Appendicular Skeleton Ch 8. Flashcards
1
Q
The Appendicular Skeleton
A
- Pectoral girdle: attaches the upper limbs to the upper trunk
- Pelvic girdle: attaches the lower limbs to the lower trunk
- Upper and lower limbs differ in function but share a similar structural plan
2
Q
The Pectoral Girdle
A
- Consists of the clavicleand the scapula
- Pectoral girdles do not encircle the body completely
- Scapulae are positioned on superior posterior thorax and do not join each other or articulate with the axial skeleton
- Clavicles extend horizontally across superior anterior thorax
- Medially: sternal endof each clavicle articulates with the manubrium and first rib of the axial skeleton
- Tuberosity for costoclavicular ligament is near sternal end of clavicle
- Laterally: acromium end of the clavicle joins the scapula at the acromioclavicular joint
3
Q
The Pectoral Girdle
A
- Provides attachment for many muscles that move the upper limb
- Girdle is very light and upper limbs are mobile
- Socket of the shoulder joint (glenoid cavity of scapula) is shallow and provides for good flexibility, but relatively poor stability
4
Q
Clavicles
A
- Provide attachment for muscles
- Articulate with the scapulae laterally
- Articulate with sternum medially
- Transmit compression forces from the upper limbs to the axial skeleton
5
Q
Scapulae
A
•Lie on the superior dorsal surface of rib cage •Located between ribs 2–7 •Have three borders –Superior –Medial (vertebral) –Lateral (axillary) •Have three angles –Lateral (location of glenoid cavity) –Superior –Inferior
6
Q
Scapula
A
- Subscapular fossa (anterior surface)
- Supraspinous fossa (posterior surface)
- Suprascapular notch
- Spine (posterior surface)
- Infraspinous fossa (posterior surface)
- Acromium attaches to clavicle
- Glenoid cavity attaches to humerus head
- Coracoid process
7
Q
The Upper Limb
A
•30 bones form each upper limb •Grouped into bones of the: –Arm: 1 bone (humerus) –Forearm: 2 bones (radius and ulnar) –Hand/wrist: 27 bones
8
Q
Arm = region between shoulder & elbow Humerus is only bone in arm
A
- Longest and strongest bone of the upper limb
- Articulates with the scapula at the shoulder
- Articulates with the radius and ulna at the elbow
SLIDE 19 the humerus bone on the left is anterior view the bone on the right is posterior view
9
Q
Proximal humerus structures
A
- Humerus head
- Greater tubercle
- Lesser tubercle
- Intertubercular sulcus: in between lesser and greater tubercles on anterior side of bone
- Anatomical neck: slight constriction inferior to the head
- Surgical neck: inferior to the tubercles and is a frequent site of humerus fracture
10
Q
Mid-humerus structures
A
- Deltoid tuberosity: on lateral surface of shaft
* Radial groove: on posterior surface of shaft marks course of radial nerve
11
Q
Arm: Humerus
A
- Many structures of the humerus provide sites for muscle attachment
- Other structures of the humerus provide articulation sites for other bones
- Condyle: “knuckle”or rounded projection at the distal end of a bone that articulates with another bone
- Epicondyle: A rounded projection at the end of a bone, located on or above a condyle and usually serving as a place of attachment of ligaments and tendons
12
Q
Distal Humerus structures
A
- Medial epicondyle
- Lateral epicondyle
- Medial supracondylar ridge
- Lateral supracondylar ridge
- Trochlea
- Capitulum (anterior)
- Radial fossa (anterior)
- Coronoid fossa (anterior)
- Olecranon fossa (posterior)
13
Q
Forearm =region between elbow & wrist
A
- Formed from the radius and ulna bones
- Proximal ends articulate with the humerus
- Distal ends articulate with carpal bones
14
Q
Proximal radius bone interface with distal humerus
A
- Head of proximal radius boneinterfaces with capitulumof distal humerus
- Radial tuberosity below head of radius
- With elbow flexion, radial head moves into radial fossa of distal humerus
15
Q
Proximal ulna bone interface with distal humerus
A
- Main bone responsible for forming the elbow hinge joint with the humerus
- Anterior coronoid process andposterior olecranon process of ulna interfaces with trochleaof distal humerus
- With elbow flexion, coronoid process of ulna moves into coronoid fossa of distal humerus
- With elbow extension, olecranon process of ulna moves into olecranon fossa of distal humerus
16
Q
Forearm:radius and ulna articulate with each other
A
- At the proximal & distal radioulnar joints
- Proximal ulna has radial notch
- Distal radius has ulnar notch
- The interosseous membraneinterconnects radius and ulna
- In anatomical position (palms facing forward), radius is lateral& ulna is medial
17
Q
Distal Ulna with ulnar head & styloid process
A
- Distal ulna is separated from carpal bones by fibrocartilage
- Plays little to no role in hand movement
18
Q
Distal radius
A
- Distal radius articulates with carpal bones of the wrist
- Articulation with scaphoid boneof hand
- Articulation with lunate boneof hand
- When radius moves, the hand moves with it
- Ulnar notch of distal radius articulates with ulnar bone
- Styloid process
19
Q
Wrist & Hand bones
A
- Carpals—wrist: 8 bones •Metacarpals—palm: 5 bones
* Phalanges—fingers: 14 bones
20
Q
Carpals
A
- Form the true wrist made of the proximal region of the hand
- Composed of eight marble-sized bones
21
Q
Carpal bones
A
- Form true wrist in proximal hand
- Arranged in two rows
- Proximal row, radial (lateral) to ulnar (medial): scaphoid, lunate, triquetrum & pisiform
- Scaphoid & lunate articulate with distal radius
- Distal row, radial (lateral) to ulnar (medial): trapezium (at base of 1stmetacarpal) trapezoid (at base of 2ndmetacarpal) capitate (at base of 3rdmetacarpal) hamate (at base of 4th & 5thmetacarpals) •A mnemonic to help remember carpals:
- Sally left the party to take Carmen home
22
Q
Metacarpus
A
- Five metacarpals radiate distally from the wrist and form the palm
- Numbered 1–5, beginning with the pollex (thumb)
- Each with base, shaft, and head
- Articulate proximally with the distal row of carpals
- Articulate distally with the proximal phalanges
23
Q
Phalanges
A
•Numbered 1–5, beginning with the pollex (thumb)
•Except for the thumb (which has two phalanges), each finger has three phalanges
–Proximal
–Middle
–Distal
24
Q
Pelvis
A
•The deep basin-like structure formed by the coxal bones, sacrum and coccyx.
25
Q
Pelvic Girdle
A
- Consists of paired coxal bones (hip bones)
- Coxal (hip) bones unite anteriorly with each other at pubic symphysis
- Coxal (hip) bones articulate posteriorly with the sacrum to form sacroiliac joints
26
Q
Pelvic Girdle
A
- Consists of paired coxal bones (hip bones)
- Attaches to lower limbs
- Supports visceral organs
- Attaches to axial skeleton by strong ligaments
- Acetabulumis deep socket on lateral coxal (hip) bone where femur head attaches
- Femur bones in hip joint have less range of movement and are more stable than humerus bones in shoulder joints
27
Q
Three regions of Coxal Bones
A
- Ilium
- Ischium
- Pubis
28
Q
Ilium
A
- Large, flaring superior region of coxal bone
- Consists of inferior body and superior wing-like ala
- Iliac crest: thickened superior margin of the ala
- Iliac fossa: the internal concave surface of the ala
- Anterior superior iliac spine
- Anterior inferior iliac spine
- Posterior superior iliac spine
- Posterior inferior iliac spine
- Articulation with the sacrum forms sacroiliac joint
- Illium is preferred site for bone marrow biopsy
- Site of attachment for many muscles
29
Q
Ischium
A
- Forms inferior region of the coxal bone
- Anteriorly—joins the pubis
- Ischial tuberositiesand ischial spines are a very strong insertion sites on the hip bone
30
Q
Pubis
A
- Forms anterior region of the coxal bone
- Lies horizontally in anatomical position
- Pubic symphysis: the two pubic bones are joined by fibrocartilage at the midline
- Pubic arch: inferior to the pubic symphysis
- Pubic crest: thickened anterior superior border of the body of the pubis
- Pubic tubercle
31
Q
Pelvis
A
- Pelvic brim (= pelvic inlet):continuous oval ridge that runs from the pubic crest around to the sacral promontory
- Pelvic inlet: delineated by the pelvic brim
- Pelvic outlet: inferior margins of true pelvis
- True pelvis: extends inferior from the pelvic brim (= pelvic inlet) and forms a deep bowl containing the pelvic organs
- False pelvis:superior to the pelvic brim and is actually part of the abdomen and contains abdominal organs
32
Q
Pelvic Outlet
A
- Anteriorly: pubic arch
- Laterally: ischial tuberosities
- Posteriorly: tip of coccyx
33
Q
Differences between male and female pelves
A
- Female pelvis is adapted for childbearing
- Female pelvis wider, with a wider pelvic inlet and outlet compared to males
- Pubic angle of pubic arch is > 80°in females and < 60°in males
34
Q
The Lower Limb
A
•Carries the entire weight of the erect body
•Bones of lower limb are thicker and stronger than those of upper limb
•Divided into three segments
–Thigh: 1 bone (femur) between hip & knee
–Leg: 2 bones (tibia & fibula) between knee & ankle
–Foot/ankle: 26 bones
35
Q
Thigh = region of lower limb between hip and knee that contains the femur
A
•Femur—the single bone of the thigh
–longest and strongest bone of body
–ball-shaped femoral head articulates with the acetabulum
36
Q
Proximal femur
A
- Femur head
- Fovea capitis
- Femur neck
- Greater trochanter
- Intertrochanteric crest (posterior view)
- Intertrochanteric line (anterior view)
- Lesser trochanter
- Gluteal tuberosity (posterior view)
37
Q
Distal femur
A
- Medial epicondyle
- Lateral epicondyle
- Medial condyle
- Lateral condyle
- Medial and lateral supracondylar lines
- Intercondylar fossa (posterior view)
- Adductor tubercle
38
Q
Patella
A
- Triangular sesamoid bone
- Imbedded in the tendon that secures the quadriceps muscles
- Protects the knee anteriorly
- Improves leverage of the thigh muscles across the knee
39
Q
Leg = region of the lower limb between the knee and the ankle with tibia & fibula bones
A
- Tibia: more massive medial bone of the leg that receives weight of the body from the femur
- Fibula: stick-like lateral bone of the leg
- Interosseous membrane connects the tibia and fibula
40
Q
Proximal tibia
A
- Proximal tibia articulates with distal femur to form the knee joint
- Interchondylar eminance
- Articular surface of medial chondyle
- Articular surface of lateral chondyle
- Articular surfaces articulate with distal femur
- Tibial tuberosity (anterior)
41
Q
Proximal fibula
A
•Medial part of proximal fibula head articulates in proximal tibiofibular joint
42
Q
Distal tibia and fibula
A
- Distal tibiofibular jointarticulates distal lateral side of the tibia and distal medial side of the fibula
- Distal tibia articulates with trochlea of talus bone in foot to form the ankle joint
- Distal medial tibiaforms medial malleolus which articulates with the talus bone and is felt as the hard medial bulge in ankle
- Distal lateral fibulaforms lateral malleolus which articulates with the talus bone and is felt as the hard lateral bulge in ankle; contributes to stabilization of ankle joint
43
Q
The Foot
A
•Foot is composed of
–Tarsal bones: 7 bones
–Metatarsal bones: 5 bones
–Phalange bones: 14 bones
•Important functions
–Supports body weight
–Acts as a lever to propel body forward when walking
–Segmentation makes foot pliable and adapted to uneven ground
44
Q
Tarsal bones
A
•Makes up the posterior half of the foot
•Contains seven bonescalled tarsals
•Body weight is primarily borne by the talusand calcaneus •Calcaneous is the “heel”bone
•Trochlea of the talus
–Site of articulation with the tibia
•Other tarsals are:
–navicular (medial)
–cuboid (lateral) (at base of 4th& 5thmetatarsal)
–lateral cuneiform (at base of 3rdmetatarsal)
–intermediate cuneiform(at base of 2ndmetatarsal)
–medial cuneiform (at base of 1stmetatarsal)
45
Q
Metatarsal bones
A
- Consists of five small long bones called metatarsals
- Numbered 1–5 beginning with the hallux (great toe)
- First metatarsal supports a lot of body weight
46
Q
Phalanges of the Toes
A
- 14 phalanges of the toes
- Smaller and less nimble than those of the fingers
- Structure and arrangement are similar to phalanges of fingers
- Except for the great toe (which has two phalanges), each toe has three phalanges
- Proximal
- Middle
- Distal
