251 Unit 2 Review

1
Hand Muscles Innervations
Hand muscles
3 subgroups
Midpalmar
Thenar (D1 Side)
Hypothenar (D5 Side)
Includes
Includes
2 subdivisions
AdP
FPB
OP
AbPB
AbDM
FDMB
ODM
Interossei
Lumbricales
4 total
PAD, DAB
Ulnar Nerve
2 Lateral
2 Medial
Median Nerve
Remember All intrinsic hand by Ulnar Nerve,
except 4 LL, (AbPB, OppP, FPB) last 3
thenar group
2
Forearm Muscles Innervations - Overview
Forearm muscles
2subgroups
Posterior Compartment
Anterior Compartment
2 subdivisions
2 subdivisions
Deep
Superficial
Deep
Superficial
3 muscles
5 muscles
5 muscles
7 muscles
PT
PQ
FDP
FPL
FCR
PL
FCU
FDS
EI
Sup
AbPL
ECRL
ED
ECRB
EDM
EPB
EPL
ECU
Anc
BR
Lat 1/2
snuffbox
Median Nerve
Med 1/2
Radial Nerve
Ulnar Nerve
3
Anterior Forearm Muscles and Innervations (Flexors
and Pronators)
Anterior Compartment
2 subdivisions
Deep
Superficial
3 muscles
5 muscles
PT
PQ
FDP
FPL
FCR
PL
FCU
FDS
Lat 1/2
Median Nerve
Med 1/2
Ulnar Nerve
Most anterior compartment by Median Nerve except
1.5 FCU Medial half of FDP
4
Posterior Forearm Muscles and Innervations (Extens
ors and Supinators, except BR)
Posterior Compartment
2 subdivisions
Deep
Superficial
5 muscles
7 muscles
EI
AbPL
ECRL
ED
ECRB
EDM
Sup
EPB
EPL
ECU
Anc
BR
snuffbox
Radial Nerve
(PI branch of )
All posterior compartment by Radial Nerve (or PI
branch of) Also note BRachioradialis Breaks the
Rule Is a flexor on the extensor side, is a
flexor innervated by Radial N Is the Beer
Raising muscle (works best when flexed and
semi-pronated) BB action turns corkscrew (sup)
and pulls cork (elbow flex)!
5

Additional Upper Extremity Innervations (not
including Radial N)
Rhomboid Major
Long thoracic
Serratus Anterior
Innervates
Dorsal Scapular N.,
Rhomboid Minor
Innervates
Levator Scapulae
Infraspinatus
Suprascapular
Innervates
Supraspinatus
Biceps Brachii
Musculocutaneous N.
Brachialis
Innervates
Teres Major
Lower
Coracobrachialis
Subscapular
Innervates
Upper Lower
Subscapularis
Pectoralis Major
Med Lat.
Pectoral N (lat/med)
Innervates
Pectoralis Minor
Med.
Teres Minor
Axillary
Innervates
Deltoid
SCM
CNXI (Accessory N)
Innervates
Trapezius
Thoracodorsal
Latissimus Dorsi
Innervates
6
Skeletal Muscle Structure/Microstructure
Skeletal Muscle
Has modified SER called
Covered by
Bundles of
Innervated by
Epimysium
Alpha MN
Blends into
Continuous w/
Axon of contacts muscle cell at
Fasicles
Perimysium
M.End Plate
Blends into
Covered by
Sarco. Retic
Bundles of
Continuous w/
specialized region of
forms
Muscle Fibers/cells
Endomysium
Sarcolemma
Term. Cist.
Is plasma. membr. of
Blends into
Covered by
Tendons
Bundles of
Communicates via T-tubules with
Regions that store
Ca2
Attach muscles to bones at
Chain of contractileunits called
Myofibrils
O I
Bundles of
Striped due to banding pattern of
Sarcomeres
House proteinscalled
Myofilaments
Note T tubules are invaginations of sarcolemma
that allow AP to reach terminal cisternae Triad
T-Tub 2 Cist
Sarcoplasmic rectic ER of striated muscle cells
7
Banding Pattern of the Sarcomere
Sarcomere
Have regular pattern of
Delimit ends of
A-bands
I-bands
Z-discs
Attach to
Are light bandscontaining
Are dark bands containing
Troponin
Thin Filaments
Thick filaments
Have regulatory Proteins
Overlap with
Attached to
Have backbone of
mainly made of
Has binding site for
Tropomyosin
Myosin
Actin
Has binding site for
Entwines around /covers binding sites on
Anchored to eachother at
ATP
When bound to Ca2 can uncover binding sites on
H-line

• Titin also attaches z-discs to thick filament
• Internal tension is the tension that must
  overcome the elasticity of titin fibers

8
Membrane Potential
Na
Cl-
K
A-
Hi
Concentration
Resting Memb Pot.
K
A-
Na
Cl-
Lo
Value
Is example of
Voltage, V
Two points
Electric Potential Energy
measure of PE called
Always measured wrt
due to sep. of
Depends on
Electrical charges
Current , I (amps)
Movement of called
Depends on
Resistance R
In body
In body, provided by
in body charges
Ions
Inside cell
Outside cell
Cell membrane
Can only cross cell membrane via
Contains
Have dift. Ion concentrations due to
Cations
Anions
Channels
examples
examples
Na, K
Cl-, A-
Chem Gated
Passive
Voltage Gated
Selective Perm.
Na/K pump
e.g. for
Na
K
Na
K
due largely to
-70 mV
Inside wrt ECF
Out faster
In slower
Passive Channels
3 out
2 in
Can change
Away from 0
Toward 0
Less (more )
More neg (less )
More s out than s in, means inside more neg
More s out than s in, means inside more neg
Depolarized
Hyperpolarized
9
Graded Potentials, Action Potentials
100 mV ? from - 70 to 30
Brief reversal of
Graded Potential
Membrane Potential
Action Potential
Short-lived change in
If reaches threshold, causes
Graded means
NOT Graded
Only in
All or noting
Exists in
Strength
Direction
Can be
Varies with intensity of
Depolarizing
Stimulus
Hyperpolarizing
All living cells
Excitable cells
Less (more )
More neg (less )
e.g.
Nerve
Muscle
Note repolarization process after
depolarisation whereby cell is polarised again,
with positive charges outside the membrane and
negative charges inside the membrane.
10
Banding Pattern in Sarcomere

• I-bands (light) The I bands primarily consist of
  thin filaments
• Z-line/disc (zig-zag) a coin-shaped protein disc
  that anchors the thin filaments and connects each
  myofibril to the next
• Sarcomeres (the functional contractile units) are
  delimited by successive z-lines

11

• Arrival of AP at axon terminal
• AP arrives at axon terminal
• Voltage change around membrane opens Ca2 gated
  ion channels
• Allow Ca2 ions to enter axon terminal
• Fusion of synaptic vesicles
• Ca2 ions cause synaptic vesicles to fuse with
  membrane of axon terminal
• Release of ACH
• Vesicles release ACH by exocytosis into synaptic
  cleft
• Also, Ca2 ions are pumped out of axon terminal
• ACH Binding to Receptor Sites on MEP
• ACH binds to receptor sites of chem regulated ion
  channels MEP
• Causes ion channels to open, permitting influx of
  Na, efflux of K
• Ion exchange causes local depolarization of MEP
• Breakdown of ACH
• ACH diffuses away from receptor site and ion
  channel closes
• ACH esterase breaks down ACH
• AP Propagation
• Depolarization initiates AP which propagates
  along sarcolemma anddown t tubules
• Calcium release from terminal cisternae