Nakamura Human Anatomy ch 7,8

Question 0

Two divisions of the skeleton

Answer 0

●Axial skeleton (80 bones) less moveable

●Appendicular skeleton (126 bones)

Question 1

Skeleton

Answer 1

• Consists of bones, cartilage, joints, and ligaments

* Composed of 206 named bones grouped into two divisions

Question 2

Axial skeleton

Answer 2

•Consists of skull, vertebral column, and bony thorax

Question 3

Skull

Answer 3

•Formed by cranial and facial bones

• sutures: as babies we can feel these because they are larger
• medullary oblongata connects to spinal chord in foramen magnum
• occipital condyle connects with C1

Question 4

Vertebral column

Answer 4

•Formed from 26 bones in the adult
•Transmits weight of trunk to the lower limbs
•Surrounds and protects the spinal cord
-divided in cervical curvature (C1-7), thoracic curvature (T1-12), lumbar curvature (L1-5), sacrum(5 fused), and coccyx (4 fused)

Question 5

Ligaments and intervertebral discs

Answer 5

Supraspinous ligament and interspinous ligament made up of dense regular connective tissue (becomes less dense with age bcuz of water content and collagen, thus we become shorter as we get older)
Also have anterior and posterior longitudinal ligaments
Intervertebral discs made up of annulus fibrosus (outer) and a nucleus pulposus (inner) fibrocartilage

Question 6

Bony thorax

Answer 6

Sternum: jugular notch, clavicular notch, manubrium, stern all angle, body, xiphisternal joint, xiphoid process
Ribcage: true ribs 1-7 false 8-12 floating ribs (11-12)

Question 7

Xiphisternal process

Answer 7

Estimate area that divides thoracic and abdominal cavity

Question 8

Appendicular skeleton

Answer 8

• Pectoral girdle attaches the upper limbs to the trunk

* Pelvic girdle attaches the lower limbs to the trunk

Question 9

What is the Pectoral girdle

Answer 9

•Consists of the clavicle and the scapula
•Pectoral girdles do not quite encircle the body completely
●Medial end of each clavicle articulates with the manubrium and first rib
●Laterally – the ends of the clavicles join the scapulae
●Scapulae do not join each other or the axial skeleton

Question 10

What does the pectoral girdle do

Answer 10

•Provides attachment for many muscles that move the upper limb
•Girdle is very light and upper limbs are mobile
●Only clavicle articulates with the axial skeleton
●Socket of the shoulder joint (glenoid cavity) is shallow
•Good for flexibility – bad for stability (more moveable, but can become easily disconnected)

Question 11

The upper limb

Answer 11

•30 bones form each upper limb
•Grouped into bones of the:
●Arm
●Forearm
●Hand

Question 12

Arm

Answer 12

•Region of the upper limb between the shoulder and elbow
•Humerus – the only bone of the arm
●Longest and strongest bone of the upper limb
●proximal end Articulates with the scapula at the shoulder
●distal end Articulates with the radius and ulna at the elbow

Question 13

Forearm

Answer 13

•Formed from the radius and ulna
•Proximal ends articulate with the humerus (forms elbow)
•Distal ends articulate with carpals
•Radius and ulna articulate with each other
●At the proximal and distal radioulnar joints
•Interconnected by a ligament – the interosseous membrane
•In anatomical position, the radius is lateral and the ulna is medial

Question 14

Ulna

Answer 14

• Main bone responsible for forming the elbow joint with the humerus
• Hinge joint allows forearm to bend on arm
• Distal end is separated from carpals by fibrocartilage
• Plays little to no role in hand movement (bcuz doesn’t form joint with carpals)

Question 15

Radius

Answer 15

•Medially – the head of the radius articulates with the radial notch of the ulna
•Contributes heavily to the wrist joint
●Distal radius articulates with carpal bones
●When radius moves, the hand moves with it

Question 16

Hand

Answer 16

•Includes the following bones
●Carpus – wrist
●Metacarpals – palm
●Phalanges – fingers

Question 17

Pelvic girdle

Answer 17

•Consists of paired hip bones (coxal bones)
•Hip bones unite anteriorly with each other
•Articulates posteriorly with the sacrum
-attaches lower limbs to the spine
-supports visceral organs (urinary, repro, part of digestive)
-attaches to the axial skeleton by strong ligaments (connective tissue)
-acetabulum is a deep cup that holds the head of the femur
-lower limbs: less freedom of movement, more stable relative to upper limbs, thus able to support body weight

Question 18

Bony pelvis

Answer 18

• A deep, basin-like structure

* Formed by 2 coxal bones, sacrum, and coccyx (if this is too long can cause problems)

Question 19

Coxal bones

Answer 19

•Consist of three separate bones in childhood
●Ilium, ischium, and pubis
•Bones fuse – retain separate names to regions of the coxal bones
•Acetabulum – deep hemispherical socket on lateral pelvic surface (holds femur)

Question 20

Female pelvis

Answer 20

●is adapted for childbearing
-tilted forward
-bones less thick, lighter, thinner, smoother
•Pelvis is lighter, wider, and shallower than in the male
•Provides more room in the inferior/lower (true) pelvis
-upper structure can expand bcuz of pubic symphysis
True pelvis: defines the birth canal, is broad and shallow with a greater capacity
Acetabula: smaller and farther apart
Pubic angle or arch: broader and more rounded (80 to 90 degrees)

Question 21

Male pelvis

Answer 21

• adapted for support of males heavier build and stronger muscles
• true pelvis cavity is narrow and deep
• greater bone thickness, markings are more prominent
• acetabula are larger and closer together
• pubic angle/ arch is more acute (50 to 60 degrees)

Question 22

The lower limb

Answer 22

•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, leg, and foot

Question 23

Thigh

Answer 23

•The region of the lower limb between the hip and the knee
•Femur – the single bone of the thigh
●Longest and strongest bone of the body
●Ball-shaped head articulates with the acetabulum

Question 24

Patella

Answer 24

•Triangular sesamoid bone (irregular bone) -attached by ligaments, does not articulate with other bones •Imbedded in the tendon that secures the quadriceps muscles •Protects the knee anteriorly •Improves leverage of the thigh muscles across the knee

Question 25

Leg

Answer 25

* Refers to the region of the lower limb between the knee and the ankle * Composed of the tibia and fibula

Question 26

Tibia

Answer 26

– more massive – medial bone of the leg •Receives weight of the body from the femur -articulates with femur at superior end ●Forms the knee joint •Tibia articulates with talus at the inferior end ●Forms the ankle joint

Question 27

Fibula

Answer 27

stick-like – lateral bone of the leg Interosseous membrane – connects the tibia and fibula •Fibula does not contribute to the knee joint ●Stabilizes the ankle joint

Question 28

The foot

Answer 28

•Foot is composed of: ●Tarsus, metatarsus, and the phalanges •Important functions ●Supports body weight ●Acts as a lever to propel body forward when walking ●Segmentation makes foot pliable and adapted to uneven ground

Question 29

Arches of the foot

Answer 29

``` Transverse arch Medial longitudinal arch (middle) Lateral longitudinal arch (outside) Longitudinal: whole length Important for athletic training ppl No arch, less arch means sport performance may be poorer ```

Question 30

Hip replacement surgery

Answer 30

Neck of femur - replace with metal - bcuz of bone density decrease - problems with older people, all weight goes through this structure