Muscles And Nerves Flashcards
Striped muscle?
Skeletal and cardiac
Non-striped muscle?
Skeletal
Myoepithelium
Myofibroblasts
Skeletal muscle? Characterisitics?
Rapid contraction
Subject to fatigue
Voluntary control
Cardiac muscle? Characterisitics?
Heart only
Resists fatigue
Contracts quite rapidly for 80+ years
Involuntary control
Smooth muscle? Characteristics?
Slower contraction but powerful
Little fatigue
Energy efficient
Involuntary
Epimysium? Description
Covers the muscle
Fascicles? Description?
Muscle fibres
Perimysium? Description?
Covers the fascicles
Endomysium? Description?
Between muscle fibres
CT
Sarcoplasmic reticulum? Description?
Mesh work beneath the sarcolemma
Sarcomere? Description?
Functional component of the muscle
Contractile unit, from one z line to the next
I bands get narrower but a bands don’t
Sliding filament model? Process?
Myosin and actin myofilaments Innervated by nerves forming the NMJ Secretion of neurotransmitters Activates the release of Ca Ca binds to troponin freeing tropomyosin Allowing the formation of the cross bridge Assocatation of ATP, allows the power stroke This allows muscle contraction
Difference of cardiac compared to skeletal? Characteristics?
Much smaller fibres, joined end to end
Fibres only have 1 or 2 central nuclei
By intercalated discs
More mitochondria
Smooth muscle? Characterisitics?
Long
Spindle shaped fibres
1 singular nucleus (sausage shaped)
Types of muscle?
Cardiac
Smooth
Skeletal
Skeletal muscle? Characterisitcs?
Voluntary movement or stabilising movement
Attached directly or indirectly to bones, cartilage and ligaments
Function: locomotion, static support and give form to the body (heat)
Stimulated by the somatic
Cardiac muscle? Characterisitics?
Myocardium
String, quick, continuous rhythmic contracts (pump blood)
Stimulation: autonomic (para/sympth)
Smooth muscle? Characterisitics?
Hollow organs and BVs
Actvitiy: - weak sustained tonic contractions
- propel substances (peristalsis) and restrict flow (vasoconstriction)
Stimulation: autonomic
In the wall of GI mixes and propels chyme
And controls sphincter
Regulates resistance to BVs (control blood pressure)
Systemic integration? Characterisitics?
Repro: SM, propel sperm and egg (uterine contractions)
Urinary: SM in arterioles (kidney) regulate glom infiltrate and contracts bladder (during micturition)
Nervous system: SM, distribute blood flow
Immune system: propel lymph
Cardiac: Generates arterial pressure and drives blood flow
Resp: reg BVs and ventilation and perfusion
Digestive: In the wall of GI mixes and propels chyme
And controls sphincter
Regulates resistance to BVs (control blood pressure)
Skeletal muscle? Anatomy? Basic?
Belly fleshy contractile part of muscle
Bicep 2 belly
Tendon provides attachment to bone
Shapes of muscles?
Flat: oblique muscle of abdomen Pennate: feather like Multipennate: deltoid Fusiform: spindle Quadrate: big Circular: circle Multi-head
Basics of muscle naming?
Basis of function
Attachment
Basis of position
Length
Types of muscle of contractions?
Reflexive: movements are autonomic
Tonic: slight contraction even when relaxed (tone)
Phasic: isotonic; changes in muscle length
isometric; no change in length, force increased above tonic level
Muscle functions?
Agonist: specific action
Antagonist: opposes another muscle
Fixators: steady proximal part when distal is moving
Synergist: compliment agonist
Neurovascular bundle?
Bundle of nerves, muscles and vessels
Motor unit? Composition?
Muscle Fascicles Muscle fibres NMJ Myofibrils Motor nerve Axon
Function unit of muscle
Buck teeth?
Tone lost in lip muscles which would keep aligned
Somatic vs autonomic motor reflex?
Somatic: sensory to SC via dorsal root ganglion then to the interneuron to motor neurons
Autonomic: sensory to dorsal root ganglion to interneurone to pre ganglion neurons to autonomic ganglion to post ganglion neuron
Tendon reflexes?
Knee jerk: L3/L4
Ankle jerk: S1/S2
Muscles of facial expression?
Orbital
Oral
Nasal
Muscles of mastication?
Strap (ribbon) muscle of the neck
Infrahoud and suprahyoid
Deep muscles of the head, neck and face?
Intrinsic muscles of tongue, pharynx and larynx
Muscle compartments????**
All on slides called muscle tissue dental lectures
Skeletal muscle? Histology?
Very long, giant thread like cells with thousands of nuclei Striated Nucleus in the periphery A band dark I band light Z line dark Myosin is in hexagonal array
How does the muscle know when to contract?
Via motor end-plates
Mechanism of excitation?
When excited, AP generated across the sarcolemma and t-tubule travels to the deeper parts
A DHP receptor senses the depolarisation and alters its conformation, activation RyR receptors to release Ca from SR binding troponin and activating the contraction process
Cardiac muscle? Histology?
Smaller fibres joined end to end by specialised junction called intercalated disks
Fibres have one or 2 nucleus which are central
Single cells joined in branching pattern bu intervals disks
With many capillaries
Many mitochondria
