ch 7 Flashcards
axial skeleton bones
skill: cranium, facial bones
thoracic cage: sternum, ribs
vertebral column: vertabrae, sacrum, coccyx
appendicular skeleton
pectoral girdle: clavicle, scapula
upper limbs: humerus, radius, ulna, carpals, metacarpals, phalanges
pelvic girdle: os coxae
lower limbs: femur, patella, tibia, fibula, tarsals, metatarsals, phalanges
functions of axial skeleton
- provides framework: support and protects brain, spinal cord, organs of dorsal and ventral body
- provides extensive surface area for the attachment of muscles of head, neck and trunk
- stabilizes or positions parts of the appendicular skeleton
- performs respiratory movements
roughly 80 bones
functions of appendicular skeleton
allows us to move and manipulate objects
126 bones
thoracic cage
includes thoracic vertebrae, ribs, sternum
2 functions:
1. protects the organs of thoracic cavity
2.muscle attachment points for muscles involved in respiration, maintenance of the position of the vertebral column, movements of the pectoral girdle and upper limbs
rib cage
ribs (costae): 12 pairs numbered 1-12
true ribs(vertebrosternal ribs): 1-7 gradually increase in length and radius of curvature, attaches directly to sternum
false ribs (8-12): ribs 8-10: vertebrochondral ribs, ribs 11-12: floating ribs, vertebral ribs
sternum: flat bone, midline of thoracic wall. Has 3 parts: manubrium, sternal body, xiphoid process
vertebral regions
Cervical vertebrae: C1-C7 ; c1 is atlas, c2 is axis Thoracic vertebrae: T1-T12 Lumbar: L1-L5 Sacrum: S1-S5 coccyx: Co1- Co3/o5
normal spinal curvatures
- cervical curve
- thoracic curve
- lumbar curve
- sacral curve
primary curves (accommodation curves): thoracic and sacral curves present at birth, appear late in development, accommodate internal organs of thoracic and abdominopelvic cavities
secondary curves (compensation curves): cervical and lumbar curves, present after birth several months later, help shift body weight for upright posture
abnormal curvature of vertebral column
- kyphosis: hunchback, bent or slouching posture. thoracic curvature is exaggerated posteriorly. Causes include osteoporosis, interverbral disk degeneration, abnormal vertebral growth
- Lordosis: swayback. lumbar curvature is exaggerated anteriorly. Causes include: pregnancy, obesity, weakness in muscles of abdominal wall
- Scoliosis: crookedness. Abnormal lateral curvature o f spin in one or more of the vertebrae, most common distortion. Causes include result from development problems, muscular paralysis affecting one side of body, idiopathic in girls during adolescences.
Male vs female pelvis
female pelvis: smoother and lighter.
less prominent muschle and ligament attachments
pelvis modifications for childbearing: enlarged pelvic outlet, broad subpuic angle (less than or equal to 90-100 degrees), less curvature of sacrum and coccyx, wide, circular pelvic inlet, broad, low pelvis, ilia project laterally not upwards.
pectoral girdle
connects the arms to the body, positions the shoulders, provides a base for arm movement
consists of 2 clavicles, 2 scapulae; connects with axial skeleton only at manubrium
upper limbs
consists of arms, forearms, wrists, and hands.
humerus, ulna, radius, carpals, metacarpals, phalanges.
pelvic girdle
made up of 2 hip bones (coxal bones or os coxae)
strong to bear body wight and stress of movement. part of the pelvis
coxal bones made up of 3 fused bones: ilium, ischium, pubis.
pelvis
Os Coxae (coxal bones)+ Sacrum+ Coccyx stabilized by ligaments of pelvic girdle, sacrum, and lumbar vertebrae
true pelvis
encloses pelvic cavity.
pelvic brim: upper edge of true pelvis; encloses pelvic inlet
perineum region: inferior edges of true pelvis, forms pelvic outlet, perineal muscles support organs of pelvic cavity