Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Histology > Exam 2 > Flashcards

Exam 2 Flashcards

1
Q

General characteristics of cartilage

A

Avascular connective tissue
Typically found in areas of support (weight-bearing) and movement
Contains chondrocytes and matrix
3 subtypes - Hyalin, elastic, fibrous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Chondrocytes

A

Large rounded cells with light cytoplasm and small nucleus
Produce matrix
Inactive
Function in lipid and glycogen storage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Composition of cartilage matrix

A

Firm, high in glycosaminoglycans (GAG), and hyaluronic acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Hyalin cartilage

A

Binds bones together (i.e. in synchondrosis)
- Low friction surfaces for joints
Model for developing skeleton of the fetus (endochondral ossification) - much of the cartilage is replaced by bone, while remaining cartilage forms the epiphysial growth plate
- Matrix - firm, glassy with mostly Type II fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Why isn’t collagen detectable with H&E staining in hyaline cartilage?

A

It is present in the form of fibrils, and its refractive index is the same as the ground substance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the cavities in the matrix called?

A

Lacunae, which contain chondrocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Chondroblasts

A

Originate from mesenchymal cells
Basophilic cytoplasm, synthesize the cellular matrix
Do not aggregate into clusters
Located in growing cartilage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Isogenous groups

A

Recently divided chondrocytes are sitting in clusters in the lacunae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Territorial Matrix

A

Basophilic “capsule” around isogenous groups - high concentration of Glycosaminoglycans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Interterritorial matrix

A

Lighter matrix around the territorial matrix

- low concentration of Glycosaminoglycans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Perichondrium

A

Collagenous membrane on the surface of the cartilage
Carries vessels and nerves essential for the avascular cartilage
- destruction of perichondrium usually results in destruction of underlying cartilage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What two layers are found in perichondrium?

A

An outer fibrous layer of dense connective tissue

An inner chondrogenic layer - contains mesenchymal cells, source of chondrobalsts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

When is perichondrium not present?

A

When the cartilage contacts with bone

Articular surfaces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Elastic cartilage

A

Contains elastic fibers in the matrix in addition to ground substance
Stains with resorcin-fuchsin or orcein
Elastic properties - ear, cartilages of the larynx
Does not calcify with aging Unlike hyaline cartilage)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Fibrocartilage

A

Combination of dense regular connective tissue and hyaline cartilage
Chondrocytes are sitting in rows - isogenous groups
Large amount of collagen fibers between them
- No perichondrium
- Like a tendon, but instead of fibroblasts there are cartilage cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Appositional growth

A

A type of cartilage growth
Chondroblasts are formed by the inner layer of perichondrium - cells produce collagen type I
These produce matrix (collagen type II) and turn into chondrocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Interstitial growth

A

A type of cartilage growth

Division of chondryctes within the lacunae, forming isogenous groups

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Cartilage growth and repair

A

Appositional and interstitial growth
Very limited repair - avascular tissue, dependent on the perichondrium
Hyaline cartilage often calcifies (is replaced by bone)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

General characteristics of bone

A

Connective tissue characterized by a mineralized extracellular matrix
Functions - support, proteciton, storage site for calcium and phosphate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What does bone extracellular matrix consist of?

A

Hydroxyapatite crystals
Collagen type I, small amount of collagen V
Glycoproteins - osteocalcin, osteoectin, osteopontin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the histological components of bone?

A

Bone tissue
Hemopoietic tissue (i.e. red marrow in the epiphysis)
Fat tissue (yellow bone marrow at the shaft)
Dense connective tissue - outer fibrous layer of periosteum - Sharpey’s fibers extend into bone)
Vessels and nerves
Endosteum - covers the inner surface of the marrow cavity - osteoprogenitor or endosteal cells that differentiate into osteocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Haversian lamellae

A

Concentrical lamellae surrounding the haversian canal forming cylindrical units called Osteon or Haversian systems - axis is usually parallele with the shaft
Haversian canals contain vessels and nerves
- Connected by Volkmann’s canal
Lacunae between lamellae with osteocytes
Canaliculi penetrate lamellae with osteocytic processes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Interstitial lamellae

A

Between the osteon space is filled with old Haversian systems

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Outer circumferential lamellae

A

Line the outer surface of the bone under the periosteum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Inner circumferential lamellae

A

Lining the inner surface of the bone under the endosteum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Immature bone

A
  • In the skeleton of the developing fetus, adult alveolar sockets, tendon attachments
  • nonlamellar (woven) bone - interlacing collagen fibers
  • more cell-rich than mature bone
  • cells tend to be randomly arranged
  • matrix is less mineralized and has more ground substance than bone - thus, it stains more basophilic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Periosteum

A

Collagenous membrane on the outer surface of the bone
- carries vessels and nervs, contains nociceptors
2 layers - outer fibrous layer and inner osteogenic layer

28
Q

Endosteum

A

Membrane covering the marrow cavity

Composed mostly of osteoprogenitor cells

29
Q

Osteoprogenitor cells

A

Flattened cells that resemble fibroblasts
Basophilic cytoplasm
Location - inner layer of periosteum, endosteum (endosteal cells), line the haversian and volkmann’s canals
Capable to divide and differentiate into osteoblasts
Also can form chondroblasts, adipocytes, fibroblasts
Participate in appositional bone formation

30
Q

Osteoblasts

A

Secretory cells capable of division
Secretes collagen and ground substance that forms the initial unmineralized bone, the osteoid (light staining vs. eosinophilic calcified bone tissue)
When surrounded by osteoid - called osteocyte
Basophilic cytoplasm - lots of rER
For a single cuboidal cell layer on the surface of the growing bone, sitting on a light band of osteoid

31
Q

How is the calcification process initiated by osteoblasts?

A

Osteoblasts secrete vesicles containing alkaline phosphatase

32
Q

Osteocytes

A

Completely surrounded by osteoid or mineralized bone (lacunae)
Maintains the matrix - secretes/reabsorbs - death of osteocyte results in reabsorption of bone
- Elongated cells with numerous processes (spider shape)
Processes communicate with the neighboring cells by gap junctions and occupy the canaliculi

33
Q

What do canaliculi do?

A

Connect lacunae

34
Q

Types of osteocytes

A

Inactive (quiescent) - few organelles
Formative osteocytees - rER
Resorptive osteocytes - lysosomes

35
Q

Osteoclasts

A

Large, multinucleated acidophilic cells responsible for bone resorption
Originate from the monocytes (macrophages) of blood
Nuclei are sitting on the side of the cells farther away from the bony trabecula
- surface contacting bone forms membrane infoldings - ruffled border

36
Q

What is a Howship’s lacuna?

A

Resorption bay for osteoclast, where it rests when it’s not active

37
Q

How does the osteoclast resorb bone?

A

Probably releases organic acids (i.e. carbonic acid?) that decalcify the underlying bone
- releases lysosomal hydrolases that digest organic components

38
Q

What hormones regulate osteoclast activity?

A 
Parathyroid hormone (PTH) increases osteoclast activity
- calcitonin decreases osteoclast activity
39
Q

Intramembranous ossification

A

Mesenchymal cells aggregate and turn into osteoblasts

  • osteoblasts secrete osteoid, mineralize it, enclose themselves in lacunae, and turn into osteocytes
  • occurs in embryo skull bones and in fractures when the broken ends are very closely aligned to each other
40
Q

Endochondral ossification

A

Everything starts with a hyaline cartilage model of the bone
- perichondrium forms a bony collar around the cartilage model (appositional growth) - periosteum
Primary ossification center develops - chondrocytes in the middle of the model become hypertrophic, secrete alkaline phosphatase, and surrounding matrix undergoes ossification
- the calcified matrix inhibits diffusion of nutrients - apoptosis
- death of chondrocytes - matrix breaks down, forming a cavity

41
Q

What are the layers of enchondral ossification?

A

Zone of reserve cartilage
Zone of proliferation - cartilage cells are arranged into rows
Zone of hypertrophy
Zone of calcified cartialge
Zone of resorption - resorption of dead chondrocytes

42
Q

Golgi Stain

A
  • Developed by Camillo Golgi
  • Uses silver precipitation - once a grain of silver attaches to a neuron, the rest of the neuron plates out entirely faster than the next neuron
  • Only about 5% of the neurons are stained, which enables us to see their structure
43
Q

What are the 3 predominant types of cells in the nervous system?

A

Neurons
Neuroglia
Blood vessel cells

44
Q

Neurons

A
  • Conducting cells specialized to conduct electrical activity
  • Sensory neurons - somatic or visceral afferent
  • Motor neurons - somatic or visceral efferent
  • Interneurons - communication between sensory and motor neurons (most neurons are interneurons)
  • Terminally differentiated - rarely become cancerous
45
Q

Neuroglia

A

Supporting cells, nonconducting
Provide physical and metabolic support, electrical insulaiton, surface of the brain and ventricles, can divide and thus can become cancerous

46
Q

Multipolar Neurons

A 
Multiple poles (dendrites) coming out of the cell body
Most cells are multipolar
47
Q

Bipolar Neurons

A

2 poles coming out of cell body - dendrite and axon
Sensory
Found in retina, cochlear and vestibular ganglia

48
Q

Pseudounipolar Neurons

A

One branch coming off of cell body, but still has an axon and a dendrite
Sensory
Found in spinal and most cranial sensory ganglia

49
Q

What type of cells reside in the dorsal root ganglion?

A

Pseudounipolar sensory cells

50
Q

Types of multipolar cells

A 
Cell body size can range from 4 to 150 micrometers
Motor PNS
- Spinal and motor
Integrative PNS
- Pyramidal
- Granule Cells
Cerebellar purkinje cells
51
Q

What are the cortical layers?

A
  1. Molecular layer
  2. External granular layer
  3. External pyramidal cell layer
  4. Internal granular layer
  5. Ganglionic layer (internal pyramidal cells)
  6. Multiform (polymorphic) cell layer
52
Q

Purkinje cells

A

Primarily involved in motor coordination

53
Q

Histologically, how are neurons different from neuroglia?

A

Much larger
Nucleus is large, lightly stained (euchromatic) with a prominent nucleolus
Perinuclear cytoplasm shows Nissl bodies (rER, ribosomes, high level of metabolism) and axon hillock - are where axon is just forming outside of cell body

54
Q

Glia

A

Glia means glue; supporting cells of nervous system
PNS - schwann cells, satellite cells
CNS - oligodendroglia, astrocytes, microglia, ependyma

55
Q

Schwann cells

A

Found in peripheral nervous system

Same function as oligodendrocytes - provide the myelin found on peripheral nervous system nerves

56
Q

Satellite cells

A

Surround neuron cell bodies of spinal ganglia
Found in peripheral nervous system
Function - electrical and metabolic insulation (controlled microenvironment)

57
Q

Oligodendroglia

A

Found in central nervous system
Same function as Schwann cells: provide myelin found on neurons (in CNS)
Responsible for the “white matter” of CNS

58
Q

Astrocytes

A 
Star-shaped cells
Form blood-brain barrier
Most numerous of the glial cells
some have "end feet"
Contain GFAP (easily stained protein)
2 types: Fibrous type in white matter, protoplasmic type found in gray matter
59
Q

Microglia

A

Smallest of the glia
Phagocytic cells
Derived from bone marrow (not neural tube like all the others)

60
Q

Ependyma

A

Line the ventricles and central canal

Appear cuboidal or columnar

61
Q

Myelin Sheath

A

Formed by Schwann cells in PNS and Oligodendrocytes in CNS
Function - electrically isolates axon from the surroundings
Composed of multiple layers of cell membrane wrapped around the axon

62
Q

Dendrites

A

Receive Information

63
Q

Cell body of neuron

A

Aka perikaryon

Gray matter and ganglia

64
Q

Axon

A

Single process

Conducts signal

65
Q

Terminal arborization

A

Branches, i.e. in Purkinje cells

66
Q

End bulbs

A

Boutons

67
Q

Synapses

A

Junctions between neurons

Histology (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions