anatomy: muscoskeletal Flashcards
skull major function
to protect the brain
thorax major function
to facilitate breathing
spine major function
to support the weight of the upper body
upper limb major function
to allow for manual dexterity
lower limb major function
to allow for weight-bearing locomotion
skull link to anatomy
enclosed rigid box with minimal movement at the joints
thorax link to anatomy
semi-rigid box which uses its attachments to the muscular diaphragm to alter pressures and drive air into the lungs
what is the anatomical position
- standing erect with feet flat on the floor under the hip joints. - straight back with head and eyes facing forward - arms by the side with forearms and hands facing forwards - eyes focused at infinity on the horizon
what is the sagittal plane
sagittal plane is the vertical plane passing through the midline of body, dividing it into right and left parts
what is a parasagittal plane
parasagittal plane runs parallel to the sagittal plane but to one side
what is a coronal plane
coronal planes are vertical planes which pass through the body at right angles to the sagittal planes; they divide the body into anterior and posterior parts (front and back)
what is an axial plane
axial planes divide the body into superior and inferior parts (top-superior)
superior and inferior meaning
above and below
lateral meaning
further from the sagittal plane
medial meaning
closer to the sagittal plane
superficial meaning
closer to the surface
deep meaning
further from the surface
anterior meaning
closer to the front of the body
prosterior meaning
closer to the back of the body
proximal meaning
closer to the starting point
distal meaning
further from the starting point
ipsilateral meaning
same side of the body (eg right arm and right leg)
contralateral meaning
opposite sides of the body
supine meaning
supine position is a variation of the anatomical position where the person is lying flat on the back
prone meaning
prone position is a variation in the anatomical position, here lying face down
what is a joint
a joint is connection between two or more bones is a joint, irrespective of whether movement can occur between the two bones
3 types of joints (named after what kind of tissue lies between them)
fibrous, cartilaginous or synovial (histological classification)
1?
joint cavity
2?
joint capsule
3?
synovium
4?
articular cartilage
5?
bone
joint cavity contains…
lubcricating synovial fluid
what is a fibrous joint
bones in a fibrous joint are united by fibrous tissue. the amount of movement depends on the length of the fibrous joints
which joints have joint cavities and which dont
synovial joints do
fibrous and cartilaginous dont
what are primary cartilaginous joints
bones are united solely by hyaline cartilage which provides some flexibility
what are secondary cartilaginous joints
bones are covered with a layer of hyaline cartilage and then united by fibrocartilage which provides strength
example of primary cartilaginous joint
attachment of ribs to sternum
example of secondary cartilaginous joint
joints between vertebral bodies
plane joint
- articular surfaces are flat
- joint capsules are tight
- sliding movements in planes of articular surfaces
hinge joints
- permits flexion and extension only
saddle joints
- articular surfaces are convex and concave
- two axes of movement
- permits flexion, extension, abduction, adduction and circumduction
condyloid joints
- similar to saddle joints with movement in two axes but one is usually restricted.
- permits flexion, extension, abduction, adduction and circumduction
ball and socket joints
- spherical and concave articular surfaces
- multiple axes of movement
- permits flexion, extension, abduction, adduction, circumduction and rotation.
pivot joints
-rotation around the central axis
1?
anterior cruciate ligament
2?
lateral condyle
3?
lateral meniscus
4?
fibular collateral ligament
5? (bone at posterior leg)
fibula
6?
patella
7?
patellofemoral groove
8?
posterior cruciate ligament
9?
tibial collateral ligament
10?
medial meniscus
11?
tibial plateau
12?
tibia
what protects the articulating surfaces of the knee joint?
two discs of fibrocartilage
what kind of joint is the knee joint
the knee joint is a synovial hinge joint with articulations between the lateral and medial condyles of the distal femur
which ligaments are on either side of the knee joint
lateral and medial collateral ligaments
function of the lateral and medial collateral ligaments
stabilise the femur and tibia in the coronal plane
what kind of tissue are lateral and medial collateral ligaments
fibrous connective tissue
what are the four ligaments inside the knee joint that prevent excessive movements in the sagittal plane
medial and lateral collateral ligaments
AND
anterior cruciate ligament (ACL)
posterior cruciate ligament (PCL)
what does the ACL attach to?
the ACL attaches the posterior aspect of the lateral condyle of the femur and to the anterior part of the tibial plateau
what does the PCL attach to?
the PCL arises from the posterior tibial plateau and attaches to the anterior part of the
medial condyle of the femur
function of the ACL
the ACL prevents excessive forward movements of the tibia in relation to the femur
function of the PCL
the PCL prevents excessive movements of the femur anteriorly in relation to the tibia
how can you injure the ACL?
excessive twisting or anterior movement of the tibia when fully weight-bearing
how can you injure the PCL?
excessive backward movement of the tibia on the femur (eg. Dashboard injury)
3 types of muscle
cardiac
smooth
skeletal
which nervous system controls smooth muscle
autonomic nervous system
smooth muscle function
involuntary bodily functions such as digestion, blood pressure control, micturition, temperature control, etc.
smooth msucle description
- narrow tapered rod-shaped cells
- non-striated, uninucleated fibres
- occurs in walls of internal organs and blood vessels
- involuntary
cardiac muscle description
- striated, tubular, branched, uninuleated fibres
- occurs in walls of heart
- involunatry
skeletal muscle description
- striated, tubular, multinucleated fibres
- usually attached to skeleton
- voluntary
function of skeletal muscle
to move the skeleton for locomotion and feeding etc.
skeletal muscles are attached to the skeleton via
joints
contraction of skeletal muscle does what
pull the two attachments closer together and cause a movement at the joint
what is the origin of the muscle
the muscle attachment that moves the least
what is at the opposite end to the origin of the muscle
the insertion
what is the widest part of the muscle called (skeletal)
belly
name this
fusiform
name this
parallel
name this
convergent
name this
unipennate
name this
bipennate
name this
multipennate
name this
circular
what is the motor unit
a single fibre (axon) within the nerve will innervate a number of muscle cells
what happens when a muscle conntracts
it pulls its origin and insertion closer together
AND
causes another muscle to relax (usually)
which muscles flex the carpus (wrist) joint
flexor carpi ulnaris
flexor carpi radialis
what is synergistic?
when muscles act together to produce one action
what muscles oppose the flexors?
antagonistic muscles
antagonistic muscles in wrist?
extensor carpi radialis longus
extensor carpi ulnaris
raising your arm is
abduction
lowering your arm is
adduction
circling your arm is
circumduction
bending over is
flexion
tilting your head back is
extension
turning OUT your legs is
lateral rotation
turning IN your leg is
medial rotation
turning your head either way is
rotation
flexion definition
when a joint becomes more bent
extension definition
when the joint is moved to a less bent/more straight position
abduction definition
movement away from the midline
adduction definition
movement towards the midline (eg second toe for toes)
lateral flexion definition
movement of the trunk which takes place at the intervertebral disks (upper body or neck bends to the side)
pronation definition
rotation of the forearm bones so the palm of the hand posteriorly
supination definition
rotation of the forearm bones so that the palm of the hand faces anteriorly (up)
why are upper and lower limbs similar
they both develop in the same way
proximal bones on the upper and lower limbs
LEG- femur
ARM- humerus
distal bones on upper and lower limbs
LEGS- tibia and fibula
ARMS- radius and ulna
what features make the hip joint stable and able to bear the weight of the body?
- femoral head lies deep in the acetabulum so theres high surface area of contact
- there are 3 strong ligaments holding it in place
why cant the shoulder resist large forces (why isnt it very stable)?
the upper limb is evolved for dexterity so the shoulder needs to be mobile. it is a shallow ball and socket joint with no strong ligaments
why is the humerus head much more likely to dislocate than the femoral head?
the shoulder joint is surrounded by groups of muscles that stabilise it but it has no strong ligaments inside the joint whereas the femoral head has a “screw like” formation of ligaments that effectively tighten to prevent excessive movement
compare the muscles in the feet and hands
in the hands there are small intrinsic muscles for increased dexterity, but in the feet there are much bigger muscles needed for weight bearing (which also increases the weight of feet compared to hands)
other name for C1 and function
atlas- supports the weight of the skull
adaptations of C1
- large articular surfaces to transmit the force down the vertebral column
- no vertebral body (fused with axis)
- has articular surfaces on the superior and inferior surfaces
other name for skull
occiput
name of fused atlas and axis
odontoid peg
other name for C2
axis
where is the odontoid peg found
just behind the anterior arch of the atlas
what holds in place the odontoid peg?
cruciate ligament
which part of the spine do th eribs attach to?
thoracic vertebrae
largest vertebrae?
lumbar vertebrae
other name for the cervical curve
lordosis
when does the cervical curve form?
when the baby is 8 weeks old
thoracic curve other name
kyphosis
when does lumbar lordosis (lumbar curve) form?
when the infant starts to walk
the spinal nerve passes through the
intervertebral foramen
what is in between the vertebral bodies
a secondary cartilagenous joint:
- made up of fibrocartilage and hyaline cartilage
- these are separated by and intervertebral disc
