Exam 2 Flashcards
(200 cards)
1
Q
What are the three types of muscles?
A
- Cardiac
- Skeletal
- Smooth
2
Q
What is the function of muscle?
A
To move body and things within the body (contraction)
3
Q
What is the sarcolemma?
A
Plasma membrane of muscle fiber
4
Q
What is the sarcoplasmic reticulum?
A
Smooth ER of muscle cell
5
Q
What are the functions of the sarcoplasmic reticulum?
A
Storage for fiber, calcium release control
6
Q
Smooth Muscle
1. Striation and is it voluntary?
2. Shape of cells
3. Where is the nucleus located
4. What regulates it?
5. Where is it found?
A
- non-striated and involuntary
- spindle-shaped
- centrally located
- The autonomic nervous system (ANS)
- Found in hollow viscera, eye, attached to hairs (arrector pili)
7
Q
Cardiac Muscle
1. Striation and is it voluntary?
2. Where is it found?
3. What is it controlled by?
4. Shape of cells
5. Where do the ends of the cells join?
A
- Straited and involuntary
- Only in the heart
- regulated by the ANS
- elongated and branching
- Intercalated disk
8
Q
What is an intercalated disk?
A
A specialized membrane that facilitates transmission of electrical impulses
9
Q
Skeletal Muscle
1. Striation and is it voluntary?
2. Nuclei (number and location)
A
- striated and voluntary, except for reflexes
- Multiple nuclei and off-center location
10
Q
What type of muscle makes up the majority of the muscle mass in the body?
A
Skeletal muscle
11
Q
True or false? Cardiac muscle does not branch and does not have intercalated disks. If false, which type of muscle does this refer to?
A
False, Smooth muscle
12
Q
True or false? Skeletal muscle, is innervated by cranial and spinal nerves. If false, which muscle type does this refer to?
A
True
13
Q
Origin
A
Least movable attachment, proximal and medial
14
Q
Insertion
A
most movable attachment, distal or lateral
15
Q
What brings insertions and origins together?
A
Contractions
16
Q
Extensors
A
Extend/increase angle between body parts
17
Q
Flexors
A
Flex/decrease angle between body parts
18
Q
Adductors
A
pull limb towards median plane
19
Q
Abductors
A
move limb away from median plane
20
Q
Constrictors (sphincters)
A
surround circular opening, close when contracted
21
Q
Dilators
A
surround circular opening, open when contracted (rare in mammals)
22
Q
Agonist muscle
A
muscles promote given movement ex. biceps
23
Q
Antagonist muscle
A
muscles inhibit movement, prevent hyperextension ex. triceps
24
Q
What do red muscle fibers contain (3) and what are they used for?
A
- myoglobin for oxygen storage
- glycogen for glucose storage
- mitochondria for ATP production
25
Slow twitch muscle fibers
slow to contract, slow to fatigue. Used for endurance
26
Fast twitch muscle fibers
fast to contract, lose energy quickly
27
Are red muscle fibers fast or slow twitch? What about white muscle fibers?
red are slow-twitch
white are fast-twitch
28
Parallel in regards to tendons
tendon comes off ends of fibers to attach to bone ex. pec muscles
29
Pennate (tendons)
feather-like with central tendon, wide at the top and converges to tendon ex. biceps
30
Fleshy
appears to attach directly at bone, but has short (microscopic) tendons between fibers and bone. Ex. brachialis
31
Oblique
circular or convergent (abdomen)
32
What are the three layers of the connective tissue harnessing muscle?
1. endomysium
2. perimysium
3. epimysium
33
What is the endomysium?
Loose connective tissue around muscle cells
34
What is the perimysium?
Loose connective tissue around muscle bundles (fascicles)
35
What is the epimysium?
regular/dense connective tissue around the whole muscle
36
What converges at the center or end of pennate cells?
The three layers of the harnessing muscle
37
What are muscle fibers composed of?
myofibrils
38
What are myofibrils composed of?
myofilaments
39
What is myosin? What does it look like?
Thick filament. Individual filaments resemble golf clubs and fit together with the heads sticking out
40
What is actin?
Thin filament
41
How does the muscle contract?
Myosin pulls on actin
42
Sarcomere
The arrangement of actin and myosin
43
How many sarcomeres are on a myofibril?
Hundreds/Thousands
44
Banding pattern
striations
45
A-band
length of myosin filament, includes overlap with actin, stains dark
46
I-band
actin only, no overlap with myosin, stains light
47
Z-line
ends of sarcomere. connects actin filaments
48
M-line
middle of sarcomere, connects myosin filaments
49
What are the 3 parts of actin?
1. G-actin
2. F-actin
3. Tropomyosin
50
What part of actin are the molecules globular? How do they fit together? How many make actin filament?
G-actin, fit together like beads on a string, 2 G-actin filaments twisted around each other make actin filament
51
Where is tropomyosin located and what does it have on it?
Groove of actin filament (between actin strands). Has globular protein, troponin spaced along it.
52
What are the binding sites on actin for?
binding with myosin
53
What covers the binding sites so actin and myosin don't bind?
Tropomyosin
54
What binds to troponin to relax tropomyosin?
Calcium
55
What is packed with myofibrils and is responsible for muscle contraction?
Muscle fibers
56
Why are the organelles pushed to the outside?
Because of the space myofibrils take up.
57
Terminal cisternae
enlarged sacs of the SR, located at the end of A-bands
58
T-tubules
On the sarcolemma, extend into cell around myofibrils
59
How many t-tubules between terminal cisternae? What is this structure called?
One, triad
60
Motor Unit
one motor neuron and all skeletal muscle fibers it innervates (synapses with)
61
Synapse of motor neuron with skeletal muscle fiber
connection between motor neuron and skeletal muscle fiber, allowing for communication
62
Where are the motor neuron cell bodies located?
ventral horns of spinal cord
63
Motor end plate
region of sarcolemma at the neuromuscular junction where the neuron synapses with the muscle fiber.
64
Synapse
Junction between two neurons
65
What are the four muscle shapes?
1. oblique
2. fleshy
3. pennate
4. parallel
66
What level does the muscle contract at?
Sarcomere (each unit contracts)
67
What causes striations?
A and I bands
68
____ band is always the same length while the ___ and ___ bands change
A, I + H
69
Ventral Root
Motor Neuron
70
In the spinal cord, all motor stuff comes out of the ___ aspect
ventral
71
A nerve impulse in the motor neuron travels down the ______ to the _____ ________
axon; synaptic bulb
72
What happens when the protein channel reaches the threshold?
It opens up the voltage gated gate and calcium enters the axon
73
What does the synaptic bulb do? Where is it located?
It is located at the end of the axon terminal and releases neurotransmitters
74
What is released when calcium enters the axon?
ACh (acetylcholine)
75
The nerve and the muscle ____ touch
Never touch; fluid filled gap between them
76
What is a synaptic cleft?
gap between nerve and muscle
77
Where does ACh bind to?
receptors on the sarcolemma
78
What is action potential?
transmission of electricity
79
How does action potential initiate contraction?
it causes the calcium channels to open in terminal cisternae which releases calcium into the sarcoplasm
80
ATP is __________ to how much the muscle contracts
directly correlated
81
ATP becomes ____ which is released so it can become ______
ADP; ATP again
82
What does anaerobic mean? What does it lead to?
No oxygen required, does not produce enough ATP and results in lactic acid buildup (less effective)
83
What does aerobic mean?
requires oxygen, yields more ATP (much more effective)
84
What does the buildup of lactic acid cause?
muscle cramping
85
What does creatine phosphate do?
Regenerates ADP to form ATP
86
What is contracture? What happens? (4 parts)
abnormal, rigor, muscle shorting in the absence of actin potentials, constant contracted muscle state without relaxation; ATP runs out and myosin heads can't release actin, calcium is not re-sequestered into S.R. terminal cis.
87
What is rigor mortis?
contracture after death
88
When nerve impulse stops calcium is __________ into _______________.
re-sequestered; terminal cisternae
89
What is a muscle twitch?
Contraction of one motor unit (and all muscle fibers that neruron is attached/sends signials to)
90
Latent Phase
Cross-bridges (myosin & actin) are interacting, but nothing is moving, no tension
91
Contraction Phase
Myosin moves actin filaments closer together, muscle fibers shorten
92
Refractory Phase
short period where the muscle can not be stimulated right after muscle relaxes
93
Strong vs weak contractions
a weak contraction stimulates one muscle unit, a strong one stimulates multiple
94
Fatigue
Decrease in ATP and oxygen
95
Acetylcholine is released and received then __________ recycles it
acetylcholinesterase
96
What is wave summation?
The phenomenon where increased frequency of contraction leads to increased strength of contraction.
97
What happens when a muscle is stimulated to contract before it has relaxed?
The strength of the subsequent contraction is increased.
98
What occurs when the frequency of stimulation is increased past the threshold?
Individual muscle twitches become fused into a single prolonged contraction known as Tetany.
99
What is the Treppe (staircase effect)?
The gradual increase in muscle contraction strength when a muscle is stimulated multiple times with equal intensity, a few seconds apart, until it reaches optimal contraction strength.
100
Why does the Treppe effect occur?
Due to increasing calcium ion concentration in the sarcoplasm and the warming up of muscle fibers, which enhances enzyme efficiency.
101
How does Treppe differ from tetanus?
Treppe involves successive muscle twitches with increasing strength, while tetanus is a sustained contraction due to high-frequency stimulation.
102
What happens during the initial contractions of a rested muscle?
The contractions gradually increase in strength as calcium builds up in the sarcoplasm and the muscle warms up.
103
What do acetylcholinesterase inhibitors do? (4)
1. prevent acetylcholine from being broken down
2. Muscle keeps contracting, runs out of ATP
3. Death often occurs due to contraction of respiratory muscle without relaxation
4. Spastic muscle paralysis
104
What proteins are involved in cardiac contraction?
Cardiac contraction involves actin and myosin.
105
How does the sarcomere arrangement in cardiac muscle compare to skeletal muscle?
Cardiac muscle has the same sarcomere arrangement and contraction mechanism as skeletal muscle (sliding filament), with slight differences in sarcotubular arrangement and number of triads.
106
Where does the action potential originate in cardiac contractions?
The action potential originates in the heart itself.
107
What controls cardiac contraction?
The autonomic nervous system (ANS) controls cardiac contraction.
108
What is the role of Purkinje fibers in the heart?
Purkinje fibers in the heart spread the action potential very fast.
109
Smooth muscle contraction (3)
1. Loose arrangement and interaction of action and myosin filaments
2. More actin to myosin
3. Actin attached to dense bodies
110
Acellular matrix that surrounds a relatively small number of cells is called
Chondrocytes
111
What are the two primary functions of synovial fluid?
lubrication and nourishment
112
Vascular Connective Tissue
lines the inner surface of the joint capsule but does not cover the bearing surfaces
113
What type of joints allow one surface to glide over another?
Synovial joints
114
What facilitates the gliding motion in synovial joints?
The presence of articular cartilage and synovial fluid
115
What encloses synovial joints?
Joint capsule
116
What is arthritis?
Inflammation of joint
117
The connection between any of the skeletons rigid component parts is known as a ______
Joint; articulations
118
Hypocalcemia
Lack of calcium, causes milk fever
119
bungarotoxin
binds irreversibly and competitively to receptor found at neuromuscular junction and causes respiratory failure and death
120
Botulism
inability to release acetylcholine at motor end plates; flaccid paralysis
121
Tetanus
TeNT absorbed by nerves and transported to spinal cord, spasmodic contractions of voluntary muscles with release of inhibitory neurotransmitters from presynaptic nerve endings, can cause fractures and lead to resp failure
122
What is Osteology the study of? What about arthrology?
bones; joints
123
What is a bone?
cellular structures in which the extracellular fluid environment of the cell is surrounded by a ridged, calcified frame
124
What is the medullary cavity?
the hollow space in the center of bones that stores bone marrow (principle location of blood formation)
125
Bones are dynamic structures capable of accommodating to different loads and stress by __
remodeling shape
126
What is the synovial membrane? What does it produce?
inner lining of joint capsule; synovial fluid
127
Axial Skeleton
skull, spine, ribs, sternum
128
Appendicular skeleton
appendages and the girdles that attach them
129
Articular cartilage
covers surface of bones when they come together to form joints
130
The neurocranium protects ___
the brain and openings for cranial nerve connections (brain case)
131
Viscerocranium protects ___
the organs of the special senses and openings for the digestive and respiratory system (bones of the face, surrounding mouth)
132
What are the 5 spinal locations?
1. Cervical (neck)
2. Thoratic (upper back)
3. Lumbar (lower back)
4. Sacral (above butt)
5. Caudal (tail)
133
Transverse Process
site of muscle and ligament attachment
134
Transverse Foreman
Where cervical arteries come out, only seen in cervical vertebrae (blood vessels & nerves pass through)
135
The cranial and caudal surfaces of contiguous vertebrate have a covering of _________ cartilage
hyaline
136
Nucleus Pulposus
soft, gelatinous interior of intervertebral disc
137
Annulus Fibrosus
The fibrocartilaginous collar that supports the periphery of the disk (outer layer)
138
What three things does the pectoral girdle consist of?
1. scapula
2. clavicle
3. coracoid
139
What does the pelvic girdle consist of? (3)
1. ilium
2. ischium
3. pubis
140
Acetabulum
socket that connects hip joint and femur
141
What is the os coxae What 3 bones does it consist of?
hip bone; ischium, pubis, ilium
142
What is the ilium?
What is the ischium?
What is the pubis?
Top of pelvic girdle
Bottom of girdle
Middle of girdle
143
Obturator Foreman
opening found by the pubis cranially and the ischium caudally
144
What are the components of the thoracic limb?
Pectoral girdle
brachium
antebrachium
carpals
metacarpals
phalanges
145
What are the components of the pelvic limb?
pelvic girdle
thigh
crus
patella
tarsus
metatarsus
phalanges
146
How many metacarpal bones do humans, dogs, and cats have?
5; labeled 1 to 5 starting with thumb
147
Examples of even toed animals
cows, sheep, goats
148
Examples of odd toed animals
rhinos, tapirs, horses
149
Cannon Bone
Between knee and ankle, third metacarpal
150
Splint Bones
Alongside cannon bone
151
A horse has ___ digits and ___ phalanges
1 digit; 3 phalanges; walk on third (middle finger)
152
Fetlock
Joint between cannon bone and first phalanx (long pastern)
153
Pastern Bone
joint between 1st and 2nd phalanx
154
Compact Bone
smooth, strong
looks to be solid, not completely
on the outside of the bone
155
Spongy Bone
spicules of bones with osteocytes surrounded by matrix
appears spongy due to trabeculate of mineralized tissue
spaces between spicules are filled with red marrow
156
Epiphysis
ends of bone
157
diaphysis
middle of bone/shaft; contains medullary cavity
158
metaphysis
flared part of shaft
159
The epiphyseal plate is composed of _______ and represents growth in a _____________ direction
hyaline cartilage; longitudinal
160
Periosteum
tough fibrous membrane on the outside of the bone
161
Endosteum
inner membrane lining marrow cavity and spaces in spongy bone
162
Long Bones
stretched in one direction ex Femur
163
Short Bones
Equal in all dimensions ex. wrist bones
164
Flat Bones
thin (skull bones, ribs)
165
Sesamoid Bones
sesame seed shaped ex. patella
166
Irregular Bones
No definite shape (vertebrate)
167
Pneumatic Bones
Hollow (sinuses)
168
Compact bone has ____, while spongy bone has ___
osteons; trabeculae
169
Where is red marrow found in young vs adult animals? What does it do?
young: medullary cavity
adult: spaces of spongey bone
active in blood formation
170
What is yellow marrow?
fatty, replaces red marrow in the marrow cavity as the animal matures
171
Osteons
Structural unit of compact bone, cylindrical
172
Features of Osteons (3)
1. circumferential lamellae
2. canaliculi
3. central (haversian) canals
173
Circumferential lamellae
layers of bone matrix that surround entire bone
174
Canaliculi
connect lacunae/osteocytes
175
Lacunae
small spaces within bone matrix to protect osteocytes
176
Central (haversian) canal
In each osteon, contains blood vessels and nerves
177
Perforating Canals
connect central canals or marrow cavity to outside of bone (contain blood vessels & nerves)
178
1. Osteoblasts
2. Osteocytes
3. Osteoclasts
1. young, actively depositing matrix, new bone
2. less active once surrounded by hard matrix
3. bone destroyers
179
Hydroxyapatite
Formation of bone, depositing calcium and phosphate
180
Calcification
Depositing calcium phosphate in tissues to make them hard, can be abnormal if occurs in soft tissue
181
Bones are __% water, __ % minerals, and __ % organic
25, 45, 30
182
Ossification center begins as ___________ move into tissue
osteoblasts
183
184
185
Endochondral
base layer of cartilage, acts as scaffolding, growth in length
186
Zone of Cartilage Proliferation
nearest epiphysis
dividing cartilage cells
nearest diaphysis: lined in columns
187
Zone of Calcification
1. zone of hypertrophy: chondrocytes swell and die
2. zone of calcification: calcium salts deposited
188
Osteoblasts can form from inner layers of _________ and ________ to deposit new bone
periosteum, endosteum
189
Epiphyseal Fracture
Fracture in growth plate, damage growth
190
Communuted Fracture
multiple pieces
191
Greenstick Fracture
often occurs in young bones, break halfway through
192
Compound fracture
break in skin, lead to infection of blood or bone
193
Osteoblasts and osteoclasts work together to move ______ around
bone matrix
194
Simple Fracture
No break in skin
195
Steps in healing fracture (7)
1. bone breaks
2. immobilize fracture/appose ends
3. new blood vessels enter
4. C.T. enters and fibrous C.T. bridges gap
5. soft callus of hyaline cartilage forms
6. hard callus of bone replaces hyaline cartilage
7. remodeling by osteoclasts to reform marrow cavity and smooth bumps
196
What are the 4 types of stressors that can injure bone? What does each mean?
1. Compression: chronically, bones become short and thick
2. Tension: chronically, long, thin
3. Shear Force: not chronic, acute, opposing forces
4. Torsion: chronic, bone bends
197
Why is calcium important? (4)
1. muscle contraction
2. action potential of cardiac muscle
3. enzyme cofactor
4. blood coagulation
198
PTH (parathyroid hormone)
When is it released and what does it do?
releases when blood calcium is low
it increased bone respiration, increases kidney resorption of calcium, and stimulates kidney to convert vit D to active form
199
What is Vitamin D? When is it released and what does it do?
cholecalciferol
released due to low blood calcium
increases intestinal calcium absorption and kidney resorption
200
Calcitonin
What is it released and what does it do?
released due to high blood calcium
inhibits bone resorption and increases urinary excretion of calcium
