Anatomy: Bones and Muscles of the Lower limb Flashcards
What are the 3 portions of a long bone called, from joining end to long end?
Epiphysis
Metaphysis
Diaphysis
Describe 3 things about a sesamoid bone
Give an example of a sesamoid bone
Patella
Found within tendons
Reduce wear
Improve muscle efficiency
Describe 3 things about a flat bone
Give an example of a flat bone
Scapula
Large surface area for muscle attachment
Weight/force transfer region
Protection (pelvic girdle and skull)
What is Wolff’s Law?
Bone is deposited and reabsorbed in accordance with the stresses placed upon it (it is able to remodel)
Name the 2 types of bone?
within a single bone
Cancellous/trabecular/spongy bone
Cortical bone
What 6 things make up the axial skeleton?
Skull Ribs Sternum Vertebrae Sacrum Coccyx
What 3 things make up the appendicular skeleton
Hip bones (pelvic girdle)
Pectoral girdle
Limbs (upper and lower)
Define Amelia
No limb growth
Define Meromelia
Partial limb
Define Phocomelia
Seal-like limb/flipper
Define Polydactyly
Additional digits
Define Syndactyly
Webbing/joining of digits
Name the 2 large groups of bone to bone joint
Fibrous joints
Cartilaginous Joints
What are the 3 types of fibrous joints?
Give an example and characteristic of each type of joint
Suture
- do not move
- skull
Gomphosis
- small degree of movement
- teeth to jaw
Syndesmosis
- fibrous sheet of tissue that keeps 2 long bones in proximity to each other
- forearm
What are the 2 types of cartilaginous joints?
Give an example and characteristic of each type of joint
Epiphysis
- mainly in children
- growth plate of a bone
Symphysis
- movable discs between joints
- vertebral discs
Describe 3 things about hyaline cartilage
Found at the ends of 2 adjoining bones
Avascular, smooth and slippy
Sits withing a joint capsule
What lines a joint capsule and produces synovial fluid?
Synovium (serous membrane)
What is a bursae?
Pockets of synovium and synovial fluid found in regions of friction/wear
Inflammation of the bursae causes bursitis
Where are synovial sheaths found?
Around tendons at points of wear/friction/direction change
Inflammation of the synovium causes synovitis
Inflammation of the sheath and the tendon causes
What is a nerve plexus?
A region where the ventral rami of spinal nerves join and exchange neurons
What wraps the compartments in the forearms?
Connective tissue fascia
Wraps around the muscles and tissues to form anterior and posterior compartments
Anterior compartments are mainly responsible for….
Flexor function
Posterior compartments are mainly responsible for….
Extensor function
What does the anterior thigh compartment contain?
Hip flexor and knee extensor
Femoral nerve (L2, L3, L4)
Femoral artery
What is a retinacula?
Thick bands of fascia that connect tendons to bone and stop them lifting off when activated
Venous drainage runs from….
Superficial to deep
The origin site of a muscle is
Generally more fixed and proximal
The insertion site of a muscle is
Normally more mobile and distal
Give 5 roles of connective tissue
Structural support
Metabolic support
Cell adhesion
Medium of exchange
Defense, protection and repair
What 2 things is connective tissues made from?
Cells
Extracellular matrix
What 2 things is extracellular matrix formed of?
Give properties of each
Fibrous proteins
- collagen
- elastin
Ground substances
- transparent
- colourless
What 3 things is ground substance formed from?
Give properties of each
Proteoglycans
- repeated disaccharides (GAG) around a protein core
- GAG attracts water
Glycoproteins
-allow cells to adhere to the ECM
Water
-attracted by GAG
What provides the rigidity of bones?
Mineralised extracellular matrix (hydroxyapatite)
What provides the resilience of bones?
Type 1 collagen fibres
part of the fibrous proteins component of ECM, other component is ground substance remember
Name the 5 functions of bone
Movement
Mineral homeostasis
Support
Protection
Site of haematopoiesis
Describe the structure and function of the periosteum
Dense, irregular connective tissue layer covering the bones where tendons and ligaments insert
Out fibrous layer
Inner cellular layer
-osteoprogenitor cells and osteoblasts
Helps the bone grow in thickness, # repair nourishes bone tissue
Where is the endosteum?
Lines the inside of the bones
What are the 2 types of bone (mature/immature)
Woven bone
Lamellar bone (mature)
Describe the structure of woven (immature) bone
First bone formed at any site
Collagen fibres are arranged randomly
Occurs at site of # healing
Describe the structure of lamellar (mature) bone
Collagen fibres remodel into orderly arrangement
What are the 2 types of mature (lamellar) bone?
Trabecular
Cortical
Describe the characteristics of trabecular bone and how structure is related to function
Looks like beams and struts.
Orientated along the lines of stress and redistributes stress along the bone.
Spaces make the bone lighter and give space for bone marrow as well
Describe the characteristics of cortical bone and how structure is related to function
Dense and compacted bone
Arranged into Haversian systems (osteons)
What is a lamellae?
A bony plate made up of collagen fibres arranged in parallel
Describe the composition of lamellar bone
And outer circumferential lamellae runs along the shape on the bone
Concentric lamellae form around Haversian canals, which contain blood vessels, lymph vessels and nerves.
Collagen fibres in the Haversian systems (osteons) form around the Haversian canals in parallel to each other
Volkmann’s canals run transversely and allow communications between the Haversian systems and between the periosteum and the osteons
What type of cell are osteoprogenitor cells derived from?
Mesenchymal stem cells
What do osteoprogenitor cells turn into?
Osteoblasts
What do osteoblasts mature into?
Osteocytes
What type of cell produces osteoid?
Osteoblasts
What is in osteoid?
Type 1 collagen
Proteoglycans
Glycoproteins
List 2 features of osteocytes
Mature bone cells
Do not undergo cell division
Give 2 functions of osteocytes
Mechanotransduction (detecting stresses and triggering action of other bone cells)
Calcium homeostasis
Name the space that an osteocyte sits in within the bone
Lacunae
What are the channels within bone called?
What sits within these channels?
Canaliculi
Dendritic processes of osteocytes
What role do osteoclasts have?
Remodeling, growth and repair of bones
What do osteoclasts derive from?
Monocyte-macrophage system
What do osteoclasts secrete?
Enzymes and acid
Name the space the osteoclasts sit in
Howship’s lacunae
Which type of cell secretes RANKL?
Osteoblasts
When do osteoblasts secrete RANKL?
In response to calcitrol and PTH
Where is the RANK receptor located?
Osteoclasts
What 2 things do osteoblasts secrete?
RANKL
OPG
Which hormone increases the amount of OPG?
Oestrogen
What does OPG do?
Mops up excess RANKL so that bone re-absorption does not get out of control
Fill in the gaps:
Many different hormones regulate bone remodelling. Osteoblasts secrete _____ in response to ______ and ___. RANKL binds to ____ receptors on ______ and stimulates bone reabsorption. _____ secrete OPG: this mops up excess ______ so that bone reabsorption does not get out of control.
Many different hormones regulate bone remodelling. Osteoblasts secrete RANKL in response to calcitriol and PTH. RANKL binds to RANK receptors on osteoclasts and stimulates bone reabsorption. Osteoblasts secrete OPG: this mops up excess RANKL so that bone reabsorption does not get out of control.
What are the 2 types of bone development?
Intramembronous ossification
Endochondral ossification
Draw out the pathways for the 2 types of ossification
Intramembranous:
mesenchyme –> bone
Endochondral:
mesenchyme –> cartilage –> bone
What is mesenchyme?
Undifferentiated embryonic connective tissue
Which bones undergo intramembronous ossification?
Flat bones of the skull, clavicle and mandible
How are the flat bones of the skull, clavicle and mandible formed?
Intramembranous ossification
Which enzyme leads to calcification of the ECM?
Hydroxyapatite
Where are primary ossification centres found?
Diaphysis of weight bearing bones
In endochondral ossification, what does the mesenchyme develop into?
Chondroblasts (cartilage building cells)
Where are secondary ossification centres found?
Epiphyses of weight bearing bone
What is the difference between primary and secondary ossification sites
Primary found at diaphysis and forms bony structure all around. Develop as a foetus.
Secondary found and epiphysis and doesn’t lay bone down on articular surfaces and epiphyseal growth plate. Develop after birth
What are the 6 stages of fracture healing?
Haematoma
Granulation tissue
Callus
Woven bone
Lamellar bone
Remodelling
What are the 2 types of bone growth?
Longitudinal growth
Appositional growth
Where does longitudinal growth occur?
At the epiphyseal growth plates of weight bearing long bones
Name the 5 zones in the epiphyseal growth plate
Resting zone
Proliferation zone
Hypertrophic zone
Calcification zone
Ossification zone
In which zone of the epiphyseal growth plate to chondrocytes undergo mitosis?
Proliferation zone
What are cartilage cells called?
Chondrocytes
In which zone of the epiphyseal growth plate are chondrocytes stacked like coins in columns?
Proliferation zone
In which zone in the epiphyseal growth plate do chondrocytes die?
Calcification zone
In which zone in the epiphyseal growth plate do osteoprogenitor cells invade?
Ossification zone
What is the name given to a fracture of the epiphyseal growth plate?
Salter-Harris fracture
What is a fracture?
A breach in the integrity of part or the whole of a bone
What 3 factors aid fracture healing?
Stability of the fracture
Apposition of bone ends
Adequate blood supply
What 4 factors delay fracture healing?
Excessive movement of bone ends
Poor blood supply
Infection
Foreign bodies
What forms the ball and socket join of the hip?
Femoral head (ball)
Acetabulum of pelvis (socket)
Name the 4 symptoms visible in a posterior hip dislocation
Limb shortened
Limb flexed
Limb adducted
Internal rotation
Name the 2 symptoms visible in an anterior hip dislocation
Limb abduction
External rotation
What makes up the bony pelvis?
Sacrum
2 hip bones
What joints connects the sacrum to the 2 hip joints?
What type of joints are they?
Sacroiliac joints
Synovial joints
What joints the anterior portions of the hip bones together?
What type of joint is this?
What are some common features of this type of joint?
Pubic symphysis
Secondary cartilaginous type joint
These joints are found typically in the midline and typically symphysis type joints e.g. IV discs
What is a ligament?
Fibrous tissue that connects bone to bone
What is a tendon?
Fibrous tissue that connects muscle to bone
Where is the sacrospinous muscle?
Connects sacrum to spine of ischium
Where is the sacrotuberous ligament?
Connects the sacrum to the ischial tuberosity
What 2 foramen are made by the sacrospinous and sacrotuberous ligaments?
Great and lesser sciatic foramen
Which muscle divides the greater sciatic foramen?
What is the function of this muscle?
Piriformis muscle
Lateral rotatory muscle of the hip
What does the greater sciatic foramen connect with?
Pelvic cavity
Gluteal region
What does the lesser sciatic foramen connect with?
Perineal region
Gluteal region
Which 3 bones fuse together at the acetabulum?
Ilium
Ischium
Pubis
Which muscles insert on the greater trochanter of the femur?
Gluteus medius
Gluteus minimus
Which muscle has an attachment point at the lesser trochanter of the femur?
Iliopsoas muscle
a hip flexor muscle
Along which bony prominence do all 3 thigh compartments attach?
Linea Aspera of the thigh (posterior)
What 3 ligaments help stabalise and reinforce the external hip joint?
Can they be viewed anteriorly or posteriorly?
Iliofemoral
Pubofemoral
(anterior)
Isciofemoral
(posterior)
Name the 3 layers of joints/connections around the hip joint from deep to superficial
Synovial membrane
Fibrous membrane
3 ligaments
What would a valgus hip do to the knee?
Knee would move away from midline (bow legs)
What would a varus hip do to the knee?
Move the knee towards the midline
Name the 3 compartments of the thight
Anterior
Posterior
Medial
What fascia covers all 3 compartments of the thigh?
Fascia lata
What is the iliotibial tract?
Lateral thickening of fascia lata
Which vein runs superficial to the fascia lata?
Saphenous vein
Which large muscle inserts into the iliotibial tract?
Gluteus maximus
What nerve innervates the gluteus maximus?
Inferior gluteal nerve
L5-S2
What are the proximal attachments of the gluteus maximus?
Ilium
Sacrum
Sacral ligaments
What are the distal attachments of the gluteus maximus?
Femur
Iliotibial tract (ITT)
What nerve supplies gluteus medius?
Superior gluteal nerve
L4-S1
What nerve supplies gluteus minimus?
Superior gluteal nerve
L4-S1
Which muscles insert on the greater trochanter?
Gluteus medius
Gluteus minimus
What sign is illicited when gluteus medius and minimus are damaged?
What nerve could be responsible?
Trendelenburg sign
-when patient lifts right leg, left hip droops as loss of stabilising muscles
Superior gluteal nerve
Which nerves innervate the lateral rotators of the hip?
L4 - S2
Which 4 muscles laterally rotate the hip?
Piriformis
Gemelli (superior + inferior)
Quadratus femoris
Obturator internus
Which 3 muscles are in the posterior compartment of the thigh?
Semimembranous
Semitendinous
Biceps femoris
What is the common point of origin for the hamstring muscles (posterior thigh compartment)?
Ischial tuberosity
Where is the safe zone for IM injections in the gluteal region and how would you identify it?
Sits superolaterally
- Vertical line through highest point of iliac crest
- Line from PSIS to greater trochanter
Which 4 muscles are found in the medial thigh compartment?
Pectineus
Adductor longus
Adductor magnus
Adductor brevis
What are the 3 types of muscle?
Skeletal
Cardiac
Smooth
Give 6 features of skeletal muscle
Cylindrical cells
Striated
Multinucleated
cm in length
Limited regeneration
Voluntary control
Give 6 features of cardiac muscle
Branched cells with intercalated discs
Striated
Mono/binucleate
Length: 100 μm
No regeneration
Spontaneous contraction
Give 6 features of smooth muscle
Spindle shaped
Central nucleus
Length: 20-200 μm
Regenerate
Vessels, hollow organs, glands
Regulated by ANS & endocrine system
By what process do muscles get bigger?
Cell hypertrophy
What is the epimysium?
A tough dense connective tissue that surrounds a muscle
What smaller structures make up a muscle?
Muscle fascicles
What covers the muscle fascicles?
Perimysium
What is the perimysium?
Slightly lose connective tissue surrounding muscle fascicles
What is contained within the perimysium?
Muscle fascicle
Blood vessels
Lymphatics
Nerves
What smaller structures make up a muscle fascicle?
Muscle fibres
What surrounds the muscle fibres?
Endomysium
thin lose connective tissue
Why are muscle fibres sometimes called muscle cells?
Because they are individual muscles cells that have their membranes fused together to form multinucleated cells
What is found in the endomysium?
Muscle fibres
Capillaries
Nerve fibres
What makes up muscle fibres?
Myofibrils
How are myofibrils arranged?
Arrangements of myofilaments (actin and myosin)
What is a motor unit?
A motor neuron and the muscle fibres it innervates
What is myasthenia gravis?
An autoimmune disease that effect the nicotinic acetylcholine receptors on post-synaptic membranes of muscle fibres
Affects extraocular muscles, facial muscles, bulbar muscles
How would you test for myasthenia gravis?
Raise your finger up and see if the extraocular muscles start to droop and cause ptosis
How is myasthenia gravis treated?
Acetylcholinesterase inhibitors
NEOSTIGMINE
What is neostigmine and what is it used to treat?
Acetylcholinesterase inhibitor
Prevents the breakdown of acetylcholine so has more effect on the nicotinic acetylcholine receptors of muscles
Used to treat myasthenia gravis
What is botulinum toxin and what can it cause?
Produced by C. botulinum
Degrades the protein complex that binds ACh vesicles to the presynaptic cell membrane
Results in total blockade of ACh release, causing flaccid paralysis
What is the cell membrane of the muscle fibre called?
Sarcolemma
What are invaginations in the sarcolemma (cell membrane) of the muscle fibres called?
T-tubules
What are T-tubules closely aligned with?
What do these store?
Sarcoplasmic reticulum
Store calcium
What is the name for the region in the middle of the sarcomere where thin and thick filaments overlop?
A band
What is the name for a thick filament within a sarcomere?
Myosin
What is the name for a thin filament within a sarcomere?
Actin
What is found in the I band of a sarcomere?
How many per sarcomere?
Think actin filaments only
2 per sarcomere wither side of the A band
What is the M line in a sarcomere?
The point at which thick myosin filaments connect with a cell membrane
Which 3 proteins make up the thin filaments of muscle?
Actin
Tropomyosin
Troponin
Which of the 3 proteins on a thin filament attaches to myosin?
Actin
What protein surrounds actin?
What does it cover?
Tropomyosin
The myosin binding sites
What protein is attached to tropomyosin?
What are its 3 parts?
Troponin
I
C
T
What are the 3 parts of troponin responsible for?
Troponin I - helps tropomyosin block the myosin binding site on actin
INHIBITION
Troponin C - binds CALCIUM
Troponin T - aTTaches troponin to tropomyosin
What protein is absent in Duchenne Muscular dystrophy?
Absence of dystrophin
Name the most dorsal vein in the foot
Doral venous arch
What 2 branches does the dorsal venous arch give off?
Small saphenous vein
Great saphenous vein
Where does the small saphenous vein run near to?
Runs laterally from the dorsal venous arch of the foot
Goes behind the lateral malleolus
Where does the great saphenous vein run near to?
Why is the great saphenous important to remember?
Runs medially from the dorsal venous arch of the foot
Goes in front of the medial malleolus
Can be used for grafting
Venous cut-down cannulation access if no other access available e.g. burns to rest of the body
Describe the course of the great saphenous vein from distal to proximal
What nerve does it ascend near?
Dorsal venous arch of the foot
Ascends medially at the ankle
Anterior to the medial malleolus
Along the posterior region of the medial tibial border alongside saphenous nerve
Passes 7-10cm posterior to the patella
Passes through the saphenous opening lateral and inferior to the pubic tubercle
Joins the femoral vein in the femoral triangle
Ascends near the SAPHENOUS NERVE
Describe the course of the short saphenous vein from distal to proximal
What nerve does it ascend near?
Dorsal venous arch of the foot
Ascends laterally at the ankle
Runs posterior to the lateral malleolus
Ascends midline posterior leg alongside sural cutaneous nerve
Travels deep into popliteal fossa via crural fascia and into popliteal vein
Ascends near the SURAL CUTANEOUS NERVE
Where do the greater and small saphenous veins join deep veins, and what veins do they join?
Greater saphenous vein
- saphenous opening in the femoral triangle
- joins the femoral vein
Small saphenous vein
- popliteal fossa
- joins popliteal vein
What 4 muscles form the border of the popliteal fossa?
Lateral above the knee
- biceps femoris
Medial above the knee
- semimembranous
- semitendonous
Below the knee
- lateral and medial heads of the gastrocnemius
What nerve descends through the popliteal fossa?
Sciatic nerve
Which muscle sits on the anterior border of the popliteal fossa?
Plantaris
What 2 nerves does the sciatic nerve split into?
How do they descend in relation to the sciatic?
Common fibular nerve
- superficial and laterally
Tibial nerve
- medially and deep
Which 2 muscles insert into the greater trochanter of the femur? What do they do?
Gluteus medius and minimus
Stable the lower limb during walking
What muscle inserts into the lesser trochanter of the femur?
Iliopsoas
Hip flexion
What attaches at the linea aspera (femur)?
Where is it?
3 intermuscular septa (compartments of the thigh)
Attachment point for many thigh muscles
What is Wolff’s Law?
Bone is deposited and reabsorbed in accordance with the stresses placed upon it
What is the acetabular labrum?
Horseshoe shaped fibrocartilage rim of tissue that surrounds the acetabulum
(Pelvic portion of hip joint)
What 3 ligaments reinforce the hip joint?
What do they sit on top of?
When are the ligaments the tightest?
Iliofemoral
Pubofemoral
Ischiofemoral
Sit on top of synovial membrane and fibrous membrane
Tightest when standing
Describe the blood supply to the femoral head
Deep femoral artery gives off medial and lateral femoral circumflex arteries
Anastomose to form circumflex femoral arteries that flow back up towards the femoral head
What divides the greater sciatic foramen?
Piriformis muscle
What structures pass through the greater sciatic foramen above the piriformis?
Superior gluteal nerve
What structures pass through the greater sciatic foramen below the piriformis?
Sciatic nerve
Inferior gluteal nerve
Posterior femoral cutaneous nerve
Quadratus femoris nerve
Give the root values of the superior gluteal nerve
L4 - S1
Give the root values of the superior gluteal nerve
What does it supply?
L4 - S1
Gluteus medius
Gluteus minimus
Give the root values of the interior gluteal nerve
L5 - S2
Gluteus maximus
Which ligament separates the greater and lesser sciatic foramen?
Sacrospinous ligament
When the distal part of a limb points laterally, what is this type of deformity called?
Valgus
l - laterally
When the distal part of a limb points medially, what is this type of deformity called?
Varus
thrust towards
Which vein runs superficial to the iliotibial tract?
lateral aspect of the thigh
Saphenous veins
Which large muscle inserts into the ITT?
Gluteus maximus
Which nerves arise from the sacral plexus?
What are their root values?
Superior gluteal nerve (L4 - S1)
Inferior gluteal nerve (L5 - S2)
Posterior cutaneous nerve of thigh (S1 - S3)
Pudendal nerve (S2 - S4)
Sciatic nerve (L4 - S3)
Which 4 muscles laterally rotate the hip?
Obturator internus
Quadratus femorus (S + I)
Gemilli
Piriformis
How do you find the safe zone for IM injections in the gluteal region?
Vertical line through highest point of iliac crest
Line from PSIS to greater trochanter
Superiorlaterally to the 2 lines
What are the borders of the adductor canal?
In which compartment is the adductor canal found?
What are the contents of the adductor canal?
Sartorius
Vastus medialis
Adductor longus/magnus
Anterior compartment of the thigh
Saphenous nerve
Superficial femoral artery
Superficial femoral vein
Which muscle is a powerful flexor of the hip that inserts onto the lesser trochanter?
Iliopsoas
Which 3 muscles form the pes anserinus tendon?
Where does it insert?
Sartorius
Gracilis
Semitendonous
Medial aspect of the tibia
The subclavian nerve passes ______ to the middle scalene
Anterior
The subclavian vein passes _______ to the anterior scalene
Anterior
What structures passes through the quadrangular space?
Humerus
Axillary nerve
Posterior circumflex artery
What is the anatomical order in which a needle must pass in order to reach CSF during a spinal anaesthetic?
Skin
Supraspinous ligament
Interspinous ligament
Ligamentum flavum
Epidural space
Subdural space
Subarachnoid space
Which rotator cuff muscle causes internal rotation?
Subscapularis
Where do the movements of inversion and eversion of the foot take place?
At the talonavicular joint
Which nerve supplies the pectoralis major?
What does this muscle do?
Medical and lateral pectoral nerve
Adducts and medially rotates the shoulder
Which nerve supplies the pectoralis minor?
What does this muscle do?
Where do the 3 heads of pec minor insert into?
Medial pectoral nerve
Depresses and protracts the scapula
Ribs 3, 4, 5
Which nerve supplies the deltoid muscle?
How can this nerve be damaged?
Axillary nerve
Shoulder dislocation
Surgical neck of humerus #
IM injection
What are the 4 borders of the axilla?
Anterior - anterior axillary fold and pectoral muscles
Posterior - posterior axillary fold, subscapulaaris and scapula
Medial - serratus anterior and lateral thoracic wall
Lateral - intertubercular groove
Which nerve supplies sorratus anterior?
Where does this muscle go to/from?
How would damage in a patient show/what test would you do?
Long thoracic nerve
Medial scapula border - ribs 1-8
If broken, scapula will ‘wing’ - get patent to put hands on wall and lean in
Which nerve supplies the anterior compartment of the arm?
Musculocutaneous (radial/brachialis)
Which nerve supplies the posterior compartment of the arm?
Radial nerve
