Exam 2 Flashcards
(429 cards)
1
Q
what are the functions of muscle contraction
A
allow material to move through the body
allow parts of the body to move
generation of heat
2
Q
what are the different types of muscle tissue
A
skeletal, cardiac, smooth
3
Q
what does the skeletal muscle do
A
moves the skeleton under voluntary control
4
Q
is skeletal muscle multinucleated? is it striated?
A
yes
yes
5
Q
what is another term for muscle cell
A
muscle fiber
6
Q
where is cardiac muscle found
A
in the heart wall
7
Q
how many nuclei does cardiac muscle have? is it striated?
A
one nucleus per cell
yes, it is striated
8
Q
are cardiac and smooth muscle under voluntary or involuntary control
A
involuntary
9
Q
where is smooth muscle found
A
in the walls of hollow organs
10
Q
how many nuclei does smooth muscle have? is it striated?
A
it has one nucleus per cell
no striations
11
Q
what are the properties of muscle tissue
A
excitability
contractility
extensibility
elasticity
12
Q
what does excitability mean in relation to the properties of muscle tissue
A
nerve signal excites the muscle, causing a contraction
13
Q
what does contractility mean in relation to the properties of muscle tissue
A
when a muscle contracts, it shortens
-occurs at a microscopic level as myofilaments pull past each other
14
Q
what does extensibility mean in relation to the properties of muscle tissue
A
after contraction, the muscle can go back to resting length (by gravity or an antagonist)
15
Q
what does elasticity mean in relation to the properties of muscle tissue
A
after being stretched, a muscle recoils passively and resumes its resting length
-when muscle is stretched beyond its resting length, it can return to its resting length (titin)
16
Q
what do arteries provide to muscle cell
A
provide oxygen and nutrients
17
Q
what do veins do for the muscle cell
A
remove cellular wastes
18
Q
what do nerves do in a muscle cell
A
innervate the muscle cell
19
Q
what are the subunits of the WHOLE muscle called
A
fascicles
20
Q
what are fascicles made of
A
individual muscle fibers (muscle cells)
21
Q
what does the epimysium surround?
A
the whole muscle
22
Q
what is the epimysium made of
A
dense irregular CT
23
Q
what does the perimysium surround
A
fascicles
24
Q
what is the perimysium made of
A
fibrous CT
25
what does the endomysium surround
individual muscle fibers
26
what is the endomysium made of
loose CT
27
what are individual muscle fibers (muscle cells) made of
myofibrils
28
what are myofibrils made of
sarcomeres
29
what are sarcomeres made of
proteins called myofilaments
30
what gives skeletal muscle its striated appearance
the sarcomeres
31
what are the boundaries of the sarcomere called
z-disc
32
what are the two different myofilaments
thick filament and thin filament
33
what is the thick filament made of
myosin
34
what is the thin filament made of
actin, troponin, tropomyosin
35
what is the myosin anchored to
the M line
36
what is the actin anchored to
the z line
37
what is the elastic filament
titin that attaches the z disc to the thick filament
-provides elasticity
38
what binds to the active site during muscle contraction
the myosin head
39
how do myosin heads cause muscle contraction
they use leverage to move the thin (actin) filaments inward
40
which protein blocks the active sites in muscle contraction
tropomyosin
41
how does the actin binding site become unblocked
Ca2+ binds to troponin which causes tropomyosin to unblock the binding site
42
which does not change with contraction?
-I band
-H zone
-A band
-Z disc
the A band does not change length with contraction
43
what is the A band? what will it include?
the length of the thick filament (myosin)
-will include thick and thin filaments
44
what is the H zone? what will it include?
the area between thin filaments (actin) within a single sarcomere
-will include only thick filaments
45
does the H zone change size with contraction
the H zone gets smaller with contraction
-it can disappear completely with full contraction
46
what is the I band? what will it include?
the area between 2 thick filaments of adjacent sarcomeres
-will include the Z disc, thin filament, elastic filament
47
does the I band change length with contraction
it gets shorter with contraction but cannot completely disappear because of the elastic filament
48
what is the M line
the middle of the H zone
-filaments hold thick filament (myosin) in place
49
what is the sarcolemma
the plasma membrane of a muscle fiber
50
what is the sarcoplasm
the cytoplasm of the muscle fiber
51
what direction to myofibrils run in relation to the muscle fibers
parallel to each other and the muscle fiber
52
what are t tubules
extensions of the sarcolemma that extend into muscle fiber
53
what do the t tubules wrap around
myofibrils
54
what do t tubules do for the muscle cell
carry electrical stimulus to the myofibrils
55
where is Ca2+ stored in the muscle
sarcoplasmic reticulum
56
what is the sarcoplasmic reticulum? what does it do?
modified smooth ER
-stores and releases calcium ions
57
what is the sliding filament theory
during a contraction, actin and myosin myofilaments slide over each other
-thin slide over thick
58
what is a motor unit
1 motor neuron and all the muscle fibers it innervates
59
what causes a larger/stronger contraction
more muscle fibers are stimulated
60
what is the neuromuscular junction
where a motor neuron meets a muscle fiber
61
what occurs at the neuromuscular junction
stimulation of the muscle fiber
62
what does the motor neuron release to start an action potential
ACh
63
when the action potential travels down the T tubule, what is released
Ca2+ from the sarcoplasmic reticulum
64
how does an action potential of a muscle occur
ACh is released from vesicles in the axon terminal by exocytosis
- this ACh binds to receptors that open channels to trigger the action potential
65
what does the action potential ultimately cause
sarcomere shortening
66
how are muscle fibers arranged
in a pattern that provides the most efficient movement for an extended action
67
what does muscle power depend on
the total number of muscle fibers in the muscle
-more fibers --> stronger contraction
68
how much is each muscle fiber able to shorten
to about 1/3 of its resting length
-longer muscle fibers are able to shorten more than short muscle fibers
69
which muscle would you expect to shorten the most during a contraction
the one with the longest fibers
70
which muscle would you expect to apply the most force during a contraction
the one with the largest amount of muscle fibers
71
what are the different fascicle arrangements in muscles
parallel
pennate
convergent
circular
72
which direction do parallel muscles run in
parallel to the axis of the muscle
73
what is on either end of parallel muscles
tendons
74
do parallel muscles have more or less fibers than other types
fewer fibers
75
do parallel muscles have long or short fibers
long
76
what is the major characteristic of pennate muscles
the tendon runs the whole length of the muscle
77
how and where to the fascicles attach in a pennate muscle
attach to the tendon at an angle (feather-like)
78
do pennate muscles have longer or shorter fibers
shorter fibers
79
do pennate muscles have more or less fibers than parallel muscles
more fibers
80
what is the main characteristic of convergent muscles
the origin of the muscle is broad (ex. pectoralis major)
81
where do the fascicles converge in a convergent muscle
converge into a tendon at the insertion
82
what are convergent muscles shaped like
a fan
83
do convergent muscles have more or less fibers than parallel muscles
more fibers
84
do convergent muscles have longer or shorter fibers than pennate
longer fibers
85
which type of muscle arrangement is the weakest
parallel (few muscle fibers)
86
which type of muscle arrangement is the strongest
pennate (most muscle fibers)
87
which type of muscle arrangement can shorten the least
pennate (shortest muscle fibers)
88
which type of muscle arrangement can shorten the most
parallel (longer muscle fibers)
89
how are the fascicles shaped in circular muscles
arranged in a ring
90
what muscles are circular muscles
sphincter muscles
91
what happens to circular muscles when contracted
the muscle constricts an orifice (opening), closing it
92
what is the origin of a muscle
attachment site that is not moved, or is moved the least during a muscle contraction
93
what is the insertion of a muscle
the attachment site that is moved when a muscle shortens
94
what is the action of a muscle
the resulting movement of a muscle contraction
95
what are tendons continuous with
the periosteum of bones
96
what CT does the direct muscle attachment use? what is it connecting?
short, dense regular CT fibers connect origin of muscle to bone
97
what CT does the indirect muscle attachment use? what is it connecting?
long, dense regular CT fibers connect insertion of muscle to bone
98
what are examples of indirect muscle attachments
tendons and aponeuroses
99
what is the aponeuroses
flat sheet of muscle (external oblique)
100
what is visible on the bone where muscles attach
raised bone markings
101
what causes an increase in muscle strength and size
with injury (during exercise) satellite cells fuse with muscle fibers and proliferate
-the new satellite cells produce proteins that help repair the damages muscle fibers
102
do skeletal muscle cells divide
no
103
what are satellite cells
stem cells, immature cells that resemble undifferentiated myoblasts
104
what happens if there is too severe of an injury to the skeletal muscle cells
muscle cells will be replaced by scar tissue
105
what are some characteristics of cardiac muscle (is it striated, multinucleated, voluntary or involuntary)
striated, branched, uninucleate, involuntary control
106
do cardiac muscle cells have regenerative ability
some, ~1% a year
107
what are cardiac muscle cells surrounded by
endomysium
108
what are cardiac muscle cells connected by
intercalated discs
109
what is an intercalated disc made of
gap junctions and desmosomes
110
what is the role of gap junctions in intercalated discs
allow for coordinated contractions by allowing action potentials to quickly spread from cell to cell
111
what is the role of desmosomes in intercalated discs
provide strength
site where intermediate filaments attach
112
what is the inherent rhythmicity of cardiac muscle
cardiac muscle cells are able to initiate their own contraction without stimulation from the nervous system
113
what are smooth muscle cells shaped like
small, spindle shaped cells
114
how many nuclei do smooth muscle cells have
uninucleate (one)
115
are smooth muscle cells striated
no
116
do smooth muscle cells contain myofilaments
yes but they are not arranged in sarcomeres
117
what covers the smooth muscle cell
endomysium
118
do smooth muscle cells have a regenerative capacity
yes
119
what anchors actin and myosin in a smooth muscle cell
intermediate filaments
120
what does a contraction in a smooth muscle cell consist of
myosin and actin filaments moving against one another
121
how is smooth muscle typically arranged
in two distinct layers
122
what are the two distinct layers that smooth muscle cells are arranged in
circular layer
longitudinal layer
123
what is the circular layer in a smooth muscle cell
the layer closest to the lumen of the organ
124
what is the longitudinal layer in a smooth muscle cell
the layer that wraps around the circular layer
125
what is the typical orientation of cells in the layers of smooth muscle
typically perpendicular to each other
126
what is mobility
the amount of movement at a joint
127
what is mobility dependent on
the type of materials joining the bones and the articulating surfaces of the bones
128
what are the three types of joint classification based on mobilty
synarthrosis
amphiarthrosis
diarthrosis
129
what is synarthrosis
immobile, mostly axial
130
what is amphiarthrosis
slightly moveable, mostly axial
131
diarthrosis
freely movable, mostly appendicular
132
what are the three joint classifications based on joint structure
fibrous
cartilaginous
synovial
133
what is the structural classification of joints based on
the type of material that binds the bones together and whether or not there is a joint cavity
134
what are the characteristics of a fibrous joint
no joint cavity
dense regular CT connects bones
135
what are the characteristics of a cartilaginous joint
no joint cavity
cartilage connects bones
136
what are the characteristics of a synovial joint
yes joint cavity
ligaments and articular capsule connect bones
ends of bones covered with articular cartilage (hyaline)
137
what is a suture
fibrous joint is held together by short, interconnecting fibers
bone edges interlock
138
where are sutures found
between bones of the skull
139
what are sutures connected with
short dense regular CT fibers
140
what does synarthrotic mean
bones do not move independently
141
what is the reason for sutures in the skull
allow for skull growth
142
when do skull bones fuse together
during middle age
143
what are syndesmoses
fibrous joints where the joint is held together by a ligament
144
what does syndesmoses mean
with ligament
145
what does amphiarthrotic mean
a small amount of movement
(longer fibers=more movement)
146
what are syndesmoses made of
dense regular CT
-longer than sutures
147
where are syndesmoses usually found
between long bones
148
what is a gomphosis
peg-in-socket fibrous joint
149
where are gomphoses found
in teeth
-attach tooth to bone of socket
150
what are the types of fibrous joints
sutures
syndesmoses
gomphoses
151
what are the types of cartilaginous joints
synchondroses
symphyses
152
what is a synchondroses
a cartilaginous joint where bones are united by hyaline cartilage
153
do synchondroses move
no, they are synarthrotic
154
where are synchondroses found
epiphyseal plates
between first rib's costal cartilage and sternum
155
what are symphyses
cartilaginous joint where the bones are united by fibrocartilage
156
can symphyses move
amphiarthrotic: small amount of movement
157
what are bones united by in a symphyses joint
fibrocartilage pad
158
where are symphyses joints found
intervertebral disc
pubic symphysis
159
do synovial joints move
yes, they are diarthrotic (freely movable)
160
what are the three things that synovial joints have
ligaments
joint cavity
articular capsule (joint capsule)
161
what do ligaments connect
bone to bone
162
what are ligaments made of
dense regular CT
163
what is the joint cavity
potential space with small amount of synovial fluid
164
what protects the synovial fluid
the synovial membrane
165
what is the articular capsule
the outer fibrous layer and the inner synovial membrane
166
what is the fibrous layer of the articular capsule made of? what is it continuous with?
dense irregular CT
continuous with the periosteum
167
what is the synovial membrane of the articular capsule? what is it made of?
the inner lining of the capsule and all other internal joint surfaces not covered in cartilage
loose CT
168
is the synovial membrane vascular
yes
169
what does the synovial membrane produce
synovial fluid
170
what is synovial fluid
blood filtrate
acts as a lubricant within the capsule
171
what makes the synovial fluid slippery
glycoproteins
172
where is synovial fluid located
in articular cartilages (as nutrient source) and in joint cavity
173
what is weeping lubrication
pressure placed on cartilages causes synovial fluid to move in and out of articular cartilages
174
why is weeping lubrication important
it nourishes the chondrocytes in the articular cartilage
175
where are sensory nerves located in synovial joints
in the articular capsule
176
what do sensory nerve fibers detect in the articular capsule of synovial joints
some pain
amount of stretch of joint capsule
177
where is the blood supply in a synovial joint
most supply to synovial membrane for production of synovial fluid
178
what is an articular disc
a disc of fibrocartilage that is found in some synovial joints
179
what is the purpose of an articular disc
helps improve the fit of articulating cartilages
180
what is an example of a synovial joint with an articular disc
the meniscus of the knee
181
what is the function of a labrum
increases stability in a joint
182
what are the two types of labrums
glenoid labrum and acetabular labrum
183
what is a glenoid labrum
lip of fibrocartilage around glenoid cavity
184
what is an acetabular labrum
circular rim of fibrocartilage around acetabulum of hip joint
185
what is the bursa
part of the synovial joint
closed fibrous sac lined with synovial membrane and filled with synovial fluid
186
what is the purpose of the bursa
reduces friction as parts move over each other
187
where is the bursa found
often where ligaments, tendons overlie bone
188
what is bursitis
inflammation of the bursa
189
what is a tendon sheath
part of the synovial joint
elongated bursa that wraps around tendons in high friction areas
190
what is an example of where a tendon sheath is found
in the tendons in the carpal tunnel of the wrist
191
what are the four classifications of synovial joints
nonaxial
uniaxial
biaxial
multiaxial
192
what is a nonaxial synovial joint
joint can move in multiple directions but only within one plane
no axis of rotation
ex. sacroiliac joints
193
what is a uniaxial synovial joint
joint moves only around 1 axis
one axis of rotation
ex. hinge joint
194
what is a biaxial synovial joint
joint moves around 2 axes
2 axes of rotation
ex. saddle joints in hands
195
what is a multiaxial synovial joint
joint moves around 3 or more axes
3+ axes of rotation
ex. ball in socket joint
196
what is a plane joint
a synovial joint that has a side to side gliding movement in one plane
nonaxial
197
what are examples of plane joints
intercarpal joints, joints between vertebral articular surfaces, sacroiliac joint
198
what are hinge joints
a synovial joint that allows flexion and extension
uniaxial
199
what are examples of hinge joints
elbow, interphalangeal joints (fingers)
200
what are pivot joints
synovial joints that are responsible for rotational movements
uniaxial
201
what are examples of pivot joints
radioulnar joints (palm up to palm down)
atlantoaxial joints (no motion of head)
202
what is a condylar joint
synovial joint that allows for flexion/extension and abduction/adduction
biaxial
203
what are examples of condylar joints
metacarpophalangeal (knuckle) joints, carpals and radius joint, occipital condyles (eyes), atlas (yes motion of head)
204
what is a saddle joint
synovial joint that allows for flexion/extension and abduction/adduction
biaxial
205
what is an example of a saddle joint
carpometacarpal joint of thumb
206
what are ball-and-socket joints
synovial joints that allow for flexion/extension, adduction/abduction, and rotation
multiaxial
207
what are examples of ball-and-socket joints
shoulder, hip
208
what bones make up the knee
femur, patella, tibia
209
what are the two joints in the knee
femoropatellar, tibiofemoral
210
how many joint capsules/cavities do the joints of the knee share
one
211
where is the femoropatellar joint located
between the patella and the femur
212
what type of joint is the femoropatellar joint
a plane joint: gliding action
213
what muscle does the femoropatellar joint work with to extend the leg
quadriceps femoris
214
where is the tibiofemoral joint located
between the tibia and the femur
215
what type of joint is the tibiofemoral joint
bicondylar hinge joint
216
where is the meniscus located
in between the femur and the tibia
217
how many axes does the tibiofemoral joint move in
two
218
what are the two most important characteristics of the tibiofemoral joint? why?
stability and mobility because it is a weight bearing joint
219
how is stability achieved in the tibiofemoral joint
ligaments, tendons, menisci
220
what are the layers of the articular capsule that surrounds the tibiofemoral joint
fibrous outer layer
inner synovial membrane (produces synovial fluid)
221
what are the four ligaments that support the tibiofemoral joint
tibial (medial) collateral
fibular (lateral) collateral
anterior cruciate ligament
posterior cruciate ligament
222
what does the tibial collateral attach
the tibia to the femur
223
what does the fibular collateral attach
the fibula to the femur
224
which ligament of the tibiofemoral joint prevents medial movement? lateral movement?
medial movement: tibial collateral
lateral movement: fibular collateral
225
where are the anterior and posterior cruciate ligaments found
between the femur and the tibia
centered in between the two menisci
226
what does the anterior cruciate ligament prevent
anterior sliding of the tibia
227
what does the posterior cruciate ligament prevent
posterior sliding of the tibia
228
what are the menisci
fibrocartilaginous discs that sit on top of the tibia
229
what are the functions of the meniscus
greater contact area between tibia and femur
guide and support condyles
increase surface area of weight
230
which ligament is attached to the medial meniscus
tibial (medial) collateral ligament
231
what is the triad of three for knee injuries
1. torn tibial collateral ligament
2. torn medial meniscus
3. torn anterior cruciate ligament
232
what is the difference between a sprain and a strain
sprain: ligament stretched or torn
strain: tendon/muscle stretched or torn
233
what is rheumatoid arthritis? what causes it
autoimmune (immune system attacks synovial membranes) chronic inflammatory disorder
234
what does the inflamed synovial membrane cause in rheumatoid arthritis
a granular pannus that damages cartilage and bone which can lead to fusion of bones
235
what is osteoarthritis and what causes it
articular cartilage breaks down resulting in bone to bone contact
caused by normal aging process
236
what is gouty arthritis and what does it form
crystals in synovial joints because of high levels of uric acid in blood
forms a tophus
237
what is carpal tunnel syndrome
inflammation of tendon sheaths puts pressure on the median nerve passing through the carpal tunnel
238
what is the primary function of the digestive system
to break down food/liquids into smaller units of absorbable nutrients to be used to generate energy
239
what is the alimentary canal
structures form long tube that breaks down food
240
what is the role of the accessory digestive organs
participate in digestive process but food does not pass through them
241
what are examples of accessory digestive organs
liver, pancreas, gallbladder, salivary glands
242
what is ingestion
food into mouth
243
what is propulsion
movement of food through canal
swallowing and peristalsis
244
what is mechanical digestion
physical breakdown of food particles
chewing, churning, segmentation
245
what is peristalsis
organizes contraction and relaxation of smooth muscle layers that propels food through the alimentary canal in one direction
246
what is segmentation
contractions of smooth muscle move food produce back and forth within canal to allow mixing and further breakdown
247
what is chemical digestion
enzymes and chemicals break down food
248
what is absorption
particles are transported from canal into blood and lymph capillaries
249
what is defecation
indigestible products are eliminated as feces
250
what are the layers of the alimentary canal from lumen to outer layer
lumen
mucosa
submucosa
muscularis externa
serosa
251
what are the three layers of the mucosa
epithelium
lamina propria
muscularis mucosa
252
which sublayer of the mucosa contains many digestive glands
the epithelium
253
which layer of the mucosa is made of loose areolar CT and is capillary rich to provide defense
lamina propria
254
which layer of the mucosa helps glands expel contents and supports localized movements
muscularis mucosa
255
what kind of CT is the submucosa
loose areolar but has more collagen fibers
highly vascularized
256
what is the submucosal nerve plexus
where the control of muscle cells and glandular secretions is
257
what are the two layers of the muscularis externa
circular (inner)
longitudinal (outer)
258
what are the functions of the layers of the muscularis externa
peristalsis and segmentation
259
what is the myenteric nerve plexus
innervates muscularis externa and is between the longitudinal and circular muscles
260
what does the enteric nervous system control
smooth muscle and glands of the alimentary canal
261
what two nerve plexuses make up the enteric nervous system
submucosal nerve plexus
myenteric nerve plexus
262
where is the serosa found
around organs within the abdominal cavity
263
what is the serosa made of
simple squamous epithelium and thin loose areolar CT
264
what is the esophagus lined with
adventitia
fibrous CT
265
where is the enteric nervous system located
within the wall of the alimentary canal
266
what chemical mixes with saliva during chemical digestion
amylase
267
what kind of epithelium makes up the mouth
stratified squamous
268
do the lips have glands? are the keritinized?
no glands and are poorly keratinized
269
what is the superior surface of the tongue covered in
keratinized stratified squamous epithelium
270
what are filiform papillae
on front part of tongue with no taste buds
271
what are fungiform papillae
on front part of tongue with taste buds
272
what are circumvallate papillae
on back of tongue with taste buds
273
what is the lingual frenulum
a fold of mucosa layer that connects the tongue to the floor of the mouth
274
what is ankyloglossia
when the lingual frenulum extends too far forward, speech is difficult
275
what kind of glands are salivary glands
exocrine (have duct)
276
what do salivary glands produce
saliva
277
what does the enzyme amylase break down
carbohydrates
278
what does the enzyme lipase break down
fats
279
what do serous cells secrete
digestive enzymes
280
what do mucous cells secrete
mucus
281
what is the largest salivary gland
parotid gland/duct
282
what type of cells does the parotid gland contain
serous cells
283
where does the parotid gland empty
near 2nd upper molar
284
what is mumps
a viral infection where the parotid glands swell
285
what kind of cells does the submandibular glad have
equal amounts of serous and mucus
286
where does the submandibular gland empty
lateral to the lingual frenulum
287
what kind of cells does the sublingual gland have
mostly mucus cells
288
where does the sublingual gland empty
below the tongue
289
what does heterodont dentition mean
different shapes of teeth for different jobs
290
what are the deciduous teeth
baby teeth
291
what are the four types of permanent teeth
incisors, canines, premolars, molars
292
what is the crown of the tooth
part above the gum line
293
what is the neck of the tooth
part contained within the gum tissue
294
what is the root of the tooth
contained within the bone
295
what is the pulp of the tooth
loose areolar CT with blood vessels and nerves
296
what does the pulp do for the tooth
provides nutrients and sensation to the tooth
297
what is dentin in teeth
collagen and minerals
298
what is the function of dentin in teeth
forms bulk of tooth, has dentinal tubules that can contribute to tooth sensitivity, no cells or blood vessels
299
What is the enamel
top layer of the tooth; hardest substance in the body
300
what is the cement of the tooth
calcified CT that covers the root
301
what is the periodontal ligament
dense CT that attaches cement of tooth to bony socket
302
what is a carie
cavity
303
what is a cavity caused by
demineralization of enamel and dentin
304
what does a cavity begin with
dental plaque
305
why would a root canal procedure be required
if the pulp becomes infected
306
what happens to the pulp during the root canal procedure
the pulp is drilled out and the tooth is capped
307
what is connected by the pharynx
the oral cavity and the esophagus / nasal cavity
308
which two parts of the pharynx relate to the digestive system
the oropharynx and the laryngopharynx
309
where is the oropharynx located
immediately behind oral cavity
310
what is the oropharynx made of
stratified squamous epithelium
311
where is the laryngopharynx located
below the oropharynx
312
what is the laryngopharynx made of
stratified squamous epithelium
313
what does the esophagus connect
the pharynx to the stomach
314
what is the esophagus made of
stratified squamous epithelium
315
what lubricated food as it passes through the esophagus
mucous glands in submucosa and mucosa
316
what kind of muscle makes up the muscularis externa of the esophagus
upper 1/3: skeletal
middle 1/3: mix of smooth and skeletal
lower 1/3: smooth
317
what is a hiatal hernia
the superior part of the stomach pushed through the esophageal sphincter (GERD)
318
what is barretts esophagus
lower esophageal ulcers and precancerous epithelium due to persistent exposure of acidic stomach contents
319
what does the esophagus have instead of serosa
adventitia (fibrous connective tissue)
320
what kind of epithelium is the mucosa lining of the stomach
simple columnar epithelium
321
what are rugae
the folds of mucosa that increase surface area and allow the stomach to expand
322
where is the cardia of the stomach
closest to the heart
323
where is the fundus of the stomach
the hump on the top of the stomach
324
what is the pyloric antrum of the stomach
the bottom of the stomach
325
what is the pyloric sphincter
the valve that regulates movement into the small intestine
326
what is the cardiac sphincter
valve that prevents food from moving back into the esophagus
327
what are the three layers of the muscularis externa in the stomach
longitudinal, circular, oblique (innermost)
328
what do the mucous neck cells do in the stomach
secrete mucus
329
what is the gastric pit in the stomach
regions where the epithelium cups downward and meets with the gastric gland
330
what are the specialized cell types of the gastric gland
parietal cells, chief cells, enteroendocrine cells, undifferentiated stem cells
331
what do parietal cells of the gastric gland do
secrete HCl which destroys bacteria
produce gastric intrinsic factor which is necessary for vitamin B12 absorption in small intestine
332
what do chief cells of the gastric glands secrete
pepsinogen and gastric lipase
333
what is the purpose of enteroendocrine cells of the gastric gland
release hormones
334
where are undifferentiated stem cells found
junction between gastric glands and gastric pits
335
why does the stomach need stem cells close
because of harsh environment, stomach cells are replaced every 3-7 days
336
what does pepsin do in the stomach
breaks down proteins in food
337
what is the basic pathway of pepsin formation
food enters stomach
release of gastrin into bloodstream
chief cells release pepsinogen (inactive)
parietal cells release HCl
HCl reacts with pepsinogen to make pepsin (active)
pepsin breaks down proteins
338
why was alexis st martin studied
he had a gastric fistula: abnormal connection between stomach and skin that left an open hole to the stomach
339
what is the longest segment of the alimentary canal
small intestine
340
where does most absorption and chemical digestion take place
small intestine
341
what are the three segments of the small intestine and where are they in relation to each other
duodenum (closest to stomach)
jejunum
ileum (closest to large intestine)
342
which segment of the small intestine is the shortest
duodenum
343
which segment of the small intestine is the longest
ileum
344
which segment does the most absorption occur
jejunum
345
what are the four layers of the small intestine wall
mucosa
submucosa
external muscularis
serosa
346
what are the four contributors to the large surface area of the small intestine
length, circular folds, villi, microvilli
347
what is the main purpose of the circular folds of the small intestine
to slow down chyme to increase nutrient absorption
348
what kind of cells make up the villi
absorptive cells
349
the part of the villi that has blood capillaries and a lymphatic capillary is called what
lacteal
350
what is the brush border
microvilli
351
what part of the villi is highly vascular
lamina propia
352
what part of the villi absorbs proteins and carbs
capillaries
353
what part of the villi absorbs fats
lacteals
354
what part of the villi allows the villi to move within the lumen
muscularis mucosa
355
what do the absorptive cells of the villi assemble absorbed lipids into
chylomicrons
356
what do chylomicrons do
help transport hydrophobic molecules in a hydrophilic environment
357
what is the purpose of the goblet cells on the villi
secrete mucus to lubricate chyme
358
what do the enteroendocrine cells of the villi do
secrete hormones to control the release of other substances
359
what are intestinal crypts
invaginations of mucosa between villi that produce intestinal juice
360
what is the purpose of paneth cells and where are they found
destroy unwanted bacteria; found at the base of the intestinal crypt
361
where do the ducts of duodenal glands open
into intestinal crypts
362
where are duodenal glands found
submucosa of duodenum
363
what are the two areas of lymphoid tissue in the small intestine
MALT and aggregated lymphoid nodules
364
what do the lymphoid structures of the small intestine do
prevent unwanted bacteria
365
what does the stomach contribute to the duodenum
chyme
366
what does the gallbladder contribute to the duodenum
bile (breaks down fats)
367
what does the pancreas contribute to the duodenum
digestive enzymes, pancreatic juice
368
what is the final control valve of the duodenum called
hepatopancreatic sphincter
369
once the chyme enters the duodenum, what happens when fats are detected
release of CCK which signals release of stored bile
370
once chyme enters the duodenum, what happens when acids are detected
release of secretin signals release of pancreatic juice
371
what is the epiploic of the large intestine
fat filled pouched on the outside
372
what are the teniae coli on the large intestine
longitudinal strips of smooth muscle that cause puckering of the haustra
373
what are the haustra of the large intestine
saclike structures
374
what does the ileocecal valve of the large intestine connect
connects ileum to cecum
375
what are the four parts of the colon
ascending (R side of body), transverse, descending (L side of body), sigmoid
376
what type of epithelium lines the large intestine
simple columnar
377
does the large intestine have circular folds or villi
no
378
what do the colonocytes (absorptive cells of the large intestine) primarily absorb
water and electrolytes
379
what reduces the friction of fecal movement in the large intestine
mucus from stem cells
380
what type of cell is contained in the intestinal crypts of the large intestine
stem cells to replace epithelium every 7 days
381
what does the rectum connect
sigmoid colon to anal canal
382
what are rectal valves
transverse folds that prevent feces being passed with flatus
383
what kind of epithelium is in the anal canal
stratified squamous
384
what is the difference between the external and the internal anal sphincter
external: skeletal, voluntary
internal: smooth, involuntary
385
what is a hemorrhoid
varicose veins of the hemorrhoidal veins in anal canal
386
what are hemorrhoids caused by
excessive straining
387
what are the accessory organs of the abdominal cavity
liver, gallbladder, pancreas
388
what is the digestive function of the liver
produces bile
389
what is the metabolic function of the liver
processes blood coming from stomach and intestines
390
what are the four lobes of the liver
right, left, quadrate, caudate
391
where is the caudate lobe located in relation to the quadrate lobe
caudate lobe is on top back if liver is facing in correct orientation
392
what does the hepatic portal vein of the liver do
gathers blood from digestive organs and transports it to the liver
393
what provides O rich blood to liver
hepatic artery proper
394
what provides the liver with nutrient rich blood
hepatic portal vein
395
what removes blood from the liver after it is processed
inferior vena cava
396
where is the bile (produced in the liver) stored
gallbladder
397
what are the hexagonally-shaped cells of the liver called
lobules
398
what are organized into portal triads in the liver
blood vessels and ducts
399
what transports bile out of the lobule
bile duct
400
what transports nutrient rich blood into the lobule
portal venule
401
what transports oxygen rich blood into the lobule
portal arteriole
402
what do the portal triads release blood into
sinusoids
403
what are hepatocytes
primary cell of the liver
404
what are the two main functions of hepatocytes
produce bile
metabolize and store substances from blood
405
what are the liver sinusoids
large capillaries between plates of hepatocytes
406
what happens to the blood in the liver sinusoids
arterial and venous blood mix
407
where does blood go after it is in the sinusoids
into the central vein to drain out of the liver
408
what do stellate macrophages move through
sinusoids in liver
409
what is the function of stellate macrophages (two)
destroy organisms that have made it through intestine
destroy worn out blood cells
410
what is the correct order of movement for bile in the liver
hepatocytes --> bile canaliculus --> bile duct
411
how many capillary beds does the blood in the liver move through before returning to the heart
two
412
what connects the liver to the gallbladder and duodenum
series of ducts
413
what is the function of the gallbladder
stores and concentrates bile
414
what are gallstones
cholesterol that precipitates out of bile while in gallbladder
415
what controls the release of bile into the duodenum
a sphincter at the duodenum
416
what is the exocrine function of the pancreas
produce and secrete enzymes that breakdown different food types and neutralize chyme
417
what kind of cell in the pancreas produces and secretes pancreatic enzymes
acinar cells
418
what is the hormone controlling the release of pancreatic enzymes
secretin
419
what is the endocrine function of the pancreas
produce hormones
420
kind of cells produce insulin in the pancreas
beta cells
421
what kind of cells produce glucagon in the pancreas
alpha cells
422
will insulin raise or lower blood sugar
lower
423
will glucagon raise or lower blood sugar
raise
424
what is the mesentary
double sided serous membrane that suspends organs within cavity
425
what are ulcers
erosions of the mucosa caused by bacterium
426
what is inflammatory bowel disease
abnormal immune/inflammatory response to bacterial antigens in intestine
427
what are the two types of inflammatory bowel disease
crohns (more severe)
ulcerative (less severe)
428
what does irritable bowel syndrome affect
large intestine
429
what is celiac disease
autoimmune disease where gluten triggers an immune response that damages villi of the small intestine (decreased absorption)
