOOD INDICATOR 9/23/2018
71
What tissue is this 9/23/2018
72
Elastic cartilage Has perichondrium and is fibrous looking 9/23/2018
73
Questions? Do not hesitate: boggusrl@email.uc.edu
THE END Questions? Do not hesitate:
Similar presentations
