exam 2 Flashcards
(269 cards)
1
Q
what is osteology?
A
the study of bone
2
Q
what is bone?
A
an active, dynamic CT
3
Q
what are the properties of bone?
A
calcium salts and collagen fibers
4
Q
what do calcium salts and collagen fibers work together to maintain?
A
structural integrity
5
Q
what are the functions of bone?
A
structure, protection of vital organs, leverage (locomotion), storage (of minerals)
6
Q
what is the order of bones in the axial skeleton? (cranial to caudal)
A
- skull
- vertebral column
- sternum
- ribs
7
Q
what is the order of bones in the thoracic limb? (proximal to distal)
A
- scapula
- humerus
- ulna
- radius
- carpals
- metacarpals
- phalanges/digits
8
Q
what is the order of bones in the pelvic limb? (proximal to distal)
A
- pelvis
- femur
- patella
- tibia
- fibula
- tarsals
- metatarsals
- phalanges/digits
9
Q
what are the three bones of the pelvis?
A
ilium, ischium, pubis
10
Q
what are the different divisions of the vertebrae? (cranial to caudal)
A
- cervical
- thoracic
- lumbar
- sacral
- caudal
11
Q
what are the six types of bones?
A
long, short, flat, irregular, sesamoid, pneumatic
12
Q
what is the purpose of long bones?
A
to give structure and support
13
Q
what is the function of short bones?
A
to create more complex structures (ex: carpus, tarsus, wrists, ankles, knees, hock)
14
Q
what is the function of flat bones?
A
protection
15
Q
what are examples of flat bones?
A
ribs, sternum, top of skull
16
Q
what categorizes irregular bones? what is their function?
A
irregularly shaped; provide protection for CNS
17
Q
what is the function of sesamoid bones?
A
to protect tendon and ligament dense areas
18
Q
what is an example of a sesamoid bone?
A
patella
19
Q
what species are pneumatic bones only found in?
A
avian species
20
Q
what are pneumatic bones?
A
bones are filled with sacs of air that allow for flight
21
Q
what is another word for spongy bones?
A
cancellous
22
Q
what is the medullary cavity?
A
inside of bone, where bone marrow is located
23
Q
where is the epiphysis?
A
both ends of long bones
24
Q
what part of the long bone is the diaphysis?
A
creates length of long bones
25
what part of the long bone is the metaphysis?
the junction between the epiphysis and diaphysis
26
where is epiphyseal cartilage found?
in between the metaphysis and epiphysis
27
what is epiphyseal cartilage?
the location of growth in the long bone
28
what is the periosteum?
wraps around the surface of all bones; is slightly protective
29
what is the endosteum?
in the medullary cavity; all structures inside of bone
30
what is articular cartilage?
surfaces of bones that make physical contact
31
what are oseocytes? where are they found?
mature bone cells found lacunae; derived from osteoblasts; stuck in hardened bone tissue; maintain bone and repair itself
32
what are osteoblasts?
cells that build bone; secretes collagen and ground substance that makes up unmineralized bone, called osteoid; derived from osteoproginitor cells
33
what are oseoclasts?
cells that break down bone; large multinuceated bone resorbing cells derived from monocytes
34
what are oseoproginitor cells?
most general bone cell; doesn’t have a job yet; these are precursors to osteoblasts
35
what is the function of spongy bone?
helps reduce the weight of bones; keeps the skeleton light while preventing it from being damaged by force
36
where is spongy bone found?
inside of bones; in long bones, usually concentrated at the epiphysis
37
what is the purpose of haversian canals?
small tunnels in the bone allowing for blood vessels, lymph nodes, and nerves to go throughout compact bone
38
what is the structure of compact bone?
makes up the shaft of long bones and the outside of all bones
39
where is bone marrow found?
it fills the spaces within bones
40
what is the function of red bone marrow?
forms blood cells (RBCs and WBCs)
41
what is white/yellow bone marrow made of?
made primarily of fat
42
what is the function of white/yellow bone barrow?
fat storage; can return to red bone marrow if needed by the body
43
what is the function for articular cartilage?
protection; maintains integrity and function of the bone
44
what is articular cartilage made of?
hyaline cartilage
45
what is the function of epiphyseal cartilage?
growth plates; the site of long bone lengthening as animal grows
46
what happens during long bone lengthening?
cartilage cells create new cartilage and osteoblasts replace the cartilage with bone
47
what makes up 1/3 of the weight of mature bone?
organic components (glycosaminoglycans and collagen fibers)
48
what is the function of glycosaminoglycans?
modulate activity of osteogenesis and osteoclastic factors (bone remodeling or making new bone)
49
what makes up 2/3 of the weight of mature bone?
inorganic compounds within the organic layers
- Ca and P salts: hydroapotite crystals (80%) (harden the matrix during ossification)
- Ca carbonate and Mg P (20%)
50
what are the two steps to creating new bones?
ossification and calcification
51
what happens during ossification?
osteoblasts produce matrix
52
what is the bone matrix/ bone jelly?
soft collagen fibers in gelatinous ground substance
53
what is heteroplastic ossification?
calcification of tissue other than bone (os penis; os cardis)
54
what are the two types of ossification?
- intramembranous ossification
- endochondral ossification
55
what are the steps of intramembranous ossification?
1. ossification center appears in the fibrous CT membrane
2. osteoblasts secrete osteoid within the fibrous membrane and it calcifies within a few days; trapped osteoblasts become osteocytes
3. osteoid is laid down between the blood vessels in a random pattern resulting in a network of woven bone
- vascularized mesenchyme condenses on the face of
the woven bone and becomes the periosteum
4. lamella bone replaces woven bone and red bone marrow appears
56
what is the function of intramembranous ossification?
flat bone formation
57
what is endochondral ossification?
the transformation of existing tissue; replacement of hyaline cartilage with usable bones
58
what are the steps of endochondral ossification?
1. formation of bone collar around hyaline cartilage model
2. cavitation of the hyaline cartilage within the cartilage model
3. invasion of internal cavities by the periosteal bud and spongy bone formation
4. formation of the medullary cavity as ossification continues; appearance of secondary ossification centers in the epiphyses
5. ossification of the epiphyses; when completed, hyaline cartilage only remains in the epiphyseal plate and articular cartilages
59
why does bone growth happen?
cartilage grows and is replaced by bone
60
what is bone remodeling?
the growing shaft is remodeled by the bone being resorbed and bone added by appositional growth
61
what is arthrology?
the study of articulations between bones (aka joints)
62
what are joints?
supporting connective tissue
63
what are the classes of joints based off structure?
- fibrous
- cartilaginous
- synovial
- other structures
64
what are the characteristics of fibrous joints?
connected to fibrous tissue, no joint cavity
65
what are the characteristics of cartilaginous joints?
limited movement, no joint cavity
66
what are the characteristics of synovial joints?
- true joints
- most moveable joints in the body
- contains synovial cavities
- has bursae (reduces friction between bones of joint)
67
what are the three types of fibrous joints?
suture, gomphoses, syndesmosis
68
what are suture joints?
thin layer of dense fibrous CT uniting the bones of the skull
69
what are gomphoses joints? example?
cone shaped pegs in bony sockets; teeth
70
what are syndesmosis joints?
two adjacent bones connected by a strong membrane/ligament
71
what is the movability of synarthroses joints? what skeleton are they part of?
immovable; axial skeleton
72
what is the movability of amphiarthroses joints? what skeleton are they part of?
slightly moveable; axial skeleton
73
what is the moveability of diarthroses joints? what skeleton are they part of?
freely movable; appendicular skeleton
74
what are the two types of cartilaginous joints?
synchondroses and symphyses joints
75
what are synchondroses joints? examples?
epiphyseal plate; united by hyaline cartilage
ex: joint of sternum and ribs
76
what are symphyses joints? examples?
connected by fibrocartilage
ex: pelvis and intervertebral disks
77
what is the function of bursae?
provides cushion and reduces friction between bones of the joint
78
what does blood supply to the joints look like?
arteries form a network around the joint; capillaries supply nutrition to articular cartilage
79
what is the lymph function for the joints?
lymph vessel leaves joint and drains into local lymph node
80
what is the nerve function in joints?
pain and reflex response; assist with locomotion and pasture
81
what is abduction?
joint movement away from the midline
82
what is adduction?
movement of a joint toward the midline
83
what are the four tarsal joints? (proximal to distal)
- tibiotarsal
- proximal intertarsal
- distal intertarsal
- tarsometatarsal
84
what makes up the CNS?
brain and spinal cord
85
what are the functions of the nervous system?
- regulation: being able to take in info and give a response (motor/muscle movement and glandular secretion (ex: salivary, endocrine, and sweat glands))
- response may be connected to command muscles to move or produce glandular secretions
- integration: analyzing info, takes in info inside (pH of blood, ion concentration, body temp) and outside body (outside temp, barometric pressure)
- the brain and spinal cord received, analyzed, stored, and integrated to produce a response
- sensory reception: the nervous system senses changes from within the body and outside the body to convey information to the spinal cord and brain
- consciousness
- thirst, hunger, emotional behaviors necessary for survival
86
what are the two divisions of the nervous system?
CNS and PNS
87
what makes up the CNS?
brain and spinal cord
88
what is the function of the CNS?
integrative and control center
89
what is the function of the brain?
receives and processes sensory information, initiates responses, stores memories, generates thoughts and emotions
90
what is the function of the spinal cord?
conducts signals to and from the brain; controls reflex activities; form a two way path between the brain and spinal cord for motor and sensory neurons
91
what is the structure of the PNS?
cranial nerves and spinal nerves
92
what’s the function of the PNS?
communication lines between the CNS and the rest of the body
93
what is the pathway of motor neurons?
CNS to muscles and glands
94
what is the pathway of sensory neurons?
sensory organs to CNS
95
what is the function of sensory neurons?
takes in information and sends it to the CNS
96
what are the two divisions of motor neurons?
somatic nervous system and autonomic nervous system
97
what is the function of the somatic nervous system?
controls voluntary movements; conducts impulses from CNS to skeletal muscles
98
what kind of muscles are under the control of the somatic nervous system?
skeletal muscle
99
what kind of muscles are under the control of the somatic nervous system?
smooth and cardiac muscle
100
what is the function of the ANS?
controls involuntary responses; conducts impulses from the CNS to cardiac muscles, smooth muscles, and glands
101
what are the two divisions of the ANS?
sympathetic and parasympathetic
102
what is the function of the sympathetic division of the ANS?
fight or flight
103
what is the function of the parasympathetic division of the ANS?
rest or digest
104
are motor neurons efferent of afferent?
efferent
105
are sensory neurons efferent of afferent?
afferent
106
where is the CNS located in reference to the body?
centrally
107
what is the top portion of the skull called?
maxilla
108
where does the spinal cord end?
ends at L1
109
what protects the spinal cord?
the vertebrae/ vertebral column
110
what are meninges?
the membranes of the CNS; fibrous connective tissue that covers the brain and spinal cord
111
what are the three types of meninges?
- dura matter
- arachnoid
- pia matter
112
what is the dura matter?
outside membrane of CNS
113
what is the arachnoid?
the middle membrane layer of the CNS
114
what is the pia matter?
inner layer(membrane) that adheres to the CNS
115
what does the pia matter make up?
the blood/brain barrier
116
what is the blood/brain barrier?
capillary bed with tight junctions, functions as a physical barrier (protective); the place where blood delivers to the CNS
117
what is the structure of cerebrospinal fluid?
clear fluid derived from blood that circulates throughout the CNS in between meninges
118
what is the function of cerebrospinal fluid?
keeps brain from hitting skull; shock protector to protect the brain and spinal cord; maintains pressure between brain and spinal cord and surrounding bone
119
what are the two neural tissue subtypes of the cerebrum?
- cortex/ gray matter
- medullary/ white matter
120
where is the cerebellum located?
at the back of the brain towards the brainstem
121
what is the function of the brainstem?
connects the area between the brain and spinal cord
122
what glands are located in the interbrain?
pituitary, hypothalamus, subthalamus, thalamus, epithalamus
123
what makes up the midbrain?
visual and auditory, nuclei and fiber tracts (brain protecting itself)
124
where is the spinal cord located?
begins at foramen magnum(connection between brain and spinal cord) to the lower of L1 and extends out to cauda equina
125
what are the four divisions of the spinal cord?
cervical, thoracic, lumbar, sacral
126
what is gray matter?
unmeylinated nerve cell bodies (clusters of cell bodies in CNS)
127
what does gray matter contain?
contains sensory and motor nuclei
128
what makes up white matter?
myelinated axons; few cell bodies
129
what is the purpose of myelination?
allows for info to be transmitted faster
130
where is white matter found?
connections between brain stem and higher brain centers with spinal nerves
131
what are afferent pathways?
6 major ascending tracts that carry sensory info from body to brain
132
what are efferent pathways?
the 4 major descending tracts sending motor information from the brain the the body
133
what are the three orders of the reflex center in the spinal cord?
1st order: spinal cord (knee-jerk reactions)
2nd order: brain stem (breathing, sweating, more complex responses)
3rd order: cerebral cortex (most complex responses such as tying shoes)
134
What makes up the PNS?
composed of 12 pairs of cranial nerves and both the sensory and motor spinal nerves
135
what makes up the spinal nerves?
afferent and efferent fibers enclosed in CT
136
what is the pathway of afferent fibers?
carries info from sensors and enter spinal cord through the dorsal root
137
what are the two types of stimuli carries by afferent fibers?
sensory stimuli and visceral stimuli
138
what are the sensory stimuli’s?
touch, pain, pressure, vibration, temperature, hearing, equilibrium, vision
139
what are the visceral stimuli’s?
stretch, pain, temp, chemical, hormones, taste, smell
140
afferent neurons =
sensory neurons
141
efferent neurons =
motor neurons
142
where are the cell bodies of afferent neurons located?
inside of the spinal cord
143
where are the cell bodies of efferent neurons located?
in the ventral horn of the spinal cord
144
what is the function of afferent neurons?
to carry sensory info from receptors in skin and other organs to the CNS
145
what is the function of efferent neurons?
to carry motor info from the brain to the PNS (away from the CNS)
146
what is the pathway of efferent fibers?
transmits instructions from CNS to effector organs; leaves spinal cord through the ventral root
147
what is a neuron?
the cell type of the nervous system/nervous cell; structural and functional unit of the nervous system
148
what is the nucleus of the CNS?
a clump of neuronal cell bodies inside the CNS (in gray matter)
149
what is a tract?
bundle of nerves inside the CNS
150
what are neuralgia/glial cells?
CT of the CNS (nerve glue)
151
what are ganglion?
clump of neuronal cell bodies outside of the CNS (in the PNS)
152
what is a nerve?
bundle of axons around CNS
153
what is the cellularity of nervous tissue?
high
154
what are the two primary cell types of the nervous system?
neuroglial cells and neurons
155
what do schwann cells form?
the myelin sheath in PNS
156
what is the primary function of neurons?
conduct neural impulses
157
what are the specialized characteristics of a neuron?
- all have a cell body
- extreme longevity (lasts entire life of animal)
- amniotic (can’t replicate)
- high metabolic rate (needs glucose and oxygen to function)
158
what is the cell body of a neuron?
biosynthetic center of the neuron
159
what is the structure of the cell body of the neuron?
- transparent, spherical nucleus
- similar components as a cell (rough ER, mitochondria, neurofilaments, plasma membrane)
160
what is the structure of a dendrite?
short, tapering, branching extensions coming off the cell body of a neuron
161
what is the function of a dendrite?
primary reception of input region of a neuron; conveys messages to cell body
162
larger axon diameter =
more efficient
163
what is the function of an axon?
the conduction region of the neuron that generates and transmits nerve impulses away from the cell body
164
what is the structure of a myelin sheath?
protein, lipid rich; goes along axon
165
what is the function of a myelin sheath?
increases speed, protects axon
166
more myelin =
signals are sent faster
167
what are the nodes of ranvier?
sites of Na channels for sodium propegation
168
what is the neurilemma?
schwann cell cytoplasm; outer membrane
169
what is the flow of info through neurons?
dendrites (collect electrical signal) —> cell body (integrates incoming signals and generates outgoing signal to axon) —> axon (passes electrical signals to dendrites of another cell or to an effector cell)
170
what are the three types of active ion channels?
voltage gated, chemically gated, and mechanically gated channels
171
what are ion channels?
membrane channels selective to a certain type of ion
172
what is the sodium potassium pump?
voltage gated ion channel; Na is outside of the cell and K is inside; the pump exchanges 3 Na entering for 2 K leaving
173
what are nerve impulses?
signals transmitted along a nerve fiber by a wave of depolarization (rapid change in electrical charge)(carry info btwn PNS and CNS)
174
what are the only cell types with excitable membranes that can generate action potentials?
neurons and muscle cells
175
what is RMP?
plasma membrane charge at rest; cytoplasmic side is negatively charged relative to outside membrane which is positively charged; -70mV; Na is concentrated outside of the cell
176
what happens during depolarization of AP?
- stimuli causes sodium channels to open
- Na enters
- reduction of MP
- less negative, moving to a positive mV
177
what happens during repolarization of AP?
- K enters
- increase in MP
- more negative, moving towards a negative mV
- Na/K pump becomes active to get the membrane back to RMP
- Na channels close and K channels open
178
what happens during hyperpolarization of AP?
K channels stay open briefly too long before closing; a period where membrane potential is less than -70mV
179
what is the threshold of an AP?
the level/amt of stimulus needed to create an AP, causing the neuron to depolarize
180
what is the refractory period of the AP?
the period when the neuron is insensitive to a nerve impulse because it has not completely depolarized
181
what is a graded potential?
small short-lived, localized changes in membrane potentials
- cause ion channels to open briefly
- can be either depolarization or hyperpolarization
- dendrites often generate GPs to the cell body
- potentials decrease in strength with distance
182
what is the function of a synapse?
mediates transfer of info
183
what is a neurotransmitter?
chemical messenger that carries a signal from pre to post synaptic neurons
184
what is the function of a gap junction?
gives a physical pathway for a signal
185
what are electrical synapses?
very broad transfer of information; immediate, large; in smooth and cardiac muscle; whole organ contraction; gap junctions causes there to be a direct connection between pre and post synaptic neurons
186
what are chemical synapses?
specific transfer of info; controlled, slower; skeletal muscle; uses neurotransmitters
187
what are the two important neurotransmitters?
acetylcholine and norepinephrine
188
what is the function of acetylcholine?
- skeletal muscle: excititory
- internal organs(smooth muscle): excitatory or inhibitory
- signal transmission from motor neuron to the muscle itself
189
where is acetylcholine found?
primarily in neuromuscular junction
190
what is the function of norepinephrine?
- controls the PNS, specifically the autonomic division
- big role in fight or flight and rest or digest
- excitatory or inhibitory
- plays a role in emotions
191
where is norepinephrine released?
areas of the brain and spinal cord; ANS
192
what facilitates the release of neurotransmitters?
Ca+
193
what neurotransmitters does the sympathetic division of the ANS use?
acetylcholine and norepinephrine
194
what neurotransmitters does the parasympathetic division of the ANS use?
only acetylcholine
195
what is the structure of the sympathetic division of the ANS?
nerve fivers arise from thoracic and lumbar regions of the spinal cord and connect to the vital organs
196
what is the structure of the parasympathetic division of the ANS?
nerve fibers arise from the brainstem and sacral region of the spinal cord to join the nerve fibers in the muscles and glands
197
what are the functions of the sympathetic division of the ANS?
- dilation of pupils and bronchioles
- increases heart rate, blood glucose concentration, blood to skeletal muscles
- slows peristaltic action
- decreases glandular secretions, blood to digestive organs
- relaxes muscles of gallbladder and urinary bladder
198
what are the functions of the parasympathetic division of the ANS?
- constricts pupils and bronchioles
- decreases heart rate, blood glucose concentration, blood to skeletal muscles
- increases peristaltic action, glandular secretions, blood to digestive organs
- contracts muscles of the gallbladder and urinary bladder
199
what is a muscle?
a tissue type
200
what are the main functions of the muscular system?
- contraction (shortening of muscle) (allows for movement to happen)
- locomotion (ability to seek resources)
- support (esp. with abdominal organs, pelvic organs, etc.)
201
what are the three types of muscle?
skeletal, cardiac, smooth
202
what are cutaneous muscles?
just below skin, responsible for skin twitch, little attachment to bones
203
what is the function of head and neck muscles?
facial expression, neck movement, movement of sensory structures
204
what are the functions of abdominal muscles?
supports abdominal muscles, flex the back, defecation, urination, parturition
205
what are the functions of thoracic limb muscles?
locomotion, abduction (lateral movement) and adduction (medial movement) of shoulder and movement of the lower limb
206
what are the functions of the pelvic limb muscles?
locomotion, abduction (lateral movement) and adduction (medial movement) of hip and movement of the lower limb
207
what is the origin of a muscle?
the fixed proximal end
208
what is the insertion of a muscle?
distal, movable end that contracts toward the origin
209
what is a flexor of a muscle?
closes/angulates a joint
210
what happens with extension of a muscle?
opens/straightens a joint
211
what is an agonist?
a muscle that directly produces a desired movement
212
what is an antagonist?
a muscle that directly opposes the movement of the agonist muscle (undoes movement)
213
what is a fascicle?
small bundles of skeletal muscle fibers within a specific muscle
214
what are muscle fibers?
individual muscle cells; made up by hundreds of muscle myofibrils that run together lengthwise
215
what is the neuromuscular junction?
where motor neuron terminal axon meets muscle fibers (chemical synapse); give structure of multi-nucleation; made up of protein filaments
216
what are muscle myofibrils?
composed of lots of actin and myosin that run parallel to each other in groups
217
what are protein filaments?
bundles of actin and myosin; contractile proteins that contribute to muscle contraction
218
what are the 3 types of CT that surround bundles of striated muscle fiber groups?
endomysium, perimysium, epimysium
219
what is the endomysium?
CT around individual muscle fibers; within fascicle; between muscle fibers that make up the fascicle
220
what is the perimysium?
CT around a bundle of muscle fibers; wraps around/ goes between fascicles
221
what is the epimysium?
dense CT sheet covering whole muscle; delineates muscles from each other and other adjacent tissues; gives muscle definition and separation
222
what is the sarcolemma?
muscle cell membrane; thin translucent sheet surrounded by each myofibril; location for nervous system interaction; controls contraction and relaxation
223
what is the sarcoplasmic reticulum?
calcium jail; equivalent to ER of other cells but is modified to store calcium
224
what are T tubules?
extends inward from the sarcolemma to help carry nerve impulses into the cell (allow for transmission of electrical signal for muscle to contract)
225
what is glycogen?
energy store; storage form of glucose (mostly stored in liver but also stored in skeletal muscles for emergencies)
226
how do cardiac muscle cells compare to skeletal muscle cells?
cardiac muscle cells are much smaller than skeletal muscle; cardiac is single-nucleated while skeletal is multi-nucleated
227
what are gap junctions?
connects cardiac muscle cells, allowing electrical impulses to flow rapidly and ensure synchronized contraction
228
what are intercalated disks?
located at attachment sites end-to-end between cells that for the branching network of cardiac muscle cells (unique to cardiac muscle)
229
what is the function of nerve supply to cardiac muscle?
does not initiate contractions but can modify them
230
what are the two types of smooth muscle?
visceral (99%) and multiunit (<1%) smooth muscle
231
what is the structure of visceral smooth muscle?
large sheets of cells in walls of organs
232
where is visceral smooth muscle found?
stomach, intestine, uterus, urinary bladder
233
what is the function of visceral smooth muscle?
large rhythmic waves of contractions (peristaltic contraction, parturition); as tissue stretches, contraction strength increases; not capable of fine movement
234
what is the structure of multiunit smooth muscle?
small discrete groups of cells
235
what is the function of multiunit smooth muscle?
fine movements
236
where is multiunit smooth muscle found?
eye, walls of blood vessels, dilation of bronchioles
237
what are the sources of energy for muscle contraction?
ATP, creating phosphate, glycogen stores, fatty acids
238
what are the two contractile proteins?
actin (thin) and myosin (thick)
239
what does bringing Z lines together do?
shortens the muscle fiber
240
what happens to Z lines during muscle contraction?
they visually disappear
241
what is acetylcholine?
neurotransmitter for a specified AP
242
what is the function of Ca during muscle contraction?
the limiting factor of contraction; stored by SR; binds to troponin complex which moves tropomyosin out of the way and exposes myosin binding sites
243
what is ATPase?
the enzyme that breaks down ATP into ADP and inorganic phosphate
244
what are the contractile properties of muscle fiber?
myosin ATPase and oxidative capacity
245
what are the three types of muscle fibers?
1. dark - type I
2. intermediate - type IIA
3. lightest - type IIB(x)
246
what are characteristics of dark - type I muscle fibers? what is an example of when they are used by the body?
slow twitch; aerobic; long distance running
247
what are characteristics of intermediate - type IIA muscle fibers? what is an example of when they are used by the body?
fast twitch fibers; anaerobic; middle distance running
248
what are characteristics of lightest - type IIB(x) muscle fibers? what is an example of when they are used by the body?
fast twitch; anaerobic; sprinting
249
what is hypertrophy?
muscle enlargement by increase in cell size
250
what is hyperplasia?
muscle enlargement by increase in number of muscle fibers
251
what is distrophy?
shrinking of the muscle
252
what is disuse atrophy?
muscles shrink because they aren’t being used
253
what is denervation atrophy?
muscles shrink because there is no longer a nervous pathway to the muscle
254
what happens during concentric muscle contraction?
shortening (flexion)
255
what happens during eccentric muscle contraction?
lengthening (extension)
256
what happens during isometric muscle contraction?
muscle stays the same length, tension changes (work was not performed)
257
what happens during isotonic muscle contraction?
muscle length changes, tension stays the same (work was performed)
258
what is summation?
a whole muscle contracting at varying strengths
259
what are the two types of summation?
spatial summation and temporal summation
260
what is spatial summation?
several EPSP traveling down multiple presynaptic neurons and arrive at axon hillock at the same time to cause AP
261
what is temporal summation?
several EPSP traveling down the same presynaptic neuron in quick succession that can cause an AP (EPSP loses signal as it travels across cell body)
262
what are the steps of muscle contraction?
1. AP arrives via chemical synapse and ACH travels into muscle through neuromuscular junction. Signal will travel along sarcolemma and T tubules. Signal will arrive at SR.
2. SR will release Ca into cytoplasm
3. Ca binds with troponin; binding causes a change on troponin/myosin complex; troponin moves off and exposes myosin binding site
4. myosin is bound by ADP and phosphate; myosin kicks off Pi; myosin that is bound to ADP attaches to actin; myosin kicks off ADP
5. contraction occurs; 90 degree myosin head movement caused by energy stored in myosin head
6. ATP comes and attaches to myosin; makes myosin let fo of actin
7. myosin goes back to its neutral state
8. troponin/tropomyosin complex has to recover binding sites; Ca pump sucks all Ca ions and puts them back in the SR
9. myosin stores ATPase in the head which breaks down ATP; this produces energy that is stored in the myosin head
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what are the four main bone cells?
osteoprogenitor cells, osteocytes, osteoblasts, osteoclasts
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what are osteoprogenitor cells?
cells that have been assigned a part of the body but not a job; precursor to osteoblasts and osteoclasts
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what are osteoclasts?
cells that break down bone into components; derived from osteoprogenitor cells
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what are osteocytes?
mature bone cells that come from osteoblasts
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how does an AP spread through a neuron?
info arrives at dendrites, travels through the dendrites which deliver information to the cell body, it flows through the axon which connects to the effector cell to carry out action
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what are synapses?
the contact point between neurons where information is passed from one neuron to the next
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how do chemical synapses pass info between neurons?
an AP arrives at axon terminal; voltage gated Ca channels open allowing Ca to enter the cell. Ca signals to synaptic vesicles that contain neurotransmitters to move to the membrane. It docks onto a protein on the membrane and triggers the presynaptic neuron to release neurotransmitters via exocytosis. These diffuse across synaptic cleft and bind to receptors on the postsynaptic neuron to cause action.
