Download BIO 2310 - MSU Denver

APPENDICULAR MUSCLES

Muscles of girdles and appendages
 Innervated by ventral ramus of spinal
nerves
Key Point

What is a girdle?
 What is a ramus/rami?
Appendicular Muscles - fish

Originated as extensions of hypaxials of
body wall
 Paired fins are appendicular (from
myotome)
 Median dorsal fins are NOT appendicular,
from myotome of epaxials
 Median ventral fins are NOT appendicular,
from myotome of hypaxials
Osteichthyes skeleton
Dorsal fins
Caudal fin
Pectoral fin
Anal fin
Pelvic fin
Appendicular Muscles - fish

Dorsal mass on paired fins are extensors or
abductors
 Ventral mass on paired fins are flexors or
adductors
Appendicular Muscles

Tetrapod
 Pectoral Limb
Pectoral Limb Muscles
Deltoid – arm abductor
 Latissimus dorsi – limb retractor
 Teres Major
 Subcoracoscapularis >>Subscapularis

Pectoral Limb Muscles
Triceps – forearm extensor
 Forearm & hand extensors – LATERAL
 Cutaneous trunci = Cutaneous maximus

Key Points

What is the function of cutaneous
maximus? Do humans have this muscle?
Pectoral Limb Muscles
Pectoralis – Humerus adductor, largest
flight muscle that lowers wing
 Supracoracoideus – Elevates wing

– Supraspinatus
– Infraspinatus
Sternal
keel
Scapula
Humerus
Tendon
Wing elevator muscle
(Supracoracoideus muscle)
Wing depressor muscle
(Pectoralis muscle)
Sternal keel
Pectoral Limb Muscles

Coracobrachialis – Arm flexor
Pectoral Limb Muscles
Biceps brachii – forearm flexor
 Brachialis – forearm flexor
 Wrist and Digit Flexors - MEDIAL

Pectoral Limb Muscles

See Vertebrate Muscle page
Key Points

What are the most important flight muscles &
what are their functions?
 Wrist & digit flexors are found on what side of the
forearm? What about the extensors?
 Latissimus dorsi is similar among tetrapods.
Where is it & what does it do?
 Deltoids are similar among tetrapods. What does
it do? Name the three deltoids in the cat.
Pelvic Limb Muscles
(Iliofemoralis) and Iliofibularis – thigh
abductors
 Become Gluteus and Tensor fasciae latae in
mammal

Key Points

These muscles function as thigh (femur)
abductors. What is thigh abduction?
Pelvic Limb Muscles

Iliotibialis, (femorotibialis), Ambiens
 Extend tibia, protract thigh
 Quadriceps
 Sartorius from Ambiens in reptiles
Key Points

Name the quadriceps femoris muscles.
Pelvic Limb Muscles
Puboischiofemoralis Internus – limb
protractor
 Iliacus, Psoas major in mammals
 Pectineus in mammals

Pelvic Limb Muscles

Ankle and foot extensors course
LATERALLY
Pelvic Limb Muscles
Puboischiotibialis – thigh retractor, knee
flexor
 Gracilis in mammals

Pelvic Limb Muscles
Pubotibialis and (Flexor Tibialis) – Thigh
retractor and knee flexor
 Hamstrings

– Semimembranosus
– Semitendinosus
– Biceps femoris

Adductor longus
Pelvic Limb Muscles

Adductor femoris in reptiles & mammals
 Ankle & foot flexors course MEDIALLY
Pelvic Limb Muscles

See Vertebrate Muscles page
Key Points

What is the action of Adductor femoris,
based on its position?
 Which muscles are antagonists (works
opposite) to the quadriceps?
 Based on its action, which muscle is a
synergist (works similar) with the
hamstrings?
 Name the hamstrings.
Branchiomeric Muscles

These muscles operate the pharyngeal
arches
 Visceral in origin, not somatic, from
hypomere
 Striated, voluntary
 Innervated by cranial nerves. What does
innervate mean?
Key Points

What is a cranial nerve?
Visceral Arch I

Adductor mandibulae
 Closes jaw
 Temporalis
 Masseter
Visceral Arch I

Intermandibularis
 Raises floor of mouth
 Mylohyoid
 Anterior part of Digastric
 (Tensor tympani)
Visceral Arch I

Look at Vertebrate Muscles page
Key Points

What do you recall about Visceral Arch I
that will make it easier to remember the
muscles adductor mandibulae &
intermandibularis
Visceral Arch II

Levator hyomandibulae
 Raises upper jaw in hyostylic suspension
 Stapedius
Visceral Arch II

Dorsal hyoid constrictor = Levator hyoideus
 Constricts pharyngeal cavity
 Stylohoid, which is deep to mylohyoid
Visceral Arch II

Interhyoideus = ventral hyoid constrictor
 Depressor mandibulae in all but mammals
 Digastric (posterior belly)
 Sphincter colli and Platysma in mammals
Visceral Arch II

Look at Vertebrate Muscles page
Key Points

What do you recall about Visceral Arch II
that will make it easier to remember the
muscles Levator hyomandibulae, Levator
hyoideus, Interhyoideus.
Visceral Arch III
Constrictors – compress pharynx
 Levators – lift gills
 Adductors – close internal angles of gills
 Interarcuals – expands pharynx
 Swallowing muscles in tetrapods

Key Points

What does the root arc- mean?
Visceral Arch IV - VI

Constrictors
 Levators
 Adductors
 Interarcuals
 Breathing & swallowing muscles
Visceral Arch IV - VI
Cucullaris – raises posterior gill
 Trapezius
 Sternomastoid
 Cleidomastoid

Key Points

What does the root cleido- mean?
 To what does the term mastoid refer?
Key Points

There are three parts to the trapezius in cats.
Name them in order from anterior to
posterior.
Visceral Arches

See Vertebrate Muscles page
Key Points








Use the following list to categorize the list of
muscles on the next slide
Extrinsic Eye Muscle
Hypobranchial/Tongue Muscle
Epaxial Muscle
Hypaxial Muscle
Pectoral Muscle
Pelvic Muscle
Branchiomeric Muscle
Categorize these muscles







Interhyoideus
Superior oblique
Dorsalis trunci
Biceps femoris
Biceps brachii
Longissimus
Masseter








Styloglossus
Trapezius
Teres major
Deltoid
Sartorius
Rectus abdominis
Medial rectus
Temporalis
Electric Organs
Incidence – found in more than 500 species
 Derivation is primarily from muscle cells

Electric Organs

Function
 Communication
 Orientation with objects in environment
 Detection of prey
 Offense & defense
Electric Organs

ELECTROPLAX is functional unit
 It is a modified muscle cell
 It is multinucleate with numerous associated
nerves & mitochondria
 It forms columns which together comprise
the electric organ
Electric Organs

Salt water eel can emit up to 50 V
 Fresh water eel can emit up to 500 V
Key Points

Are salt water eels safer to touch than fresh
water eels?
 Think about conduction of electricity in
fresh vs. salt water