Download Muscles

Anatomy & Physiology 120
Lab #7
Muscle Tissue and Skeletal Muscles
What you Need to Know
•
Look briefly at the Structure of:
1) Skeletal, 2) Smooth & 3) Cardiac Muscle
• Naming, Identification, Functions
You are only responsible for the identification of
ALL muscles which are on your Lab Packet
In general:
Generates force to move your bones
Propel body fluids & ingested food
Generate and distribute heat
Skeletal Muscle Structure
Skeletal Muscle is an
organ of the
muscular system
How they move:
utilizing the counter
effects of a flexor
& an extensor
Antagonistic
Agonist – prime mover
Antagonist - opposes
the prime mover
Structure of Skeletal Muscle
• Connective Tissue coverings
– Epimysium = CT Surrounds muscle
– Perimysium = CT Separates fascicles
– Endomysium = CT Separates muscle fibers
• Skeletal Muscle Fibers
– Fiber = single muscle cell
• Thin
• Elongated
• Cylindrical
• Multinucleate
CT – Connective Tissue
To Do:
- Some Help –
– Origin – place where the muscle attaches (usually
does not move
– Insertion – Place where the muscle attaches (the
end that moves (ex Biceps)
– Prime mover (agonist) / Synergist (helper) /
Antagonist
Very good website
http://faculty.ucc.edu/biology-potter/Musculature
Muscles of the Face / Head / Neck
• Facial Expression and mastication (chewing)
– Frontalis – Raises Eyebrows
– Orbicularis oculi – Closes Eyes (oculi = eye)
– Orbicularis oris – Closes lips (oris = mouth)
(Orbic = Round muscle)
– Platysma – pull lower lip back & down
– Buccinator – sucks in cheeks
– Masseter – closes jaw (chewing)
– Temporalis – closes jaw
• Muscles That move the Head
– Sternocleidomastoid – Rotates head to opposite
shoulder
• Muscles that move the Shoulder
– Trapezius – Elevates & Retracts Scapula
– Serratus anterior – Draws Scapula Forward
– Pectoralis minor – Scapula Forward & Downward
• Muscles that move the Upper Arm
– Pectoralis major – Flexes & adducts arm
– Latissimus dorsi – Extends & adducts arm
– Deltoid – Abducts arm
Trapezius
Deltoid
Pectoralis
Major
Latissimus dorsi
anterior
posterior
Location: Found beneath and
posterior (to the pectoral muscle
on the Lateral rib cage
Action: Draws Scapula Forward
Location: Flat / thin muscle –
under the Pectoralis major
Action: Scapula Forward &
Downward
• Muscles of the Lower Arm (Forearm)
– Biceps brachii – Flexes
– Brachialis – Flexes (synergist)
– Triceps brachii – Extends
• Know the general surface location of
– Flexors & Extensors of the Hand
– Flexor: Anterior forearm (Palm side – anatomical
position) ex: You flex to lift a dumbell
– Extensors: Posterior forearm (they pull the arm
back once the flexors have done their job)
Triceps brachii
Extends the forearm
(Antagonist to the Biceps brachii)
Brachialis - Synergist (helper)
Flexes the Forearm
Extensors
Flexors
Anterior portion of the forearm
Posterior
portion of the
forearm
• Muscles that move the abdominal wall
– External oblique – Compresses abdominal wall,
trunk rotation & lateral flexion
– Internal oblique – Compresses abdominal wall, trunk
rotation & lateral flexion
– Transversus abdominis – Compresses abdomen
– Rectus abdominis – Flexes the vertebral column
• Muscles the move the chest wall
– External intercostals – Elevates rib cage
(inspiration)
– Internal intercostals – Depresses rib cage
(forced exhalation)
– Diaphragm - Inspiration
Action: Depresses rib cage
(Forced exhalation)
Location: Superficial & Lateral
(Fibers run Medially)
Action: Lateral flexion & Trunk
rotation & Compresses abdominal
wall
Location: Deepest muscle
of the Abdominal wall
Location: Medial superficial
abdominal muscle
Action: Compresses
abdomen
Action: Flexes the vertebral
column (Bow or a sit up) &
Forced expiration
External Intercostal – Between the ribs
(Fibers run downward Pull the ribs together)
Action – Raised the rib cage (Inspiration)
Internal Intercostal - Between the ribs
(Fibers run at a right angle to External
Intercostal)
Action – Depresses the rib cage (Expiration)
• Muscles that move the lower leg
– Quadriceps femoris group – Extends the Knee
– Sartorius – Flexes & Laterally rotates thigh
– So you can sit cross legged
– Hamstring group – Extends thigh and flexes knee
• Muscles that move the thigh
– Iliopsoas – Flexes the thigh
• (Psoas major & Iliacus muscle)
– Rectus femoris – Extends knee & Flexes thigh
– Gluteus maximus – Extends thigh
– Tensor fascia latae – Flexes and abducts thigh
patella
Hamstring Group – 3 muscles
Quadriceps consists of 4 muscles
Located on the Posterior thigh.
(united by a common tendon)
Extension of the thigh & flexion of
the lower leg
Extension of the lower leg
Psoas major
Iliopsoas Muscle
Tensor fasciae latae
Sartorius
(Moves the lower leg)
Rectus femoris
Rectus Femoris
1. Iliacus
2. Psoas major
Muscles that move the foot
Tibialis anterior – Dorsilflexes the foot
Gastrocnemius – Plantar flexes foot, flexes knee
Soleus – Planter flexes foot
Deep flat muscle
Under the
Gastrocnemius
Anterior surface of the leg
Posterior surface of the leg
Internet Figure Cites
http://www.laboratorium.dist.unige.it
www.sante.cc/.../dossiers/quadrifemo/fig01.htm
http://www.gpc.edu/~jaliff/forearm.gif
www.milady.com/corrections/1562538799
http://webanatomy.net/histology/muscle/s
keletal_muscle.jpg
yorku.ca/.../current/dept/dispatch/dsp4.htm
http://fajerpc.magnet.fsu.edu/Education/
2010/Lectures/37_Muscle_System_files/i
mage010.jpg
http://www.muscleblitz.com/176df300.jpg
http://people.uleth.ca/~little/PE2110/funca
natomy/2front%20muscle.jpg
http://www.magazines.com/magcom/cove
rs/0/06/088/0060884.jpg
http://www.emc.maricopa.edu/faculty/farab
ee/BIOBK/muscle1.gif