Muscles Flashcards
Myo
Muscle
Sarco
Muscle cell
3 types of muscle
Smooth
Cardiac
Skeletal
Smooth muscle
Involuntary
No striations
Spindle shaped cells
Single nucleus
Cardiac Muscle
Involuntary
Striations
Intercalated disks
Single nucleus
Branching cells
Skeletal Muscle
Striated
Voluntary
Multiple nuclei
Attachments of skeletal muscles
Tendon
Aponeurosis
Tendon
CT bands
Connect muscle to bone
Aponeurosis
Broad sheets of CT
Attach muscle to bone or another muscle
OIA
Origin
Insertion
Action
Skeletal Muscle COntrations
Prime mover(agonist)
Antagonist
Synergist
Fixator
Prime mover(agonist)
Principal muscle that preforms the action
Antagonist
Muscle that opposes the action of the prime mover
Can smooth out movements
Synergist
Assists the prime mover
Fixator
Stabilizes joints during movements
Muscle fiber
Skeletal muscle cell; very long
Cylindrical
Multiple nuclei
Sarcolemma
Plasma membrane
Myofibrils
1000s in one fiber
Myofilaments
Proteins in myofibril
Contains actin and myosin
Sarcomere
Contractile unit
Myofilaments line up in the myofibril
Lay end to end in the myofibril
I band
Light band
Actin Myofilaments
Z-line in the middle
A-band
Dark bands
Myosin filaments
Overlapping actin Myofilaments
H-zone(only myosin)
M-line(myosin attaches)
Z line
Actin filaments attach
Middle of I-band
M line
Myosin filaments attach
Middle of a-band and h-zone
Sarcoplasm
Cytoplasm
Sarcoplasmic Reticulum(SR)
Stores calcium
T Tubules( Transverse tubules)
Extensions of sarcolemma
Close association w/SR
Fascicles
Groups of muscle fibers
Muscle
Multiple fascicles
Connective Tissue layers
Endomysium
Perimysium
Epimysium
Endomysium
Surrounds fibers
Perimysium
Surrounds fascicles
Epimysium
Surrounds entire muscle
Mechanism of Muscle Contraction
Sarcomere, action potential and neuromuscular junction
Cutaneous
Cutaneous trunci or Panniculus muscle
Muscles of the Head
Mastication
Tongue
Swallowing
Muscles of Mastication
Masseter
Temporalis
Digastricus
Masseter
Cheek
To close the mouth
Temporalis
Muscle on temple; to close the mouth
Digastricus
Mandible; to open the mouth
Tongue Muscles
Intrinsic
Extrinsic
Intrinsic muscles
Muscles in the tongue
Change the shape of the tongue
Extrinsic muscles
Muscles not in the tongue
Alter the position of the tongue
Glossus
Tongue
Swallowing muscles
Hyoid
Pharyngeal
Hyoid
Attached to hyoid
Raise and lower larynx when swallowing
Pharyngeal
Constrict pharynx (throat)
Muscles of the Neck
Sternocephalicus
Trapezius
Omotransversarius
Brachiocephalicus
Sternocephalicus
From occipital to proximal humerus
Trapezius
Cervical and thoracic
Omotransversarius
Atlas to scapula spine
Clavicular Intersection
Origin of Brachiocephalicus; joins cleidocephalicus and Cleidobrachialis
Brachiocephalicus
Cleidocephalicus and Cleidobrachialis
Extrinsic Muscles of the Thoracic limb
Pectorals
Brachiocephalicus
Omotransversarius
Trapezius
Serrated ventralis
Latissimus Dorsi
Pectoral Muscles
Superficial and deep
Serratus Ventralis
Between the limb and the body wall
Suspended between thoracic limbs
Latissimus Dorsi
O-thoracic spinous
I- humerus tuberosity
Muscles of Respiration
Inspiration
Expiration
Inspiration
Muscles increase size of thoracic cavity
Expiration
Muscles decrease the size of the thoracic cavity
Muscles of inspiration
Diaphragm
External intercostals
Muscles of expiration
Internal intercostals
Diaphragm
Flattens when it contracts
Intercostal muscles
Cross each other in between the ribs
Neuron
Principle cell of the nervous system
Body
Dendrites
Axon
Motor neuron
Carry nerve impulses to skeletal muscles
Motor units
One motor neuron and all muscle fibers it innervates
Small and large
Neuromuscular Junction
Axon terminal of motor neuron
Synapse
Muscle
Axon terminal
Synaptic vesicles
Neurotransmitter
Acetylcholine (ACh)
Initiation of Muscle Contraction
Nerve impulse- axon terminal
ACh released
ACh binds to channels on sarcolemma
Action potential/wave of depolarization
ttubules- Sarcoplasmic reticulum
Ca+ released
Muscle contraction
Cross-bridge formation
Sliding filament theory
Cross-bridge cycle
Myosin binds to actin
Power stroke pulls actin over myosin
ATP binds to myosin
Myosin unbinds from actin
Sliding filament theory
Sarcomere shortens (z-z)
What happens after the muscle contraction?
Nerve impulses
Acetylcholine is released into synapse
Nerve impulses stop
Acetylcholinesterase breaks down ACh in the synapse
Cellular respiration
Use glucose to make ATP
Anaerobic
Without O2; 1 glucose molecule
Lactic acid and 2 ATP
Aerobic
With O2; 1 glucose molecule
CO2, H2O and 38 ATP
Glucose
From blood supply
Glycogen= stored glucose
Oxygen
From red blood cells in the blood supply
Stored on myoglobin in muscle
Twitch
Contraction of a single muscle fiber; whole contraction cycle takes about 0.1 sec
All or Nothing Principle
When stimulated an individual muscle fiber either contracts completely or not at all
Force of contraction
Which and how many motor units stimulated
Neuromuscular Diseases
Some insecticides
Curare (poison)
Botchilysim
Expaxial Muscles
Located dorsal along the spine
Transversospinalis
Longissimus dorsi
Iliocostalis
Intramuscular injections (IM)
In the expaxial muscles
Abdominal Muscles
Rectus abdominis
Transversus abdominis
Internal abdominal oblique
External abdominal oblique
External abdominal oblique
Most superficial
Fibers run Dorso-cranial to ventro-caudal
Inserts on the linea alba
Internal abdominal oblique
Deep to external
Fibers run ventro-cranial to Dorsi-caudal
Inserts on the linea alba
Transverse abdominis
Deepest
Fibers run dorsal to ventral
Inserts on the linea alba
Rectus abdominis
Runs from sternum to pubis on either side of linea alba
Perineal Muscles
Internal anal sphincter
External anal sphincter
Pelvic diaphragm
Levator ani
Coccygeus
Caudal border of pelvic cavity
Muscles lie on either side of rectum
Intrinsic Muscles of the Thoracic Limb
Deltoideus
Infraspinatus
Supraspinatus
Subscapularis
Muscles of Brachium
Muscles of antibrachium
Scapula to humerus
Deltoideus
Infraspinatus
Supraspinatus
Subscapularis
Flexes shoulder
Deltoideus
Infraspinatus
Extends shoulder
Supraspinatus
Adducts limb
Subscapularis