characteristics of connective tissue Flashcards
1
Q
3 components of connective tissue
A
- cells
- protein fibers
- ground substance
2
Q
what do the ground substance and the protein fibers form?
A
extracellular matrix
3
Q
what causes the diversity in connectivity tissue (2)
A
- different types and amounts of protein fibers
- varying proportions of the ground substance
4
Q
what differentiates connective tissue to epithelial tissue? (2)
A
- connective tissue aren’t in direct contact with each other
- and are randomly scattered throughout the tissue
5
Q
what are the functions of connective tissue? (3)
A
support, protect and bind organs
6
Q
what are all connective tissue derived from?
A
an embryonic connective tissue (mesenchyme)
7
Q
what are the 2 classes of cells of connective tissue proper?
A
- resident cells
- wandering cells
8
Q
4 examples of resident cells
A
- fibroblasts
- adipocytes
- mesenchymal
- fixed macrophages
9
Q
function of fibroblasts
A
produce the fibers and ground substance components of the extracellular matrix
10
Q
what are the functions of resident cells (3)
A
help support, maintain and repair the extracellular matrix
11
Q
description of adipocytes (3)
A
- fat cells
- appear in small clusters of connective tissue proper
- if large clusters of them, the connective tissue is called adipose connective tissue
12
Q
description of fibroblasts (2)
A
- flat cells with tapered ends
- most abundant in connective tissue proper
13
Q
function of mesenchymal
A
these cells will divide if the connective tissue becomes damaged
14
Q
description of mesenchymal
A
type of embryonic stem cell within connective tissue
15
Q
function of fixed macrophages (2)
A
- they phagocytize damaged cells or pathogens
- they release chemicals that will stimulate the immune system and attract numerous wandering cells to the tissue when they encounter foreign materials
16
Q
function of wandering cells (2)
A
- may help repair damaged extracellular matrix
- protect the body against harmful agents
17
Q
what are wandering cells primarily types of?
A
leukocytes (white blood cells)
18
Q
function of mast cells
A
- secrete haparin and histamine
19
Q
what does heparin do
A
inhibit blood clotting
20
Q
what does histamine do (2)
A
dilate blood vessels and increase blood flow
21
Q
description of fixed macrophages (3)
A
- large, irregular shaped cells
- derived from a type of white blood cell called monocyte
- dispersed throughout the matrix
22
Q
description of mast cells
A
- small, mobile
- usually found close to blood vessels
23
Q
when are plasma cells formed
A
when B lymphocytes are activated by exposure to foreign bodies
24
Q
function of plasma cells
A
produce antibodies
25
what are antibodies
proteins which immobilize a foreign material and prevent it from causing further damage
26
description of free macrophages
mobile, phagocytic cells that wander through the connective tissue
27
function of free macrophages
function as fixed macrophages, but mobile
28
2 other leukacytes
- neutrophils (phagocytizes bacteria)
| - T-lymphocytes (attacks that materials)
29
4 examples of wandering cells
- mast cells
- plasma cells
- free macrophages
- other leukacytes
30
function of protein fibers
strengthen and support the tissue
31
3 basic types of protein fibers found in connective tissue
- collagen fibers
- reticular fibers
- elastic fibers
32
description of collagen fibers (6)
- unbranched, 'cablelike' long protein fibers
- strong, flexible and resistant to stretching
- comprises about 25% of the body's protein
- appears white in fresh tissue (called white fibers)
- appear pink in tissue sections stained with hematoxylin and eosin
- numerous in tendons and ligaments
33
description of reticular fibers
abundant in the stroma (connective tissue framework) of organs such as the lymph nodes, spleen and liver
34
differences between collagen fibers and reticular fibers (2)
- reticular fibers are much thinner, although they are similar to collagen fibers
- they contain the same protein subunits found in collagen, but their subunits are combined in a different way
35
what protein do elastic fibers contain
elastin
36
description of elastic fibers (5)
- fibers branch and rejoin, appear wavy
- stretch and recoil easily
- fresh fibers have a yellowish colour (called yellow fibers)
- appear black when tissue sections are stained with special stains
- abundant in skin, arteries and lungs which allows them to return to their normal shape after being stretched
37
what is ground substance
noncellular material produced by fibroblasts
38
where do connective tissue cells and protein fibers reside in
ground substance
39
what are the 3 consistencies of ground substance
- viscous (blood)
- semisolid (cartilage)
- solid (bone)
40
what does the viscous nature of the extracellular matrix restrict?
the movement and spread of pathogens
41
what is GAG
glycosaminoglycans
42
what are 3 examples of GAGs
- chondroitin sulfate
- heparan sulfate
- hyaluronic acid
43
what happens when GAG is linked to a protein
it forms a larger molecule, proteoglycan
44
what is the composition of proteoglycans
>90% carbs (GAGs)
45
why do proteoglycans have a large structure
the large number of negative charges in GAGs repel each other, causing the molecule to spread
46
function of proteoglycans in connective tissue
act as glue to bond connective tissue cells and fibers to the ground substance
47
functions of connective tissue (6)
- physical protection
- support and structural framework
- binding of structures
- storage
- transport
- immune protection
48
what are the 2 types of embryonic connective tissue
- mesenchyme
| - mucous
49
what is mesenchyme connective tissue
the first type of connective tissue to emerge in the developing embryo
50
what are the three connective tissue types
- connective tissue proper
- supporting connective tissue
- fluid connective tissue
51
what are the 3 types of loose connective tissue
- areolar
- adipose
- reticular
52
what are the 3 types of dense connective tissue
- denser regular
- dense irregular
- elastic
53
what are the 2 types of connective tissue proper
- loose connective tissue
| - dense connective tissue
54
what are the 2 types of supporting connective tissue
- cartilage
| - bone
55
what are the 3 types of cartilage
- hyaline
- fibrocartilage
- elastic
56
what are the 2 types of bone
- compact
| - spongy
57
what are the 2 types of fluid connective tissue
- blood
| - lymph
58
what are the differences between loose and dense connective tissue
- loose has fewer fibers and more ground substance
| - dense has more fibers and less ground substance
59
what is the predominant cell of areolar connective tissue
fibroblast
60
where can areolar connective tissue be found (3)
- in the skin (papillary layer of the dermis)
- in the subcutaneous layer that is deep to the skin
- surrounds organs, some individual nerve and muscle cells and blood vessels
61
function of areolar connective tissue (2)
- binds skin and some epithelia to deeper tissue
| - protects and surrounds organs, some individual nerve and muscle cells and blood vessels
62
functions of adipose connective tissue (4)
- stores energy
- insulates
- cushions
- protects
63
locations of adipose connective tissue (2)
- subcutaneous layer
| - surrounds and covers some organs
64
function of reticular connective tissue
provides stroma (supportive framework) to lymphatic organs
65
locations of reticular connective tissue (3)
- spleen
- lymph nodes
- red bone marrow
66
what are the 2 types of adipose connective tissue
- white
| - brown
67
where is brown adipose connective tissue found?
- in newborns
68
why is dense connective tissue known as collagenous tissue
collagen fibers are the dominant fiber type
69
what does dense regular connective tissue have few of
blood vessels, so it takes a long time to heal following an injury
70
functions of dense regular tissue (3)
- attach bone to bone (most ligaments)
- attach muscle to bone (tendons)
- resists stress applied in one direction
71
location of dense regular tissue (2)
- tendons
| - ligaments
72
function of dense irregular tissue
withstands stresses applied in all directions - durable
73
location of dense irregular tissue (6)
- most of dermis of skin
- periosteum covering bone
- perichondrium covering cartilage
- epineurium (sheath covering nerves)
- epimysium (sheath covering skeletal muscle)
- some organ capsules (liver, kidneys and spleen)
74
function of elastic connective tissue
allows for stretching and recoil
75
location of elastic connective tissue (3)
walls of arteries (aorta), trachea and vocal chords
76
what is elastic connective tissue composed of
numerous fibroblasts among densely packed elastic fibers
77
what is dense irregular connective tissue containing
bundles and clumps of collagen fibers that extend in all directions and has an extensive blood supply between the collagen fibers
78
what does dense regular connective tissue contain
few fibroblasts and limited ground substance, abundant collagen fibers packed tightly and aligned parallel to each other
79
what does cartilage consist of
a firm, semisolid extracellular matrix that contains variable amounts if collagen and protein fibers
80
what are mature cartilage cells called
chondrocytes
81
what are the small spaces within the extracellular matrix called
lacunae
82
is mature cartilage vascular
no its avascular
83
how do chondrocytes exchange nutrients and waste products
by diffusion with blood vessels outside the cartilage
84
what is the most common type of cartilage
hyaline cartilage
85
what sort of appearance does hyaline cartilage have
clear, glassy
86
how do chondrocytes and collagen appear in hyaline cartilage
irregularly scattered chondrocytes and collagen within the extracellular matrix not readily observed by light microscopy
87
functions of hyaline cartilage (2)
- provides support
| - forms most of fetal skeleton
88
locations of hyaline cartilage (6)
- tip of nose
- trachea
- most of larynx
- costal cartilage
- both of the epiphyseal plates and articular ends of long bones
- most of fetal skeleton
89
functions of fibrocartilage (2)
- resists compression
| - acts as a shock absorber in some joints
90
locations of fibrocartilage (3)
- intervertebral discs
- pubic symphysis
- menisci of knee joints
91
functions of elastic cartilage
maintains shape while permitting extensive flexibility
92
locations of elastic cartilage (2)
- external ear
| - epiglottis of larynx
93
what contributes to the durability of fibrocartilage
the densely interwoven collagen fibers
94
what sort of cartilage is fibrocartilage
a weight-bearing cartilage
95
what sort of cartilage is elastic cartilage
a flexible, springy cartilage
96
what differentiates elastic cartilage and elastic connective tissue
- elastic cartilage has a semisolid ground substance and contains chondrocytes
- elastic connective tissue has a fluid ground substance formed by fibroblasts
97
description of bone connective tissue
makes up most of bones and is more solid than cartilage and provides greater support and not as flexible
98
what are the organic components of extracellular matrix of bone connective tissue
collagen and glycoproteins
99
what are the inorganic components of the extracellular matrix of bone connective tissue
a mixture of calcium salts, primarily calcium phosphate
100
what are bone cells called
osteocytes
101
what are the two forms of bone tissue
- compact bone
| - spongy bone
102
what are osteons
cylindrical structures which display concentric rings of bone connective tissue (lamellae)
103
functions of bone (5)
- provides levers for body movement
- supports soft structures
- protects organs
- stores calcium and phosphorus
- spongy bone contains hemopoietic tissue and is the site for hemopoiesis
104
what is blood
a fluid connective tissue composed of formed elements (inc. cells, erythrocytes and leukocytes, cellular fragments (platelets))
105
functions of blood (5)
- erythrocytes transport respiratory gases (O2 and CO2)
- leukocytes help protect the body from infectious agents
- platelets help with blood clotting
- dissolved protein fibers coalesce and assist with blood clotting
- plasma transport nutrients, wastes and hormones throughout the body
106
location of blood
- primarily within blood vessels and in the heart
107
what is lymph derived from
blood plasma but it contains no cellular components or fragments
