Chapter 8 - Skeletal: Appendicular System Flashcards
What are the bones of the appendicular skeletal system?
The bones that make up the upper and lower limbs
Bones of the two girdles that attach the limbs to the axial system
How does the appendicular skeletal system contribute to homeostasis?
By providing attachment points and leverage for muscles, (aids in body movement)
Support and protection for internal organs
Storing and releasing calcium
What does the pectoral girdle consist of?
A clavicle and a scapula
What is the clavicle? What does it articulate with?
“Collarbone” - Anterior bone
Articulates with the manubrium of the sternum and the scapula
What does the scapula articulate with?
Clavicle and the humerus
How are the pectoral girdles held in place?
By a large group of muscles that extend from the vertebral column and ribs to the scapula
* do not articulate with the vertebral column
What is the function of the pectoral girdle?
Attach the bones of the upper limbs to the axial skeletal system
What is the medial end of the clavicle called?
Sternal end
Rounded, and articulates with the manubrium of the sternum
What is the lateral end of the clavicle called?
Acromial end
Broad, flat, articulates with the acromion of the scapula
What is the conoid tubercle?
Inferior surface of the lateral end of the clavicle is the point of attachment for the conoid ligament
Attaches the scapula to the clavicle
What is the impression for the costcoclavicular ligament?
Inferior surface of the medial end of the clavicle
Point of attachment for the costcoclavicular ligament
Attaches the clavicle to the first rib
What joints are formed by the articulation of the clavicle with other bones?
Sternoclavicular - sternum and clavicle
Acromioclavicular - scapula and clavicle
What joints are formed by the articulation of the scapula with other bones?
Acromioclavicular - scapula and clavicle
Glenohumeral - scapula and humerus
What is the scapula?
The shoulder blade
Large, triangular, flat bone situated in the superior part of the posterior thorax between the levels of the 2nd and 7th rib
What is the glenoid cavity?
Shallow depression that accepts the head of the humerus
Forms the glenohumeral joint
How many bones are in each upper limb?
30 bones in three locations 1. Humerus in the arm 2. Ulna and radius in the forearm 3. 8 carpals in the wrist 5 metacarpals in the palm 14 phalanges
What does each upper limb include?
Humerus Ulna Radius Carpals Metacarpals Phalanges
What is the humerus?
Arm bone
Longest and largest bone of the upper limb
What does the humerus articulate with?
Proximally with the scapula and distally with the ulna and radius
What does the proximal end of the humerus feature?
A rounded head that articulates with the glenoid cavity of the scapula to form the glenohumeral joint
What is the former site of the the epiphyseal growth plate on adult humerus?
Anatomical neck, distal to the head
Visible as an oblique groove
What is the capitulum?
Distal end of the humerus
Rounded knob, articulates with the head of the radius
What is the radial fossa?
Anterior depression above the capitulum
Articulates with the head of the radius when the forearm is flexed
What is the surgical neck?
A constriction of the humerus, where the head tapers to the shaft
What is the ulna?
Located on the medial aspect of the forearm
Longer than the radius
(Little finger side)
What is the olecranon?
At the proximal end of the ulna
Forms the prominence of the elbow
What is the radius?
Smaller bone of the forearm
Located on the lateral aspect of the forearm
(Thumb side)
What is the elbow joint?
Where the ulna and radius articulate with the humerus
Head of radius + capitulum of humerus
Trochlear notch of ulna + trochlea of humerus
How do the ulna and radius connect with each other?
At three places:
- Broad, flat fibrous connective tissue called interosseous membrane, between the two shafts of the bones
- Head of radius + ulna radial notch (proximally)
- Head of ulna + ulnar notch of the radius (distally)
What is the carpus?
Proximal region of the hand
Consists of 8 small bones joined to one another by ligaments
What are intercarpal joints?
Articulations among carpal bones
How are carpals arranged?
In two transverse rows of 4 bones each
What is the mnemonic for the carpal bones?
Stop letting those people touch the cadavers hand
Scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate, harnate
What are the 4 carpal bones in the proximal row?
- Scaphoid
- Lunate
- Triquetrum
- Pisiform
What are the 4 carpal bones of the distal row?
- Trapezium
- Trapezoid
- Capitate
- Harnate
Which is the largest carpal bone?
- Capitate
Which carpal is most likely to break?
Scaphoid (70% of the time)
What forms the carpal tunnel?
Pisiform and hamate on the ulnar side
Scaphoid and trapezium on the radial side
What passes through the carpal tunnel?
Long flexor tendons of thumb and digits
Median nerve
What are the metacarpals?
Intermediate region of the hand
Consists of 5 bones
What does each metacarpal bone consist of?
Proximal base
Intermediate shaft
Distal head
How are the metacarpals named?
1-5
Starting with the thumb (1) through to pinky (5)
What forms the carpometacarpal joint?
Proximal bases articulate with the distal row of carpal bones
What forms the metacarpophalangeal joint?
Distal head articulate with proximal phalanges
What are commonly called the knuckles?
Heads of the metacarpals
What are the phalanges?
Bones of the digits
Make up the distal part of the hand
14 bones
How are the phalanges named?
1-5
Thumb (1), pinky (5)
What does each phalanx consist of?
Proximal base
Intermediate shaft
Distal head
What is different about the thumb?
Has two phalanges instead of three
Has no MIDDLE phalanx
What are the three rows of phalanges called?
- Proximal row (first row) - articulates with metacarpals & second row
- Second row (middle row) - articulates with proximal row & distal row
- Third row (distal row)
What does the pelvic girdle consist of?
Two hip bones (coxal or pelvic bones or os coxa)
What is the public symphysis?
Where the hip bones unite anteriorly
Where do the hip bones join posteriorly?
At the sacroiliac joints
What is the bony pelvis?
The compete ring
Hip bones, pubic symphysis, sacrum
What is the function of the bony pelvis?
Provides a strong and stable support for the vertebral column and pelvic and lower abdominal organs
Also connects the bones of the lower limbs to the axial skeleton
What do the hip bones of a newborn consist of?
Three bones separated by cartilage
- Superior ilium
- Inferior and anterior pubis
- Inferior and posterior ischium
Which part of the hip bone articulates with the femur?
The femur articulates with the acetabulum of the hip bone
Which part of the hip bone articulates with the sacrum?
The sacrum articulates with the auricular surface of the hip bone
What is the ilium?
The largest of the three components of the hip bone
Composed of a superior ala and inferior body
What passes through the greater sciatic notch?
Sciatic nerve
Longest nerve in the body
Just below the posterior inferior iliac spine