ppt actividad fisica y salud

1. Estructura del tejido muscular
esquelético.
Configuración de la célula muscular.
Estructura molecular del sarcómero.
Unión neuromuscular y sinapsis
neuromuscular.

2. Nunca consideres el
estudio como una
obligación, sino
como una
oportunidad para
penetrar en el bello
y maravilloso mundo
del saber.

3. Nucleus
Muscle fiber
(cell)
Striations
Skeletal muscle

4. Depósitos
Energéticos
Corrientes
Iónicas
AMP/ATP [Ca2+]i
Switch Metabólico [Utilización de Sustratos
Energéticos]
Expresión Génica [Adaptación Estructurales y
Funcionales]
Contracción Muscular

5. Vaina de
mielina
Fibra Muscular
La unión neuromuscular
consiste en la sinapsis
entre el botón terminal
del axon y la placa
motora del sarcolema de
la fibra muscular.
Arbolización Terminal

6. Placa motora
Terminaci
ón
Axonal

7. Vesícula
s
Sináptic
as
Espaci
o
Sinapti
co
Membrana
Postsinápt
ica
Receptores
Nicotínicos
Membrana
Presinapti
ca

8. Postsynaptic
cell
Synaptic
vesicle
Action
potential
Axon
terminal
An action potential depolarizes
the axon terminal.
1
1

9. Voltage-gated
Ca2+ channel
Postsynaptic
cell
Ca2+
Ca2+
Synaptic
vesicle
Action
potential
Axon
terminal
An action potential depolarizes
the axon terminal.
The depolarization opens voltage-
gated Ca2+ channels and Ca2+
enters the cell.
1
2
1
2

10. Voltage-gated
Ca2+ channel
Postsynaptic
cell
Ca2+
Ca2+
Docking
protein
Synaptic
vesicle
Action
potential
Axon
terminal
An action potential depolarizes
the axon terminal.
The depolarization opens voltage-
gated Ca2+ channels and Ca2+
enters the cell.
Calcium entry triggers exocytosis
of synaptic vesicle contents.
1
2
3
1
2
3

11. Voltage-gated
Ca2+ channel
Postsynaptic
cell
Ca2+
Ca2+
Docking
protein
Synaptic
vesicle
Action
potential
Axon
terminal
Receptor
An action potential depolarizes
the axon terminal.
The depolarization opens voltage-
gated Ca2+ channels and Ca2+
enters the cell.
Calcium entry triggers exocytosis
of synaptic vesicle contents.
Neurotransmitter diffuses across
the synaptic cleft and binds with
receptors on the postsynaptic cell.
4
1
2
3
4
1
2
3

12. Voltage-gated
Ca2+ channel
Postsynaptic
cell
Ca2+
Ca2+
Docking
protein
Synaptic
vesicle
Action
potential
Axon
terminal
Receptor
An action potential depolarizes
the axon terminal.
The depolarization opens voltage-
gated Ca2+ channels and Ca2+
enters the cell.
Calcium entry triggers exocytosis
of synaptic vesicle contents.
Neurotransmitter diffuses across
the synaptic cleft and binds with
receptors on the postsynaptic cell.
Cell
response
Neurotransmitter binding initiates
a response in the postsynaptic
cell.
4
5
1
2
3
4
5
1
2
3

14. Skeletal
muscle
fiber
AChE
Action potential
ACh Acetyl + choline
Nicotinic
receptor
Motor end
plate
Somatic motor
neuron
Axon terminal
Voltage-gated
Ca2+ channel Ca2+
Ca2+

16. Figure 11-13b

17. Skeletal muscle
Muscle fascicle:
bundle of fibers
Muscle fiber
Connective tissueConnective tissue
Tendon
Nerve and
blood vessels
Nucleus

20. II a
I
II b
• Fibras I // oscuras // mioglobina y enzimas oxidativas //
• Fibras II // claras // enzimas glicolíticas //
–II a // enzimas glicolíticas y oxidativas //
–II b // enzimas glicolíticas //

21. FT 1
FT 2 b
FT 2 a

22. Mitochondria
Myofibril
Thick
filament
Thin
filament
T-tubules
Sarcoplasmic
reticulum
Sarcolemma
Nucleus

23. Sarcolemma
Thin filament
Thick filament
Triad Terminal
cisterna
T-tubule brings action
potentials into interior
of muscle fiber.
Sarcoplasmic reticulum
stores Ca2+.

24. Myofibril
(c) A band
Z disk
I band
M line
H zone
Z disk
Sarcomere

25. Sarcomere
A band
(a)
I band H zone I band
Z diskZ disk
M line
Thick
filament
Thin
filament

27. Z disk Z disk
Titin
M line

28. Z disk
M line
Z disk
MyosinTitin provides
elasticity and
stabilizes myosin.
ActinNebulin helps
align actin.

29. Myosin tail
Myosin heads
Myosin molecule
(e)
Thick filaments
Hinge
region
M line

30. Thin filaments
Tropomyosin
Troponin
Actin chain
G-actin molecule
(f)
Titin
Nebulin

32. Skeletal
muscle
fiber
AChE
Action potential
ACh Acetyl + choline
Nicotinic
receptor
Motor end
plate
Somatic motor
neuron
Axon terminal
Voltage-gated
Ca2+ channel Ca2+
Ca2+

36. Muscle fiber
Motor end plate
ACh
Axon terminal of
somatic motor neuron
Sarcoplasmic reticulum
Actin
Troponin
Tropomyosin
Myosin
head
Z disk
Myosin thick filament
M line
T-tubule
DHP
receptor
Ca2+
Somatic motor neuron
releases ACh at neuro-
muscular junction.
(a)
1
1

37. Muscle fiber
Motor end plate
ACh
Axon terminal of
somatic motor neuron
Sarcoplasmic reticulum
Actin
Troponin
Tropomyosin
Myosin
head
Z disk
Myosin thick filament
M line
T-tubule
DHP
receptor
Ca2+
Somatic motor neuron
releases ACh at neuro-
muscular junction.
Net entry of Na+ through ACh
receptor-channel initiates
a muscle action potential.
Na+
K+
(a)
potential
1 2
1
2 Action potential

38. (b)
Action potential in
t-tubule alters
conformation of
DHP receptor.
3
3
Ca2+

39. Ca2+
Ca2+
released
(b)
Action potential in
t-tubule alters
conformation of
DHP receptor.
DHP receptor opens Ca2+
release channels in
sarcoplasmic reticulum
and Ca2+ enters cytoplasm.
3 4
3
4

40. Ca2+
Ca2+
released
(b)
Action potential in
t-tubule alters
conformation of
DHP receptor.
DHP receptor opens Ca2+
release channels in
sarcoplasmic reticulum
and Ca2+ enters cytoplasm.
Ca2+ binds to troponin,
allowing strong actin-
myosin binding.
3 4 5
3
4
5

41. M line
Ca2+
Ca2+
released
Myosin thick filament
(b)
Action potential in
t-tubule alters
conformation of
DHP receptor.
DHP receptor opens Ca2+
release channels in
sarcoplasmic reticulum
and Ca2+ enters cytoplasm.
Ca2+ binds to troponin,
allowing strong actin-
myosin binding.
Myosin heads execute
power stroke.
3 4 5
6
3
4
5
6

42. M line
Ca2+
Distance actin moves
Ca2+
released
Myosin thick filament
(b)
Action potential in
t-tubule alters
conformation of
DHP receptor.
DHP receptor opens Ca2+
release channels in
sarcoplasmic reticulum
and Ca2+ enters cytoplasm.
Ca2+ binds to troponin,
allowing strong actin-
myosin binding.
Myosin heads execute
power stroke.
Actin filament slides
toward center of
sarcomere.
3 4 5
6 7
3
4
5
6
7

43. Pi
Pi
ADP
ADP
G-actin moves
Cytosolic Ca2+
Tropomyosin shifts,
exposing binding
site on G-actin
TN
TN
Power stroke
TroponinG-actin
Tropomyosin
blocks binding
site on G-actin
Myosin head
(b)(a) Initiation of contractionRelaxed state
Ca2+ levels increase
in cytosol.
Ca2+ binds to troponin.
Troponin-Ca2+ complex
pulls tropomyosin away
from G-actin binding site.
Myosin binds to actin and
completes power stroke.
Actin filament moves.
3
4
3 4
1 2
1
2
5
5

44. PiADP
TN
TroponinG-actin
Tropomyosin
blocks binding
site on G-actin
Myosin head
(a) Relaxed state

45. PiADP
G-actin moves
Cytosolic Ca2+
Tropomyosin shifts,
exposing binding
site on G-actin
TN
Power stroke
(b) Initiation of contraction
Ca2+ levels increase
in cytosol.
Ca2+ binds to troponin.
Troponin-Ca2+ complex
pulls tropomyosin away
from G-actin binding site.
Myosin binds to actin and
completes power stroke.
Actin filament moves.
3
4
3 4
1 2
1
2
5
5

46. ADP
Cytosolic Ca2+
Ca2+ levels increase
in cytosol.
1
1

47. ADP
Cytosolic Ca2+
TN
Ca2+ levels increase
in cytosol.
Ca2+ binds to
troponin.
1
2
1
2

48. ADP
Cytosolic Ca2+
Tropomyosin shifts,
exposing binding
site on G-actin
TN
Ca2+ levels increase
in cytosol.
Ca2+ binds to
troponin.
Troponin-Ca2+
complex pulls
tropomyosin
away from G-actin
binding site.
1
2
3
1
2
3

49. ADP
Cytosolic Ca2+
Tropomyosin shifts,
exposing binding
site on G-actin
TN
Power stroke
Ca2+ levels increase
in cytosol.
Ca2+ binds to
troponin.
Troponin-Ca2+
complex pulls
tropomyosin
away from G-actin
binding site.
Myosin binds
to actin and
completes power
stroke.
1
2
3
4
1
2
3
4

50. Pi
ADP
G-actin moves
Cytosolic Ca2+
Tropomyosin shifts,
exposing binding
site on G-actin
TN
Power stroke
Ca2+ levels increase
in cytosol.
Ca2+ binds to
troponin.
Troponin-Ca2+
complex pulls
tropomyosin
away from G-actin
binding site.
Myosin binds
to actin and
completes power
stroke.
Actin filament
moves.
1
2
3
4
5
1
2
3
4
5