Musculoskeletal Flashcards
Name and describe the 4 main planes
Cardinal Planes:
Coronal plane: Cuts the body into front and back
Saggital plane: Cuts the body into left and right. Median plane is down the middle, others are para-saggital planes
Axial (transverse/cross-sectional/horizontal): Cuts the body into upper and lower sections
Oblique plane: Any plane not parallel to the three cardinal planes
What is the anatomical position?
Feet together, toes forward. Palms forward. Standing upright, head and eyes forward with arms by the sides.
What is caudal?
Inferior
What do proximal and distal mean? (2 different contexts)
Limbs: Proximal is closer to the trunk, distal is further away
Circulation: Proximal is upstream, distal is downstream. Most things (except lymph and venous blood) flow proximal to distal
Flexion/Extension
Flexion: Bending, or decreasing angle between bones/body parts
Extension: Straightening (hyperextension is movement beyond necessary to straighten
Abduction/Adduction
Abduction: Movement apart, or away from median plane.
Adduction: Moving together or towards median plane
Elevation/Depression
Elevation: Moving superiorly
Depression: Moving inferiorly
Protraction/Retraction
Protraction: Moving anteriorly
Retraction: Moving posteriorly
Curcumduction
To draw in a circle- combo of flexion, abduction, extension and adduction, to form a circle distally
Supination/Pronation
Supination: Rotation of the palm to face anteriorly
Pronation: Rotation of the palm to face posteriorly
Opposition/Reposition
Opposition: Thumb moves across palm to finger pad
Reposition: Returning thumb to anatomical position
Dermatome
Area of skin mainly supplied by cutaneous branches (nerves reaching the skin) of a single spinal nerve.
Myotome
Group of muscles from a single somite (paired structures in embryos) supplied by a single spinal nerve.
Dorsiflexion
Flex foot
Plantiflexion
Point foot
Give three patterns of myotomal supply (with examples)
Muscles with the same action have the same segmental supply (eg. all hip flexors come from L2 and L3)
Opposing muscles have subsequent segmental supplies (eg. knees extended by L3/4, flexed by L5/S1)
The distal end of a joint is supplied by a segment one level lower than the proximal end (eg. knee movement is L3-S1, ankle movement is L4-S2)
Fascie:
Layers of connective tissue throughout the body- deep fascia is dense and fibrous, surrounding muscles, groups of muscles, blood vessels and nerves.
What is the clinical significance of deep fascia?
It is unyielding, so:
- When muscles in each compartment contract, they are forced to compress the veins and force blood to circulate
- They contain and direct the spread of infection- eg. a scratch in one compartment with an infected nail can contain tendonitis to that compartment
- They can lead to compartment syndrome. Emergent when happens suddenly as can constrict the blood supply and cause ischaemia (eg. broken leg and central bone canal leaks) Non emergent in exertional compartment syndrome (athletes)
Describe 4 bone types
Long: Carry weight, levers for movement
Short: Provide compactness, elasticity, limited motion
Flat: Protection, areas for muscle attachment
Irregular: Complex, form dictates function
How do the pectoral and pelvic girdles differ?
Shoulder attached mainly with muscle, so is very mobile, while lower limb sacrifices mobility for stability
Describe 4 areas of the upper limb
Pectoral girdle: Scapula, clavicle, acromion. Connects upper limb to trunk
Arm: Humerus. From shoulder to elbow
Forearm: Radius and ulna. From elbow to wrist
Hand: Carpals, metacarpals and phalanges. Distal to wrist
Describe 4 areas of lower limb:
Hips and Pelvis: Ilium, Ischium and pubis. Connects lower limb to trunk and vertebral column
Thigh: Femur and patella. Between hip and knee
Leg: Tibia and fibula. Between knee and ankle
Foot: Tarsals, metatarsals and phalanges. Distal to ankle.
What are the 2 phases of the gait cycle?
Stance and swing
What are the 3 stages of the stance phase?
Heel strike, foot progression, toe off
What are 3 main gait disorders, their presentation and origins?
Antalgic Gait: Shortened stance phase, (resulting in a limp). Usually due to pain
Cerebellar Ataxia: Slowness of pace and wide stance. Due to loss of balance and coordination. Central neuroplogical problem
High Steppage Gait: Weakness of dorsiflexion, so high stepping gait with no heel strike phase. Central neuro, peripheral nerve or muscular problem
What is the profile of MS disease in NZ?
Account for 25% of health costs, 1/4 adults affected.
Includes arthritis, osteoporosis, injuries, low back pain, spinal disorder, deformities.
What are the layers of the skin?
Epiderpis
- Stratum Corneum
- Stratum lucidum
- Stratum granulosum
- Stratum spinosum
- Stratum germinativum
Basal Lamina
Dermis
- Papillary layer
- Reticular layer
Subcutaneous Layer/Hypodermis
Investing Fascia
What is the function of epidermal derivatives (hair, sweat glands, sebacious glands, nail)
The first 3 provide epithelial cells when healing
Also some protection, secretion etc.
How does the arrangement of skin help its function?
The reticular layer of the dermis is key to skin.
It contain collagen, with tropocollagens in a quasi-crystalline arrangement to aid tension
It also contain elastin, with tropoelastin in a complex arrangement to withstand stretch and relaxation (tension)
The two fibres have a 3D basket weave pattern aligned with the skin tension lines (Langer’s Lines). This is important for wound healing and hypertrophic scars
Therefore, when the fibres are gradually loaded, they extend quickly as they stretch, but stretch little more once straightened, even at higher loads. It works kind of like the laundry rack at home- they stretch out until you can’t extend them further
How are tendons and ligaments arranged?
Closely packed parallel bundles of collagen, compressed and elongated fibroblasts, sparse capillaries/ Some elastic fibres, more prominent in ligaments. Tendon sheaths (inner epitendineum, outer parietal) allow sliding, with space between containing synovial fluid
What are the mechanical properties of tendons/ligaments, and how can they change?
Normally, they resist tension with minimal (only 2%) elongation, as the collagen fibres are already straightened out.
If tension is lost, they are rapidly remodelled.
Applying lateral pressure leads to remodelling with formation of fibrocartilage to improve compression resistance. If the pressure is removed they can return to their previous composition
What are the physical properties of hyaline cartilage and how are these maintained?
They resist compression very well due to their proteoglycan aggregates. These repel each other.
While they only need a small amount of input for maintenance, coompletely unloaded joints rapid, significant loss of PGs. This is prevented by passive movement of unloaded joints
What is the trouble with hyaline cartilage?
Describe two conditions involving this tissue
It is very poor at regenerating, resulting in chronic conditions difficult to treat.
Rheumatoid arthritis: A.I. disease. Antibodies destroy cartilage, severe inflammation
Osteo-arthritis (degenerative arthritis): Assoc. with age, pathological if onset premature. Caused by increased mech. stress to regions with low PG (mainly peripheral)
What are fibrocartilage and elastic cartilage?
FC: Resists tension and compressive forces
EC: Supports flexible structures, contains elastic fibres with type 2 collagen.
What happens when tendons and ligaments are remodelled?
The collagen becomes less regular
The tenocytes/fibroblasts become rounded instead of elongated
There is increased PG and H2O secretion
What is lost when adding and removing pressure to tendons/ligaments?
The PGs formed are easy to lose, but hard to regain- it takes a long time for a second application of pressure to result in cartilage formation
Where is hyaline cartilage found?
Most articulating bones, costal area in ribs
How does the high PG content of hyaline cartilage help withstand pressure?
- CS and KS GAGs with -ve charges are attached to core proteins, which attach via link proteins to HA. These -ve charges repel
- H2O binds to HA between the PGs, which is hard to compress
- -ve charges on the GAGs also bind to collagen fibres, making the tissue very stiff
How do you test PG content of cartilage?
The 2 second creep modulus: When a probe is pushed into cartilage for 2 seconds, how much does it depress?
The greater the PG content, the greater the resistance to pressure
How does PG content change across a layer of articular cartilage along a joint?
There is more PG content in the middle, as the edges of the joint are used less.
How can you prevent articular cartilage loss?
Either weightbearing or passive movement of unloaded joints- it only really remodels when weight and movement are removed.
What is special about the rabbit’s ankle?
The region of the tendon around the sesamoid part of the ankle is similar to fibrocartilage as it is under pressure. Due to this, it has a high concentration of CS in aggrecan. This is opposed to the low concentration of GAGs in other regions of the tendon, with low levels of DS in decorin PGs
What does bone resist and why?
Bone resists tension, pressure and torsion, as its collagen is arranged in lammelae with differing direction, and it has hydroxyapatite in its matrix
What is special about the arrangement of cancellous bone?
The trabeculae are aligned with the direction of force, to transfer these from the middle to the compact outer shell of the bone
What is special about the arrangement of compact bone?
It is found more in the articulating edges and shell of the bones, with greater thickness in areas with greater pressure.
The osteons are arranged paralled to the direction of compressive forces
Compare the bone of fetuses with adult bone
Fetuses have fine cancellous bone only, with collagen in a woven pattern
Adults have coarse cancellous bone, and compact bone. Their collagen is arranged in lamellae.
What structures and composition would you expect to allow resistance to tension?
- High collagen content
- Woven structures, or lamellar sheets
- Slight bending in the collagen, to allow straightening
- Elongated cells
What structures and composition would you expect to allow resistance to compression?
- High PG content
- Retention of H2O
- Presence of Hydroxyapatite
- Rounded cells
What forces would you expect a tissue with elongated cells, densely aligned collagen, and low to mid PG to resist?
Tension in 1-2 directions (either tendon/ligament or fascia)
What forces would you expect a tissue with rounded cells, a high PG content and fine woven collagen to resist?
Compression
What forces would you expect a tissue with elongated cells and a moderately dense woven collagen network, as well as elastic fibres, to withstand?
Tension in 3 directions, while allowing recoil
What forces would you expect a tissue with rounded cells, lamellated collagen and hydroxyapatite to withstand?
Tension, compression and torsion
What is the difference between tendons and ligaments?
Ligaments can have more prominence of elastic fibres, and more PGs
What are the 3 meninges, and their associated spaces? What do they do?
Outermost is the epidural space, containing fat, arteries and veins. It’s a good place for local anaesthetic as it is near the main nerves and fairly large
The dura mater is very tough
The subdural space is a virtual space where some veins cross over, so if shrinkage of the CNS occurs, the veins can burst, causing an hemorrhage.
The arachnoid mater is shimmery and weblike
The subarachnoid space contains the most CSF of anywhere in the body, and can also hemorrhage
The pia mater adheres tightly to the spinal cord and roots themselves.
On the edges of the roots, the three combine to form the epineurium, surrounding the nerves themselves
What are the 3 rami of the spinal nerves?
The posterior ramus (smallest) innervates the back muscles
The Ramus Communicans connects the spinal cord with the ANS
The anterior ramus innervates the front muscles and organs
What is the conus medularis and cauda equina?
Conus medularis is the cone shaped ending to the spinal cord proper. The cauda equina descends past this, in a trail of spaghetti-like nerves.
What are the filium terminale?
The filium terminale internum is when the pia mater comes together past the conus medularris, and forms a single fiber above the lower limit of the subarachnoid space
The Filium terminale externum occurs when the arachnoid mater joins with this fiber and continues down to be attached to the coccyx. It can be identified as it is bluer/whiter and tighter than the other fibres.
Where is a spinal tap usually done and why?
It is usually done around L3 as there is little chance of hitting the spinal cord if done after the conus medullaris ends.
How is the arachnoid mater held in place?
There are denticulate ligaments between it and pia/dura, to prevent the expansion and contraction of AM and keep the volume and pressure of CSF constant.
What and where is the fascia lata?
A dense layer of connective tissue surrounding and compartmentalizing the thigh.
Superiorly it attaches to the pubic tubercle, pubis and inquinal ligament.
Laterally attaches to the iliac crest
Posteriorly to sacrum, coccyx and ischial tuberosity.
Extends to the knee where it becomes continuous with fascia in the leg
1 Opening: Saphenous to allow the saphenous vein to enter beneath the fascia lata (inf. to inguinal ligament)
What is the ITB?
Iliotibial Band.
A lateral fusion of the TFL muscle tendon and fascia lata, attaching to the lateral tibia.
What and where is the femoral triangle?
A space in the superior thigh. Superior border: Inguinal ligament Lateral border: Sartorius Medial border: adductor longus Deep border: Iliopsoas & Pectineus Superficial border: Skin and fascia lata
Contains Femoral nerve, artery, vein, and lymph vessels. Femoral sheath contains all but femoral nerve. Subcompartment (femoral canal) contains the lymph, with femoral ring at the proximal end.
What are the muscles of the anterior compartment of the thigh and their Or/In ?
Rectus femoris: border between hip and femur, to superior patella
Vastus lateralis: greater trochanter to superior patella
Vastus medialis: top of femur (dip) to superior patella
Vastud intermedius: Along the upper 2/3 of femur to superior patella
Sartorius: ASIS to medial tibia
(TFL- ASIS to greater trichantor)
What are the functions, innervation and blood supply of the anterior thigh muscle compartment?
All extend the knee, sartorius and rectus femoris also flex the hip
Innervated by Femoral nerve
Blood supply from Femoral artery
Drained by femoral vein & saphenous vein
What are the muscles of the medial compartment of the thigh and their Or/In?
Adductor Magnus: From Pubis to shaft of femur
Adductor Brevis: From Pubis to upper third of femur
Adductor Longus: From pubis to middle third of the femur
Gracilis: From pubis to superior medial tibia
Pectineus: from upper pubis to inferior to lesser trochanter
What is the function of the medial compartment of the thigh and their innervation and blood supply?
Adduction of the thigh, although some flex the hip
Supplied by Obdurator nerve, femoral artery, femoral and saphenous veins
Where are the femoral and obdurator nerves’ locations?
From L2-4 in the spinal cord
What is the femoral nerve profile?
Levels L2-4
Branches into saphenous nerve
Supplies iliopsoas, pectineus, sartorius, vastus and rectus femoris muscles
Supplies anterior thigh and medial leg/food (sensation)
What is the obturator nerve profile?
Levels 2-4
No branches
Supplies obturator externus, abductor and gracilis muscles
Supplies medial thigh (sensation)
What is the adductor canal?
A gap underneath the middle third of sartorius, allowing the femoral vessels to reach the popliteal fossa to become the popliteal vessels. Inlet is the apex of the femoral triagle, outlet is adductor hiatus in adductor magnus.
How can the thigh be useful clinically?
- Fem vein = direct line to the heart for cannulation (putting in lines) and taking RHS heart blood pressure and blood samples
- Femoral artery good for taking pulses and angiography
- Femoral nerve block using femoral artery as a landmark (to relieve pain)
- Femoral hernia can occur when digestive tract extends into femoral ring and even through saphenous opening
What are the two types of HUMAN bone?
Rapid Expansion (fetal, fracture callus, pathologically induced) Leisurely consolidating/remodelling
What are the two types of Rapid Expansion bone and their descriptions?
Fine cancellous bone can be:
- Membrane bone, where mesenchymas connective tissue takes on bone-growing properties, with woven collagen fibrils in random orientations
- Cartilage bone, where trabeculae forming have a core of calcified cartilage surrounded by woven bone. This is then replaced by adult bone
What are the two adult bone types, and their descriptions?
- Cancellous bone. Lamellar bone in trabeculae with marrow between. Osteocytes in lacunae, no more than .4mm in diameter
- Compact bone. Lamellar bone arranged in haversian canals, with vessels and nerves in the middle. Surrounded by fibrous periosteum.
How does bone grow?
Appositional growth: Osteogenic cells divide, with one becoming an osteoblast. These secrete matrix, which then hardens. Osteocytes linked by canaliculi, with osteogenic cells remaining at the periosteum and endosteum of bones.
How do osteons form? (2 ways)
Primary: Bone grows appositionally, with ridges forming around the vessel that then fuse together. The peri (now endosteum) grows inwards, surrounding the vessel.
Secondary: Osteoclasts dig a cutting cone into the bone, while blood vessels and endosteum follow. Note, the blood vessel loops back out, giving the new canal two vessels in cross section.
How do osteoclasts break down bone?
Firstly, they secrete acids, causing decalcification and removing hydroxyapatite.
Then, they secrete enzymes called acid hydrolases (to work in the acidic conditions). These digest the newly exposed collagen.
Any surrounding osteoblasts move out of the way of osteoclasts.
How does the shape of an osteoclast aid its function?
They have a collar attaching them to surrounding bone, preventing their secretions from leaking
They also have a ruffled border to increase SA
They sit in hoships lacunae.
How is bone resorption controlled by hormones?
PTH increases osteoblast and clast activity (but clast to a greater degree) and decreases bone mass
Calcitonin decreases osteoclast activity, ruffles, numbers and movement
Calcium supplements reduce PTH
Hormone therapy, biphosphates, cathepsin K inhibitors decrease osteoclast activity
Denosumab inhibits osteoclast formation
Sclerostin stops production of bone, so antisclerostin aids bone formation
What are the receptors involved in osteoclast formation>
RANK receptors are on osteoclast precursors
RANKL ligands are on osteoblasts
When the two link, the osteocyte is encouraged to mature
OPG is a ligand that can bind, preventing maturation of osteoclasts
How do long bones grow in length? How does this change over a lifetime?
Growth occurs in epiphyseal plate, a hyaline cartilage area in the epiphysis of long bones
One side of the plate accumulates cartilage, the other side has cartilage hypertrophing, and then dying.
Osteoblasts and blood vessels then migrate in, converting the dead tissue to bone.
Until the age of 18, these processes occur in equal amounts, but then the growth stops and resorption continues, closing the plate and stopping further growth.
What is the process of healing fractures of bone?
Osteogenic cells in the broken end of the peri/endosteum divide, producing osteoblasts that turn into chondrocytes due to lack of blood supply. These put down cartilage in a collar around the fracture for support, which is then remodelled into bone when the blood vessels arrive.
Internally, secondary osteon formation causes the bone to knit back together.
How do metal plates and screws both help and hinder bone formation?
They can give external support and prevent callus formation, as they hold bits of bone together. However, it takes a longer time for the fracture to heal and the bone formed is weaker.
How do dermal papillae (pegs) aid the skin’s function?
They provide greater grip between the epidermis and dermis
They give a higher surface area for nutrient diffusion
How is skin anisotropic?
The collagen weave isn’t uniform in all directions, meaning the skin stretches more in some directions than others.
How is skin damaged?
Thermal, abrasive and puncturing wounds
Surgical incisions
How do different wounds heal?
Superficial (to the dermis) wounds heal with little to no scarring
Deep wounds heal with scarring and sometimes contraction.
1. Hoemostasis and haemotoma
2. Inflammation (redness and oedema)
3. Matrix formation (fibroblasts, collagen and elastin form)
4. Neovascularisation
5. Re-epithelialization
6. Wound contraction and remodelling
What is a scar, and what is the difference between normal, hypertrophic and keloid scars?
Scars are collagen patches intended to aid wound strength. The collagen is aligned along lines of stress,
In hypertrophic scars, the collagen is in a random orientation surrounded by oriented bands. It is raised red, itchy and stays within the confines of the wound. They remain indefinitely, and may contract.
Keloid scars are also red, itchy and raised, but are invasive. They occur anytime after injury, often recur, do not contract or regress, and commonly occur on the trunk, back, face and earlobes.
What are tension lines of the skin and how do they have an impact on surgical incisions?
These are lines along which the collagen is more tense, with elastic fibres running parallel to these lines.
This means that when the skin is cut, the elastic fibres will pull the wound closed rather than stretching it open, aiding scar formation and preventing hypertrophic scars.
This is of particular import in joints.
What are the muscle compartments of the leg?
Anterior, lateral, posterior
What are the muscles and their origins/insertions in the ant and lat compartments?
Anterior:
- Tibialus anterior (Superior lateral tibia/IO membrane to superior medial cuneiform and 1st MT)
- Extensor digitorum longus (Lateral condyle of tibia, sup. med. tibia and IO membrane to lateral 4 toes)
- Extensor halucis longus (Middle ant. fib. and IO membrane to base of distal great to phalanx)
- Peroneus Tertius (inf. ant. fibula and IO membrane to base of 5th metatarsal)
Lateral: Peroneus Longus (Sup. lat. fibula to inferior medial cuneiform) Peroneus Brevis (inf. Lat. fibula to inf. 5th MT)
What is the function of the muscles of the anterior and lateral compartments of the leg?
Ant:
- TA: dorsiflexion and inversion
- EDL: Dorsiflexion
- EHL: Extends big toe
- PT: Eversion
Lateral:
Both eversion.
What is the nervous supply of the anterior and lateral leg?
Anterior compartment: Deep peroneal nerve
Lateral compartment: Superficial peroneal nerve
What is the vascular supply of the anterior and lateral leg?
Anterior compartment: Anterior tibial artery
Lateral compartment: Peroneal artery
What are the 4 retinaculi, what do they hold and where do they stretch?
Sup. Extensor Retinaculum: From inferior tibia to fibula, sup. to malleoli. Binds ant. compartment tendons
Inf. Extensor Retinaculum: Y shaped, from upper calcaneus to medial malleolus and plantar aponeurosis.
Sup. peroneal retinaculum: Above lateral malliolus to lateral calcaneus
Inf. peroneal retinaculum: Continuous with cruciate crural ligament, attached to lateral surface of calcaneus. Some fibers fixed to peroneal trochlea, making a septum between the lateral tendons
These hold the lateral muscle tendons down.
What cutaneous regions do the superficial and deep peroneal nerves supply?
Deep: Wedge between 1st and 2nd toes
Superficial: medial superior food
What is the innervation of the foot?
Lateral: Sural nerve
Medial: Sup. peroneal nerve
1st and 2nd toes: Deep peroneal nerve
Medial: Saphenous nerve
What is the main arterial supply of the foot?
The Dorsalis Pedis artery
This branches off the popliteal artery’s anterior tibial artery
What are the two main muscles of the dorsal foot?
Extensor digitorum brevis (inf. Ext. Retinaculum to middle of lateral 4 toes
Extensor Hallucis Brevis: Inf. Ext. reticulatum (with the insertion of EDB) to base of great toe.
What is the presentation of compartment syndrome and how is it treated?
5 Ps: Pain, Pallor, Pulselessness, Paresthesia and Paralysis
Treat by opening affected and nearby muscle compartments.
What are the two joints and three bones associated with the knee?
The patellofemoral joint (patella and femur)
The tibiofemoral joint (tibia and femur)
What is contained within the articular (joint) cavity of the knee? What is excluded?
The synovial cavity includes the articular surfaces of the three bones, the suprapatellar bursae, and the menisci (medial fused, lateral not)
Superficial to this, but within the fibrous joint cavity, are the cruciate ligaments.
Superficial to the fibrous membranes are the MCL and LCL, as well as the prepatellar and infrapatellar bursae.
What are the 5 ligaments of the knee joints, their orientations and functions?
Prepatellar tendon: continuation of quadriceps tendon, from inf. patella to tibial tuberosity. It moves superiorly to inferiorly to extend the leg.,
MCL and LCL: Medial runs from med. femoral epicondyle to medial tibia. Prevents valgus (tibia moving laterally and femur medially) LCL runs from lat. femoral epicondyle to fibula head. Medial attached to fibrous capsule, lateral discrete. Prevents varus (tibia moving medially and femur laterally)
Cruciate ligaments: Anterior goes from ant. tibial spine to lateral condyle. Prevents anterior translation of tibia. Posterior goes from posterior tibial spine to medial epicondyle. Prevents posterior translation of tibia.
What is the significance of the difference between the lateral and medial sides of the knee joint?
The structures on the medial sides are all fused together, so it’s more likely that injuries on the medial side will involve multiple structures. The lateral side is more flexible.
What are the bursae of the knee joint, and how do they become inflamed?
Suprapatellar bursa: between quads tendon and femur, continuous with knee joint. Where fluid accumulates during knee joint effusion
Prepatellar bursa: Anterior to patella, inflamed with excessive kneeling etc.
Infrapatellar bursae: Superficial and deep to patellar ligament, inflamed when kneeling upright.
What are the menisci and their functions within the knee?
They are two wedges of fibrocartilage within the tibiofemoral joint, absorbing shock and improving joint articulation. The medial meniscus is more likely to be injured than lateral as it is adherent to the joint capsule and MCL
What is the vascular supply of the knee?
The knee receives blood superiorly from the femoral, lateral femoral circumflex and popliteal vessals
Inferiorly it receives blood from the anterior tibial and circumflex peroneal arteries.
What is pes anserinus and terrible triad?
Pes anserinus- insertion of sartorius, gracilis and semitendinosus on med. prox. tibia. They can be used to reconstruct a torn Anterior cruciate ligament
Terrible triad is an injury resulting from valgus force. The three structures involved are the MCL, ACL and medial meniscus
What are the borders of the gluteal region, and the important features of the pelvic bones?
Posterior to pelvis, bordered superiorly by iliac crests and inferiorly by gluteal folds
The ilium has the ASIS, iliac spine proper and AIIS
The Ischium has the ischial tuberosity and ischial spine (which is important for pain relief during childbirth)
The pubis has the pubic tubercule.
What are the ligaments of the bony pelvis and what do they do?
Sacrospinous ligament (sacrum to ischial spine) Spinotuberous ligament (sacrum to ischial tuberosity) These bind the bones of the pelvis together and separate the hold of the pelvis into the greater and leser sciatic foramina. Greater is superior, allowing passage of nerves and vessels TO lower limb, while the inferior lesser allows passage FROM the lower limb.
What are the 3 superficial muscles of the gluteal region, what are their origins/insertions, nerve supply and functions?
Gluteus maximus: Sacrum and iliac crest to the ITB and lateral femur . Supplied by inferior gluteal nerve. Extensor of the hip and lateral thigh rotator
Gluteus medius and minimus: Ilium to greater trochanter. Supplied by superior gluteal nerve. Abducts and internally rotates thigh
What are the 5 deep external rotators of the gluteal region, their origins/insertions, nerve supply and functions?
- Piriformis: Sacrum to greater trochanter.
- Gemellus superior and inferior, Obturator internis: Ischium to greater trochanter
- Quadratis femoris: Lateral ischial tuberosity to intertrochanteric crest.
All are supplied by sacral plexus, and externally rotate the thigh
What are the 3 bursae associated with gluteus maximus?
- Trochanteric bursa: between GM and greater trochanter
- Ischial bursa: between GM and ischial tuberosity
- Gluteofemoral bursa: Between ITB and vastus lateralis
What are the muscles of the posterior thigh, their origins, insertions, nerve supply and functions?
- Biceps femoris: Ischial tuberosity (long) and linea aspera (short) to head of fiibula. externally rotates leg
- Semitendinosus: ischial tuberosity to sup. med. tibia in pes anserinus. Internally rotates leg
- Semimembranosus: Ischial tuberosity to med. condyle of tibia. Internally rotates leg
- Adductor magnus: Ischial tuberosity to linea aspera, adductor tubercle, supracondylar ridge.
All extend thigh
All innervated by tibial nerve
What are the arteries and nerves of the gluteal region?
The internal iliac artery branches to give the superior and inferior gluteal nerves, while the sciatic is simply a large nerve.
There are plexuses superior and inferior to the piriformis muscle.
