Chapter 4 Flashcards
(138 cards)
1
Q
All tissues share 2 basic components. What are they?
A
-discrete population of cells related in stucture and function
-surrounding material (ECM) differs in composition in each tissue type
2
Q
what does ecm stand for
A
extracellular matrix
3
Q
what is the ecm
A
the surrounding material/area between cells
4
Q
what is histology
A
study of normal structure of tissues
5
Q
what is a tissue
A
group of cells w the same function
6
Q
what are the 4 primary types of tissues
A
- epithelial
- connective
- muscular
- nervous
7
Q
what are epithelial tissues
A
- skin
- sheets of tightly packed cells
- little ecm
- covers and lines body surfaces and cavities
- forms parts of glands
8
Q
what are connective tissues and what are it’s purposes
A
- connect all tissues together
- scattered through the ecm
- bind, support, protect
- allow transport of substances
9
Q
what are muscular tissues
A
- cells contract and generate force
- little ecm
10
Q
what are nervous tissues
A
- cells (neurons) generate, send, recieve messages (electrical impulses)
- includes cells that support the neurons with some ecm
11
Q
what does the ecm do
A
- provide tissue w strength to resist tensile and compressive forces
- direct cells to their proper places w/in a tissue
- regulate development, mitotic activity, and survival of cells
- hold cells in their proper positions
12
Q
ecm has 2 main components
A
- ground substance
- protein fibers
13
Q
what is the ground substance of the ecm
A
gel like substance contains extracellular fluid (ECF) with:
- water
- ions
- nutrients
- solutes
- 3 families of macromolecules
14
Q
What are the families of macromolecules in ground substance of ecm
A
- glycosaminoglycans (GAGs)
- proteoglycans
- glycoproteins
15
Q
what are glycosaminoglycans (GAGs)
A
are carbohydrate polymers that attract water and form a gel-like substance in the ECM, providing hydration and cushioning (ex. Hyaluronic Acid).
16
Q
what are proteoglycans
A
large molecules with GAG chains attached to a core protein, contributing to tissue structure, cell signaling, and ECM organization. Act as a barrier to diffusion of substances through the ECM (ex. Aggrecan).
have protein
17
Q
what are glycoproteins
A
are proteins with carbohydrate chains that play roles in cell adhesion, matrix formation, and signaling (ex. Fibronectin).
18
Q
what are protein fibers
A
- entwined fibrous protein subunits that provide tensile strength
- 3 types in the ecm
19
Q
types of protein fibers in ecm
A
- collagen fibers
- elastic fibers
- reticular fibers
20
Q
what are collagen fibers
A
- at least 20 types made in body
- make up 20-25% of all protein in body
- resemble entwined pieces of a steel cable
- very resistant to ** tension and pressure**
21
Q
what are elastic fibers
A
- made of elastin protein surrounded by glycoproteins
- may stretch up to 1/2 times their resting length without breaking and return to their original length
22
Q
what is distensibility
A
ability to stetch without breakingw
23
Q
what is elasticity
A
ability to return back to its original length after being stretched
24
Q
what are reticular fibers
A
- type of collagen fiber that is thinner and shorter than regular collagen
- interweaves to form a scaffold that supports the cells and ground substance of tissues
- form “webs” in some organs to trap foreign cells
25
what are cell junctions
connections of neighbouring cells in a tissue linked together by integral proteins
26
what are the types of cell junctions
- tight (occluding) junctions
- desmosomes
- gap junctions
27
what are occluding junctions
- junctions composed of integral "locking" proteins in adjacent plasma membranes
- prevents passage of macromolecules
- some are leaky and don't provide a complete seal
28
what are desomosomes
- junctions composed of integral "linker" proteins in adjacent plasma membranes
- distribute mechanical stress
29
what are gap junctions
- small pores made of protein channels in adjacent plasma membranes
- allow small substances to pass freely
30
epithelial tissue acts as a ___________ between the _________ and the __________
barrier between the body and the environment
31
main functions of eithelial tissue
- protection
- immune defences
- secretion
- transport into other tissues
- sensation
32
protection - epithelial tissue
- continuous surface that sheilds underlying tissue from mechanical and thermal injury
- produce hard protein keratin
- undergoes mitosis rapidly and frequently
33
immune defences - epithelial tissue
cells of the immune system are scattered through the epithelial tissues
34
secretion - epithelial tissue
form glands that produce substances such as sweat, oil, and hormones
35
transport into other cells - epithelial cells
selectively permeable barriers that allow certain substances to pass by passive or active transport
36
sensation - epithelial tissue
- most epithelia are supplied with nerves that detect changes in the internal and external environments
- specialized epithelia cells are responsible for some sensations
37
components of epithelia
- basement membrane
- basal lamina
- reticular lamina
38
apical surface
side of epithelial cells in contact with extracellular space
39
basal surface
side of epithelial cells in contact with deeper cells
40
what is the basement membrane
anchors the epithelial tissue to the underlying connective tissue with 2 components
41
2 components of basement membrane
- basal lamina
- reticular lamina
42
what is the basal lamina
- 1/2 components of basement membrane of epithelial cells
- the ecm of the epithelial tissue
- consists of collagen fibers and ground substance
43
what is the reticular lamina
- 1/2 components of basement membrane of epithelial cells
- manufactured by the connective tissue deep to the epithelial tissue
- consists of reticular fibers and ground substance
44
types of epithelia based on number of cells
- simple
- stratified
- pseudostratified
45
simple epithelia
- single layer of cells
- does not work for protection
- lines hollow organs and surfaces where diffusion or transport occurs
46
stratified epithelia
-more than one layer of cells
- Thicker than simple epithelia
- Effective protective barriers, so common in areas of high stress
- Cell shape changes throughout the thickness of the tissue, so named according to the shape in their apical layers
47
pseudostratified epithelia
single layer of cells that appears to be multilayered
48
types of epithelial cells based on shape
- squamous
- cuboidal
- columnar
49
squamous cells
-flattened cells
50
flattened cells
squamous
51
cuboidal cells
short cells
52
short cells
cuboidal
53
columnar cells
tall and elongated cells
54
tall and elongated cells
columnar
55
simple squamous epithelia
- single layer of flat cells
- resemble fried eggs that fit together like floor tiles
- diffusion occurs quickly across
- found in air sacs of lungs, serous membranes, and lining of blood vessels
56
simple cuboidal epithelia
- single layer of roughly cube shaped cells
- appear square w a large central nucleus
- diffusion occurs and some secrete substances
- found in kidney tubules and glands
57
simple columnar epithelia
- single layer of tall cells
- appear rectangular in a section
- some have folds of the apical surface
- some have cilia which move something along the apical surface
- some produce secretions
- found in small intestine, uterine tube, kidney tubules and glands
58
pseudostratified columnar epthelia
- Single layer of cells that appears to be stratified
- Looks this way because nuclei are at different heights and some cells are shorter
- Most are ciliate
- Include goblet cells that secrete mucus
- Found in respiratory passages and nasal cavities for protection
59
stratified squamous epithelia
- Nonkeratinized stratified
squamous epithelia has distinct nucleated cells on the apical surface
- Found in epithelium of mouth, pharynx, esophagus,
anus, and vagina
60
Stratified Cuboidal Epithelia
- Rare in the human body
- Two layers of cuboidal cells
- Lines the ducts of sweat glands
61
Stratified Columnar Epithelia
- Rare in the human body
- Few layers of cells that are columnar in apical layers and cuboidal in basal layers
- Found in ducts of salivary glands, parts of male urethra, and the conjunctiva (membrane lining the surface of the eye)
62
transitional epithelia
- Cells in the basal layer are cuboidal and apical cells are dome-shaped when the tissue is relaxed
- When stretched, apical cells appear squamous
- Found in lining of kidneys, ureters, urinary bladder, and urethra
63
connective tissue functions
- connecting and binding
- support
- protection
- transport
64
connecting and binding - connective tissue
Bind tissue layers together in organs and anchor organs in place and to one another
65
support - connective tissue
Certain connective tissues, such as bone and cartilage, support the weight of the body
66
protection - connective tissue
Bone protects internal organs
- Cartilage and fat tissue provide shock absorption
- Elements of the immune system are found within connective tissues
67
transport - connective tissue
Blood, which is the main transport medium in the
body, is a type of connective tissue
68
types of connective tissue
- general
- specialized
69
general connective tissue aka
connective tissue proper
70
general connective tissue
- widely distributed in the body
- it connects tissues and organs to one another
- forms part of the internal architecture
71
types of general connective tissue
- loose
- dense
- reticular
- adipose tissues
72
types of specialized connective tissue
- cartilage
- bone
- blood
73
cells that form general connective tissue
- fibroblasts
- adipocytes
- mast cells
- phagocytes
- other immune cells
74
what are fibroblasts
- produce protein fibers, ground substance, and other ECM elements
- usually lie close to collagen fibers that they produce
75
what are adipocytes
fat cells w single large inclusion that contains lipids w organelles pushed to the perimeter
76
what are mast cells
Cells of the immune system with cytosolic
inclusions (or granules) containing inflammatory mediators
such as histamine
77
what are phagocytes
Immune cells that phagocytize foreign
substances, microorganisms, and dead and damaged
cells; Includes macrophages and neutrophils
78
loose connective tissue aka
areolar connective tissue
79
what is areolar connective tissue
Ground substance
with all 3 types of protein fibers, fibroblasts, and other cells
including immune cells
- Jelly-like consistency
- Found deep to
the epithelium of the skin and in membranes
- Supports and
houses blood vessels
80
what is dense irregular connective tissue
Composed of protein
fibers with mostly collagen fibers that are arranged
haphazardly;
- Strong tissue that resists tension in all 3
planes
- Found in dermis and around organs and joints
81
what is dense regular collagenous connective tissue
- Contains thick collagen fibers arranged in parallel bundles
- Resist tension in one direction;
- Found in tendons (which join
muscle to bone) and ligaments (which join bone to bone)
82
what is dense regular elastic connective tissue
- Also known as
“elastic tissue;”
- Consists of mostly parallel elastic fibers with
randomly oriented collagen fibers;
- Allow organs to stretch;
- Found in the lining of the large blood vessels and some
ligaments
83
what is reticular tissue
- Includes numerous reticular
fibers(typically collagenous fibers) produced by surrounding
fibroblasts;
- Form fine, meshlike networks for support and
weblike nets that trap foreign cells;
- Forms part of basement
membrane
84
what is adipose tissue
- Fat tissue consisting of adipocytes and
surrounding fibroblasts and ECM;
- Adipocytes can increase in
size;
- Functions in insulation, warmth, shock absorption,
protection, and energy reserve
85
what is cartilage
* Tough, flexible tissue that absorbs shock and is resistant
to tension, compression, and shearing forces
* EC M is solid and gel-like with glycosaminoglycans,
proteoglycans, collagen fibers, and elastic fibers
* Chondroblasts—Immature cartilage cells
* Chondrocytes—Mature cartilage cells, which live in small
cavities called lacunae
* Surrounded by an outer sheath of dense irregular
connective tissue called the perichondrium, which supplies blood to
the cartilage
86
what are chondroblasts
immature cartilage cells
87
what are chondrocytes
- mature cartilage cells
- live in small cavities called lacunae
88
what are the small cavities where chondrocytes live
lacunae
89
what are lacunae
the small cavities where chondrocytes live
90
cartilage is surrounded by ...
an outer sheath of dense irregular
connective tissue called the perichondrium
91
how does cartilage recieve blood
the perichondriumm
92
what is the perichondrium
an outer sheath of dense irregular connective tissue which supplies blood to the cartilage
93
what does bone do
Supports the body, protects vital organs, provides
attachment sites for muscles, stores calcium salts, and
houses bone marrow, which produces our red blood cells
and stores fat
94
what are the types of bone cells
- osteoblasts
- osteocytes
- osteoclasts
95
what are osteoblasts
Carry out bone deposition
96
what are osteocytes
Mature osteoblasts that are surrounded by
EC M; Produce substances for bone maintenance
97
what are osteoclasts
Multinucleated cells that carry out bone
resorption (break down)
98
what is bone remodeling
Bone deposition and bone
resorption are constantly occurring in healthy bone
99
what is the ecm like in blood
- fluid
- called plasma
- water, solutes, globular proteins
100
cells in blood
- erythrocytes
- leukocytes
- platelets
101
what are erythrocytes and what do they do
- red blood cells
- carry oxygen
102
what are leukocytes and what do they do
- white blood cells
- function in immunity
103
what are platelets and what do they do
- blood cell fragments
- function in blood clotting
104
muscle cells aka
myocytes
105
myocytes aka
muscle cells
106
what are myocytes
- excitable cells that respond to electrical or chemical stimulation;
- Cytoplasm is filled with bundles of proteins called Myofilaments;
- Surrounded by a small amount of EC M called Endomysium
107
types of muscle cells
- striated muscle cells
- smooth muscle cells
108
striated muscle cells
Myofilaments are organized into
regions that produce dark and light areas called “bands;”
Alternating light-dark bands are called Striations
109
smooth muscle cells
Myofilaments are in irregular bundles scattered in the cytoplasm so no striations are visible
110
what are myofilaments
bundles of protein in cytoplasm of muscle tissue
111
ecm of muscle tissue
endomysium
112
types of muscle tissues
- skeletal
- cardiac
- smooth
- nervous
113
skeletal muscle tissue
Found attached to the skeleton to
produce body movement; Controlled by the nervous system;
Typically voluntary movements; Formed by the fusion of
embryonic myoblasts resulting in large, multinucleate cells
(also called Muscle Fibers)
114
What is cardiac muscle tissue
- Found only in the heart;
- Involuntary contractions;
- Shorter than skeletal muscle cells with branches and a single nucleus;
- Intercalated discs, which
contain gap junctions and tight junctions, are found between
cells and permit heart muscle to contract as a unit
115
smooth muscle tissue
Found in the walls of hollow organs, walls
of blood vessels, the eyes, the skin, and the ducts of some
glands; Involuntary contractions; Cells are flattened, with a
single nucleus; Gap junctions in the plasma membrane
connect cells to other smooth muscle cells
116
nervous tissue
Makes up majority of the brain, spinal
cord, and nerves; EC M is different from other tissues and
contains few protein fibers but is mostly ground substance
with unique proteoglycans
117
cells of nervous tissue
- neurons
- neuroglial cells
118
neuroglial cells
Supportive cells that anchor neurons and
blood vessels in place, speed up the rate of nerve impulse
transmission, and circulate fluid around the brain and spinal
cord
* Neuroglial cells can divide by mitosis
119
neurons
Generate,
conduct, and receive nerve
impulses (electrical
signals); Include 3 main
parts; amitotic
120
main parts of a neuron
- cell body
- axon
- dendrites
121
cell body of neuron
Large center with
the nucleus and
organelles
122
What does the axon of a neuron do
Moves impulse to
the target cell
123
dendrites of a neuron
Arms that receive
messages
124
What is tissue repair
Process of wound healing; Occurs
differently in different tissues and is dependent on the tissues
ability to regenerate
125
types of tissue repair
- regeneration
- fibrosis
126
regeneration
Damaged or dead cells are replaced with cells of the
same type
127
fibrosis
Fibroblasts divide by mitosis and produce collagen to
fill in the defect left by the injury; Results in Scar Tissue,
which is dense irregular connective tissue
128
what is scar tissue
dense irregular connective tissue as a result of fibrosis
129
conditions favouring regeneration
- cell type
- extent of damage
- presence of stem cells
- minimal scarring
130
conditions leading to fibrosis
- severe injury
- chronic inflammation
- lack of regenerative capacity
- disruption of ecm
131
regeneration - cell type
Tissues with high regenerative capacity, such as epithelial tissues (skin, gastrointestinal lining) and some connective tissues (liver, bone), are more likely to regenerate.
132
regeneration - extent of damage
Regeneration is more likely when the damage is not extensive and the tissue architecture is minimally disrupted.
133
regeneration - presence of stem cells
Tissues with abundant stem cells or progenitor cells can regenerate effectively. For example, skin and liver tissues have significant regenerative potential due to their stem cell populations
134
regeneration - minimal scarring
When the underlying extracellular matrix (ECM) is intact and not excessively damaged, regeneration can occur with less fibrosis.
135
fibrosis - severe injury
Extensive damage to tissue structure and the ECM can make regeneration difficult, leading to fibrosis.
136
fibrosis - chronic inflammation
Prolonged or chronic inflammation can lead to excessive deposition of collagen and other ECM components, resulting in fibrosis.
137
fibrosis - lack of regenerative capacity
Some tissues, such as cardiac muscle or nervous tissue, have limited regenerative capacity and are more prone to fibrosis following injury.
138
fibrosis - disruption of the ecm
Significant damage to the ECM can interfere with the ability of tissues to regenerate normally, favoring scar formation instead.
