A & P (Ch. 12-16) Flashcards
What makes up the axial skeleton?
- skull
- hyoid
- spine
- thorax
What makes up the appendicular skeleton?
- upper extremities
- shoulder girdle
- lower extremities
- hip girdle
How many bones make up the skull?
28
How many cranial bones are there?
-8 in total
How many facial bones are there?
-14 in total
How many ear bones are there?
-6 in total
Fetal Skull
- unique anatomical features that aren’t seen in adult skull
- 4 soft spots (fontanels), which allow the skull to be flexible
Hyoid Bone
- ‘U’ shaped bone located just above the larynx & below the mandible
- suspended from the styloid processes of the temporal bone
- only bone in the body that doesn’t articulate with any other bones
- tongue movement & swallowing
- attached to muscles of the tongue & floor of the mouth
How many vertebrae are there?
- 24 total
- 7 cervical
- 12 thoracic
- 5 lumbar
- sacrum (fused ligaments)
- coccyx (tailbone)
What is the role of the vertebrae?
- strength & flexibility to the spine
- movement of the spine
Characteristics of Vertebrae
- all have similar features (except C1)
- all have a foramen
- C2 has an upward projection (dens) to allow rotation of the head
- C7 has a long, blunt spinous process
- vertebrae articulate with each other
- thoracic vertebrae articulate with the ribs
- as a whole, the vertebral column articulates with the head, ribs & iliac bones
What is the thoracic cavity made of?
- vertebral column
- sternum
- ribs
Thorax- Sternum
- ‘dagger’ shaped
- middle of chest
- 3 parts: manubrium, body, xiphoid process
- manubrium articulates with the clavicle & 1st rib
- next 9 ribs join to its body directly or indirectly via costal cartilage
Thorax- Ribs (12 pairs)
- each pair attach posteriorly to the thoracic vertebrae
- all except the lower 2 pairs also attach anteriorly to the sternum by costal cartilage
- 8th, 9th & 10th pairs attach to the cartilage of the 7th ribs (false ribs)
- 11th & 12th pairs don’t attach to any costal cartilage (floating ribs)
Upper Extremities
- pectoral/shoulder girdle
- humerus (arm- from shoulder to elbow)
- radius & ulna (arm- from elbow to wrist)
- carpal (8) & metacarpals (5) (wrist & palm)
- phalanges (14) (fingers): 3 phalanges per finger, 2 on thumb
Upper Girdle (Shoulder Girdle)
- made up of scapula (shoulder blade)
- clavicle (collar bone)
- connects upper extremity to axial skeleton
- only point of connection= sternoclavicular joint
Humerus
- long bone of arm
- 2nd largest bone in body
- held in place at the scapula by rotator cuff
Radius & Ulna
- forearm (between elbow & wrist)
- anatomical position (radius-lateral & ulna-medial)
Elbow Joint
-bony process of ulna (olecranon) fits into ‘big crater’ (olecranon fossa) on posterior of humerus
Lower Extremities
- pelvic girdle (hip)
- femur (thigh bone)
- patella (kneecap)
- tibia (shinbone)
- fibula (slender bone in the lower leg)
- tarsal (7) & metatarsal (5) (heel & base of foot)
- phalanges (14) (toes)
Pelvic Girdle
- 2 pelvic (coxal) bones: ilium, ischium, pubis
- sacrum
- strong base to support torso & connect lower extremities to axial skeleton
Lower Extremities
- femur
- patella
- fibula
Femur
- thigh bone
- longest in the body
- hip to knee
- head joins hip at acetabulum
- distal end joins with tibia & fibula at knee
Tibia
- shin bone
- sharp edge along front of lower leg
Fibula
- very delicate
- doesn’t bear weight
- lower leg (lateral)
Tarsals (7)
- heel, back of foot & ankle
- calcaneous (heel bone) is the largest one
Metatarsals (5)
-toes attach to them
Phalanges (14)
- toe bones
- compact
- provide strong & ‘springy’ base for body
Male Skeleton
- larger
- shape of pelvis: deep & narrow
- pelvic outlet is not as wide as females
Female Skeleton
- smaller
- shape of pelvis: broad & shallow
- pelvic outlet is broad & shallow in females (wider for giving birth)
- pubic angle is wider (angle between pubic bones)
What does reduced bone density cause?
- fractures more likely
- changes in posture
- changes in height
What is an articulation?
- a joint
- point of contact between bones
- allow movement
- can be classified according to structure or function
Which is the only bone that does not connect to at least one other bone at a ‘joint’?
-hyoid
Classification by Structure & Function (3 types)
1) fibrous
2) cartilaginous
3) synovial
Fibrous (Synarthroses) Subtypes
- syndesmoses
- sutures
- gomphoses
Syndesmoses
-ligaments connect the bones (ex. distal radioulnar joint)
Sutures
- only found in skull
- interlocking ‘teeth like’ projections connect bones
Gomphoses
-joints between teeth roots & jaw bones
Cartilaginous (Amphiarthroses) Subtypes
- synchondroses
- symphyses
Synchondroses
-hyaline cartilage between bones
Symphyses
- a pad or disk of fibrocartilage connects the bones (ex. pubis symphysis; between vertebrae)
- limited movement
Synovial (diarthroses) Subtype
- freely movable
- most numerous type of joint in the body
- most complex type of joint in the body
- most joints of the appendicular skeleton are synovial joints
Structure of Joints
- joint capsule
- synovial membrane
- articular cartilage
- joint cavity
- menisci
- ligaments
- bursae
Joint Capsule
- sleeve like casing around ends of the 2 joining bones
- made of tough, strong, fibrous connective tissue
- lined with synovial membrane
- firmly attached to shaft of each bone at periosteum (actually an extension of the periosteum)
- provides very secure attachment while allowing movement at joint
Synovial Membrane
- ‘lining’ of joint capsule
- secretes synovial fluid which lubricates & nourishes joint
- facilitates movement
Articular Cartilage
- thin layer of hyaline cartilage
- rubbery/smooth
- covers ends of bones at joints
- decreases friction
- absorbs jolts
Joint Cavity
-small space between articulating surfaces of the 2 bones of the joint
Menisci (articulating disk)
- pads of fibrocartilage between articulating bones of some diarthrotic joints
- usually divide joint cavity into 2 separate spaces
Ligaments
- bands made of tough, fibrous, connective tissue
- originate from periosteum
- attach bones together
Bursae
-synovial fluid filled sacs that cushion some ‘boney’ joints to cushion joint & facilitate tendon movement
Uniaxial Joints
-permit movement around ONE axis & only in ONE plane
1) hinge
- allows flexion & extension
- ex. elbows, knees, fingers
2) pivot
- allows rotation
- ex. cervical (neck) vertebrae
Biaxial Joints
-permit movement around 2 perpendicular axes & 2 perpendicular planes
1) saddle
- only one pair
- excellent ROM
- ex. opposing thumbs
2) condyloid
- flexion/extension
- adduction/abductor
- ex. wrist, fingers
Multiaxial Joints
-permit movement around 3 or more axes & 3 or more planes
1) ball & socket
- allows widest ROM
- ex. shoulder & hip
2) gliding
- allows gliding motion
- ex. between vertebrae
How is ROM assessed & determined during a joint injury?
-a goniometer
All synovial joints allow 1 or more of these movements…
1) angular (flexion, extension, abduction, adduction)
2) circular (rotating, circumduction, supination, pronation)
3) gliding (gliding with no angular or circular movement)
4) special (inversion, eversion)
Flexion
-movement that decreases the angle between two bones at their joint (bending)
Extension
-movement that increases the angle between two bones at their joint (straightening)
Dorsiflexion
-elevation of the dorsum or top of the foot
Plantarflexion
-bottom of the foot is directed downward
Abduction
-movement of a body part AWAY from the midline
Adduction
-movement of a body part TOWARD the midline
Rotation
-movement around a longitudinal axis (ex. shaking head ‘no’)
Circumduction
-movement of a limb or extremity so that the distal end traces a circle, while the proximal end is fixed (still)
Supination
-palms face anterior
Pronation
-palms face posterior
Gliding Movements
- simplest movement
- articular surface of one bone moves over the articular surface of another bone
- occurs between carpals & tarsals, and between spinal vertebrae
Inversion
-bottom of foot faces toward midline of body
Eversion
-bottom of foot faces toward the side of the body
Protaction
-moves a body part forward
Refraction
-moves a body part back
Elevation
-moves a body part up
Depression
-lowers a body part
How many skeletal muscles are in the body?
over 600
How much of your body weight is skeletal muscle?
-40% to 50%
Muscles fill in the ______ & ______ of the body.
- form
- contour
Endomysium
-delicate CT membrane that covers skeletal muscle fibres (muscle fibres=muscle cells)
Perimysium
-tough CT that binds groups of skeletal muscle fibres (fascicles) together
Epimysium
-coarse sheath that covers muscle as a whole
Synathroses Joints
-no movement
Amphiarthroses Joints
-slight movement
Diarthroses Joints
-free movement
Upper Extremity Muscles
-act on the shoulder girdle & move the arm
- trapezius
- pectoralis minor
- pectoralis major
- latissimus dorsi
- deltoid
- biceps brachii
- brachialis
- brachioradialis
- triceps brachii
Which muscles move the thigh & leg?
- illiopsoas (major & minor)
- gluteus maximus
- adductor group
Which muscles move the lower leg?
- quadriceps group
- hamstring group
Which muscles move the foot?
-gastrocnemius
What are the 3 primary functions of skeletal muscles?
1) movement
2) posture/muscle tone
3) heat production
How is posture maintained?
muscles exert a continual pull on bones in the opposite direction from gravity
- nervous system is responsible for the existence of muscle tone & also for regulation & coordination of the amount of pull excepted by individual muscles
- respiratory, digestive, excretory & endocrine systems all contribute to maintain posture
