Bone and Muscle Flashcards
superior
closer to the head (ie. higher)
what plane does rotation occur in
the transverse plane
rotation
the turning/pivoting of a bone at a joint
what plane(s) does circumduction occur in?
sagittal, coronal
circumduction
the sequence of flexion, abduction, extension, adduction
what plane does abduction and adduction occur in
the coronal
Abduction
the movement away from the median line of the body
adduction
the reverse of abduction
the movement towards the median line of the body
Extension
the opposite of flexion
increasing the angle between the two bones at a joint to straighten
Extracellular material (and/or fluids) and cells combine to form
Tissues
radius rotating over ulna is
pronation
radius and ulna are parallel is
supination
Long bones are ________ and have __________ and _____________
- bones that are longer than they are wide
- have a long shaft (diaphysis)
- have two expanded ends (epiphyses)
short bones
bones that are roughly the same width and length and are often rounded or cube shaped
irregular bones
bones that do not fit the other categories (long, short, flat) and often have a foramen (hole) through them
flat bones
bones that are thin, flat and often curved
Axial skeleton includes
skull, vertebral column, rib cage, sternum
appendicular skeleton includes
pectoral girdle, upper limbs, pelvic girdle, lower limbs
What are the 5 regions of the vertebral column?
cervical, thoracic, lumbar, sacrum, coccyx
describe the cervical region of the vertebral column
the smallest vertebrae in the neck - they allow greater range of motion of the head and neck
How many cervical vertebrae are there?
7
describe the thoracic region of the vertebral column:
allowing some movement and providing attachments to the thorax (ribs)
How many thoracic vertebrae are there?
12
describe the lumbar region of the vertebral column:
the largest vertebrae of the body because they needs to support the weight of the trunk, and allow movement
How many lumbar vertebrae are there?
5
describe the sacrum in the vertebral column:
five fused vertebrae that form the posterior view of the pelvic girdle
describe the coccyx in the vertebral column:
two of the five vertebrae (of the sacrum) forming a single bone (vestigial tail bone)
how does the appendicular and axial skeleton join?
the pectoral girdle and pelvic girdle
what 3 bones make up each hip bone?
ilium, ischium, pubis
What are the 5 functions of the skeleton?
- support
- movement
- protection of vital organs
- storage of minerals
- bone marrow formation
describe compact bone
- strong
- good at transmitting force and resisting compression
- dense, organised
- found in the diaphyses
describe trabecular bone
- spongy
- shock absorbing in multiple directions
- found in the epiphyses
what is bone tissue made of?
cells
calcified extracellular matrix
what are the cells in the bone matrix
osteocytes
osteoblasts
osteoclasts
what do the osteocytes do
Communicate when to build bone and when to break bone (they are the maintainers)
what do the osteoblasts do?
secrete extracellular matrix to build new bone
what do the osteoclasts do?
reabsorb the bone matrix (bone destroyers)
what material makes up the extracellular matrix of bone?
organic material
inorganic material
describe the inorganic material of the bone matrix
- makes up 67% of the bone matrix
- Hydroxyapatite
- makes the bone hard and resistant to compression
which is important because of weight bearing
describe the organic material of the bone matrix
- makes up 33% of the bone matrix
- Collagen
- resists tension (without it the bone is brittle and breaks too easily)
- this is important to resist forces coming in many directions
Compare the structure of cancellous bone vs compact bone
cancellous bone has a spongy trabecular structure whereas compact bone has an osteon structure
Describe the osteon structure of compact bone
Osteons are cylindrical structures running lengthways down compact bone.
Each osteon contains a central canal, lacunae, lamellae and canaliculi
Describe the central canal
in the very centre of an osteon, surrounded by cylinders of lamellae
carry nutrients and nerves to the bone
Describe the lacunae
- sit in between the lamellae
- they hold the osteocytes
- the osteocytes (and therefore the lacunae) is what needs the nutrients
Describe the lamallae
series of cylinders running down the bone creating the osteon
describe the canaliculi
tiny channels radiating outwards from the central canal to the outer lamellae to deliver nutrients
Describe the trabecular structure of compact bone
- the lamellae are arranged in fragile struts called trabeculae
- Each strut contains a lacunae, lamellae, lacunae and canaliculi
- the canaliculi are on the surface of the struts and blood diffuses in from the marrow through here
Describe bone remodelling
the osteoblasts build new bone of the outside of the bone at the same time as osteoclasts are destroying bone from the middle out
what happens if bone homeostasis is not maintained?
the amount of bone that is destroyed is greater than the amount of bone that is being formed - osteopenia and if serious, osteoporosis. The trabeculae in the cancellous bone gets thinner which can lead to fractures
Describe the principles of bone growth
in the womb, we begin to grow a cartilage model instead of bones. This cartilage is converted to bone in a process called endochondral ossification
Describe endochodral ossification
In the womb, blood vessels grow on the outside of the cartilage model. This allows osteoblasts to secrete bone matrix on the outside, forming hard real bone. Eventually the vessels penetrate the cartilage and osteoblasts can build bone from the middle out.
What are the two types of endochondral ossification?
- Primary ossification (this is how diaphyses grow)
- Secondary ossification (this is how epiphyses grow)
Why are the diaphysis and epiphysis separated?
they are separated by a growth plate because it allows the diaphysis to keep growing and then the two join during puberty
How do bones grow? (width and length)
- Width (appositional growth - osteoblasts building on the outside and osteoclasts destroying in the middle)
- Length (due to the growth plate)
What is a joint?
Where two bones meet
A joint holds bones together and allows free movement or the control of movement
What are the soft tissue associated with joints?
- Cartilage (hyaline/articular, fibrocartilage)
- Ligaments
- Tendons
Describe the general cartilage composition
made up of collagen fibres in a ground substance (proteins and water) and chondrocytes in the lacuna
Describe hyaline cartilage
- this cartilage coats the surface of bones to create a frictionless movement
- the collagen fibres are a thin mesh
- degrades with age which can cause stress of the bone structure
Describe fibrocartilage
bundles of collagen in different angles in the matrix to be able to resist stress from different angles
function: resist compression and tension
What are ligaments?
Ligaments connect bone to bone
Their function is to “restrict movement away from themselves”
What are ligaments made of?
DFCT
What does DFCT consist of?
Collagen, elastin and fibroblasts that form the DFCT
There is minimal elastin because ligaments need to restrict movement
There is more elastin in tendons because more movement is required
What are tendons?
Connect muscle to bone
What are tendons made of?
DFCT
Do tendons or ligaments have more elastin?
tedons
Types of joints
fibrous, cartilaginous, synovial
Describe fibrous joints
Fibrous joints connect bones what can not be separated (such as the bones of the skull or the tibia and fibula)
The bones are essentially sewn together
Structure: ligament
Tissue: DFCT
Describe cartilaginous joints
more movement allowed (eg. in the vertebrae or pubis symphysis)
Structure: various with different structures
Tissue: fibrocartilage
Describe synovial joints
free moving joints consisting of:
- hyaline/articular cartilage
- a joint capsule
- a joint cavity
- synovial membrane
- ligaments
Purpose of hyaline cartilage in a synovial joint
covers both ends of the bone
because of the high water content in it, it creates a smooth, frictionless end for the bones to slide over each other
the subchondral bone is also smooth
Describe the joint capsule in a synovial joint
the joint capsule is made of DFCT and it surrounds the two bone ends to create a capsule
Describe the joint cavity in a synovial joint
The joint cavity is the space that is between the bones and the DFCT that encloses the joint capsule. This is a fluid filled space (synovial fluid) which lubricates the bone ends to make frictionless movement
Describe the joint synovial membrane in a synovial joint
a thin sheet of epithelial cells on the inside of the joint capsule that secrete synovial fluid
What ligaments are involved in a synovial joint?
- capsular ligament
- intracapsular ligament
Describe the capsular ligament in a synovial joint
this is the ligament that makes up the joint capsule made of DFCT hold bones together tight and thick where support is needed thinner where more movement is required
Give an example of a capsular ligament and describe how it works
- the collateral ligaments in the knee:
the medial collateral ligament restricts adduction
the lateral collateral ligament restricts abduction
Describe the function of intracapsular ligaments in synovial joints
restricts movement between bones
Give an example of an intracapsular ligament and describe how it works
- the cruciate ligaments in the knee:
they go from the proximal end of the tibia into the distal head of the femur
the anterior cruciate ligament restricts posterior movement of the femur
the posterior cruciate ligament restricts anterior movement of the femur - the menisci in the knee:
low bony congruence so menisci needed to deepen articulation
What is range of movement determined by? (3 things)
- bone end shape
- ligament location and length
- body surface contact
List the synovial joint shapes (7)
- plane joint
- ball in socket joint
- saddle joint
- hinge joint
- pivot joint
- condylar joint
- ellipsoid joint
describe a plane joint
- multiaxial
- 3 planes
- on flat articular surfaces
what plane(s) does a plane joint move in?
saggital
coronal
transverse
describe a ball in socket joint
- multiaxial
- circumduction (ie. flexion, extension, abduction, adduction)
- rotation
what plane(s)does a ball and socket joint move in?
saggital, coronal, transverse
describe a saddle joint
- biaxial
- circumduction (ie. flexion, extension, abduction, adduction)
- obligatory rotation
Describe a hinge joint
- Uniaxial
- flexion and extension
what plane(s) does a hinge joint move in
saggital
what plane(s) does a saddle joint move in?
saggital and coronal
Describe a pivot joint
- uniaxial
- rotation
what plane(s) does a pivot joint move in
transverse
describe an ellipsoid joint
- biaxial
- circumduction ((ie. flexion, extension, abduction, adduction)
- NO rotation
what plane(s) does an ellipsoid joint move in?
sagittal, coronal
describe a condylar joint
- biaxial
- flexion and extension
- rotation only WHEN FLEXED
what plane(s) does a condylar joint move in?
sagittal, coronal
What are the three types of muscle tissue called?
skeletal, cardiac, smooth
Function of a muscle depends on
form
Shape/form of a muscle depends on
- length of muscle fibres
- number of muscle fibres
- arrangement of muscle fibres
how does the length of a muscle fibre affect movement?
Longer muscles = movement over a greater distance = greater range of movement
Types of levers with muscle attachments
- first lever
- second lever
- third lever
what does the first lever do?
stabilise the joint position
give an example of a first lever attachment and describe its function
the head is very heavy with the brain and facial muscles (internal load) and the muscles in the neck need to apply force to keep the head upright
- the fulcrum is the joint between the skull and the C1
what does the second lever do?
it is effective at overcoming loads
give an example of a second lever and describe its function
Plantarflexion
the body weight on the legs acts as the internal load. To overcome this load, force is applied from the muscles at the back of the leg
*the fulcrum is at the front of the foot
what does the third lever do?
it provides a greater range of motion and speed
give an example of the third level and describe its function
when you are lifting a weight (bicep curl), the load is the external weight of the dumbbell and force is applied from the biceps brachii to move quickly and efficiently
*the fulcrum is the elbow
what are the three types of muscle action
concentric, isometric, eccentric
describe a concentric contraction and give an example
- shortening of the muscle
- change in joint position
- eg. bicep curl, shortening bicep brachii and decreasing angle of elbow joint
Describe an isometric contraction and give an example
where muscle tension does not cause muscle shortening because the load is too heavy, can be voluntary (like weigh lifting above head)
there is no change to the joint poition
describe an eccentric muscle contraction and give an example
tension is developed to lengthen muscle in a controlled manner. there is a change in the joint position
eg. bringing down a bicep curl
what are the four types of muscle roles?
- agonist
- antagonist
- stabiliser
- neutraliser
agonists acts
concentrically
antagonists act
eccentrically
give an example of an antagonist and an agonist
when doing a bicep curl (upwards):
- biceps brachii concentrically contract to bring the weight up towards the body. This decreases the angle so there is flexion at the elbow
- biceps brachii is the agonist (it shortens)
- triceps brachii contract eccentrically to control the movement upwards
- triceps brachii is the antagonist (it lengthens)
- this is the opposite for bringing the weight back down
stabilisers act
isometrically
describe a stabiliser muscle
hold a joint still
there is no change to the length of biceps brachii
describe a neutraliser muscle and give an example
- minimise unwanted movement caused by another muscle
eg. the biceps brachii cause flexion at the elbow but pronators in the forearm act as neutralisers to prevent unwanted supination (eg. when lifting a glass to take a drink)
what muscle is associated with the shoulder joint?
deltoid
what two muscles are associated with the elbow joint?
biceps brachii
triceps brachii
what two muscles are associated with the hip joint?
Iliopsoas
Gluteus maximus
what two muscles are associated with the knee joint?
hamstrings
quad femoris
what two muscles are associated with the ankle joint?
tibialis anterior
triceps surae
any muscle that lies anterior to a joint will always produce
flexion
any muscle that lies posterior to a joint will always produce
extension
any muscle that lies medial to a joint will always produce
adduction
any muscle that lies lateral to a joint will always produce
abduction
The actions of muscles applies for all joints except the
Knee
what is the location of the deltoid muscle?
in the shoulder - from clavicle and scapular to an attachment at the humerus
what is the principle movement of the deltoid muscle?
flexion (the anterior muscle fibres)
abduction (the lateral muscle fibres)
extension (the posterior muscle fibres)
what is the principle movement of biceps brachii?
- produce flexion of the shoulder
- produce flexion of the elbow
- produce supination at the radioulnar joint
describe the form of biceps brachii and how that links to its movement
There are two heads (long head and short head) which both come from the scapula and fuse at the radial tuberosity. Because they are connected to two joints, they influence both flexion of the elbow and the scapula.
The tendon of biceps brachii attaches to medial side of the radius (which sits laterally on the anatomical position) which means that when you pronate, the tendon wrap around to be underneath the radius.
What are the major and minor role of the triceps brachii?
- major: produce extension at the elbow
- minor: produce extension of the shoulder
describe the form of triceps brachii and how that links to its movement
There are three heads (long head, lateral head and medial head). The bulk of the muscle crosses over and inserts into the radius so when flexed, the muscles can powerfully extend the elbow
Describe the form of iliopsoas and how that relates to
made up of psoas major (which goes into the femur) and iliacus (which goes into the iliac fossa) . These fuse together on the anterior part of the hip which means that it helps produce flexion of the hip
Describe the form of gluteus maximus and how that relates to
Powerful muscle that attaches to the femur which allows extension of the hip
What four muscles make up the quadriceps femoris?
rectus femoris, vastus lateralis, vastus medialis, vastus intermedius
Where is the rectus femoris?
anterior aspect of the thigh. It is the most superficial of the quadriceps femoris muscles
Describe the function of the rectus femoris muscle (only)
It is the only muscle of the quadriceps femoris to cross anteriorly over the hip which means that it helps produce flexion of the hip
Describe the function of the quadriceps femoris
all four of the muscles cross anteriorly over the knee to produce EXTENSION (exception to the rule) of the knee
what are the three muscles of the hamstrings?
biceps femoris, semi-tendinosus, semi-membranosus
describe the form of the hamstrings and how that relates to their function
The muscles cross posteriorly over the hip and knee which means that they help produce extension of the hip, flexion of the knee and rotation of the knee (when it is flexed)
describe the form of the tibialis anterior and how that relates to their function
Attaches to the tibial tuberosity and the medial side of the foot which means that it only which means that it produces movement in the ankle and foot not the knee.
It produces dorsiflexion at the ankle and inversion of the foot
What two muscles does the triceps surae consist of?
- gastrocnemius
- soleus
describe the form of the gastrocnemius and how that relates to its functions
it attaches to the calcaneus of the foot and crosses the knee posteriorly so produces flexion of the knee and plantarflexion of the foot
describe the form of the soleus and how that relates to its function
it attaches to the calcaneus of the foot so produces plantarflexion of the foot
What’s the difference between quadrupedal and bipedal standing?
Quadrupedal: - base support - limbs are active at many joints - demands a lot of energy Bipedal: - relatively small contact with the ground - plantar surface of the feet is the only art in contact with the ground - energy efficient
does gravity act as an agonist or antagonist?
both
when the head is tipping forward, it is an agonist
when the muscles are contracting to keep our head upright, it is an antagonist
where is the line of gravity in relation to the hip?
it is posterior to the hip joint
describe how the hip joints affects bipedal standing
rather than using muscles, ligaments lock the hip joint into extension which uses a lot less energy than muscles
what are the three reinforcing ligaments of the hip?
pubofemoral ligament
iliofemoral ligament
ischiofemoral ligament
when in flexion, the ligaments of the hip are _________________ anteriorly and __________________ posteriorly
lax, taut
when in extension, the ligaments of the hip are _________________ anteriorly and __________________ posteriorly
taut, lax
describe how the knee joint affects bipedal standing
the ligaments are are tight, locking the knee into extension which is very energy efficient. The congruence is highest when the joints are in extension
where is the line of gravity in relation to the knee?
anterior
where is the line of gravity in relation to the ankle?
anterior
What are the three things to consider when describing parts of the Gait cycle
Joint position
muscles involved
type of contraction
describe how the ankle joint affects bipedal standing
due to gravity, the ankle naturally falls into dorsiflexion and it is not locked. The plantar flexors (gastrocnemius and soleus) have to stabilise the joint which means that a lot of energy is consumed
An action potential causes the release of _____ into the synaptic cleft
ACh
The release of ACh into the synaptic cleft leads to
excitation
What is excitation?
The generation of an action potential in the sarcolemma
Bundles of myofilaments combine to form
many parallel myofibrils
many parallel myofibrils form
muscle fibres (muscle cells)
Many muscle fibres form
bundles of fascicles
bundles of fascicles combine to from
the muscle organ
What is the sarcolemma?
The plasma membrane of the muscle fibre (muscle cell)
What is the sarcoplasm?
The cytoplasm of the muscle fibre (muscle cell)
