Chapter 7 Flashcards
1
Q
What is the skeletal system made up of?
A
Bones, cartilages, joints and ligaments.
2
Q
What do ligaments do?
A
Ligaments connect bones and reinforce joints.
3
Q
Axial skeleton
A
The axial skeleton consists of 80 bones.
Regions: Skull, Vertebral
Column and Thoracic Cage.
4
Q
Main functions of the axial skeleton
A
- The axial skeleton supports the head, neck and trunk.
- It protects the brain (skull), vertebrae (vertebral column) and the organs (rib cage).
5
Q
What 2 sets of bone make up the skull?
A
- Cranial bones (brain is enclosed in the cranial cavity)
- Facial bones.
Most skull bones are locked together except for the mandible which is able to move.
6
Q
What are the joints in cranial bones called?
A
Sutures
7
Q
Photo: Cranial and facial divisions of the skull
A
8
Q
!!! Photo: The human skeleton Anterior view
A
9
Q
The Cranium is divided into vault and base
A
Internally the base is divided into 3 fossae: anterior, middle and posterior fossae
The brain sits within these fossae, enclosed by the cranial vault. This area is known as the cranial cavity.
10
Q
Superior view of the Cranial fossae
A
11
Q
Other cavities contained in the cranium…
A
The middle and internal ear cavities.
The nasal cavity.
The orbits that house the eyeballs.
12
Q
What are some named openings of in the skull, and what are some of their functions?
A
Fermina, canals fissures.
They provide passage ways for the spinal cord, major blood vessels, and the 12 cranial nerves.
13
Q
Photo: Cross section of the skull including the cranial cavity…
A
14
Q
!!! What are the 8 cranial bones?
A
Frontal bone
Parietal bones (2)
Occipital bone
Temporal bones (2)
Sphenoid bone
Ethmoid bone
15
Q
Photo: Anterior view of the skull.
A
16
Q
Photo: Posterior view of the skull…
A
17
Q
Photo: Lateral aspect of the skull, external view…
A
18
Q
Photo: Lateral aspect of the skull, internal view…
A
19
Q
Photo: Temporal bone
A
20
Q
Photo: Ethmoid bone
A
21
Q
Photo: The sphenoid bone
A
22
Q
!!! What are the 14 facial bones?
A
Mandible
Maxillary bones (2)
Zygomatic bones (2)
Nasal bones (2)
Lacrimal bones (2)
Palatine bones (2)
Vomer
Inferior nasal conchae (2)
23
Q
Mandible is the largest and strongest of the facial bones.
A
24
Q
Photo: Mandible, right lateral view
A
25
Photo: Bones of the nasal cavity.
26
Describe the Hyoid bone…
- The hyoid bone is not a bone of the skull.
- The hyoid bone lies in the anterior neck inferior to the mandible.
- The hyoid is the only bone in the body that does not articulate directly with another bone (it is anchored by ligaments).
- The hyoid bone acts as a moveable base the tongue, and a site of attachment for the muscles of swallowing and speech.
27
!! What are some special characteristics of the orbit cavity?
Orbits are cavities that encase the eyes and lacrimal glands.
Orbits are sites of attachment for eye muscles.
Orbits are formed by the parts of seven bones: frontal, sphenoid, zygomatic, maxilla, palatine, lacrimal and ethmoid.
28
Photo: bones that form the orbits
29
!! What are special characteristics of the nasal cavity?
The nasal septum and conchae are covered with a mucus-secreting mucosa that moistens and warms the entering air and helps cleanse it of debris. The conchae increases the turbulence of air flow which helps to trap airborne particles in the sticky mucus.
30
!! Characteristics of the paranasal sinuses.
Paranasal sinuses are formed from 5 skull bones:
frontal
sphenoid
ethmoid
paired maxillary
All of them contain mucosa-lined, air-filled spaces.
Functions of the paranasal sinuses:
warm and humidify air
help to lighten the skull
enhance resonance of voice.
31
!! General characteristics of the vertebral column.
It extends from the skull to the pelvis.
It functions to transmit weight of the trunk to lower limbs, surround and protect the spinal cord, and provide attachment points for ribs and muscles.
It’s flexible curved structure contains 26 irregular bones called vertebrae in 5 major regions.
32
!! 5 main regions of the vertebral column.
The 28” long vertebral column is broken into 5 regions:
1. Cervical - consists of 7 vertebrae
2. Thoracic - 12 vertebrae
3. Lumbar - 5 vertebrae
4. Sacrum - one bone formed from fusion of several bones; articulates with hip
5. Coccyx - fused bones that form terminus of column
33
!! Curvatures of the vertebral column.
The 4 main curves in the column help to increase the resilience and flexibility of the spine, helping it act as a spring rather than a rigid rod.
Cervical and lumbar curvatures concave posteriorly.
Thoracic and sacral curvatures convex posteriorly.
34
!!! Photo: the vertebral column
35
Ligaments of the vertebral column
Ligaments along with trunk muscles, help support the vertebral column.
Anterior and posterior longitudinal ligaments
36
!!! The general structure of vertebrae
All have a common structural pattern consisting of…
- Body (centrum) the anterior weight bearing region.
- Vertebral arch, composed of… 2 pedicles (short pillars form sides of arch) + 2 laminae (fused flattened plates form posterior arch)
- Vertebral foramen - enclosure formed by body and vertebral arch coming together
- Vertebral canal - series of vertebral foramina.
- Intervertebral foramina: lateral openings between the vertebrae for passage of spinal nerves.
37
!! Photo: General structure of vertebrae
38
What are the 7 processes of vertebrae?
Spinous process, transverse processes (2), superior articular processes (2), and inferior articular processes (2)
39
!! Photo: Regional characteristics of vertebrae.
40
!! About the cervical vertebrae:
C1 through C7 are the lightest.
C3 to C7 share the following characteristics:
- oval shaped body
- large, triangular vertebral foramen.
- transverse foramen found in each transverse process for artery passageways
- C7 is vertebrae prominens: large and can be felt through the skin (so used as a landmark).
41
! C1 vertebrae
Is known as atlas. It has no body and no spinosus process.
It is the vertebrae that holds up the head. Allows head to move up and down (nod yes).
42
! C2 vertebrae
Axis - The dens on the axis (missing body of the atlas), allows head rotation (say no).
43
!! Photo: the difference between the cervical, thoracic and lumbar vertebral bones.
44
!! The difference between vertebrae in a table.
45
!! Thoracic vertebrae
T1 through T12 articulate with the ribs.
Unique characteristics:
- body is heart shaped with demifacets that articulate with the ribs. (T10 - T12 have a single facet)
- Vertebral foramen is circular
- Long sharp spinous process points inferiorly.
- Transverse processes have transverse costal facets that articulate with ribs.
- Location or articular facets allow rotation of this area of spine.
46
!! About the lumbar vertebrae
L1 to L5 are the small of back. They receive the most stress so their bodies are massive.
Short thick pedicles and laminae.
Vertebral foramen is triangular
Does not rotate a lot.
47
! The sacrum
Triangular body.
Shapes posterior wall of pelvis.
Sacral promontory: antersuperior margin.
Transverse ridges mark lines of fusion.
Anterior sacral formina lie at lateral ends of ridges; act as openings for nerves and vessels.
Alae: winglike expansions.
48
!! Thoracic cage: what is it made up of?
Thoracic vertebrae posteriorly
Sternum and costal cartilages anteriorly
Ribs laterally
49
!! What ar the thoracic cage functions?
Protects vital organs of the thoracic cavity.
Supports shoulder girdles and upper limbs
Supports attachment sites for muscles of neck, back, chest and shoulders.
50
Sternum consists of what 3 bones?
Aka breastbone.
Consists of 3 fused bones:
1. Manubrium: superior portion that articulates with clavicular notches and ribs 1 and 2.
2. Body: mid portion that articulates with costal cartilages of ribs 2 through 4.
3. Xiphoid process: inferior end that is site of muscle attachment (not ossified until age 40)
51
Sternum has 3 anitomical landmarks. What are they?
1. Jugular notch: central indentation in superior border of manubrium.
2. Eternal angle: Horizontal ridge across front of sternum.
3. Xiphsternal joint: point where sternal body and xiphoid process fuse.
52
!! Ribs
There are 12 pairs.
True ribs are pairs 1-7 and they attach directly to the sternum.
False ribs are #s 8-10. False ribs attach indirectly to the sternum.
Vertebral floating ribs - 11-12; No attachment to sternum at all.
53
Photo: Superior view of articulation between a rib and thoracic vertebrae
54
Photo: A typical rib
55
!! What is a pectoral girdle?
It attaches the upper limbs to the body trunk.
56
!! What is a pelvic girdle?
It attaches the lower limbs to the body trunk.
57
!! The shoulder girdle
A type of pectoral girdle that consists of the clavicles and scapulae.
Attaches the upper limbs to the axial skeleton.
Provides attachment sites for muscles that move the upper limbs.
The shoulder girdle offers a great degree of mobility because scapulae are not attached to the axial skeleton, and the socket of the shoulder joint is shallow and does not restrict movement.
58
! Photo: Pectoral girdle with articulating bones
59
!! Clavicles
- Clavicles anchor muscles and act as braces to hold the scapula and arms out laterally.
- Its s-shaped sternal end articulates with sternum medically
- It’s flattened acromial end articulated laterally with the scapula.
60
!! Scapula aka shoulder blades
Each scapula has 3 borders:
1. Superior: shortest sharpest border.
2. Medieval (vertebral) runs parallel to spine.
3. Lateral (axillary) near armpit. Ends superiorly in glenoid cavity fossa (shoulder joint).
61
What are the 3 angles where scapula borders meet?
1. Superior angle
2. Lateral angle
3. Inferior angle
62
Scapula bone features:
Spine
Acromion
Coracoid process
Superscapular notch
Plus several large fossa.
63
!! Upper limb
There are 30 bones in each upper limb.
Arm (humerus)
Forearm (Radius and ulna)
Hand (8 carpal bones in wrist, 5 metacarpal bones in palm, and 14 phalanges in the fingers).
64
!! Photo: Humerus - identify its important markings
65
Photo: right arm humerus detailed view at elbow
66
3 bones types of Hand
Carpus, metacarpus and phalanges.
67
!! Forearm
Ulna and radius.
Proximal ends articulate with humerus and each other.
Distally articulate with each other and the radioulnar joint
Interosseus membrane connects the radius and ulna along their entire length.
68
Photo: Radius and ulna of of the right forearm
69
Carpus
8 bones and 2 rows.
70
Metacarpals
5 metacarpal bones
71
Phlanges
Fingers
72
!! Pelvic girdle/hip girdle
Formed by 2 hip bones:
Coxal bones and sacrum.
The pelvic girdle transmits the weight of the upper body to the lower limbs.
The pelvic girdle has less mobility but more stability than the shoulder joint.
73
!! What are the 3 fused bones of the coxal bone (os coxae)?
Ilium
Ischium
Pubis
74
Acetabulum
A deep socket that receives the head of the femur.
75
3 main segments of the lower limbs
Thigh
Leg
Foot
76
!Photo: Lower limbs
77
!!Leg is made up of:
Tibia and fibula connected by interosseus membrane.
Tibia: medial leg bone that receives weight of body from femur and transmits it to the foot.
Fibula: Not weight bearing; no articulation with the femur; articulates with the tibia.
78
!Photo: tibia and fibula of the right leg
79
The foot
Includes tarsals, metatarsals and phalanges
80
!Intervertebral discs
Intervertebral discs are the cushion between the vertebrae; They act as a shock absorbers.
