Skeletal System: Exam 2

Ch. 5 - 8

What are the functions of the skeletal system?

Functions of the Skeletal System

• Support

• Storage of minerals (95% calcium stored in the bones)

• Blood cell production (bone marrow)

• Leverage (muscles contract to pull on bone)

• Protection (skull protect brain)

What is the structure (or matrix) of bone?

Matrix of Bone:

• Calcium hydroxide + calcium phosphate = hydroxyapatite crystals 

• Hydroxyapatite crystals resist compression

• 2/3 of the matrix is collagen which gives bone tensile strength 

  • Bones can break w/ enough force, but collagen fibers prevent it from shattering 

• Hydroxyapatite crystals + Collagen makes bone tissue extremely strong 

What is the difference between compact bone & spongy bone? 

1) Compact Bone (outer)

• Compact bone is all hard, solid matrix called Lamellae

2) Spongy Bone (inner) - aka Trabeculae bone 

• Spongy bone has these struts that go in different directions called trabeculae - allows bone to withstand pressure from different directions

Define compact bone.

Compact Bone is all hard, solid matrix called Lamellae.

• 3 rings of Lamellae fit in to create an Osteon

• In the center of each osteon there is a space called central canal - that holds blood vessels and is an important source of O2 and nutrients for the cells in the bone 

• Perpendicular to central canals - there are perforating canals - blood vessels 

Explain the lamellae of compact bone.

Lamellae = concentric (central)

• 3 layers of Lamellae

• each lamellae has collagen fibers going in different directions - this gives some flexibility to bone 

• In compact bone, you have concentric lamellae called Osteons.

  • Between the Osteons, there’s more lamellae called interstitial lamellae

  • All around the bone - circumferential lamellae

What does the structure of bone (Osteon) consist of? What is the function of central canal? Canaliculi? Lacunae? Osteocytes? 

Osteon:

• Lamellae - matrix

• Central canal - holds blood vessels 

• Canaliculi - from central canal to osteocytes, canaliculi are tiny canals that travel from lacunae to lacunae, to get to the osteocytes in each lacunae - this allows the passage of oxygen and nutrients for mature bone cells

• Osteocytes - mature bone cells 

• Lacunae - houses osteocytes 

What are the 4 types of cells in bone tissue?

1. Osteoblasts

2. Osteocytes

3. Osteoclasts

4. Osteoprogenitor cells 

What are osteoblasts?

Osteoblasts

• found on the inner & outer surfaces of bone

• make bone by laying down osteoid (unmineralized - no calcium or phosphate)

• when osteoid becomes mineralized, then it becomes the matrix of bone

• an osteogenic cell (means forming bone) → osteogenesis (process of forming bone)

… When osteoblasts stop secreting the matrix and trap themselves in that matrix/lacuna — they lose their function of secreting more matrix — therefore they become mature Osteocytes.

What are osteocytes?

Osteocytes = mature bone cells

• function: maintain the protein and mineral content of the matrix

• if osteocytes die, bone will break down

What are osteoclasts?

Osteoclasts

• secrete HCI and enzymes to breakdown calcium, phosphate, & collagen

• leads to osteolysis

  • lysis = breakdwon

  • we only want this to happen when blood calcium is low - since calcium is stored in the bone, it removes calcium from bone and put it in our blood

What are osteoprogenitor cells?

Osteoprogenitor cells → osteoblasts

• found on inner & outer surfaces of bones 

• stem cells that differentiated to form new osteoblasts

  • osteoblasts are important in laying down osteoid, which can become mineralized and give rise to the matrix of bone)

• heavily involved in the repair after a fracture (osteogenesis)

What are the 2 bone membranes? Explain.

Bone Membranes

1. Periosteum

• outer surface of the bone

• isolates & protects the bone from surrounding tissue

• actively participates in bone growth & repair

• periosteum has 2 layers:

  • inner layer: osteoprogenitor cells, osteoblasts, osteoclasts

  • outer layer: made of dense irregular connective tissue; it holds the bone to muscle 

• attached

1. Endosteum

• inner surface of bone (covers spongy bone/trabecular)

• lines the medullary cavity, incomplete

• consists of osteoprogenitor cells 

• actively involved in repair & growth 

peri = around

endo = within

How is the periosteum anchored & attached to the bone?

Sharpey’s fibers (perforating fibers): collagen fibers

• periosteum has an outer layer:

  • outer layer: made of dense irregular connective tissue; it holds the bone to muscle 

What is epiphysis, diaphysis, & metaphysis?

• Epiphysis: ends of long bones

• Diaphysis: shaft of long bones

• Metaphysis: narrow growth zone between epiphysis & diaphysis 

Define the shapes of bones: long bones, short bones, pneumatized bones, suture bones, flat bones, irregular bones, sesamoid bones. 

• Long bones: longer than wider

• Short bones: look irregularly boxy

• Pneumatized bones: air cells to make the bone lighter (pneumo = air)

• Suture bones: small bones found within suture lines

• Flat bones: spongey bone, sandwiched between 2 plates of compact bone

• Irregular bones: complex shapes

• Sesamoid bones: formed within tendons - the only one we have is the patella 

What are the 2 types of ossification (bone growth)?

Ossification = bone growth

1. Intramembranous ossification

• only head, face, clavicle

• begins at 6 weeks

1. Endochondral Ossification 

• all other bones in the body formed thru this process

• involved in the development of limbs, vertebrae, & hips

• formed initially as cartilage, then formed into bone

Define intramembranous ossification.

Intramembranous ossification

• Flat bones of the head, face, & clavicle

• This process begins w/ mesenchymal cells 

• Mesenchyme = embryonic tissue & gives rise to all kinds of CT

  • mesenchymal cells are cells of mesenchyme - which are going to start differentiating (specialized cells)

• as soon as angiogenesis (blood vessel formation) secure around mesenchymal cells, they differentiate into osteoblasts - which create matrix

• spicules grow into one another - keeps growing and builds osteoid around blood vessels until it creates spongey bone

Define endochondral ossification. What are the 2 parts to bone growth?

Endochondral ossification

• all other bones in the body formed thru this process

• the developing bone begins as cartilage cells

1. cartilage matrix grows inward (grows in length) → interstitial growth

2. cartilage matrix grows outward (grow thick) → appositional growth

Endochondral Ossification: Interstitial Growth

Endochondral Ossification: Interstitial Growth (grow longer)

• occur at around 8 weeks of development

• continues due to hormonal influence until early adulthood the growth stops

• cartilage wants to be a bone - it has chondrocytes inside and the membrane is pericardium

• once angiogenesis begins and blood vessels start coming in, the perichondrium is going to become periosteum

• periosteum contains osteoblasts - starts secreting osteoids, as they secrete osteoid they lay down a thin collar of bone around the diaphysis (shaft of bone)

• when this bone collar is created, the chondrocytes in the shaft are being deprived of oxygen and start dying - and start leaving small cavities

• the blood vessels start piercing and move in - taking some of those osteogenic cells from the periosteum in w/ them - which they start laying down spongey bone (built from osteogenic cells)

1. Primary ossification center: in the region of diaphysis

• then some things occur at the epiphysis (ends of long bone)

• blood vessels go in and take in osteogenic cells - start making spongey bone

2. Secondary ossification center: formed at epiphysis

• metaphysis: nothing happens - we save that cartilage its our growth plate

• we lay down more bone and bone elongates - continues until done growing

• when fully grown, its called Epiphysial Line (no longer spongey bone)

Endochondral Ossification: Appositional Growth

Endochondral Ossification: Appositional Growth (grows in girth, thicker)

• enlarging the diameter of bone

• blood vessels that run parallel to the bone becomes surrounded by bone cells

• “tunnels” begin to form

• each tunnel had a blood vessel in it

Explain bone maintenance, remodeling & repair.

• Injury & repair

• when a bone is broken, bleeding occurs (bone is highly vascular)

• a network of spongey bone forms

• osteoblasts are overly activated, thus resulting in enlarged callused area

• this area is now stronger and thicker than normal bone

How does a fracture repair itself?

Repair of a Fracture

• blood vessels are severed at the fracture - tear in the periosteum

• bleeding leads to hematoma (blood clot) which closes off the site of injury, blood cells in the area die off - tissue becomes swollen & painful

• phagocytic cells start cleaning up that area and lay down a soft callus

• new bone & collagen fibers laid down by osteogenic cells, fibroblasts from periosteum, and endosteum - stabilized bone

What are the 5 types of fractures?

5 Types of Fractures

• Transverse fracture: break is across the shaft - transverse axis of bone

• Displaced fracture: not aligned, sharp edges pierce into soft tissue

• Compression fracture: more common in vertebrae - looks compressed

• Colles’ fracture: distal radius - lateral forearm bone

• Spiral fracture: twisting force applied to bone

What is achondroplasia?

Achondroplasia (genetic disorder - Dwawrfism)

• A = without

• Chondro = cartilage

• a congenital condition involving defective growth of cartilage and defective endochondral ossification (process of bone formation in all other bones of body) 

• (normal head, small body)

What is osteoporosis? Which bone cells are responsible for osteoporosis?

Osteoporosis

• Bone becomes porous, loses mass & often leads to fractures

Which bone cells are responsible for osteoporosis?

• Osteoclasts are responsible for osteoporosis 

• But bone remodels to stress, so if you put stress on your bone, they will build more bones

What bones are in the axial skeleton?

Axial Skeleton (80 bones)

• Skull & associated bones

  • Cranium

  • Face

  • Auditory ossicles

  • Hyoid

• Thoracic cage

  • Sternum

  • Ribs

• Vertebral column

  • Vertebrae

  • Sacrum 

  • Coccyx

What is the top half of the head called?

Top Half of Head = Calvarium

• if you remove the calvarium, you can see the cranial floor

• notice 3 fossa (depression)

  • anterior cranial fossa

  • middle cranial fossa

  • posterior cranial fossa: cerebellum

What are the 8 cranial bones of the skull?

Cranial Bones:

• Frontal bone

• Parietal bones (2)

• Temporal bones (2)

• Occipital bone

• Sphenoid bone

• Ethmoid bone

What are the 14 facial bones of the skull?

14 Facial Bones

Unpaired bones (2):

• Mandible

• Vomer: forms inferior part of nasal septum

Paired bones (12)

• Maxillae: forms upper jaw

• Palatine bones: 2 L-shaped bones that lie posterior to the maxillae

• Nasal bones: 2 rectangular bones join medially to form bridge of the nose

• Inferior nasal conchae

• Lacrimal bones: really small, anterior to ethmoid bone - located on medial wall of orbits, lacrimal = tears

• Zygomatic bones 

Besides the nasal bone, what’s the rest of the nose made of?

Hyaline cartilage

What bone is not part of the skull but associated with it? What is its function?

Hyoid bone

• U-shaped & just inferior to the mandible (high up in neck)

• Function: to anchor the deep muscles of the tongue

• unique bc its the only bone in body that doesn’t articulate w/ any other bone

• Greater cornu & lesser cornu (horn)

What are the 3 ear ossicles in order from lateral to medial? Where are they found?

 3 Ear Ossicles

• found within petrous portion of temporal bone

• MIS

1. Malleus

2. Ineus

3. Stapes

The Vertebral Column (Spinal Column)

The Vertebral Column (Spinal Column)

• flexible, curve S-shaped structure

• the main support for the body axis

• protects spinal cord, provides attachment sites for ribs & for muscles of neck & back

• in fetus & infant, it consists of 33 bones at birth but inferiorly, 9 of those bones fuse to form the sacrum & coccyx

• end up with a total of 26 bones adult

What is in between vertebrae?

In between veterbrae, we have fibrocartilage, intervertebral discs that help w/ cushioning & separating vertebrae

What are the parts of the vertebrae?

• 7 Cervical vertebrae

• 12 Thoracic vertebrae

• 5 Lumbar vertebrae

• Sacrum (5 fused vertebrae)

• Coccyx (4 fused vertebrae)

What are the primary curvatures of the spine?

Primary Curvatures

• Thoracic & Sacral

What are the secondary curvatures of the spine?

Secondary Curvatures

• cervical & lumbar

What is the function of the transverse foramina of cervical spine?

transverse foramina: all allow blood vessels to pass through

Define bifid appearance.

Bifid appearance

• spinous process of C2 appears to be splitting almost like a wishbone

Everywhere we have articulation w/ another bone, we have ________. 

Everywhere we have articulation w/ another bone, we have hyaline cartilage. 

What are the components of the general vertebra?

General Vertebra

• Body: flat, intervertebral disc found between bodies - anterior = body

• Spinous process (posterior): when you touch your back and feel bumps

• Transverse process: project laterally (each side)

  • Lamina: connects the spinous & transverse process (2)

• Pedicle “little feet”: connects transverse process to vertebral body 

• Vertebral arch: inner rim of both lamina and both pedicle

  • the opening is called Vertebral foramen

    • this is where the spinal cord is found & protected by the vertebral foramen

• Intervertebral foramen

What are the characteristics of the Cervical Vertebra : Atlas/C1

Cervical Vertebra : Atlas/C1

• basically holding the head

• no vertebral body, kinda looks like a ring

• transverse process: projects laterally

• no spinous process 

• anterior & posterior tubercle found on anterior & posterior arch

• transverse foramina

• facet for dens  

• superior articular facet

  • forms a joint which helps to nod “yes”

  • slight depressed, occipital condyles fit here to allow for rocking head

What are the characteristics of the Cervical Vertebra : Axis/C2

Cervical Vertebra : Axis/C2

• has a body, spinous process, & other typical vertebral processes

  • transverse processes are much shorter

• Odontoid process (aka Dens): on the anterior & surface, on vertebral body, acts like a pivot for head rotation “no”

What is the importance of the Atlas and Axis of the cervical vertebra?

Atlas and Axis (C1 + C2)

• In severe head trauma or a car crash where the head is jerked forward and back, the dens may fracture and be forced posteriorly into the brain stem

• fatal → causing death

  • Dens (Odontoid Process): projection from vertebral body of Axis - rotation for “no”

  • Transverse ligament holds the Dens in place

What are the characteristics of C3 - C7 of the cervical vertebrae?

C3 - C7 

• Body is wider than the depth of vertebrae

• Spinous process are short and bifid - except for C7

• Vertebral foramen is triangular

• Transverse foramen

Characteristics of Thoracic Vertebrae

Characteristics of Thoracic Vertebrae (12)

• the 12 vertebrae all articulate w ribs

• laterally each side of the vertebral body has 2 facets called demifacets or costal facets which articulate w/ the ribs

• transverse processes have facets that articulate w the tubercles of the ribs called transverse costal facets

• vertebral foramen is circular 

Characteristics of Lumbar Vertebrae

Characteristics of Lumbar Vertebrae (5)

• Pedicles and Lamina are shorter and thicker

• spinous processes are short and flat, project out posteriorly

• processes are larger to accommodate larger muscles of the back

• vertebral foramen is triangular (kinda like cervical region is triangular)

• provide stability, no rotation between vertebrae

Characteristics of Sacrum

Sacrum

• 5 fused vertebrae

• curved, triangular shaped

• Landmarks to know:

• Base: the widest part of the sacrum at the top

• superior articular process (of S1) will articulate w/ inferior articular process (of L5)

• Promontory: on the anterior aspect of S1 body, the lip or edge of the base

• Transverse lines: created where fusion of vertebrae took place 

• Ala (wings): can be seen anterior or posterior, both sides

• Auricular surface: can be seen laterally 

• There’s more… read notebook

Coccyx - why is it important

Coccyx = “Tailbone”

• 3-5 fused vertebrae

• small & triangular

• important to anchor ligaments that help hold down your spinal cord

• coccygeal cornu: projections

Explain the Thoracic Vertebrae and Rib Articulation.

Thoracic Vertebrae and Rib Articulation

• Head of rib and tubercle of rib articulate w/ the vertebra

• Ribs have two ends:

1. the anterior end attaches to costal cartilage, which connects rib to sternal end

2. vertebral end (more rounded shape, head of rib), as you move away from the head it tapers in a little called the neck of rib, then tubercle of the rib, then the rib angles, the rest is the body 

Why is the costal groove important? Why is costal cartilage important?

(costal = ribs)

Costal groove: found on the inferior aspect of the ribs, important for nerves and blood vessels

Costal cartilage: connects rib to sternal end

Head of rib articulates with _____ of the thoracic vertebrae. Costal tubercle articulates w/ _________ of the thoracic. It angles, then curves anterior, then the sternum would be there, connected by ______.

Head of rib articulates with costal facet of the thoracic vertebrae. Costal tubercle articulates w/ transverse costal facet of the thoracic. It angles, then curves anterior, then the sternum would be there, connected by costal cartilage.

How many ribs are there? What are the 3 types of ribs?   

Ribs (24 total) 

• True Ribs: ribs 1-7 

  • each true rib has own costal cartilage - connects to sternum

• False Ribs: ribs 8-12

  • 8-10 merge w costal cartilage of true 7

• Floating Ribs: ribs 11-12

  • very short costal cartilage that they just float & don’t connect to sternum

Landmarks:

• Body or shaft w/ angle

• Costal groove: important for nerves & blood vessels, inferior view

• Costal cartilage: connects rib to sternal end

What are the 3 parts to the sternum?

Sternum

1. Manubrium (superior)

2. Body (middle)

3. Xiphoid process (inferior)

What are fontanels? Why are they important?

Fontanels = soft spots

1. Anterior fontanel (closes last by age 2)

2. Posterior fontanel

Fontanelles are the soft spots on a baby's head where the skull bones have not yet fused, allowing for the head to mold during birth and for the brain to grow rapidly in infancy

Importance: age 0-2 our brains haven’t finished growing yet, we need to pass through the birth canal. That’s why we need to have these soft spots.

What’s the different between scoliosis and kyphosis?

Scoliosis: abnormal curvature of spine

Kyphosis: exaggerated rounding of the T-spine (C shape)

What is the pectoral girdle?

Pectoral Girdle

• upper part of body

• Clavicle & Scapula

• because only the clavicle attaches to the axial skeleton, the scapula can move around quite freely across the thorax

What is the importance of the shallow socket of scapula?

Shallow socket of scapula

• scapula articulates with humerus — where the humerus fits into the scapula, there’s a shallow socket — this allows for great range of motion

What are the 2 ends of the clavicle?

Clavicle has 2 ends:

• Sternal end - more blunt, straight

• Acromial end - more rounded, articulates w the acromion on the scapula

What is the largest and longest bone of the arm?

Humerus

What is the difference between

• Coronoid fossa

• Coracoid process

• Conoid process 

• Coronoid fossa - humerus

• Coracoid process - scapula

• Conoid process - clavicle

What is the difference between the radius & ulna?

Ulna - medial bone of forearm

Radius - lateral bone of forearm

When we say “funny bone”, what are we actually talking about?

Ulnar nerves: passes between the medial epicondyle & olecranon process

• if you hit this part of elbow, it elicits numbness or tingling sensations down to the pinky - “funny bone”

What are the 3 regions of hand? How many are there

• Carpals (8)

• Metacarpals (5)

• Phalanges (14)

#1 thumb → #5 pinky

Define carpals. Name the two rows and bones in each row.

Carpals (16 total)

• gliding movements between bones making the wrist flexible 

(in order from lateral to medial)

Row 1: Proximal Carpal Bones

1. Scaphoid

2. Lunate

3. Triquetrum

4. Pisiform

Row 2: Distal Carpal Bones 

5. Trapezium

6. Trapezoid

7. Capitate

8. Hamate (hook on anterior)

What is retinaculum? What is its function?

Retinaculum - fibrous connective tissue, goes from scaphoid to pisiform

• function: hold down structures that pass from forearm down to hand 

How many phalanges do you have on one side?

14 phalanges per side

What is the total # of phalanges in the upper extremities?

28 total phalanges in upper extremitites

In metacarpals, where is the head, shaft, and base?

Metacarpals

• Head = distal end

• Shaft = middle

• Base = proximal end 

What is the Pelvic Girdle? What does it do?

Pelvic Girdle - Hip Bones or 2 Coxal Bones (aka os coxae)

• “Hip girdle” attaches lower limbs to spine & supports the viscera (organs) in the pelvis

• weight of the body passes through this girdle to lower limbs

• articulates w the sacrum

Anteriorly, the two hip bones unite, held together by fibrocartilage called: 

Pubic symphysis - connection of both pubic bones

Name the 3 parts of Coxal Bone (hip).

Coxal bone

1. ilium (largest)

2. pubis (anterior)

3. ischium (inferior)

What is the acetabulum?

Where all 3 parts of the Coxal bone fuse together at their shallow, depressed regions to create a deep socket called Acetabulum. 

What organ rests upon the pubis?

Bladder rests on pubis.

What’s the difference between the true (lesser) pelvis and the false (greater) pelvis?

True pelvis - urinary bladder and reproductive organs found

False pelvis - digestive organs found

Female vs Male Pelvis

Female Pelvis:

• inlet larger

• oval shaped

• pubic angle > 100

Male Pelvis:

• inlet smaller

• heart shaped

• pubic angle 90 or <

What is the largest, longest, & strongest bone in the body?

Femur - thigh bone

How can we tell anterior vs posterior in the Femur?

Posterior in Femur: can see linea aspara - not visible on anterior view

• Linea aspara at proximal end looks like its split - can see a few lines - Y

• Lateral aspect: gluteal tuberosity

• Medial aspect: pectineal line

What 2 bones articulate to make up the knee joint?

Knee joint: femur articulates with tibia

• fibula has nothing to do w knee joint

What is between the Tibia and Fibula? (hint: it’s also between the ulna & radius)

Interosseous membrane

what are the 3 regions of the foot? how many bones in each region?

Foot:

• Tarsus (7)

• Metatarsus (5) 

• Phalanges (14)

Name the tarsal bones. What is the largest tarsal bone?

Tarsal bones (7)

1. Calcaneous

2. Talus

3. Navicular

4. Cuboid

• Cruciforms:

5. Medial

6. Intermediate

7. Lateral

Calcaneous - largest tarsal bone

• function of talus? creates stability & balance + holds a lot of weight 

• talus articulates w 4 bones 

What are joints?

Joints: connections between bones that may or may not permit movement 

Two bones may be in direct contact w/ each other or separated by: 

Two bones may be in direct contact w/ each other or separated by: 

• Fibrous tissue

• Cartilage

• Fluid

Joints can be classified by either ____ or ____.

Joints can be classified by either function or structure.

What are the 3 ways joints can be classified based on their range of motion - function?

Classification of Joints: Function (ROM)

• Synarthrosis : immovable joints

• Amphiarthrosis : slightly moveable

• Diarthrosis : freely moveable 

What is synarthosis? Give a few examples of it.

Classification of Joints:

Synarthrosis - very strong but immovable joint

• Ex:

• Sutures (no movement)

• Gomphosis (joint between teeth and jaw bones)

• Synchondrosis (joint within epiphysis of bone)

  • binds the diaphysis to the epiphysis

• Synostosis (joint between two fused bones) 

What is Amphiarthrosis? Give a few examples of it.

Classification of Joints:

Amphiarthrosis - strong but slightly moveable joint

• Ex:

• Syndesmosis (ligaments that connect two bones but limit their motion)

  • between radius and ulna → distal radio-ulnar joint

  • between tibia and fibula → distal tibiofibular joint

• Symphysis

  • bones are seperated by a wedge or pad of cartilage

  • remember pubic symphysis?

What is diarthrosis? Give a few examples of it.

Classification of Joints:

Diarthrosis - weak but freely moveable joint - greatest range of motion!

• also called Synovial joints

• ex: shoulder, elbox, hip, knee joints

What are the classification of joints based on structure?

Classification of Joints: based on structure

• Bony fusion (fusion of frontal bones) - no ROM

• Fibrous joint (skull sutures) - no ROM

• Cartilaginous joint (pubic symphysis and intervertebral disc)

• Synovial joint (ball & socket joints, hinge joints, shoulder, elbow, hip, knee joints)

What are synovial joints? What is the function of synovial fluid?

Synovial joints: most freely moveable joints in the body

• Richly supplied by sensory nerves and has a rich blood supply

Function of Synovial Fluid: 

• lubricates the surfaces of the articular cartilages (aka hyaline cartilage) and reduces friction

• nourishes chondrocytes

• shock absorber

What is the joint cavity? 

Joint cavity: contains synovial fluid

• every time there is movement of this joint, the chondrocytes that are in articular cartilage are actually getting pumped nutrients and oxygen into the chondrocytes

What are the accessory structures of synovial joints?

Accessory Structures of Synovial Joints

• Menisci (meniscus) - knee joints

• Ligaments - all joints

• Tendons - most synovial joints

• Bursae sac (a fluid filled sac) - filled w synovial fluid

• Tendon sheath - (an elongated bursa that wraps around a tendon) 

What is the meniscus and its function?

Meniscus - made of fibrocartilage

• Function: absorb the load that it receives from body, distributes evenly, provides stability

What is the strongest synovial joint in the body?

The knee joint.

The fibular collateral ligament goes from ___ to ___ and provides ____ stability.

The fibular collateral ligament goes from femur to fibula and provides internal stability.

The tibial collateral ligament is on the ____ side and provides ____ stability. 

The tibial collateral ligament is on the medial side and provides medial stability. 

Tendon sheath

Tendon sheath

• like a blanket filled with synovial fluid that protects tendons from friction between other tendons

What two ligaments cross one another in the meniscus?

Anterior cruciate ligament

Posterior cruciate ligament

X

What are the classifications of synovial joints?

Classifications of Synovial Joints

• Plane joints: gliding joints

• Pivot joints: rotate & pivot only (ex: axis)

• Saddle joints: 

• Hinge joints: trochlea fits into trochlear notch

• Condylar joints: wrist, knuckles, toes

• Ball and socket joints: glenohumeral joint