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Celine Cercado Muscular System P.2 - Coggle Diagram
Celine Cercado Muscular System P.2
Major Functions
Heat production
Less than half of energy released in reactions of cellular respiration is used to form ATP
the rest becomes heat
This heat is carried by the blood to other tissues, and helps maintain body temperature
Muscle fatigue
muscle loses ability to contract during strenuous exercise
may arise from electrolyte imbalances and decreased ATP levels
A decrease in pH due to lactic acid accumulation may have a role
Muscle Cramps
a sustained, painful, involuntary contraction, is thought to occur due to changes in the extracellular fluid around the muscle fibers
leading to uncontrolled muscle fiber stimulation by its motor neurons
Causes all different types of movements
Hypertrophy
enlargement of the muscle due to repeated exercise
Atrophy
decrease in muscle size & strength
3 types of Muscles & functions
Smooth Muscles
Location: Wallows of hallow viscera, blood vessels
Function: Movement of viscera, peristalsis, vasoconstriction
Striation: Absent
Nucleus: Single
Involuntary
Skeletal Muscle
Location: Skeletal muscles
Function: Movement of bones at joints, maintenance of posture
Striation: Present
Nucleus: Many
Voluntary
Cardiac Muscle
Location: Wall of the heart
Function: pumping action of the heart
Strations: present
Nucleus: single nucleus
Involuntary
Names of Skeletal muscles
Sternocleidomastoid
nack
Trapizus
upper back
Deltiod
shoulder
Pectoralis Major
chest
Biceps Brachii
upper arm
serratus anterior
ribs
Rectus abdominis
abs
Brachioradialis
forearm
External oblique
anterior abdominal wall
flexor carpi radialis
superficial forearm
iliopsoas
inner hip
Palmaris longus
forearm
Sartorius
anterior of the thigh
adductor longus
thigh
vastus lateralis
largest quadricep
Gracilis
inner thigh
Rectus femoris
middle of thigh
part of the quadricep
Vastus medialis
upper part of femur
Soleus
posterior leg
Fibularis longus
leg
Extensor digitorum longus
front of leg
Infraspinatus
dorsal of scapula
Rhomboid major
back
Teres Major
below the shoulder
Triceps Brachii
back of humerus
Latissimus Dorsi
Midback
Extensor Carpi Radialis Longus
forearm
Extensor Digitorum
Forearm
Gluteus Maximus
butt
Semitendinosus
Hamstring
Semimembranosus
hamstrings
Biceps Femoris
posterior thigh
Gastrocnemius-
Calves
Facial Muscles
Temporalis- Closes jaw
Frontails- raises eyebrow
Zygomaticus- raises lateral corners of mouth (smiling)
Orbicularis oculi- blinking and squinting
Buccinator- Compresses the cheek
Masseter- prime mover of jaw closure
Orbicularis Oris- closes lips
Platysma- Tenses the skin of neck, pulls lower lips back & down
sarcomere
Many units that make up myofibrils
Z-line
Sarcomere extends from on to another
I bands
the light bands
make up the actin filaments , which are anchored to the z lines
A bands
dark bands
made up of overlapping thick and thin filaments
H zone
in center of the A band
consists of myosin filaments only
M line
in the center of the H zone
consists of proteins that hold myosin filaments in place
Neuromuscular Junction
a synapse between a motor neuron and a muscle fiber that it regulates
The cytoplasm of the distal end of the motor neuron contains numerous mitochondria and synaptic vesicles storing neurotransmitters
The muscle fiber membrane in this area contains a specialized region called the motor end plate, in which the sarcolemma is tightly folded
The motor end plate contains specific receptors for the neurotransmitter
Synaptic Cleft
gap between the membranes of the neuron and muscle fiber
When an electrical impulse reaches the end of the axon of a motor neuron, synaptic vesicles release neurotransmitter
The neurotransmitters diffuse across the cleft, bind to the motor end plate, and stimulate the muscle fiber to contract
Sliding filaments muscles
1.Muscle contraction starts in the brain and sends a signal to the motor neuron
Motor neuron contain neurotransmitter, acetylcholine
Acerylcholine reaches the receptors on the muscle sarcolemma which causes impulse
Impulse travels down to the membrane & into transverse tubules (T-tubule).
Causes calcium to be released from the sarcoplasmic reticulum
3.Calcium binds to a structure on the actin that causes it to change shape.
Change in shape allows myosin heads to form cross-bridges between the actin & the myosin
Energy from ATP is used to create "power stroke" between filaments
Actin filaments then slide inward and shorten, or contracts the whole muscle.
Actions potential in a muscle fiber
Pulling force is exerted by binding of MYOSIN molecules to ACTIN molecules
Shortening of muscle fibers results in increase in overlapping between actin & myosin filaments, as they slide past each other
shortening- results in in shortening of entire muscle
Pulls on on attached body parts to cause movement
Muscle Coverings
Connective tissue Coverings
Fascia
Layers of dense connective tissue
Surround & separate each tissue muscle
Aponeuroses
muscles connected to each other by broad sheets of connective tissue
Epimysium
Fascia blends with
Layer of connective tissue that covers the skeletal muscle
Perimysium
Extends inward from epimysium
Surrounds bundles of skeletal fibers (fascicles)
Endomysium
Covers each muscles cell fibers