Humerus

Question 1

First thing to evolve in earliest fish?

Answer 1

upper arm
- all axial “skeleton” at this point

Question 1

The tetrapod arm evolved from ________ _____ of lobe-finned fish

Answer 1

pectoral fins

Question 2

The evolution of limbs was a precursor to animals becoming terrestrial

Answer 2

True

Question 3

Pectoral fins evolved in early fish to aid in ___________

Answer 3

locomotion
- steering and stabilization

Question 4

We recently got our first look at a complete pectoral fin from a middle Devonian lobe-finned fish

Answer 4

• tetrapod-like fish with a well-preserved pectoral fin

(genus Elpistostege)

Question 5

3 bones that compose the arm

Answer 5

1.) Humerus
- proximally
2.) Ulna
- distal and medial
3.) Radius
- distal and lateral

Question 6

Brachial

Answer 6

related to the arm (especially to the upper arm)
- humerus

Question 7

Antebrachial

Answer 7

related to the forearm
- ulna and radius

Question 8

Joints of the humerus

Answer 8

• glenohumeral joint
• humeroulnar joint
• humeroradial joint

Question 9

Glenohumeral joint

Answer 9

the humeral head articulates with the glenoid fossa (scapula)

Question 10

Humeroulnar joint

Answer 10

the trochlea (humerus) articulates with ulna

Question 11

Humeroradial joint

Answer 11

the capitulum (humerus) articulates with the radius

Question 12

Tubercle

Answer 12

a rugose eminence, often the site of tendon or ligament attachment

Question 13

Epicondyle

Answer 13

a non-articular projection adjacent to a condyle

Question 14

Trochlea

Answer 14

a spool-shaped structure with a groove in the middle and raised ridges on either side

Question 15

Capitulum

Answer 15

a spherical structure

Question 16

The anatomical neck is the attachment region of the ________ joint capsule

Answer 16

glenohumeral

Question 17

Under the glenohumeral ligament is the capsule, which is also called what?

Answer 17

Bursa

Question 18

Muscles of the rotator cuff

Answer 18

1.) Supraspinatus muscle
2.) Infraspinatus muscle
3.) Subscapularis muscle
4.) Teres minor muscle

• anchors arm to body

Question 19

The subscapularis muscle inserts on the_________

Answer 19

lesser tubercle

Question 20

The supraspinatus, infraspinatus, and teres minor muscle inserts on the________

Answer 20

greater tubercle

Question 21

Soft tissue attachment is so strong that bone often breaks before the joint separates

Answer 21

breaks at the surgical neck

Question 22

The greater tubercle is _______ to the lesser tubercle

Answer 22

lateral

Question 23

Crest of the lesser tubercle (medial part of intertubercular groove) is the insertion site for what muscles?

Answer 23

• latissimus dorsi
• teres major

Question 24

The most conspicuous structure on the shaft of the humerus?

Answer 24

Deltoid tuberosity

Question 25

Because the deltoid has such a broad origin, it can produce many different movements

Answer 25

True

Question 26

The shaft changes cross-sectional shape along its length

Answer 26

Goes from more circular (proximal) to more triangular (distal)

Question 27

The shaft is divided into three surfaces

Answer 27

1.) Posterior surface
2.) Anteromedial surface
3.) Anterolateral surface

Question 28

Between the anatomical neck and the deltoid tuberosity, you will find the crest for________ on the posterior surface

Answer 28

triceps brachii

Question 29

The ___________ is located on just inferior to the deltoid tuberosity on the posterior surface

Answer 29

Radial sulcus
- spiral groove

Question 30

The radial sulcus spirals from_____________ to _____________

Answer 30

superoposterior to inferolateral

Question 31

The primary nutrient foramen is about at the deltoid tuberosity level, typically on the _________ surface

Answer 31

anteromedial

Question 32

The nutrient foramen opens_______

Answer 32

proximally

Question 33

The ________ nerve wraps around the posterior surface of the medial epicondyle

Answer 33

Ulnar nerve

Question 34

The nerve that goes numb when you “hit your funny bone”

Answer 34

ulnar nerve

Question 35

Medial epicondyle provides attachment to what?

Answer 35

• wrist flexors
• Pronator teres

Question 36

Pronator teres

Answer 36

pulls radius in to do pronation

Question 37

Lateral epicondyle provides attachment to what?

Answer 37

supinator muscle