Midterms Flashcards
(332 cards)
1
Q
- Aggregated polyhedral cells
- small amount
- Lining of surface or body cavities; glandular secretion
A
epithelial
2
Q
- Several types of fixed and wandering cells
- Abundant amount
- Support and protection of tissues/organs
A
connective
3
Q
- Elongated contractile cells
- Moderate amount
- Strong contraction; body movements
A
muscle
4
Q
- Elongated cells with extremely fine processes
- Very small amount
- Transmission of nerve impulses
A
nervous
5
Q
- Occludins, claudins, ZO proteins
- Actin filaments
- Seals adjacent cells to one another, controlling passage of molecules between them; separates apical and basolateral membrane domains
- Defects in occludins may compromise
the fetal blood–brain barrier, leading to severe neurologic disorders
A
tight junction
6
Q
- E-cadherin, catenin complexes
- Actin filaments
- Provides points linking the cytoskeletons
of adjacent cells; strengthens and stabilizes nearby tight junctions - Loss of E-cadherin in epithelial cell tumors (carcinomas) promotes tumor invasion and the shift to malignancy
A
adherens junction
7
Q
- Cadherin family proteins (desmogleins, desmocollin)
- Intermediate filaments (keratins)
- Provides points of strong intermediate filament coupling between adjacent cells, strengthening the tissue
- Autoimmunity against desmoglein I leads to dyshesive skin disorders characterized by reduced cohesion of epidermal cells
A
desmosome
8
Q
- Integrins
- Intermediate filaments
- Anchors cytoskeleton to the basal lamina
- Mutations in the integrin-β4 gene are linked to some types of epidermolysis bullosa, a skin blistering disorder
A
hemidesmosome
9
Q
- Connexin
- Allows direct transfer of small molecules and ions from one cell to another
A
gap junction
10
Q
- Lining of vessels (endothelium); Serous lining of cavities: pericardium, pleura, peritoneum (mesothelium)
- Facilitates the movement of the viscera (mesothelium), active transport by pinocytosis (mesothelium and endothelium), secretion of biologically active molecules (mesothelium)
A
simple squamous
11
Q
- Covering the ovary, thyroid
- Covering, secretion
A
simple cuboidal
12
Q
- Lining of intestine, gallbladder
- Protection, lubrication, absorption, secretion
A
simple columnar
13
Q
- Epidermis
- Protection; prevents water loss
A
stratified squamous keratinized
14
Q
- Mouth, esophagus, larynx, vagina, anal canal
- Protection, secretion; prevents water loss
A
statified squamous nonkeratinized
15
Q
- Sweat glands, developing ovarian follicles
- Protection, secretion
A
stratified cuboidal
16
Q
- bladder, ureters, renal calyces
- Protection, distensibility
A
stratified transitional
17
Q
- conjunctiva
- protection
A
stratified columnar
18
Q
- Lining of trachea, bronchi, nasal cavity
- Protection, secretion; cilia-mediated transport of particles trapped in mucus out of the air passages
A
pseudostratified
19
Q
- Elongated secretory portion; duct usually short or absent
- Mucous glands of colon; intestinal glands or crypts (of Lieberkühn)
A
simple tubular
20
Q
- several long secretory parts joining to drain into 1 duct
- Glands in the uterus and stomach
A
branched tubular
21
Q
- secretory portion is very long and coiled
- sweat glands
A
coiled tubular
22
Q
- Rounded, saclike secretory portion
- Small mucous glands along the urethra
A
acinar
23
Q
- Multiple saclike secretory parts entering the same duct
- Sebaceous glands of the skin
A
branched acinar
24
Q
- Several elongated coiled secretory units and their ducts converge to form larger ducts
- Submucosal mucous glands (of Brunner) in the duodenum
A
tubular
25
- ducts converge to form larger ducts
Several saclike secretory units with small ducts converge at a larger duct
- exocrine pancreas
acinar
26
- Ducts of both tubular and acinar secretory units converge at larger ducts
- Salivary glands
tubuloacinar
27
cells are bound tightly together structurally and functionally to form a sheetlike or tubular structure with little extracellular material between the cells.
epithelium
28
facing the sheet’s free surface
apical
29
facing a basement membrane and under- lying connective tissue
basal
30
Epithelia are often specialized for absorption
transcytosis
31
thin extracellular layer of specialized proteins, usually having two parts: a basal lamina and a more fibrous reticular lamina
basement membrane
32
thin meshwork of type IV collagen and laminin produced by the epithelial cells
basal lamina
33
contains type III collagen and anchoring fibrils of VII collagen, all secreted by cells of the immediately adjacent connective tissue.
reticular lamina
34
formed by interacting trans- membrane proteins such as claudin and occludin; linear arrangements of these linked proteins surround the apical ends of the cells and prevent paracellular passage of substances
tight junction
35
formed by interacting proteins of the cadherin family, are points of strong attachment holding together cells of the epithelium.
adherent junction
36
encircle epithelial cells just below their tight junctions or scattered, spot-like attachment sites called desmosomes or maculae adherens, both of which are attached to cytoplasmic keratins.
zonula adherens
37
composed of transmembrane integrins attach cells to proteins of the basal lamina.
hemidesmosomes
38
points of cell contact where both plasma membranes have numerous hexameric complexes of transmembrane connexons, each forming a channel allowing passage of small molecules from one cell to the other.
gap junction
39
small membrane projections with cores of actin filaments that generally function to increase epithelial cells’ apical surface area for absorption
microvilli
40
long microvilli with specialized mechanosensory function in cells of the inner ear and for absorption in tissues of the male reproductive tract.
stereocilia
41
larger projecting structures with a well-organized core of microtubules
cilia
42
epithelium in which the basement membrane has one cell layer is
simple
43
Epithelia with two or more layers of cells are
stratified
44
- move gradually from the basal to the surface layers, changing shape and becoming filled with keratin intermediate filaments.
- cover the body surface, protecting underlying tissues from excess water loss (dehydration) and microbial invasion.
statified squamous
45
thick and appear to have several cell layers; all cells attach to the basal lamina but not all extend to the free epithelial surface.
pseudostratified epithelia
46
found only in the lining of the urinary system, is stratified, with large rounded surface cells protective against urine.
transitional
47
have epithelial ducts carrying secretions to specific sites
exocrine glands
48
unbranched
simple glands
49
branched
compound glands
50
The secretory portions of exocrine glands may form round, saclike ___ or elongated ___
acini; tubules
51
lack ducts
endocrine glands
52
three basic secretory mechanisms
merocine, holocrine, apocrine
53
uses exocytosis
merocrine
54
terminally differentiated cells filled with lipid product are release
holocrine
55
apical, product-filled areas of cells are extruded.
apocrine
56
Exocrine glands producing mucus, or similar individual cells called goblet cells, are called
mucous glands
57
Exocrine glands producing largely enzymes (proteins) are called ___ and stain darkly with H&E due to the cells’ content of RER and secretory granules.
serous glands
58
Extracellular fibers and ground substance
fibroblast
59
Antibodies
Plasma cells
60
Various immune/defense functions
Eosinophilic leukocytes
61
Phagocytosis of bacteria
Neutrophilic leukocytes
62
Phagocytosis of ECM components and debris; antigen processing and presentation
to immune cells; secretion of growth factors, cytokines, and other agents
Macrophages
63
Pharmacologically active molecules (eg, histamine)
Mast cells and basophilic leukocytes
64
storage of neutral fats
Adipocytes
65
- Blood
- Precursor of macrophages
monocyte
66
- Connective tissue, lymphoid organs, lungs, bone marrow, pleural and peritoneal cavities
- lungs, bone marrow, pleural and peritoneal cavities
Production of cytokines, chemotactic factors, and several other molecules that participate in inflammation (defense), antigen processing, and presentation
macrophage
67
- Liver (perisinusoidal)
- Same as macrophages
kupffer cell
68
- Central nervous system
- Same as macrophages
microglial cell
69
- Epidermis of skin
- Antigen processing and presentation
langerhans cell
70
- Lymph nodes, spleen
- Antigen processing and presentation
dendritic
71
- Bone
- Localized digestion of bone matrix
osteoclast
72
- in connective tissue under various pathological conditions
- Segregation and digestion of foreign bodies
multinuclear giant cell
73
Resistance to tension
Fibril-Forming Collagens I
74
Resistance to tension
Fibril-Forming Collagens I
75
Resistance to pressure
Fibril-Forming Collagens II
76
structural maintenance in expansible organs
Fibril-Forming Collagens III
77
Participates in type I collagen function
Fibril-Forming Collagens V
78
Participates in type II collagen function
Fibril-Forming Collagens XI
79
Support of epithelial cells; filtration
Network-Forming Collagens IV
80
Network-Forming Collagens IV
81
increases density of the matrix
Network-Forming Collagens X
82
Anchors basal laminae to underlying reticular lamina
Linking/Anchoring Collagens VII
83
Binds various proteoglycans; associated with type II collagen
Linking/Anchoring Collagens IX
84
Interacts with type I collagen
Linking/Anchoring Collagens XII
85
Binds type I collagen fibrils, with types V and XII, strengthening fiber formation
Linking/Anchoring Collagens XIV
86
- Faulty transcription or translation of collagen type III
- Aortic and/or intestinal rupture
ehlers-danlos type IV
87
- Faulty lysine hydroxylation
- Increased skin elasticity, rupture of eyeball
ehlers-danlos type VI
88
- Decrease in procollagen peptidase activity
- Increased articular mobility, frequent luxation
ehlers-danlos type VII
89
- Lack of vitamin C, a required cofactor for prolyl hydroxylase
- Ulceration of gums, hemorrhages
scurvy
90
- Change of 1 nucleotide in genes for collagen type I
- Spontaneous fractures, cardiac insufficiency
osteogenesis imperfecta
91
- Much ground substance; many cells and little collagen, randomly distributed
- Supports microvasculature, nerves, and immune defense cells
- Lamina propria beneath epithelial lining of digestive tract
loose connective tissue
92
- Little ground substance; few cells (mostly fibroblasts); much collagen in randomly arranged fibers
- Protects and supports organs; resists tearing
- Dermis of skin, organ capsules, submucosa layer of digestive tract
dense irregular connective tissue
93
- Almost completely filled with parallel bundles of collagen; few fibroblasts, aligned with collagen
- Provide strong connections within musculoskeletal system; strong resistance to force
- Ligaments, tendons, aponeuroses, corneal stroma
dense regular connective tissue
94
- Sparse, undifferentiated cells, uniformly distributed in matrix with sparse collagen fibers
- Contains stem/progenitor cells for all adult connective tissue cells
- Mesodermal layer of early embryo
mesencyhme
95
- Random fibroblasts and collagen fibers in viscous matrix
- Supports and cushions large blood vessels
- Matrix of the fetal umbilical cord
mucoid connective tissue
96
- Delicate network of reticulin/ collagen III with attached fibroblasts (reticular cells)
- Supports blood-forming cells, many secretory cells, and lymphocytes in most lymphoid organs
- Bone marrow, liver, pancreas, adrenal glands, all lymphoid organs except the thymus
reticular connective tissue
97
Connective tissue is specialized to physically ___ and ___ other tissues and maintain the water required for metabolite diffusion to and from cells.
support ; connect
98
Connective tissues all consist primarily of ___ material rather than cells.
extracellular
99
Within most organs connective tissue proper forms the supportive
stroma
100
supports the organ’s unique functional components
parenchyma
101
consists of both large protein fibers and nonfibrous areas of unstained ground substance rich in various GAGs and water.
ECM
102
All adult connective tissues are derived from an embryonic form of connective tissue called ___, which contains uniformly undifferentiated cells scattered in a gel-like matrix.
mesenchyme
103
major cells of connective tissue proper, are elongated, irregularly shaped cells with oval nuclei that synthesize and secrete most components of the ECM.
fibroblasts
104
large cells specialized for storage of triglycerides
adipocytes
105
predominate in a specialized form of connective tissue
adipose tissue
106
short-lived cells that differentiate in connective tissue from precursor cells called monocytes circulating in the blood; they function in ECM turnover, phagocytosis of dead cells and debris, and antigen presentation to lymphocytes.
macrophages
107
originate from blood cell precursors and are filled with granules for the release of various vasoactive agents and other substances during inflammatory and allergic reactions.
mast cells
108
short-lived cells that differentiate from B lymphocytes and are specialized for the abundant secretion of specific anti- bodies (immunoglobulins).
plasma cells
109
wander through all types of connective tissue proper, providing surveillance against bacterial invaders and stimulating tissue repair.
leukocytes
110
most important and abundant fibers of connective tissue are composed of the protein
collagen
111
Upon exocytosis, the non helical ends of the procollagen subunits are removed, forming trimeric
collagen molecules
112
that aggregate and become covalently bound together in large
collagen fibrils
113
highly regular assembly of collagens in the fibrils produces a characteristic pattern of
crossbanding
114
Fibrils of type I collagen are bundled together by other forms of non- fibrillar, linking collagens to produce large
collagen bundles
115
Collagen fibrils are degraded by collagenase enzymes classified as
MMP
116
Type III collagen produces a network of delicate ___,
which stain very dark with silver stains and are abundant in immune
and lymphoid tissues.
reticular fibers
117
composed of the proteins elastin and fibrillin, which exist in a stretchable conformation that provides elastic properties to connective tissues rich in this material.
elastic lamellae
118
- watery, largely unstained extracellular material
- rich in hydrated GAGs, proteoglycans, and multiadhesive glycoproteins.
ground substance
119
- The major types of GAGs
- very long polymer of the disaccharide glucosamine glucuronate,
hyaluronan
120
- shorter chains
- composed of other disaccharide polymers.
sulfated GAG
121
chondroitin sulfate and keratan sulfate have various sizes and compositions, but they are all bound to the core proteins of ___ and are produced in the Golgi apparatus before secretion.
proteoglycans
122
Proteoglycans attach to polymers of HA via ___ to form huge complexes in ground substance
linker proteins
123
allowing temporary attachments between cells and the ECM required for cell migration and positioning.
multiadhesive glycoproteins
124
loose or dense according to the amount of collagen and ground substance present.
connective tissue proper
125
(or areolar tissue) has relatively more ground substance than collagen, and it typically surrounds small
loose connective tissue
126
filled primarily with randomly distributed bundles of type I collagen, with some elastic fibers, providing resistance to tearing from all directions as well as some elasticity.
dense irregular connective tissue
127
prominent in tendons and ligaments, features bundles of essentially parallel type I collagen, providing great strength (but little stretch) in binding together components of the musculoskeletal system.
dense regular connective tissue
128
delicate network soft type III collagen and is most abundant in certain lymphoid organs
reticular tissue
129
gel-like connective tissue
mucoid tissue
130
- dietary fats pack-aged
- intestine
chylomicrons
131
- defining cells of adipose tissue (fat)
adipocytes
132
- triglycerides produced in the liver and circulating
- from fatty acids synthe- sized locally
VLDL
133
mobilized from adipocytes by hormone-sensitive lipase activated by norepinephrine released from the adrenal gland and various peptide hormones.
lipids
134
- found in many organs
- 20% of the body weight in adults.
- very large cells
white adipose tissue
135
Fatty acids are released from white adipocytes by ___ activity when nutrients are needed and carried throughout the body on plasma proteins such as ___
lipase; albumin
136
polypeptide hormone with target cells in the hypothalamus that is released from white adipocytes and helps regulate eating behavior.
leptin
137
comprises up to 5% of the newborn body weight but smaller amounts in adults.
brown fat
138
Fatty acids released in adipocytes of brown fat are metabolized in mitochondria of these cells for
thermogenesis
139
- Homogeneous, with type II collagen and aggrecan
- Chondrocytes, chondroblasts
- Isolated or in small isogenous groups
- Many components of upper respiratory tract; articular ends and epiphyseal plates of long bones; fetal skeleton
- Provides smooth, low-friction surfaces in joints; structural support for respiratory tract
- Presence of perichondrium
hyaline cartilage
140
- Type II collagen, aggrecan, and darker elastic fibers
- Chondrocytes, chondroblasts
- Usually in small isogenous groups
- External ear, external acoustic meatus, auditory tube; epiglottis and certain other laryngeal cartilages
- Provides flexible shape and support of soft tissues
- Presence of perichondrium
elastic cartilage
141
- Type II collagen and large areas of dense connective tissue with type I collagen
- Chondrocytes, fibroblasts
- isolated or in isogenous groups arranged axially
- Intervertebral discs, pubic symphysis, meniscus, and certain other joints; insertions of tendons
- Provides cushioning, tensile strength, and resistance to tearing and compression
fibrocartilage
142
tough, resilient type of connective tissue that structurally supports certain soft tissues, notably in the respiratory tract, and provides cushioned, low-friction surfaces in joints.
cartilage
143
- Cells of cartilage, ___, make up a small percentage of the tissue’s mass, which is mainly a flexible mass of extracellular matrix (ECM)
- embedded within lacunae surrounded by the ECM
chondrocytes
144
includes collagen as well as abundant proteoglycans, notably aggrecan, which bind a large amount of water.
cartilage ECM
145
- Cartilage always lacks blood vessels, lymphatics, and nerves, but it is usually surrounded by a dense connective tissue ___
- vascularized
perichondrium
146
three major forms of cartilage:
hyaline cartilage,
(2) elastic cartilage, and
(3) fibrocartilage.
147
ECM of hyaline cartilage is ___, rich in fibrils of type II collagen and aggrecan complexes with bound water.
homogenous and glassy
148
less collagen and more proteoglycan immediately around the lacunae, producing slight staining differences in this territorial matrix.
ECM
149
occur singly or in small, mitotically derived isogenous groups.
chondrocytes
150
present, but not at the hyaline cartilage of articular surfaces or the epiphyses of growing long bones.
perichondrium
151
- resembles hyaline cartilage in its chondrocytes and major ECM components, but its matrix includes abundant elastic fibers, visible with special stains, which increase the tissue’s flexibility.
- provides flexible support for the external ear as well as certain structures of the middle ear and larynx; it is always surrounded by perichondrium.
elastic cartilage
152
- contains varying combinations of hyaline cartilage in small amounts of dense connective tissue
- consists of small chondrocytes
- layered with larger areas of bundled type I collagen with scattered fibroblasts.
- provides very tough, strong support at tendon insertions and in intervertebral discs and certain other joints.
fibrocartilage
153
All forms of cartilage form from embryonic
mesenchyme
154
grow by mitosis of existing chondroblasts in lacunae
intenstital growth
155
formation of new chondroblasts peripherally from progenitor cells in the perichondrium
appositional growth
156
Repair or replacement of injured cartilage is very slow and ineffective, due in part to the tissue’s
avascularity and low metabolic rate
157
- Irregular and random arrangement of cells and collagen; lightly calcified
- Developing and growing bones; hard callus of bone fractures
Synonyms
- Immature bone; primary bone; bundle bone
woven bone
158
- Parallel bundles of collagen in thin layers (lamellae), with regularly spaced cells between; heavily calcified
- All normal regions of adult bone
- Mature bone; secondary bone
lamellar bone
159
- Parallel lamellae or densely packed osteons, with interstitial lamellae
- Thick, outer region (beneath periosteum) of bones
- Cortical bone
compact bone
160
- Interconnected thin spicules or trabeculae covered by endosteum
- Inner region of bones, adjacent to marrow cavities
- Spongy bone; trabecular bone; medullary bone
cancellous bone
161
type of connective tissue with a calcified extracellular matrix (ECM), specialized to support the body, protect many internal organs, and act as the body’s Ca2+ reservoir.
bone
162
differentiate from (stem) osteoprogenitor cells and secrete components of the initial matrix, called osteoid
osteoblasts
163
allow matrix mineralization to occur.
osteoid
164
type I collagen, the protein ___, which binds Ca2+ and matrix vesicles with enzymes generating PO4−.
osteocalcin
165
High concentrations of Ca2+ and PO4− ions cause formation of ___ crystals, whose growth gradually calcifies the entire matrix.
hydroxyapatite
166
differentiate further from osteoblasts when they become enclosed within matrix lacunae and act to maintain the matrix and detect mechanical stresses on bone.
osteocytes
167
Osteocytes maintain communication with adjacent cells via a network of long
dendritic process
168
very large cells, formed by fusion of several blood monocytes, which locally erode bone matrix during osteogenesis and bone remodeling.
osteoclasts
169
layer of dense connective tissue on the outer surface of bone, bound to bone matrix by bundles of type I collagen called perforating (or Sharpey) fibers.
periosteum
170
Regions of periosteum adjacent to bone are rich in ___ cells and ___ that mediate much bone growth and remodeling.
osteoprogenitor; osteoblasts
171
thin layer of active and inactive osteoblasts, which lines all the internal surfaces within bone; osteoblasts here are also required for bone growth.
endosteum
172
Dense bone immediately beneath the periosteum is called ___; deep to the compact bone are small bony trabeculae or spicules of cancellous (or spongy) bone.
com- pact bone
173
occur in both the knobby, bulbous ends,
epiphyses
174
two types of mature bone tissue
epiphyses; diaphysis
175
intervening shaft
diaphysis
176
Immature bone, called ___, is formed during osteogenesis or repair and has a calcified matrix with randomly arranged collagen fibers.
woven bone
177
- By the action of osteoclasts and osteoblasts, woven bone undergoes rapid turnover and is remodeled into
- both compact and cancellous bone
lamellar bone
178
Most lamellar bone consists of lamellae organized concentrically around small central canals containing blood vessels and nerves; this organization is called
osteon or haversian system
179
allow all cells to communicate with the central canal.
canaliculi
180
Bones of the skull and jaws form initially by
intramembranous ossification
181
osteoprogenitor cells surround and then invade hyaline cartilage models of the skeletal elements in the embryo.
endochondral ossification
182
diaphyses of fetal long bones form when chondrocytes die after enclosure of the cartilage within a collar of woven bone, creating an initial cavity that is entered by periosteal osteoblasts and vasculature.
primary ossification centers
183
with cartilage of the epiphyseal growth plate between the primary and secondary ossification sites.
secondary ossification centers
184
growth plates are the key to ___ during childhood and are organized as an interrelated series of developing zones.
bone elongation
185
chondrocytes undergo mitosis and appear stacked within elongated lacunae.
zone of proliferation
186
The most mature chondrocytes in the lacunae swell up, compress the matrix, and undergo apoptosis
zone of hypertrophy
187
- Spaces created in the matrix
- invaded by osteoblasts, osteoclasts, and vasculature from the primary center.
one of cartilage calcification
188
woven bone is laid down initially by osteoblasts and remodeled into lamellae bone.
zone of ossification
189
increases the circumference of a bone by osteoblast activity at the periosteum and is accompanied by enlargement of the medullary marrow cavity.
appositional bone growth
190
occurs throughout life, with cells and matrix turning over continuously through activities of osteoblasts and osteoclasts.
growth of bones
191
Lamellae and osteons are temporary structures and are replaced and rebuilt continuously in a process of ___ by which bones change size and shape according to changes in mechanical stress.
bone remodeling
192
fracture or other injury involves the activation of periosteal fibroblasts to produce an initial soft callus of fibrocartilage-like tissue.
bone repair
193
soft callus is gradually replaced by a ___ that is soon remodeled to produce stronger lamellar bone.
hard callus of woven bone
194
key ion for all cells, is stored in bone when dietary calcium is adequate and mobilized from bone when dietary calcium is deficient.
calcium
195
activity of all three major bone cells and is largely regulated by subtle paracrine interaction among these and other cells.
blood calcium levels
196
indirectly stimulates osteoclasts to elevate lev- els of calcium in blood,
PTH
197
inhibit osteoclast activity, lowering blood calcium levels
calcitonin
198
places where bones meet, orarticulate, allowing at least the potential for bending or movement in that portion of the skeleton.
joints
199
joints with very limited or no movement
synarthoroses
200
freely mobile joints
diarthroses
201
synarthroses in the vertebral column that
cushion adjacent vertebrae.
intervertebral discs
202
consists of a thick outer layer of fibrocartilage forming a tough annulus fibrosus and a shock-absorbing inner,
gel-like core, the
nucleus pulposus.
203
ave a joint cavity filled with lubricant synovial fluid,
enclosed within a tough, fibrous articular capsule; ends of the bones involved are covered with hyaline articular cartilage.
Diarthroses
204
specialized connective tissue of the ___ lines the capsule,
synovial membrane
205
remove wear-and-tear debris from synovial fluid.
macrophage like synovial cells
206
synthesize hyaluronan that moves into the synovial fluid with water from local capillaries to lubricate and nourish the articular cartilage.
fibroblast like synovial cells
207
Chemical structure significantly different from that of other neurotransmitters; active in CNS and in both somatic and autonomic parts of PNS; binds to ACh receptors (cholinergic receptors) in PNS to open ion channels in postsynaptic membrane and stimulate muscle contraction
acetylcholine ACh
208
Excites activity in neurons to promote cognitive function in the brain (learning and memory); most common neurotransmitter in the brain; opens Na+ channels
glutamate
209
Synthesized from glutamate; primary inhibitory neurotransmitter in the brain; also influences muscle tone; opens or closes various ion channels
gamma-aminobutryic acid (GABA)
210
Inhibits activity between neurons in the CNS, including retina; opens Cl– channels
Glycine
211
Molecules with both carboxyl (—COOH) and amine (—NH2) groups and various R groups; act as important transmitters in the CNS
amino acids
212
Molecules synthesized from an amino acid by removing the carboxyl group and retaining the single amine group; also called biogenic amines
monoamines
213
Has various functions in the brain related to sleep, appetite, cognition (learning, memory), and mood; modulates actions of other neurotransmitters
Serotonin or 5-hydroxytryptamine (5-HT)
214
A distinct group of monoamines
Catecholamines
215
Produces inhibitory activity in the brain; important roles in cognition (learning, memory), motivation, behavior, and mood; opens K+ channels, closes Ca2+ channels
Dopamine
216
Neurotransmitter of PNS (sympathetic division of autonomic nervous system) and specific CNS regions
Norepinephrine (noradrenaline)
217
Has various effects in the CNS, especially the spinal cord, thalamus, and hypothalamus
Epinephrine (adrenaline)
218
Small polypeptides act as signals to assist in and modulate communication among neurons in the CNS
neuropeptides
219
Helps regulate response to noxious and potentially harmful stimuli
Enkephalin
220
Involved in memory regulation and energy balance (increased food intake and decreased physical activity)
Neuropeptide Y
221
Inhibits activities of neurons in specific brain areas
Somatostatin
222
Assists with pain information transmission into the brain
Substance P
223
timulates neurons in the brain to help mediate satiation (fullness) and repress hunger
Cholecystokinin (CCK)
224
Prevents release of pain signals from neurons and fosters a feeling of well-being
Beta-endorphin
225
Helps control and moderate the effects of dopamine
Neurotensin
226
Also part of a nucleotide, inhibits activities in certain CNS neurons
adenosine
227
Involved in learning and memory; relaxes muscle in the digestive tract; important for relaxation of smooth muscle in blood vessels (vasodilation)
nitric oxide
228
- Neural tube
- CNS
- Myelin production, electrical insulation
Oligodendrocyte
229
- Neural tube
- CNS
- Structural and metabolic support of neurons, especially at synapses; repair processes
Astrocyte
230
- Neural tube
- Line ventricles and central canal of CNS
- Aid production and movement of CSF
ependymal cell
231
- Bone marrow (monocytes)
- CNS
- Defense and immune-related activities
microglia
232
- Neural crest
- Peripheral nerves
- Myelin production, electrical insulation
schwann cell
233
- Neural crest
- Peripheral ganglia
- structural and metabolic support for neuronal cell bodies
satellite cells
234
Nervous tissue develops in the early embryo when the dorsal ectoderm ___ folds lengthwise to form the neural tube
neural plate
235
precursor of the CNS,
neural tube
236
precursors for much of the PNS.
neural crest cells
237
There are many kinds of neurons, but all consist of a
cell body (perikaryon)
238
long cytoplasmic extension
axon
239
one or more shorter processes
dendrites
240
eurons use the common cell property of excitability to produce and move an ___ along the axon to excite another neuron or other effector cell.
action potential (nerve impulse)
241
such nerve communication is transmitted to another neuron or effector cell via
synapse
242
released at the presynaptic membrane and binds receptors on the postsynaptic cell, initiating a new action potential there
neurotransmitter
243
required to support neurons in many ways, consist of six major types:
glial cells
244
wrap processes around portions of axons in
the CNS, forming myelin sheath
oligodendrocytes
245
insulate the axons and
facilitate nerve impulse
myelin sheaths
246
most numerous cell of the CNS, all produce hundreds of processes to cover and provide regulated microenvironments for neuronal perikarya, synapses, and capillaries.
astrocytes
247
epithelial-like cells, lacking basement membranes, which line the fluid-filled cerebral ventricles and central canal of the spinal cord.
ependymal cells
248
mediate immune defense activity within the CNS.
microglia
249
enclose all axons in nerves of the PNS, producing myelin sheaths around large-diameter axons, whose impulse conductivity is augmented at the nodes of Ranvier between successive Schwann cells.
schwann cells
250
- located within PNS ganglia
- enclose each perikaryon and regulate its microenvironment.
satellite
251
regions rich in neuronal perikarya and astrocytes comprise the
gray matter
252
regions containing tracts of myelinated axons comprise
white matter
253
large, unique ___ characterize the cortex of the cerebellum
Purkinje neurons
254
ayers of small ___ form the cerebral cortex.
pyramidal neurons
255
the tough external
dura natter
256
- middle layer
- contains much CSF, which helps cushion the CNS within its bony enclosure.
arachnoid layer
257
delicate ___that directly contacts neural tissue.
pia mater
258
elaborate folds of vascularized pia mater covered by ependyma that project from walls of the cerebral ventricles; there water is removed from capillaries and transferred into the ventricles as CSF.
choroid plexus
259
neurons are also protected by the blood-brain barrier,
perivascular feet of astrocytic process
260
axons from motor neurons (in the spinal cord), sensory neurons, and autonomic neurons
peripheral nerves
261
thin connective tissue layer immediately surrounding Schwann cells in peripheral nerves, containing a few non-fenestrated capillaries and much reticulin.
Endoneurium
262
Groups of axons (with Schwann cells and endoneurium) are surrounded by perineurium, consisting of layered, squamous fibroblastic cells joined by tight junctions to make a
blood-nerve barrier.
263
In large peripheral nerves, groups of axons are subdivided as
fascicles
264
Surrounding the perineurium is a thick, outermost layer of dense irregular connective tissue,
epineurium
265
sensory or autonomic, contain neuronal cell bodies and their satellite cells and are surrounded by connective tissue continuous with that of nerves.
ganglia
266
Certain regions of the CNS, such as near the ependyma, retain rare ___ that allow some replacement of neurons throughout life;
neural stem and progenitor cells
267
involving formation and remodeling of synaptic connections is also prevalent throughout life.
neural plasticity
268
neuronal and glial interconnections with the CNS make regeneration and restoration of function within this tissue after major injury very difficult.
complexity & distances
269
simply organized peripheral nerves have better capacity for ___, a process involving reactivation of the perikaryon, Schwann cells, and macrophages.
axonal regeneration
270
three major types of muscle
skeletal, cardiac, smooth
271
very long, multinucleated fibers, cylindrically shaped and with diameters up to 100 μm.
skeletal muscle cells
272
surrounded by an external lamina and thin connective tissue, endomysium, containing capillaries.
sacrolemma
273
Groups of fibers called ___ are surrounded by perimysium
fascicles
274
all fascicles are enclosed within a dense connective tissue
epimysium
275
muscle fiber is filled with ___, composed of thousands of thick myosin filaments and thin actin filaments
myofibrils
276
highly organized into contractile units
sarcomeres.
277
Within sarcomeres thick and thin filaments
interdigitate
278
project from the thick filaments toward the F-actin
filaments
globular myosin heads
279
Sarcomeres are separated by___ that bisect the light-staining I bands
Z discs
280
Between the two I bands of a sarcomere
dark-staining A
band
281
alternating light and dark bands appear as microscopic ___ along the fibers.
striations
282
sarcoplasm between parallel myofibrils
mitochondria
283
- cisternae of smooth ER
- specialized for Ca2+ sequestration and release.
sarcoplasmic reticulum
284
two terminal cisterns of SR contact a deep invagination of the sarcolemma called a
transverse or t tubule
285
causes tropomyosin to change shape and allow the myosin heads to bind the actin subunits, forming crossbridges between thick and thin filaments.
ca binding to troponin
286
myosin heads repeatedly attach, pivot, detach, and return, causing the filaments to slide past one another, shortening the sarcomere.
contraction cycle
287
Ca2+ is again sequestered, ending contraction and allowing the sarcomeres to lengthen again as the muscle relaxes.
depolarization ends
288
Synapses of motor axons with skeletal muscle
EMP, NMJ, or myoneural junctions
289
sensory axons wrap around intrafusal fibers in small specialized fascicles or around myotendinous collagen bundles, respectively.
sensory proprioceptors
290
Skeletal muscles contain fibers that can be physiologically classified as the three main types:
1) slow, oxidative (type I);
(2) fast, intermediate oxidative-glycolytic (type IIa); and (3) fast, glycolytic (type IIb).
291
striated, but they consist of individual cylindrical cells, each containing one (or two) central nuclei and linked by adherent and gap junctions at prominent intercalated discs.
cardiac muscle fibers
292
Contraction of cardiac muscle is ___ at nodes of impulse-gen- erating pacemaker muscle fibers; ___ regulate the rate of contraction.
intrinsic; autonomic nerves
293
individual small, fusiform (tapering) cells, linked by numerous gap junctions.
smooth muscle fibers
294
do not form sarcomeres, and no striations are present.
thin and thick filaments
295
attach to α-actinin located in dense bodies that are located throughout the sarcoplasm and near the sarcolemma; contraction causes cells to shorten individually.
thin actin filament
296
less well-organized in smooth muscle fibers, and there is no transverse tubule system.
sarcoplasmic reticulum
297
Conduct blood from heart and with elastic recoil help move blood forward under steady pressure
elastic arteries
298
Distribute blood to all organs and maintain steady blood pressure and flow with vasodilation and constriction
muscular arteries
299
Distribute blood to arterioles, adjusting flow with vasodilation and constriction
small arteries
300
Resist and control blood flow to capillaries; major determinant of systemic blood pressure
arterioles
301
Exchange metabolites by diffusion to and from cells
capillaries
302
Drain capillary beds; site of leukocyte exit from vasculature
venules
303
Collect blood from venules
small veins
304
Carry blood to larger veins, with no backflow
medium veins
305
Return blood to heart
large veins
306
heart has three major layers
(1) endothelium
(2) the myocardium
(3) the epicardium
307
connective tissue with many adipocytes and covered by mesothelium.
epicardium
308
stimulates rhythmic contractions and consists of modified cardiac muscle fibers forming the sinoatrial (SA) and atrioventricular (AV) nodes, the atrioventricular bundle (of His), left and right bundle branches, and Purkinje fibers.
cardiac conducting system
309
located in the subendocardial layer of both ventricles, are distinguished from contractile fibers by their greater diameter, abundant glycogen, and more sparse bundles of myofibrils.
purkinje fibers
310
Masses of dense irregular connective tissue make up the ___, which surrounds the bases of all heart valves, separates the atria from the ventricles, and provides insertions for cardiac muscle.
cardiac skeleton
311
isible blood vessels have three major layers or tunics:
- intima
- media
- adventitia
312
includes the endothelium, connective tis- sue, and an internal elastic lamina in larger vessels;
intima
313
contains alternating layers of smooth muscle and collagen or elastic lamellae;
media
314
contains connective tissue, small vessels (vasa vasorum), and nerves.
adventitia
315
not simply heart and vessel liners; they actively produce factors that prevent blood clotting, factors that cause adjacent smooth muscle cells to con- tract or relax, and factors that initiate inflammation at sites of damage or infection.
endothelial cells
316
Arteries are grouped by size and wall composition
- large elastic arteries,
- muscular, medium-sized arteries
- small arteries
317
fenestrated elastic laminae in the thick tunica media
large elastic arteries
318
fewer than 10 layers of smooth muscle in the media
small arteries
319
microvasculature too small for surgical manipulation permeates most organs and consists of
- atrioles
- capillaries
- venules
320
large lumens and thin walls, which drain capillaries.
venules
321
branch into metarterioles, in which smooth muscle sphincters contract to resist blood flow and relax cyclically to allow pulsatile flow of blood into an anastomosing capillary bed, where metabolic exchange with surrounding cells occurs.
termunal arterioles
322
Capillaries are classified as three structural and functional types
- continous capillaries
- fenestrated caoillaries
- discontinuous capillaries
323
many tight junctions so that all exchange must occur through the cells;
continous capillaries
324
small pores or fenestrations through the cells
fenestrated capillaries
325
larger lumens, large spaces between the endothelial cells, and a discontinuous basal lamina.
discontinuous capillaries
326
- endothelium of continuous capillaries and post capillary venules is frequently surrounded by thin cells called
- contractions facilitate blood flow and which can give rise to smooth muscle and connective tissue during microvascular remodeling or repair.
pericytes
327
Two alternative microvascular pathways
arteriovenous anastomoses; venous portal system
328
arterioles can bypass a capillary bed,
arteriovenous anastomoses
329
venules draining a capillary bed quickly branch again to form another capillary bed.
venous portal systems
330
Interstitial fluid that is not pulled into venules by colloidal osmotic pressure drains as lymph into blind vessels called ___, which have very thin endothelial cell walls with spaces between the cells.
lymphatics
331
lymph is propelled by movements of surrounding muscles and organs, with intimal valves keeping the flow unidirectional.
lymphatic vessels
332
largest lymphatic vessels, the___ and right ___, both with walls having tunics like those of veins, return lymph to the circulatory system by joining veins near the heart.
thoracic duct; lymphatic duct
