Terminology and Joint/Muscle Action Flashcards
What is the major sign of a proximal nerve injury?
-Patient can’t curl first two fingers and thumb when they make fist
Hand of Benediction
Term that includes the name of the discoverer
Eponym
Where two tubes come together
Anastosome
What is the eponym for Cerebral Arterial Circle?
Circle of Willis
What is the eponym for the rectouterine pouch?
Pouch of Douglas
What is the eponym for a pancreaticoduodenectomy?
Whipple Procedure
Any plane parallel to the sagittal (median) plane
Parasagittal plane
Will not cure you, but will hopefully increase your quality of life
Palliative care
Nearer to the trunk or point of origin
Proximal
Further from the trunk or point of origin
Distal
When talking about limbs, we don’t use superior and inferior, we use
Proximal and Distal
When we are referring to blood vessels or describing surgery or dissection, we use
Superficial and Deep
A bending movement that decreases the angle between a segment and it’s proximal segment
Flexion
A straightening movement that increases the angle between a segment and it’s proximal segment
Extension
Prefixes meaning no, or without
A-, An-, De
Prefixes meaning against, or opposite
Anti-, Contra-
Prefix meaning two
Bi-
Prefixes meaning out, or on outside
Ecto-, Ex-, Exo-, Extra-
Prefixes meaning within
Endo-, Intra-, Intro-
Prefix meaning upon
Epi-
Prefix meaning Half
Hemi-
Shorten (pull), they do not lengthen (push)
Muscles
A muscle cell is stimulated by a
Motor Neuron
Muscle cell contraction is referred to as being
All or none
A muscle cell is called a
Myocyte
A muscle functions by
Contracting (i.e. shortening)
A motor neuron and all muscle cells innervated byit
Motor Unit
The motor neuron is also referred to as being all or none, i.e., either
The neuron depolarizes or it doesn’t
Muscle cells contract to their full capacity when the
Neuron depolarizes
There are multiple motor units in a muscle cell, but each muscle cell is innervated by only one
Motor neuron
If muscle cells function “all or none” and motor units function “all or none,” then how do we achieve gradation of function?
Recruitment of additional motor units
In the sagittal plane, movement in the anterior direction is
Flexion
If we want to double the force that the biceps are exerting, than we must double the
Motor unit count
Muscles designed for large gross movements have a large number of muscle cells per
Motor unit (>500)
Muscles designed for large gross movements are not good for
-ex: muscles of shoulder and hip girdles
Fine control
Muscles designed for small fine movements have a small number of muscle cells per
Motor unit (less than 20)
Muscles designed for small fine movements are good for
-ex: Intrinsic hand muscles and extraoccular muscles
Fine control
What are three things that muscle contraction can do?
- ) Cause movement (concentric contraction)
- ) Prevent movement (isometric contraction)
- ) Control movement (eccentric contraction)
The muscle shortens during
Concentric contraction
The muscle length remains constant during
-often resisting gravity
Isometric contraction
The muscle lengthens during
-often resisting gravity
Eccentric contraction
Muscles are named by
- ) Shape
- ) Attachments
- ) Function
- ) Combinations
What are the three types of joints?
- ) Fibrous joint
- ) Cartilaginous joint
- ) Synovial joint
Very limited or no movement
-Joint where fibrous connective tissue connects bones
Fibrous Joints
Somewhat more mobile than fibrous joints
-cartilage is interposed between the two bones and the bones are connected by fibrous tissue
Cartilaginous joints
The most movable joint
-contains a synovial cavity
Synovial Joint
Surrounds the joint in a synovial joint
Fibrous joint capsule
Covers the inner surface of fibrous capsule and the intraarticular portion of the bone, but not the cartilage
Synovial membrane
Covers the articular surfaces of a synovial joint
Cartilage (usually hyaline)
Secretes synovial fluid into the synovial cavity
Synovial membrane
A viscous fluid, high in hyaluronic acid, which serves as a lubricant and carries nutrients and oxygen to the cartilage
Synovial fluid
What are two examples of fibrous joints?
Sutures of skull and teeth
What are two examples of cartilaginous joints?
Symphis pubis and invertebral disk
What are some examples of synovial joints?
Glenohumeral (shoulder) joint, hip joint, and elbow joint
Errosion of the articular cartilage in a synovial joint is characteristic of
Osteoarthritis (degenerative arthritis)
Inflammation of the synovium and surrounding connective tissue is characteristic of
Rheumoid arthritis (inflammatory arthritis)
The functional unit in muscle is the
Motor unit
Individual skeletal fibers are incapable of
Partial contraction
Muscles for fine movement have smaller numbers of muscle fibers per
Motor unit
Because skeletal muscle fibers fatigue very quickly, the maintenance of a sustained muscle contraction is accomplished by
Asynchronus “firing” of motor units
A muscle can cause motion at a joint only if it
Crosses the joint
In all cases, muscles have attachments on different bones with at least one joint between those
Bones
The origin and insertion of a muscle is never located on the
Same bone
Muscle action at a joint is generally the result of
Rotational force (torque)
What are the three types of movement that occur around different axes?
- ) Flexion and extension
- ) Abduction and adduction
- ) Internal and external rotation
How are the axes for flexion/extension, abduction/adduction, and internal/external rotation oriented relative to eachother?
All are perpendicular to one another
What is the torque (τ) of a muscle?
τ= F d Sinθ
May cause more than one movement because they may have vectors that cross more than one axis
Muscles
Can flex, adduct, and internally rotate at the shoulder because it has vectors that cross all three axes
Perctoralis major
Causes flexion at the shoulder and flexion at the elbow because it has vectors that cross the flexion/extension axes for each joint
Biceps Brachii
Sometimes, instead of a rotational movement, a muscle will cause a
Translational movement
At a joint, a muscle that causes extension can also resist
Flexion caused by gravity
This “anti-gravity” function of muscles is particularly important in the “postural” muscles that allow us to maintain the
Erect posture
Can extend the vertebral column and are very active while flexing the vertebral column
-very active while the vertebral column is being flexed as well
Erector Spinae Muscles
Resist the force of gravity which tries to further flex the spine
Erector Spinae muscles
When squatting, the quadriceps femoris muscles in the front of the thigh, which can cause extension of the knee, are used to prevent
Flexion of the knee due to gravity
Important tests when a patient has a weakness in a particular movement that may be caused by more than one muscle
Differential muscle tests
An effective supinator when the elbow is 90 degrees but not when it is at 180 degrees
Biceps Brachii
A muscle that assists another muscle in its primary function
Synergist
Can perform the same function as another muscle, or can stabilize another joint in order to allow the primary muscle to perform its function
Synergist
Synergists for the digital flexors because they stabilize the wrist and prevent the digital flexors from flexing the wrist instead of flexing the digits
Wrist extensors
A muscle that performs a function that is the opposite of the funtion of the primary muscle
Antagonist
To fully and accurately describe the action of a muscle, one should state the
- ) Action of a muscle
- ) Which body part is moved
- ) Which joint the movement occurs at
The fixed end of muscle is called the
Origin
The movable end of muscle is called the
Insertion
Movement in the sagittal plane about the transverse axis
Flexion/extension
Movement in the transverse plan about the longitudinal axis
Medial/lateral rotation
Movement in the coronal plane about an anteroposterior axis
Adduction/Abduction
Loose connective tissue comprised of irregularly woven collagen fibers interspersed w/ varying numbers of fat cells
Superficial Fascia
It functions to attach the dermis to the deep fascia covering muscles, as padding material to fill out the body’s contours and to conserve heat.
Superficial Fascia
Dense connective tissue comprised of irregularly woven, tightly packed collagen fibers
Deep Fascia
Deep Fascia that surrounds the skeletal muscle
Epimysium
Deep Fascia that surrounds nerves
Epineruim
Deep Fascia that surrounds bones
Periosteum
