CH 4: Tissue Level Flashcards
1
Q
tissue
A
integrated group of similar cells that usually have a similar embryological origin and are specialized for a specific function
2
Q
cell junctions - definition
A
point of contact between adjacent cells - cells can be attached together or to the basement membrane or to the connective tissue
3
Q
cell junctions - functions
A
- anchor cells together or to extracellular material (adherens junctions, desmosomes, hemidesmosomes)
- form fluid-tight seals between cells (tight junctions)
- act as channels that allow ions and molecules to pass from cell to cell (gap junctions)
4
Q
CAMs
A
cell adhesion molecules: are transmembrane proteins that bind to each other and to the cytoskeleton
5
Q
adherens junctions - structure
A
transmembrane integral proteins are attached to microfilaments in the cytoskeleton and to the integral membrane proteins of the other cell
made of:
- plaque: dense layer of proteins inside the cell membrane
- cadherins (integral membrane proteins): connect cell to cell
- microfilaments: anchor the cadherin in each cell forming adhesion belts
6
Q
adherens junctions - function
A
hold cells together
ex. join epithelial cells together
7
Q
desmosomes - structure
A
similar to adherens junctions, except that cadherins are anchored by intermediate filaments which cross the cytoplasm from one side of the cell to the othere
8
Q
desmosomes - function
A
prevent separation of cells
ex. prevent separation of epidermal cell and cardiac muscle cells under tension
9
Q
hemidesmosomes - structure
A
half a desmosome
transmembrane proteins are attached to intermediate filaments + the integrin (anchor protein) links to the protein laminin in the basement membrane
10
Q
basal lamina - structure
A
=basement membrane
- thin layer of connective tissue underlying eputhelial tissue
- thin acellular extracellular membrane made of 2 layers:
- basal lamina: secreted by epithelial cells and composed of collagen fibers, laminin, various glycoproteins and proteoglycans
- reticular lamina: secreted by connective tissue cells and composed of reticular fibers
11
Q
tight junctions - structure
A
the two plasma membranes are tightly fused together by interlocking membrane proteins
12
Q
tight junctions - function
A
prevent passage of fluids (including water) across a tissue layer
13
Q
tight junctions - location
A
line GI tract and bladder
14
Q
gap junctions - structure
A
formed by channel proteins called connexins (two connexins=connexon) that span the membrane of two cells
it’s a tiny space between the plasma membranes of two cells
15
Q
gap junctions - function
A
allow for passage of ions and small molecules between cells, enabling cells to communicate
16
Q
gap junctions - location
A
in heart and smooth muscle of the gut
- gap junctions in the heart allow the cardiac muscle cells to beat in sync
17
Q
tissue types
A
- epithelial
- muscle
- connective
- nervous
18
Q
epithelial tissue - purpose
A
- covers and lines surfaces
- provides selective barriers for movement of material
ex. barrier btw body and environment (skin, gut)
ex barrier btw different structures (blood vessels)
- provides protection from damage/abrasion
- absorbs nutrients (gut) - forms secretion portions of glands
- produces mucus, hormones and enzymes
19
Q
epithelial tissue - structure
A
- cells closely packed together (with cell junctions) with intracellular space
- cells sit on basement membrane
- consists of apical surface and basal surface
1. high rate of cell turnover/cell regeneration
2. has its own good nerve supply
3. avascular: relies on diffusion from blood blood vessels withing connective tissue from removal of waste and nutrient delivery
20
Q
basement mebrane - function
A
attachment and support for epithelial tissue
21
Q
apical surface
A
“free” surface - epithelial tissue
- region exposed to space inside the organ or lumen
22
Q
basal surface
A
adheres to basement mebrane - epithelial tissue
23
Q
basal lamina
A
layer of basement mebrane
- secreted by epithelial cells
- composed of collagen fiber, laminin, various glycoproteins and proteoglycans
24
Q
reticular lamina
A
layer of basement membrane
- secreted by connective tissue
- composed of reticular fibers
25
epithelial cells - features
- microvilli: increase SA (digestive, urinary and reproductive tracts)
- cilia: found in portions of the respiratory and reproductive tracts
- apical surface: region exposed to space inside the organ and lumen
- basal surface: attaches to underlying epithelial cells or deeper tissues
26
epithelial tissue - classification
- number of cell layers
| - shape of cells
27
epithelial tissue - classification based on number of cell layers
- simple
- pseudostratified
- stratified
28
simple (epithelial tissue)
have single layer of cells
29
pseudostratified (epithelial tissue)
have single layer but irregular cell shape and nucleus
30
stratified (epithelial tissue)
have at least two layers of cells
| - basal cells replicate by mitosis and replace more superficial layers
31
epithelial tissue - function
structure determines function
1. material exchange
- simple squamous epithelium
2. secretion and absorption of material
- simple cuboidal epithelium
- simple columnar epithelium
3. protection
- stratified squamous epithelium
- pseudostratified ciliated columnar epithelium
32
simple squamous epithelium
- single layer of flat cells
- thin: adapted for diffusion (lungs, blood, lymph vessels) and filtration (kidneys)
- specific name in some organs:
- endhothelium: lines blood vessels
- endocardium: lines chambers of heart
- mesothelium: lines serous membranes
33
simple squamous epithelium - function
- diffusion (lungs, blood, lymph vessels)
| - filtration (kidneys)
34
endothelium
simple squamous epithelim that lines blood vessels
35
endocardium
simple squamous epithelium that lines chambers of the heart
36
mesothelium
simple squamous epithelium that lines serous membranes
37
stratified squamous epithelium - structure
two or more layers of cells
- apical cells are flat
can be keratinized and non-keratinized
38
non-keratinized stratified squamous epithelium - location
lines moist surfaces:
- mouth
- esophagus
- part of epiglottis
- part of pharynx
- vagina
39
keratin
tough, fibrous intracellular protein found in skin, hair and nails
40
keratinized stratified squamous epithelium - location
superficial layer of skin
41
simple cuboidal epithelium - structure
one layer of cube-shaped cells
| - nucleus: round and centered
42
simple cuboidal epithelium - function
absorption and secretion
43
simple cuboidal epithelium - location
lines kidney tubules, thyroid gland
44
stratified cuboidal epithelium- structure
two or more layers of cells
| - cells in apical layer are cube-shaped
45
stratified cuboidal epithelium- location
in some ducts:
- sweat glands
- male urethra
- esophageal ducts
46
simple columnar epithelium - structure
single layer of column-shaped cells
| - oval nuclei usually located near the base of cells
47
simple non-ciliated columnar epithelium - structure
contain microvilli at apical surface and goblet cells (secrete mucus)
48
goblet cells - function
secrete mucus
49
simple non-ciliated columnar epithelium - function
secretion and absorption
50
simple non-ciliated columnar epithelium - location
mucus secretion lubricates:
- GI
- respiratory
- reproductive
- urinary systems
51
simple ciliated columnar epithelium - structure
single layer of column-shaped cells with cilia on apical surface
- nucleus: oval, located near the base of the cell
usually contain interspersed goblet cells
52
simple ciliated columnar epithelium - function
cilia beat in unison to move fluid, mucus and/or foreign particles
53
simple ciliated columnar epithelium - location
line:
- bronchioles
- uterine tubes
- paranasal sinuses
- central canal of the spinal cord
- brain
54
pseudostratified columnar epithelium - structure
- single layer of columnar cells
- appears layered because nuclei are at different levels
- all cells are attached to the basement membrane
- not all cells reach the apical layer
55
pseudostratified columnar non-ciliated epithelium - structure
lacks goblet cells
| no cilia
56
pseudostratified columnar non-ciliated epithelium - location
lines epididymis, ducts of larger glands and parts of male urethra
57
pseudostratified columnar non-ciliated epithelium - function
absorption and secretion
58
pseudostratified ciliated columnar epithelium - structure
contain cells with cilia or goblet cells (secrete mucus)
59
pseudostrlatified ciliated columnar epithelium - location
lines airways of upper respiratory tract
60
pseudostratified ciliated columnar epithelium - function
secretion and protection
61
stratified columnar epithelium - structure
- has at least two layers of cells
- apical layer has column-shaped cells
- cells in other layers can be short or irregularly shaped
62
stratified columnar epithelium - location
lines part of the urethra, esophageal and salivary gland ducts
63
stratified columnar epithelium - function
protection and secretion
64
transitional epithelium - structure
variable/transitional appearance
- relaxed state: looks like stratified cuboidal epithelium but has large and round apical cells
- stretched state: looks like stratified squamous epithelium as cells flatten
65
relaxed state
of transitional epithelium: looks like stratified cuboidal epithelium but has large and round apical cells
66
stretched state
of transitional epithelium: looks like stratified squamous epithelium as cells flatten
67
transitional epithelium - location
lines urinary bladder and portions of ureters and urethra
68
transitional epithelium - function
protection and ability to stretch within
69
grandular epithelium
- exocrine glands
| - endocrine glands
70
exocrine glands - function
cells that secrete a product (mucus, sweat, ear wax, saliva, digestive enzymes, ...) onto the free surface of the epithelial layer
- connected to surface by ducts (tubes)
71
exocrine glands - examples
- goblet cells
- sudoriferous
- sebaceous
- salivary glands
72
endocrine glands - function
secrete hormones into the interstitial fluid followed by diffusion to the bloodstream
73
endocrine glands - examples
- pituitary
- adrenal
- thyroid gland
74
glands that are both endocrine and exocrine
- pancreas
- ovaries
- testes
75
exocrine glands - structure
- has a duct
- free surface
- multiple layers
can be:
- unicellular - goblet cells
- multicellular: composed of many cells that form a distinctive microscopic structure or macroscopic organ - sweat glands, sebaceous glands, salivary glands
76
endocrine glands - structure
- thinner layer
| - big "blob" of stored hormone
77
unicellular exocrine glands - example
goblet cells
78
multicellular exocrine glands - examples
- sweat glands
- sebaceous glands
- salivary glands
79
exocrine glands - grandular secretion classification
- merocrine glands
- apocrine glands
- holocrine glands
80
exocrine glands - function
secretion via exocytosis
81
merocrine glands - function
- mero = part
| - discharge secretory product by exocytosis
82
merocrine glands - examples
- salivary glands
- pancreas glands
- digestive enzymes
- sweat glands
83
apocrine glands - function
- apo = away from
- accumulate secretory product at the apical surface
- apical surface of the cell pinches off from the cell to form the secretion
- the remaining part of the cell reapirs itself and the process repeats
84
apocrine glands - examples
mammary glands
85
holocrine glands - function
- holo = entire
- cells accumulate products, die and rupture to release product
- dead cells are replaced by new ones
86
holocrine glands - examples
sebaceous glands
87
connective tissue - characteristics
- made up of cells scattered in ECM
- cells rarely touch each other due to matrix
- structure of ECM determines the tissue's characteristics
- very abundant and widely distributed
- good nerve and blood supply except in cartilage and tendons
- no free surfaces
88
ECM
composed of protein fibers and ground substance secreted by connective tissue cells
89
ECM structure determining connective tissue function
- solid, liquid or somewhere in between (gel)
| - hard (like bone) or firm and pliable (cartilage)
90
connective tissue cells - origin
from mesenchyme
91
mesenchyme - definition
embryonic connective tissue composed of mesenchymal cells
92
connective tissue - constituent cells
- blast: immature cells that retain the ability to divide and produce matrix
- ex. fibroblast, chondroblast, osteoblast
- cyte: mature cells that cannot divide or produce matrix
- ex. chondrocyte, osteocyte
93
- blast
- constituent cells of connective tissue
- immature cells that retain the ability to divide and produce matrix
- ex. fibroblast, chondroblast, osteoblast
94
- cyte
- constituent cells of connective tissue
- mature cells that cannot divide or produce matrix
- ex. chondrocyte, osteocyte
95
fibroblasts
- large flat cells
| - move through tissue secreting fibers and ground substance
96
macrophages
- develop from monocytes
| - engulf microorganisms and cell debris by phagocytosis
97
plasma cells
- develop from B lymphocytes
| - produce antibodies that fight against foreign substances
98
neutrophils and eosinophils
- specialized leukocytes
- not common in normal connective tissue
- contain toxic molecules and enzymes to fight off invaders
99
neutrophils
migrate to sites of bacterial invasion and destroy microbes by phagocytosis
100
eosinophils
migrate to sites of parasitic invasion
101
mast cells
- found along blood vessels in connective tissue
| - produce histamine that causes dilation of small blood vessels
102
adipocytes
- found subcutaneously and around organs
| - fat storage and protection
103
constituent cells of connective tissue - list
1. fibroblasts
2. macrophages
3. plasma cells
4. neutrophils
5. eosinophils
6. mast cells
7. adipocytes
104
ECM - components
1. cells
2. fibers
3. ground substance
105
connective tissue - types of fibers
all made up of proteins
1. collagen fibers
2. reticular fibers
3. elastic fibers
106
collagen fibers
- made from protein collagen
- found in most connective tissue
- often occurs in parallel bundles
- very strong but flexible
- ex. bone, cartilage, tendons and ligaments
107
collagen fibers - location
- bone
- cartilage
- tendons
- ligaments
108
reticular fibers
- thin, branched fibers of collagen in fine bundles, with coating of glycoproteins
- function: provide support for blood vessels and soft organs
- ex. spleen, lymph nodes
- form part of the basement membrane
109
reticular fibers - function
provide support for blood vessels and soft organs
110
reticular fibers - location
- spleen
| - lymph nodes
111
elastic fibers
- smaller diameter fibers made of protein elastin surrounded by glycoprotein fibrillin
- branch and join to form networks of fibers
- can stretch up to 150% or relaxed length and then return to its original shape - elasticity
- ex. lungs, blood vessels, skin
112
elastic fibers - function
elasticity: can stretch up to 150% or relaxed length and then return to its original shape
113
elastic fibers - location
- lungs
- blood vessels
- skin
114
ground substance
- material between cells and fibers
- determines consistency of connective tissue
- can be liquid, semiliquid or calcifies
- supports cells, holds cells together, stores water, and allows for migration, transport of molecules and chemical reactions
- contains water and large organic molecules (combinations of proteins and polysaccharides)
115
ground substance - function
- determines consistency of connective tissue
- can be liquid, semiliquid or calcifies
- supports cells, holds cells together, stores water, and allows for migration, transport of molecules and chemical reactions
116
classification of connective tissue
- connective tissue proper
- loose connective tissue
- areolar
- adipose
- reticular
- dense connective tissue
- dense regular
- dense irregular
- elastic
- supporting connective tissue
- cartilage
- hyaline cartilage
- fibrous cartilage
- elastic cartilage
- bone tissue
- compact bone
- spongy bone
- liquid connective tissue
- blood
- lymph plasma
117
classification of proper connective tissue
- loose connective tissue
- areolar
- adipose
- reticular
- dense connective tissue
- dense regular
- dense irregular
- elastic
118
classification of supporting connective tissue
- cartilage
- hyaline cartilage
- fibrous cartilage
- elastic cartilage
- bone tissue
- compact bone
- spongy bone
119
classification of liquid connective tissue
- blood
| - lymph plasma
120
classification of loose connective tissue
- areolar
- adipose
- reticular
121
classification of dense connective tissue
- dense regular
- dense irregular
- elastic
122
classification of cartilage
- hyaline cartilage
- fibrous cartilage
- elastic cartilage
123
classification of bone tissue
- compact bone
| - spongy bone
124
broad classification of connective tissue
- connective tissue proper
- supporting connective tissue
- liquid connective tissue
125
areolar connective tissue
- most generalized type of conncetive tissue
- widely distributed: in and around nearly every body structure
- "packing material" of the body
- subcutaneous layer of skin, dermis of skin, lamina propria of mucous membranes, around blood vessels, nerves and body organs
- consists of:
- fibers: randomly arranged collagen, elastic, reticular
- cells: fibroblasts, adipocytes, wbc
- ground substance: gelatinous (semifluid)
functions: strenght, elasticity, support
126
areolar connective tissue - function
- strength
- elasticity
- support
127
loose connective tissue: adipose
- contains adipocytes (derived from fibroblasts)
- cells specialized for triglyceride storage: stored as one large, centrally located droplet (cytoplasm and nucleus are pushed to the cell periphery)
- functions: reduces heat loss, energy reserve, supports and protects organs
128
loose connective tissue: adipose - functions
- reduces heat loss
- energy reserve
- supports and protects organs
129
loose connective tissue: reticular
- network or reticular fibers and reticular cells
- forms stroma (framework) of organs
- ex. liver, spleen, lymph nodes, bone marrow
- ties cells of smooth muscles together
- reticular fibers can act as filters
- ex. in spleen: filters blood to remove worn out red blood cells
- ex. in lymph nodes: filters the lymph to remove microbes
130
loose connective tissue: reticular - function
- forms stroma (framework) of organs
- ex. liver, spleen, lymph nodes, bone marrow
- ties cells of smooth muscles together
- reticular fibers can act as filters
- ex. in spleen: filters blood to remove worn out red blood cells
- ex. in lymph nodes: filters the lymph to remove microbes
131
dense connective tissue
- contains more numerous fibers and fewer cells than loose connective tissue
- fibers are thicker and denser than in loose connective tissue
- 3 types: dense regular, dense irregular, elastic
132
dense connective tissue: regular
- collagen fibers regularly arranged in parallel bundles with fibroblast cells in between
- collagen is not living so tissue does not heal quickly
- found in tendons and ligaments
- provides great tensile strength along the fiber axis
- strong attachment
133
dense connective tissue: regular - function
- provides great tensile strength along the fiber axis
| - strong attachment
134
dense connective tissue: irregular
- collagen fibers are irregularly arranged with a few fibroblasts
- often occurs as sheets such as fasciae (tissue beneath skin and around muscles and organs)
- tissue can resist tension from any direction
- makes for very "tough tissues"
- white of eyeballs, dermis, membranes surrounding the heart, cartilage and bones
135
dense connective tissue: irregular - function
- can resist tension from any direction
- makes for very "tough tissues"
- white of eyeballs, dermis, membranes surrounding the heart, cartilage and bones
136
elastic connective tissue
- composed of elastic fibers and fibroblasts
- can stretch and return to its original shape so it's very strong
- found in lung tissue, vocal cords, ligaments between vertebrae and blood vessels
137
elastic connective tissue - function
can stretch and return to its original shape so it's very strong
138
elastic connective tissue - location
- lung tissue
- vocal cords
- ligaments between vertebrae
- blood vessels
139
cartilage
- supporting connective tissue that consists of a dense network of collagen fibes and elastic fibers embedded in chondroitin sulfate (rubbery matrix)
- collagen fibers make cartilagge strong
- the chondroitin sulfate makes the cartilage resilient
- does not have nerves or blood vessels (unlike other connective tissue)
- secretes anti-angiogenesis factor, which prevents blood vessel growth
- produced by chondroblasts: mature cartilage contains chondrocytes (cartilage cells)
- surrounded by a dense irregular connective tissue membrane called the perichondrium
- 3 types: hyaline, fibrocartilage, elastic
140
hyaline cartilage
- "glassy"
- most abundant but weakest type of cartilage
- thin, fine collagen fibers (not visible)
- abundant chondrocytes in lacunae (small spaces = little lakes) surrounded by perichondrium
- ground substance is a resilient gel
- reduces friction and absorbs shock in joints
141
hyaline cartilage - function
reduces friction and absorbs shock in joints
142
fibrocartilage
- many more collagen fibers causes rigidity and stiffness
- chondrocytes scattered among clearly visible, thick bundles of collagen fibers
- lacks perichondrium
- strongest type of cartilage
- intervertebral discs
143
elastic cartilage
- chondrocytes are located within a threadlike matrix of elastic fibers
- has perichondrium
- provides shape and elasticity so it maintains shape after deformations
- found in ear, nose, vocal cartilages, epiglottis
144
elastic cartilage - location
- ear
- nose
- vocal cartilage
- epiglottis
145
bone tissue
- mineralized extracellular matrix
- calcium and phosphate give hardness
- interwoven collagen fibers give strength
- lacunae contain osteocytes (mature bone cells)
- can be classified as compact or spongy depending on the arrangement of cells and matrix
146
liquid connective tissue
- liquid extracellular matrux
- two types of liquid connective tissue
- blood
- lymph
147
blood
- connective tissue with liquid matrix (ex. blood plasma)
- cell types include:
- erythrocytes (rbc)
- leukocytes (wbc)
- platelets (cells fragments)
- found within blood vessels and heart chambers
- functions: clotting, immune functions, transport O2 and CO2, nutrients and wastes
148
blood - funtions
- clotting
- immune functions
- transport O2 and CO2, nutrients and wastes
149
membranes
- are flat sheets of pliable tissue that cover or line a part of the body
- 2 types: epithelial and synovial
150
epithelial membrane
- consists of epithelial layer and an underlying connective tissue layer
- 3 types:
- mucous membranes
- serous membranes
- cutaneous membranes
151
types of epithelial membranes
- mucous membranes
- serous membranes
- cutaneous membranes
152
synovial membrane
- lines joints
| - contains connective tissue but no epithelium
153
mucous membranes
- consist of epithelium over a layer of areolar connective tissue
- line body cavities that open directly onto the exterior (outside) of the body
- ex. digestive, reproductive, and most of the urinary tract
- epithelial layer acts as barriers to microbes
- connected by tight junctions
- goblet cells secrete mucus onto the surface, preventing it from drying out
- also lubricates and traps pathogens
- epithelium is underlined with areolar connective tissue (lamina propria)
154
mucous membranes - function
- epithelial layer acts as barriers to microbes
- connected by tight junctions
- goblet cells secrete mucus onto the surface, preventing it from drying out
- also lubricates and traps pathogens
155
mucous membranes - location
- digestive
- reproductive
- most of urinary tract
156
serous membranes
- lines body cavities that do not open to the exterior
- abdominal and thoracic cavities
consist of parietal and visceral layers with serous fluid in between
- pleura covers lungs, pericardium covers heart, peritoneum covers the visceral organs
- membrane layers consist of mesothelium (simple squamous epithelium) underlined with areolar connective tissue
157
cutaneous membranes
- covers body surface
- consists of:
- epidermis: keratinized stratified squamous epithelium
- dermis: areolar and irregular dense connective tissue
158
epidermis
keratinized stratified squamous epithelium that makes cutaneous membranes
159
dermis
areolar and irregular dense connective tissue that makes cutaneous membranes
160
synovial membranes
- line joint cavities of all moveable joints
- contains connective tissue, but no epithelium (no epithelial cells)
- discontinuous layer of cells called synoviocytes
- produce synovial fluid to lubricate joints
161
synoviocytes
discontinuous layer of cells that make synovial membranes and produce synovial fluid to lubricate joints
162
muscular tissue
- consists of long cells called muscle fibers
- each cell contains many contractile proteins composed of actin and myosin
- use ATP to create force and movement such as motion, posture and heat
163
muscular tissue - function
to use ATP to create force and movement such as motion, posture and heat
164
types of muscle tissue
1. skeletal muscle tissue
- attaches to bones with tendons to promote voluntary movement
2. cardiac muscle tissue
- branched, interconnecting at specialized junctions for rapid relay
3. smooth muscle tissue
- contracts slowly, involuntary control, found in internal organs
165
skeletal muscle
- consists of long, cylindrical, striated fibers (cells)
- cells are long and cylindrical with many peripheral nuclei
- has visible light and dark banding
- responsible for voluntary contraction/relaxation
- attached to bones by tendons
- functions: motion, posture, heat production, protection
166
skeletal muscle - function
- motion
- posture
- heat production
- protection
167
cardiac muscle
- forms most of the walls of the heart and pumps blood to all the parts of the body
- cells are branched striated cylinders with one central nucleus
- cells are attached together and communicate with each other by intercalated discs (thickenings of plasma membrane that contain gap junctions and desmosomes)
168
intercalated discs
thickenings of plasma membrane that contain gap junctions and desmosomes
169
cardiac muscle - function
form wall of heart and pump blood to all parts of the body
170
smooth muscle
- spindle-shaped cell with a single central nucleus
- lack striations (smooth)
- cells are often connected by gap junctions to quickly send messeges back and forth
- found in walls of hollow organs (blood vessels, GI tract, bladder, ...)
- involuntary contraction/relaxation
171
smooth muscle - location
walls of hollow organs
- blood vessels
- GI tract
- bladder
172
smooth muscle - function
responsible for involuntary contraction/relaxation
173
nervous tissue
two cell types:
1. neurons: function cells of nervous system that conduct electrical impulses and are made of:
- dendrites: receive info and conduct signals toward the cell body
- cell body: contains nucleus
- axons: conduct signals away from the cell body
2. neuroglial cells: supportive cells
- insulate axons for faster conduction, nourish and regulare neuronal function
174
neurons
function cells of nervous system that conduct electrical impulses and are made of:
- dendrites: receives info and conduct signals towards the cell body
- cell body: contains nucleus
- axons: conduct signals away from the cell body
175
neuroglial cells
supportive cells
| - insulate axons for faster conduction, nourish and regulate neuronal function
176
dendrites
receives info and conduct signals towards the cell body in neurons
177
cell body
contains nucleus in the neuron
178
axons
conduct signals away from the cell body in neurons
179
nervous tissue - functions
- senses stimuli and converts them into action potential (nerve impulses)
- conducts nerve impulses to other neurons, muscle fibers or glands
- responsible for maintaning homeostasis and for everything we do
180
nervous tissue - location
- CNS: brain and spinal cord
| - PNS: nerves containing sensory and motor neurons
181
CNS
brain and spinal cord
182
PNS
nerves containing sensory and motor neurons
