Ch.10-11 muscular system Flashcards
What are the 3 types of muscle tissue
- Skeletal muscles
- associated with bones
- Smooth Muscle
- visceral organs (liver, stomach ect)
- Cardiac muscle
- heart muscle
Describe the characteristics of skeletal muscle tissue
- undergoes voluntary contractions due to concious control by CNS
- somatic nervous system
- muscle cells called muscle fibers
- striated muscles (under microscope)
- light and dark bands alternate
- multinucleated, large cylindrical cells
What are the functions of skeletal muscles?
- Motion
- gross and fine movements involving most of the body or localized function
- relies on integration between bones, joints, and skeletal muscles
- Stabilize Body positions
- postural skeletal muscles
- provide sustained contraction while awake to stabilize joints and maintian body position
- Movement of Substances
- moves blood in veins and lymph back to heart
- swallowing initially involves a contraction of skeletal muscles
- Thermogensis
- muscles generate heat when glucose is oxidized by mitochondria in muscle fibres to produce atp
- shivering is a form of thermogensis
How are skeletal muscles fibers stimulated?
by neurotransmitters from motor neurons to contraction
Describe the gross anatomy of muscle fibers
- Skeletal muscles
- Fascia
- Tendons
What do skeletal muscles consist of
- muscle cells
- neurons and sensory receptors
- connective tissue coverings
- blood vessels
- lymphatic vessels
Describe Fascia
- covers muscles
- sheets of dense irregular connective tissue
- 2 types of fascia
- Superficial
- Deep
Describe superficial fascia
seperates the muscle from skin
Describe deep fascia
surrounds muscle to hold it in place
Describe tendons
- cords of connective tissue attach muscle to bone
Describe ligaments
Cords of Connective tissue connect bone to bone
Describe the microscopic anatomy of muscle cells
- Muscle fibers
- Facicles
- Sarcolemma
- Mitochondria and nucleus
- pushed to edge of cell
- Sarcoplasmic reticulum
- Myofibrils
- filaments
- Sarcomeres
Describe muscle fibers
Individual muscle cells
Describe fascicles
bundles of mucle cells/fibers that are grouped together
Describe Sarcolemma
plasma membrane covering for the muscles
Describe sacrcoplasmic reticulum
key organelle in muscle cells that store calcium ions needed for contraction
Describe microfibrils
- cytoplasm of muscle cells
- full of proteins arranged in threadlike cylinders
Describe Filaments
- provide a striated appearance of muscle cells
- Thick filaments
- composed of protein myosin
- thin protein
- composed of the protein actin
Describe sacromeres
basic functional units of striated muscle fibers in a repeated arrangement of filaments
What is the neuromuscular junction
- synapses between a motor neuron and a skeletal muscle fiber
- typically at the midpoint of a cell
- site of an action potential
What is an action potential
nerve impulse from neuron, transmits an electrical impulse indirectly to a cell without touching it
What are neurotransmitters
- chemicals that are released from synaptic vessels of the synapic end bulb and are diffused across the synaptic cleft
What is the name for the neurotransmitter that is released by muscle?
Acetylcholine
What is the specialized region of the muscle cell membrane associated with the neuromuscular junction
- motor end plate
- possesses receptors for acetylcholine
Describe the simplified steps required for a muscle contraction
- action potential travels along axon and the neuromuscular junction
- acton potential triggers release of acetylcholine from synaptic end bulb of axon
- Acetylcholine diffuses across synapic cleft to bind receptors on the cell membrane of muscle fibers
- this triggers action potential in teh muscle fibers which release calcium ions from the sarcoplasmic reticulum, which leads to contraction
- energy as ATP is required for contraction
What are the energy sources for skeletal muscle
- Free ATP
- Creatine Phosphate Stores
- Glycogen Stores
- Blood Glucose
Describe Free ATP
- found in cytosol of muscle cell
- can supply contractions for approximately 2 seconds
Describe creatine phosphate stores
- Stores excess ATP in muscle cells as creatine phosphate in relaxed muscles
- can supply the cell for approximately 13 seconds
Describe Glycogen stores
- utilized during anaerobic cellular respiration
- supplies cells for 30-40sec
- lactic acid is a biproduct
Describe blood glucose as an energy source for skeletal muscle
- delivered by cardiovescular system
- used during areobic cellular respiration
- used for prolonged activity
- requires oxygen
What attaches muscle to bone?
Tendons
Define origin of a muscle cell
- attachment to stationary bone
- usually the proximal end of the bone
Define Insertion of muscle
- muscle Attachment point to the moveable bone
- usually distal end of the bone
Define Belly
Portion of muscle between tendon or insertion and origin
What are antagonist muscle pairs?
- most muscles are found in opposing pairs
- typically on opposite sides of the joint or bone
What is a prime mover or agonist
The muscle that does the work or contraction
What is a antagonist muscle
stretches and yeilds to the action of the prime mover
Give examples of an antagonist muscle pair
- adductors / abductors
- bicep brachii / triceps brachii
How do muscle actions occur
- muscle exert a force on tendons which pull on bones or skin
- muscle must cross at least 1 joint a move 1 of the bones in relation to the other
How are muscles like levers systems
- bones act as levers
- ridgid rods move around a fixed point
- Joints act as the fulcrum
- which are the fixed points
- muscles generate force which moves the lever (bones)
- muscles produce effort
- weight of the body part acts as resistance
- opposes the movement
What are the muscle names for direction of fibers?
- oblique
List the ways muscles are named in the body?
- Direction of fibers
- size
- shape
- actions
- # of origins
- Location of muscles
List the different muscle names derivered from the size of a muscle
- Maximus - large
- Minimus - small
- Brevis - short
- Vastus - Huge
List the muscle names that describe the shape of a muscle
- Deltoid
- triangular
- Serratus
- sawtooth
- Gracilis
- slender
List muscles names for action
- Flexor
- decrease angle at the joint
- Extensor
- increase angle at the joint
List the muscle names for the number of origins
- Bicep
- 2 origins
- Tricep
- 3 origins
- Quadriceps
- 4 origins
List the muscles of the arms
- Deltoid
- Bicep Brachii
- Tricep Brachii
- Brachioradialis
List the muscles of the Abdomen
- rectus abdominis
List the muscles of the leg
- Femor
- Tibia
- Fibula
- Gluteus Maximus
- Rectus Femoris
- Vastus Lateralis
- Gastrocnemius
- Tibalis Anterior
What is the location of the deltoid
Proximal brachium or “arm”
What is the origin of the deltoid
- acromion process
- spine of scapula
- lateral 1/3 of clavicle
What is the insertion of the deltoid muscle
Deltoid Tuberosity of humerous
What is the actions of the deltoid
- Anterior Fibers
- flexion of humerous
- Middle Fibers
- abduction of humerous
- Posterior Fibers
- Extension of humerous
What is the location of the biceps brachii
Anterior Brachium
What is the origin of the biceps brachii
- supraglenoid tubricle of scapula
- coracoid process of scapula
What is the insertion of the biceps brachii
- Bicipital tuberosity of radius
- Bicepital aponeurosis
What are the actions of the biceps brachii
- Flexion at elbow
- supination at radioulnar joint
- assists in flexion at the shoulder
What is the anatomical location of the Triceps Brachii
Posterior Brachium
What is the origin of the Triceps Brachii
- Infraglenoid tubericle of scapula
- long head
- Posterior, superior surface of humerous
- lateral head
- Posterior, inferior surface of humerous
- medial head
What is the insertion of the triceps brachii
olecranon of ulna
what are the actions of the Triceps Brachii
- Extension at elbow joint
- Long head assists with extension at shoulder joint
What are the functions of ligaments
- reinforce the joint they cross (joint stabilization)
- resist or limit particular motions at the joint they cross
What are the names of the ligaments at the shoulder joint
- coracohumeral ligaments
- glenohumeral ligaments
What is the anatomical location of the gluteus maximus
Gluteal region
What is the origin of the gluteius maximus
- Posterior gluteal line of ilium
- illiac crest (posterior aspect)
- Sacrum
- lateral margin
- Coccyx
What is the insertion of the gluteus maximus
- Gluteal tuberosity
- ITB
What is the actions of the gluteus maximus
- Assists in abduction of hip
- Extension at hp
- rotation at hip
What is the anatomical location of the rectus femoris
Anterior Thigh
What is the origin of the rectus femoris
Anterior inferior iliac spine (AIIS)
What is the insertion of the rectus femoris
- Quadricep tendon
- patellar tendon
- tibial tuberosity
What are the actions of the rectus femoris
- Extension at knee
- Flextion at hip
What is the anatomical location of the vastus lateralis
Anterior Thigh
What is the origin of the vastus lateralis
- Greater trochanter
- intertrochangeric line
- lateral line of linea aspera
What is the insertion of the vastus lateralis
- Quadriceps tendon
- patellar tendon
- tibial tuberosity
What is the action of the vastus lateralis
Extension at the knee
What is the anatomical location of the gastrocnemius
posterior compartment of the leg
What is the origin of the gastrocnemius
- Lateral head
- Lateral aspect of lateral condyle of femur
- joint capsule
- Medial head
- popliteal surface of femur superior to medial condyle
- joint capsule
What is the insertion of the gastrocnemius
- Calcaneal tendon
- Posterior surface of calcaneous
what is the action of the gastrocnemius
Plantarflexion
What is the anatomical location of the tibialis anterior
anterior compartment of leg
What is the origin of the tibialis anterior
- lateral tibial condyle
- interosseous membrane
- upper 1/2 of lateral shaft of tibia
What is the insertion of the tibialis anterior
- medial coneiform
- planter aspect
- base of 1st metatarsal
- plantar aspect
What is the action of the tibialis anterior
- dorsiflexion of the foot
- inversion of the foot
What is the anatomical location of the rectus abdominis
Anterior Abdomen
What is the origin of the rectus abdomen
- Pubic Crest
- Pubic symphysis
what is the insertion of the retcus abdomen
- xiphoid process
- costal cartilage 5-7
what is the action of the rectus abdomen
Flexion of the truck
