This document provides an outline for a project on the muscular system. It begins with an introduction and then outlines the general structures and functions of muscles. The remainder of the document compares the anatomy of muscles across different vertebrate groups including aquatic vertebrates, amphibians, reptiles, birds, and mammals. For each group, it describes the axial musculature, appendicular musculature, jaw muscles, and how muscles have evolved between groups. Tables are provided comparing muscle features across the five vertebrate classes.
1. Submitted by:
Alagao, Alia Nevin
Andres, Jocielle Marie
Atrillano, Noreen
Austria, Marion
Calsita, Bianca Joy
Cipriano, Mary Chris
MEB24
ELGA Final Project
March 5, 2014
Mrs. Ma. Luisa V. Cuaresma
2. OUTLINE:
I. Introduction
II. General Structures and Functions
III. Comparative Anatomy of Vertebrates:
1. Aquatic Vertebrates
2. Amphibians
3. Reptiles
4. Birds
5. Mammals
4. MUSCULAR SYSTEM
Concern with the body
movement
Stabilize the body in position
Act as movers and levers for every
action with the aid of skeleton
Contraction of
viscera
Heat
production
7. color
• red
• white
location
• somatic
• visceral
Nervous
system
control
• voluntary
• Involuntary
Appearance
• skeletal
• visceral
8. EMBRYONIC ORIGIN
Mesenchyme – from which smooth
muscle and some viscera develop
Paired Hypomere – differentiated into
smooth muscle layers of the alimentary
tract and its derivative
Paraxial mesoderm – skeletal muscles
develop
9. MUSCLE ORGANIZATION
SKELETAL
MUSCLES
VISCERAL MUSCLES CARDIAC MUSCLES
- Attaches to bones,
skin, fascia
- Striated
- Voluntary muscles
- Axial muscles
- Jaw muscles
- Extrinsic eyeball
muscles
- Appendicular
musculature
- Integumentary
muscles
- Attached to hair
follicles and skin
- Non-striated
- Involuntary muscles
- Includes muscle of
tubes, vessels and
hollow organs, intrinsic
eyeball muscles,
erectors of feathers
and hair
- Forms the wall of the
heart
- Striated
- Involuntary muscles
- Myocardium
- Electropaxes
10. DEVELOPMENT OF SKELETAL
MUSCLES
1. Axial muscles
- Cover the trunk and tail region
2. Jaw muscles
- Support the gill arches and contributes the
tongue.
3. Extrinsic eye muscles
- Muscles of the eye
4. Appendicular musculature
- Attached to girdles, fins or limbs.
5. Integumentary muscles
- Attached to some parts of the skeleton and
inserted on skin.
11. Jaw Musculature
Arises from two embryonic
sources:
Hypobranchial
-Contributes to the formation of
the tongue.
Branchiomeric
- Derived from somitomeres of
the head and supplied by cranial.
12. Extrinsic Eyeball Muscles
Six muscles arises form three different
somitomeres:
- Superior, inferior and medial rectus (anterior) and
inferior oblique muscles arise form the
premandibular somitomere (most anterior)
supplied by the III cranial nerve
- The superior oblique arises from the mandibular
somitomere (middle) supplied by the IV cranial
nerve
- The lateral rectus muscle (posterior) arises from
13.
14. 3 TYPES OF MUSCLE TISSUE
Striated voluntary
muscle tissue
‘skeletal muscle’
Long cylindrical
multinucleated cells
Sarcoplasm = Parallel
rows with alternating light
(I-band) and dark (A-
band) forming striations
Attached to skeleton
responsible for voluntary
movement.
15. Smooth involuntary
muscle tissue
‘visceral muscle’
Elongated cells,
tapered ends, nucleus
(center)
Sarcoplasm = clear
Found in internal
organs which bring
about involuntary
movement
3 TYPES OF MUSCLE TISSUE
16. Striated involuntary
muscle tissue
‘cardiac muscle’
Linear, branching
bundles of fibers
joined end to end by
intercalated disc
Found in walls of heart
to bring the involuntary
contraction of the
organ
3 TYPES OF MUSCLE TISSUE
17. 1. Agonist or prime mover
– principal mover for specific action
ex. Deltoid muscle in abduction of arm
2. Antagonist
– opposite movement
ex. Latissimus dorsi and pectoralis for deltiod muscle
3. Synergist
– stabilize movement of one joint
– inhibit undesirable movements
ex. brachioradialis and brachialis assist the biceps to create
the movement and stabilise the elbow joint.
4. Fixator
– fixes position of the limb when movement occurs
ex. Biceps and triceps hold shoulder and elbow in position
SKELETAL
MUSCLE AS TO
ACTION
18. TYPES OF SKELETAL MUSCLES AS
TO
SPECIFIC FUNCTION
1. Flexor – bend a limb
Extensor – straighten a limb or
component parts
2. Adductors – draw part toward a
median line
Abductors – draw part away
median line or from neighboring
part or limb
3. Pronators – turn or rotate part
downwards (axis)
Supinators – turn or rotate part
forward and upward (axis)
ex. (both) – palm of the hand
19. 4.Elevator or levator –raise or lift a part
Depressors – lower or depress a part
ex. Lower jaw
5.Constrictors – draw parts together or compress a space
ex. Pharynx and abdomen
Dilators – widens an opening or space
*Sphincters – constrictors surrounding an opening.
ex. Mouth, pylorus, anus
20. BASIS IN NAMING SKELETAL MUSCLES
direction of fibers (e.g., oblique)
location or position (e.g., superficial)
number of divisions (e.g., triceps)
shape (e.g., deltoid)
origin and/or insertion (e.g., iliocostalis)
action (e.g., levator scapulae)
size (e.g., major)
some combination of these
24. AXIAL MUSCULATURE
2 divisions:
Epaxial (Upper)
Hypaxial (Lower)
(-) Lateral septum
(+) Myomeres
(+) Myosepta
Each myotome contributes one muscle segment called
MYOMERE.
The short fibers of the myomeres are inserted on partitions
of connective tissues called MYOSEPTA, which lie between
successive myomeres.
Muscles of Aquatic
Vertebrates
30. Strap-like
hypobranchial muscles
extend from the
pectoral girdle to the
visceral arches.
Serve to open the jaws
and pull the gills
downward and
backward.
Evolved from the
hypaxial muscles
retaining the
longitudinal orientation
of fibers.
Muscles of Aquatic
Vertebrates
31. APPENDICULAR MUSCULATURE
(+) Paired appendages (evolved with fins)
Muscles of Aquatic
Vertebrates
Dorsal mass of
EXTENSOR:
Abductors/Levators
Moving the fins
UPWARD or
FORWARD
A series of levators
above the pharynx
lift the gill bars.
32. Ventral mass of FLEXOR:
Adductors/Depressors
Moving the fins DOWNWARD or BACKWARD
Adductors reduced the internal angles of each
visceral arch.
Muscles of Aquatic
Vertebrates
33. FISHES have 6 extrinsic eye muscles:
Muscles of Aquatic
Vertebrates
37. Modified from lower aquatic forms
Metameric condition = obscure
Trunk reduced in volume
38.
39. Do not have epaxial muscles
Their lateral septum is more dorsal in position
Myotomes are primitive
Muscle fibers still course form one
myocommata to the next,
The entire epaxial mass formed dorsalis trunci
Myotomes – vertically arranged
Intersegmental bundles
42. ADULT URODELES
Ventral trunk muscles
Beginning from the outside, there are
superficial and deep external oblique (course
in posteroventral direction)
Internal oblique layer extend in posterodorsal
direction
Transversus which fibers almost in a vertical
position. It lies next to peritoneum
43. Reduced the number of layers in hypaxial trunk
muscles
Rectus abdominis is large muscle extending
from sternum to pubis
Myocommata have disappeared from the
external oblique and transversus but are
retained to some extent in the rectus abdominis
as tendinous inscriptions
Lastly, the amphibians have muscle that move
the to tongue this derived from the
hypobranchial muscle
44.
45.
46. AXIAL MUSCULATURE
Epaxial muscles
– functions to extend or straighten the
spine and provide some lateral flexion.
– lack myosepta and become complex
47. AXIAL MUSCULATURE
Hypaxial muscles – functions to bend
the spine and provides lateral bending.
subvertebral group
rectus abdominis group
lateral group
48. APPENDICULAR MUSCULATURE
more numerous and diverse
than in AMPHIBIANS.
Intrinsic muscles
- quadrupedal locomotion
Dorsal extensor
Ventral flexor muscles
Extrinsic integumentary muscles
- inserted on the underside of the
dermis.
49. Forelimbs
-trapezius muscles derived from the branchial
musculature
-several muscles derived from the axial
musculature
-most appendicular muscles are derived
directly from appendicular muscles of fish
ancestors.
50. Hindlimbs
-dorsal and ventral muscle groups are again
recognized.
*caudofemoralis- a prominent flexor of the thigh
of Reptiles.
Extrinsic eyeball muscles
Eyeball can no longer be rotated around its optical
axis.
*pyramidalis-muscles inserted on the upper lids
and nictitating membrane of Reptiles.
51.
52. REPTILES is the
first group of vertebrates
to have INTEGUMENTARY
MUSCLES
capable of moving the skin.
Integumentary muscles
Snakes- locomotor apparatus may include separate
muscles, the costocutaneous, to move the ventral
scutes.
53.
54.
55. BIRDS MUSCULAR STRUCTURE
Most birds have approximately 175 different
muscles.
The skin muscles help a bird in its flight by
adjusting the feathers.
Pygostyle (tail muscle)
The pectorals, or the breast muscles
True Flight
thin, stringy muscles of the vertebral column
56. THE SUPRACORACOIDEUS WORKS USING A PULLEY
LIKE SYSTEM TO LIFT THE WING WHILE THE
PECTORALS PROVIDE THE POWERFUL DOWNSTROKE.
57.
58.
59. Epaxial Muscle
– lack myosepta
– complex
Hypaxial Muscle
– same with all tetrapods
* subvertebral group
– located below transverse
process
– ventroflexes the spine
60. Anterior ribs
– enlarged
– penetrates external and internal
obliques
– forms the intercostals muscle
– ventilation of the lungs
61. Lateral group of hypaxial muscle:
- Serrratus
- Levator scapulae
- Rhomboideus
62. Branchial muscle
*Ancestor adductor mandibulae of lower
vertebrates several muscles in
mammals
(-) depressor mandibulae
Digastric muscle (new muscle)
-ventral constrictor of 1st and 2nd
arches innervated by 5th and 7th cranial
nerves
Stapedial muscle
Muscle of the larynx
63.
64.
65. AXIAL
MUSCLES
FISHES AMPHIBIANS REPTILES BIRDS MAMMALS
Epaxial
(Upper)
Solid mass;
above the
lateral septum
Muscle masses
subdivided and
rearranged into
longitudinal
muscles
Muscle masses
subdivided and
rearranged into
longitudinal
muscles
Muscle masses
subdivided and
rearranged into
longitudinal
muscles
Hypaxial
(Lower)
Solid mass;
below the
lateral septum
2 outer oblique
layers; 1 inner
transverse
layer; rectus
abdominis
2 outer oblique
layers and 1
inner
transverse
layer; rectus
abdominis
2 outer oblique
layers and 1
inner
transverse
layer; rectus
abdominis
Oblique layers
are further
subdivided,
separated by
intercostal
muscles
Septum
Transverse/
Lateral
septum
Dorsally
position
Linea alba
Myotomes Present Present Absent
Myosepta Present Present Absent Absent
FUNCTION
To produce an
undulating
motion that
propels the
fish through
the water
Maintenance of
posture, head
movement,
and respiration
Maintenance of
posture, head
movement,
and respiration
Maintenance of
posture, head
movement,
and respiration
Maintenance of
posture, head
movement, and
respiration
Comparative Anatomy of
Vertebrates
70. JAW
MUSCLES
FISHES AMPHIBIANS REPTILES BIRDS MAMMALS
Branchiomeric
Constrictors
and levator
muscles
Associated
with
mandibular,
hyoid and
pharyngeal
arches
Associated
with
mandibular,
hyoid and
pharyngeal
arches
Associated
with
mandibular,
hyoid and
pharyngeal
arches
Highly
modified;
mandibular,
hyoid and
pharyngeal
arches
FUNCTION
Breathing and
feeding
Contribute to
larynx
(vocalization)
and throat
Contribute to
larynx
(vocalization)
and throat
Contribute to
larynx
(vocalization)
and throat
Control vocal
functions
within larynx
Hypobranchial
Attached
posteriorly to
pectoral
skeleton
Associated
with
pharyngeal
arches
Associated
with
pharyngeal
arches
Associated
with
pharyngeal
arches
Associated
with
pharyngeal
arches
FUNCTION
Serve to open
the jaws and
pull the gills
downward
and backward
Movement of
the larynx,
hyoid
apparatus and
tongue
Movement of
the larynx,
hyoid
apparatus and
tongue
Movement of
the larynx,
hyoid
apparatus and
tongue
Movement of
the larynx,
hyoid
apparatus and
tongue
Comparative Anatomy of
Vertebrates
75. APPENDICULAR
MUSCLES
FISHES AMPHIBIANS REPTILES BIRDS MAMMALS
Adductor
muscles
Dorsal; flex
fins
Ventral;
recovery
Ventral;
recovery
Ventral;
recovery
Ventral;
recovery
Abductor
muscles
Ventral;
extend fins
Dorsal;
propulsive
Dorsal;
propulsive
Dorsal;
propulsive
Dorsal;
propulsive
Other
characteristics
Intrinsic
muscles are
limited in
number &
undifferentiated
Much more
complex than
in fish
More
numerous &
diverse than
in amphibians
Intrinsic
musculature is
reduced
Similar to
reptiles but
more diverse
FUNCTION
Balance and
orientation
Support and
locomotion
Support and
locomotion
Support and
locomotion
Support and
locomotion
Comparative Anatomy of
Vertebrates
Recovery Phase
- Forward movement and
raising of the limb
(adduction)
– Flexing of arm/leg
– Extension of hand/ foot
Propulsive Phase
- Backward movement
of the limb (abduction)
– Extension of arm/leg
– Flexion of hand/foot
It has a slender eel-like body, of a uniform leaden or blackish color, and with seven purse-shaped gill openings on each side. The mouth is fitted for sucking rather than biting, and with it they attach themselves to the bodies of fishes and feed on their flesh, which they scrape off with their rasp-like teeth.
MYOMERES become more angled (zig-zag shaped) and are molded into interlocking cones.
To extend the action of each myomere over several vertebrae.
To assure that muscle fibers can all shorten at equal rates.
Rectus muscles have their origin close together deep in the posterior part of the orbit.
Oblique muscles have their origin deep in the anterior part of the orbit.
These muscles are responsible to rotate the eye around the longitudinal and vertical axes of the head.
Thus, the range of movement of fins is much more limited than that of tetrapod limbs.
Appendicular musculature is more complex than that of fishes because the limbs function in both support and locomotion.
Better support of body & increased mobility of distal segments of the limbs.