Muscular System Flashcards
What are the three types of muscle tissues?
Skeletal, smooth, cardiac
- usually attached to bones
- under conscious control (voluntary)
-striated
Skeletal muscle
- walls of most viscera, blood vessels, skin
- not under conscious control (involuntary)
- not striated
Smooth muscle
- wall of heart
- not under conscious control (involuntary)
- striated
Cardiac muscle
What are the functions of muscles?
- Movement
- Stability
- Control of openings and passageways
- Heat production by skeletal muscles
- Glycemic control
Function of muscles:
-move from place to place, movement of body parts and body contents in breathing, circulation, feeding and digestion, defecation, urination, and childbirth
-role in communication: speech, writing, nonverbal communications
movement
Function of muscles:
-maintain posture by preventing unwanted movements
-stabilize joints
stability
muscles that resist pull of gravity and prevent us from falling or slumping over
antigravity muscles
internal muscular rings that control the movement of food, bile, blood, and other materials within the body
sphincters
about what percent of our body heat comes from skeletal muscles?
85%
regulation of blood glucose concentrations within its normal range
glycemic control
-thin sleeve of loose connective tissue surrounding each muscle fiber
-allows room for capillaries and nerve fibers to reach each muscle fiber
-provides extracellular chemical environment for the muscle fiber and its associated nerve ending
endomysium
-slightly thicker layer of connective tissue
-fascicles
-carry larger nerves and blood vessels, and stretch receptors
perimysium
bundles of muscle fibers wrapped in perimysium
fascicles
-fibrous sheath surrounding the entire muscle
-outer surface grades into the fascia
-inner surface sends projections between fascicles to form perimysium
epimysium
sheet of connective tissue that separates neighboring muscles or muscle groups from each other and the subcutaneous tissue
fascia
what separates one muscle compartment from another?
intermuscular septa
____ bridge the gap between muscle ends and bony attachment
tendons
tendon is a broad, flat sheet (palmar aponeurosis)
aponeurosis
connective tissue band that tendons from separate muscle pass under
retinaculum
type of muscle attachment where the tendons bridge the gap between muscle ends and bony attachment
-collagen fibers of the endo-, peri-, and epimysium continue into the tendon
-from there into the periosteum and the matrix of bone
-very strong structural continuity from muscle to bone
-biceps brachii, Achilles tendon
indirect attachment to bone
type of muscle attachment where there is little separation between muscle and bone and where the muscle seems to immerge directly from bone
-margins of brachialis, lateral head of triceps brachii
direct (fleshy) attachment to bone
bony attachment at the stationary end of muscle
origin
thicker, middle region of muscle between origin and insertion
belly
bony attachment to mobile end of muscle
insertion
the effects produced by a muscle
-to produce or prevent movement
action
what are the four functional categories of muscles that depend on action?
- prime mover (agonist)
- synergist
- antagonist
- fixator
type of muscle that produces most of the force during a joint action
-ex: brachialis
prime mover (agonist)
type of muscle that aids the prime mover
-stabilizes the nearby joint
-modifies the direction of movement
-ex: biceps brachii
synergist
type of muscle that opposes the prime mover
-relaxes to give prime mover control over an action
-preventing excess movement and injury
-these pairs act on opposite sides of a joint
-ex: triceps brachii
antagonist
types of muscles that act on opposite sides of a joint
antagonist
type of muscle that prevents the movement of bone
-ex: muscles that hold the scapula firmly in place (rhomboids)
fixator
muscles that are entirely contained within a region, such as the hand
-both its origin and insertion there
intrinsic muscles
muscles that act on a designated region, but has its origin elsewhere
-ex: fingers- with these types of muscles in the forearm
extrinsic muscles
How are muscles named?
-describes distinctive aspects of the _____ of the muscle
structure, location, or action
a name given to ring-like muscles that encircle and orifice and that may form a constricting passage
orbicularis, sphincter
flexes joint, or brings two ends closer together, decreases joint angle
flexor
extends joint or brings two ends further apart, increase joint angle
extensor
elevates a structure or part
levator
depresses a structure or part
depressor
adducts or moves a part toward the midline
adductor
abducts or moves a part away from the midline
abductor
pronates or turns the hand or forearm downward or backward
pronator
supinates or turns the hand or forearm upward or forward
supinator
rotates one structure relative to another
rotator
refers to the thumb actions only and named for the action of opposition, which is when the tip of the thumb is brought into contact with other fingers
opponens
How are muscles named?:
The first part of the name always refers to the ____ and the second part to _____, which are joined together to form a compound word.
origin, insertion
sterno and cleido for its origin, the sternum and clavicle; and mastoid for its insertion, the mastoid process
sternocleidomastoid
brachio for its origin on the upper arm and radialis for its insertion on the radius of the forearm
brachioradialis
sterno for its origin on the sternum and hyoid for its insertion at the hyoid bone
sternohyoid
coraco for its origin on the corocoid process of the scapula and brachialis for its insertion on the humerus of the upper arm
coracobrachialis
Breathing requires the use of muscles enclosing what cavity?
thoracic
what is the main muscle for breathing?
diaphragm
air intake
inspiration
expelling air
expiration
What are the main muscles of respiration?
-diaphragm
-external intercostal
-internal intercostal
-innermost intercostal muscles
What are some other muscles of the chest and abdomen that contribute to breathing?
-sternocleidomastoid, scalenes of neck
-pectoralis major and serratus anterior of chest
-latissimus dorsi of back
-abdominal muscles: internal and external obliques, and transverse abdominis
-some anal muscles
muscular bone between thoracic and abdominal cavities
diaphragm
_____ flattens the diaphragm
contraction
enlargement of the thoracic cavity
inspiration
in relaxation of diaphragm it ____
rises
the thoracic cavity shrinks
expiration
-elevate ribs
-expand thoracic cavity
-create partial vacuum causing inflow of air
external intercostals
-depresses and retracts ribs
-compresses thoracic cavity
-expelling air
internal intercostals
same action as internal intercostals:
-depresses and retracts ribs
-compresses thoracic cavity
-expelling air
innermost intercostals
Muscles that act on opposite sides of joint
Antagonistic pairs
