Comparative Anatomy II Flashcards
Which lever system has the effort between the load and fulcrum?
A. First class lever B. Third class lever C. Second class lever D. Fourth class lever
B. Third class lever
You are a famous fossil hunter working in the deserts of Egypt at a site where early modern humans are thought to have lived. While digging at the site you come across what appears to be a fragment of bone from a human spinal column. From what you can tell, this is a vertebral segment that has a rather large vertebral body, short spinous process, and short laterally facing transverse processes. You most likely found a…
A. Cervical vertebra
B. Thoracic vertebra
C. Lumbar vertebra
D. Sacral fragment
C. Lumbar vertebra
Whn the medial pterygoid (both heads) works bilaterally, what action is seen?
A. Elevation and protraction of mandible
B. Elevation and retraction of mandible
C. Depression and protraction of mandible
D. Depression and retraction of mandible
A. Elevation and protraction of mandible
Which is the best description of humerus of living humans, compared to non-human apes?
A. In humans, the humerus exhibits a higher degree of humeral torsion with very similar distal humeral features, compared to non-human apes
B. In humans, the humerus exhibits a lesser degree of humeral torsion, with very similar distal humeral features, compared to non-human apes
C. In humans, the humerus exhibits a higher degree of humeral torsion with very different distal humeral features, compared to non-human apes
D. In humans, the humerus exhibits a lesser degree of humeral torsion with very different distal humeral features, compared to non-human apes
A. In humans, the humerus exhibits a higher degree of humeral torsion with very similar distal humeral features, compared to non-human apes
Which of the following named arteries contribues to blood supply in the hand?
A. Subclavian artery
B. Axillary artery
C. Brachial artery
D. Radial artery
D. Radial artery
Which of the following groups of features would best be attributed to a suspensory/climbing primate?
A. Long lumbar region, narrow thorax, stable shoulder joint, long digits
B. Long lumbar region, narrow thorax, stable shoulder joint, short digits
C. Short lumbar region, broad thorax, mobile shoulder joint, long digits
D. Short lumbar region, broad thorax, mobile shoulder joint, short digits
C. Short lumbar region, broad thorax, mobile shoulder joint, long digits
_____________ is a standardized way of positioning the skull so that relationships among structures can be measured in a way that allows direct comparisons among different taxa
Frankfurt horizontal
___________ is a term that is used to describe living humans and their direct ancestors
Hominins
____________ refers to a novel characteristic that is unique to a particular species and all of its descendants and can be used as a defining character for a species or group
Apomorphy
______________ refers to the ancestral state; an example would be humans having a spine
Plesiomorphy
______________ refers to a distinctive feature or derived trait that is unique to a particular taxon. AKA it is not shared among descendants, only your species has it
Autapomorphy
_____________ is a shared primitive characteristic
Symplesiomorphy
_____________ is a shared derived characteristic that is assumed to be present in the most recent common ancestor
Synapomorphy
____________ structures are shared characteristics of organisms that were inherited from a common ancestor
Homologous
____________ structures are shared characteristics that arise because of similar selective pressures, through the process of parallel or convergent evolution. These are characteristics that are similar in organisms that have separate evolutionary lineages
Analogous
________________ refers to an evolutionary trend in which selection has exerted similar pressures on two closely related organisms
Parallelism
_____________ refers to an evolutionary trend where selection has exerted similar pressure on two distantly related organisms
Convergence
A ____________ is a character shared by a set of species but not present in their common ancestor. A good example is the evolution of the eye which has originated independently in many different species.
Homoplasy
____________ evolution is the origin of a homoplasy
Convergent
Generally, a more ___________ positioned foramen magnum is associated with orthograde postures and bipedal behaviors
Anterior
Bipedality in humans is related to a relatively ______ lumbar region and a ________ shaped thorax
Short
Barrel
Bipedality in humans is related to a __________ sacral angle and a pronounced _________ curvature
Increased
Spinal (especially lumbar)
Bipedality in humans is related to a _________ coccyx and progressively ________ vertebral bodies that allow weight transmission to lower limb through a columnar structure
Reduced
Larger
Given that Australopithecines had skulls attaching more inferiorly and an S-shaped spine with small, lighter vertebrae that were not likely weight bearing, How would you describe their most likely locomotive behavior?
Likely facultative bipeds, mostly arboreal
Given that Homo ergaster/erectus had the following characteristics:
Barrel shaped rib cage, lumbar lordosis, 5 lumbar vertebrae, and small thoracic vertebrae/vertebral foramina
How would you characterize their most likely locomotive behavior?
Likely habitual, terrestrial bipeds
What are the 4 osteological parts of the human thorax?
Clavicles
Sternum
Ribs
Scapula
What are the 3 parts of the sternum from superior to inferior?
Manubrium
Body
Xiphoid
Human ribs are only associated with the _______ region. They articulate with the ________ and vertebrae.
Thoracic
Sternum
Ribs 1, 2, 11, & 12 are considered ___________
Atypical
Ribs 1-7 are considered _______ ribs
True (vertebrocostal)
Ribs 8-10 are considered _______ ribs
False (vertebrochondral)
Ribs 11 and 12 are considered _________ ribs
Floating
What does the term hominoid refer to?
Apes and humans
What does the term hominin refer to?
Humans and their direct ancestors
Compare the thorax and lumbar region of an arboreal quadruped vs. suspensory climber
Arboreal and terrestrial quadrupeds have narrow thorax and long lumbar region
Describe general characteristics of cervical vertebrae in terms of size, body shape, foramen size, and characteristics of spinous processes
Smaller, rectangular bodies
Large vertebral foramen
Spinous processes are forked
Describe characteristics of thoracic vertebrae
Facets on transverse processes for ribs
Demi-facets on ribs articulate between the vertebrae
Describe characteristics of lumbar vertebrae
Large bodies (support more weight)
Shorter spinous processes
Shorter transverse processes
Describe features of the atlas
Atlas = C1
Superior articular facet articulates with occipital condyles
What is the identifying feature of the axis?
Axis = C2
Has the dens, aka odontoid process
Which vertebrae appear concave from posterior to anterior?
Cervical and lumbar
Which vertebrae appear convex from posterior to anterior?
Thoracic
Extrinsic muscles of the back are considered ______ and are innervated by the ________ rami of spinal nerves
Hypaxial
Ventral
Intrinsic muscles of the back are considered _______ and are innervated by the _____ rami of spinal nerves
Epaxial
Dorsal
What are extrinsic muscles of the back generally used for?
Movement of the upper limbs and pectoral girdle
What are intrinsic muscles of the back generally used for?
Mainly postural muscles that support and move the vertebral column and head
The erector spinae group and transversospinalis group are considered to be a part of which type of musculature in the back?
Intrinsic (epaxial)
The muscles of the human pectoral region are innervated by the ______ rami of spinal nerves via branches of the _________ _________
Ventral
Brachial plexus
Which cervical vertebrae does not have a body?
Atlas (C1)
How does human thoracic shape compare to other primates?
Overall shape
Position of scapulae
Rib shape
Posterior invagination
What are the 5 primary hypaxial/extrinsic muscles of the back?
Trapezius
Latissimus dorsi
Levator scapulae
Rhomboid major
Rhomboid minor
Serratus posterior superior
Serratus posterior inferior
What is the primary function of the extrinsic back muscles: serratus posterior superior and inferior?
Accessory breathing muscles
What are the erector spinae muscles from most lateral to closest to the spine?
Iliocostalis
Longissimius dorsi
Spinalis
Are the erector spinae muscles intrinsic or extrinsic?
Intrinsic (epaxial)
What are the 3 muscles of the transversospinalis group of the intrinsic (epaxial) muscles of the back?
Rotatores
Multifidus
Semispinalis
What two muscles overlay the musculature of the posterior neck?
Splenius
Semispinalis capitis
What are the 4 primary muscles of the posterior neck?
Rectus capitis posterior major
Rectus capitis posterior minor
Obliquus capitis superior
Obliquus capitis inferior
[these are mainly postural and aid in extension+rotation at atlantoaxial joint]
All muscles of the upper limbs are innervated by the brachial plexus except trapezius. The trapezius muscles is innervated by what nerve?
The spinal accessory nerve (CN XI)
[this nerve also innervates the sternocleidomastoid m.
Name the 4 primary muscles of the abdominal wall from more anterior/superficial to more posterior/deeper?
External obliques
Internal obliques
Rectus abdominus
Transversus abdominus
What two muscles converge to make up the iliopsoas muscle?
Iliacus
Psoas major
What are the 4 primary posterior muscles of the abdominal wall?
Iliacus, psoas major, psoas minor, quadratus lumborum
Iliacus, psoas major (iliopsoas), and psoas minor function primarily as _______ of the trunk and/or hip
Flexors
The pair of muscles known as quadratus lumborum extends the lumbar vertebral region and also contributes to lateral ______
Flexion
What bones make up the pectoral girdle?
ONLY the clavicle and scapula
Your stylopodium is your _______
Humerus
Your zyogpodium refers to your ______
Ulna and radius
Your autopodium refers to your ______
Hand
The tip of your scapular spine is known as the ____________
Acromion
The glenoid of apes and humans is ___________ to accommodate more shoulder mobility
Rounder
In quadrupedal monkeys, the glenoid is _________ in shape
Pririform (pear-like)
Quadrupeds have a _________ scapula cranially-caudally, but __________ from the vertebral border to axillary border to facilitate movement during quadrupedal locomotion
Shorter
Broader
Climbers and suspensory forms have ________ scapulae with a more __________ oriented glenoid to allow greater mobility and rotational movement
Long
Cranially
In particular, lengthening the infraspinous portion of the ___________ provides greater attachment for muscles that superiorly rotate the glenoid, raising arm overhead
Scapula
Humeral torsion is present early in ontogeny and affects the placement of the bicipital groove on the humerus, which accommodates the tendon of biceps brachii. What is thought to be the purpose of increased humeral torsion in humans?
Related to tool use, which requires laterally oriented shoulders and anteriorly oriented elbows
What type of locomotive behavior is related to limited extension due to longer olecranon process?
Quadrupedalism
What type of locomotive behavior is related to increased extension due to shorter olecranon process?
Climbing/suspensory
Stronger flexion at the elbow joint is accommodated by a higher ___________ ___________ which is the attachment point for the brachialis m., the main elbow flexor, in climbers and suspensory forms
Coronoid process
Describe the olecranon fossa of apes as it relates to preventing hyperextension during weight bearing knuckle walking
Deep olecranon fossa with a strongly developed lateral trochlear ridge
How many bones in the wrist?
8
How many bones in the hand?
5
How many bones in the fingers?
14 bones
[each digit has 3 segments except thumb which has 2]
African ape knuckle walking features include:
Limited degree of wrist ______________
Limited metacarpophalangeal joint ____________
Deeply _________ distal radial surface
___________ expansion of metacarpal heads
Relatively _______ proximal phalangeal segments
Dorsiflexion (extension) Dorsiflexion Concave Dorsal Short
Orangutans (pongo) have the following adaptations to climbing:
_______, very curved phalangeal segments
Metacarpals II and V show a ________ degree of curvature than African apes
_______ bony cortex of all metacarpals
_________ length of the 4th digit relative to other digits
Long
Greater
Thicker
Increased
Of the anterior pectoral girdle muscles, what serves as the upward rotator of the scapula?
Serratus anterior
Of the anterior pectoral girdle muscles, what serves as the downward rotator of the scapula?
Pectoralis minor
Of the anterior pectoral girdle muscles, what 2 muscles serve as depressors of the clavicle?
Subclavius
Pectoralis minor
Of the anterior pectoral girdle muscles, what 2 muscles serve to protract the scapula?
Serratus anterior
Pectoralis minor
Of the anterior pectoral girdle muscles, what 2 muscles flex the humerus?
Deltoid
Pectoralis major
Of the anterior pectoral girdle muscles, what muscle serves to abduct the humerus?
Deltoid
Of the anterior pectoral girdle muscles, what muscle serves to adduct the humerus?
Pectoralis minor
Of the anterior pectoral girdle muscles, what muscle serves in inward (medial) rotation?
Subscapularis
In terms of posterior pectoral girdle muscles, what muscle serves as an upward rotator of the scapula?
Trapezius
In terms of posterior pectoral girdle muscles, what 3 muscles serve as downward rotators of the scapula?
Levator scapulae
Rhomboids
Latissimus dorsi
In terms of posterior pectoral girdle muscles, what 2 muscles serve to retract the scapula?
Rhomboids
Trapezius
In terms of posterior pectoral girdle muscles, what muscle elevates the scapula?
Levator scapulae
In terms of posterior pectoral girdle muscles, what 3 muscles act as extensors of the humerus?
Deltoid
Pectoralis major
Latissimus dorsi
In terms of posterior pectoral girdle muscles, what 2 muscles serve as abductors of the humerus?
Deltoid
Supraspinatus
In terms of posterior pectoral girdle muscles, what 3 muscles serve as adductors of the humerus?
Deltoid
Latissimus dorsi
Teres major
In terms of posterior pectoral girdle muscles, what 2 muscles serve in external (lateral) rotation?
Infraspinatus
Teres minor
In terms of posterior pectoral girdle muscles, what 2 muscles serve in inward (medial) rotation?
Latissimus dorsi
Teres major
What 4 muscles make up the rotator cuff?
Supraspinatus
Infraspinatus
Teres minor
Subscapularis
[Remember SITS!]
What 3 muscles make up the anterior (flexor) compartment of the arm?
Biceps brachii (long and short heads)
Brachialis
Coracobrachialis
What 2 muscles make up the posterior (extensor) compartment of the arm?
Triceps brachii (long, lateral, and medial heads) Anconeus
What are the 4 superficial muscles of the anterior forearm?
Pronator teres
Flexor carpi radialis
Palmaris longus
Flexor carpi ulnaris
What is the intermediate muscle of the anterior forearm?
Flexor digitorum superficialis
What are the 3 deep muscles of the anterior forearm?
Flexor digitorum profundus
Flexor pollicis longus
Pronator quadratus
What are the 3 muscles that make up the superficial lateral compartment of the posterior forearm?
Brachioradialis
Extensor carpi radialis longus
Extensor carpi radialis brevis
What 3 muscles make up the superficial layer of the posterior forearm?
Extensor carpi ulnaris
Extensor digitorum
Extensor digiti minimi
What 5 muscles make up the deep layer of the posterior forearm?
Supinator Abductor pollicis longus Extensor pollicis longus Extensor pollicis brevis Extensor indicis
What muscle group of the hand attaches to tendons of the flexor digitorum profundus?
Lumbricles
What muscle group of the hand adducts the fingers?
Palmar interosseous muscles
What muscle group of the hand abducts the fingers?
Dorsal interosseus muscles
Is the long hand musculature (tendons from forearm) more developed and stronger in apes or humans?
Apes
Is the short hand musculature (intrinsic hand muscles) more developed in apes or humans?
Humans
What important thumb muscle is absent as its own muscle in African apes and orangutans?
Flexor pollicis longus
What are the two major blood supplies to the posterior shoulder?
Subclavian arteries
Axillary arteries
The pectoral region is supplied by branches of the ________ artery
Axillary
The arm is supplied by the ______ artery and its branches
Brachial