Multiple Choice Questions (MCQ) on Veterinary Anatomy and Histology (Part-1)

ANSWERS & EXPLANATIONS

1

c. (Sacrum)
The bone which is part of Axial Skeleton - Sacrum
Axial skeleton comprises of bone, distributed along the main central axis of the body. Ex: Head, vertebral columns including tail, ribs and sternum.
Appendicular skeleton comprises of bone, located away from the central axis of the body. Ex: Bone of limbs, including Scapula and Ox- Coxae ( Hip bone).

2.

b. (13 pairs)

Division of the Spinal Cord and Spinal Nerve

Cervical Spinal Cord: Cervical spinal nerves originates;Thoracic Spinal Cord: Thoracic spinal nerves originates; Lumbar spinal cord: Lumbar spinal nerves originates; Sacral spinal cord: Sacral spinal nerves originates; Coccygeal or Caudal spinal cord: Coccygeal spinal nerves originates.

Notes:

All spinal nerves are paired, passes through intervertebral formina of Vertebral column. Number of Spinal nerves: Dog (35-36 pairs); cat (31pairs); Horse (44 pairs); Cattle (36 pairs); pig(39 pairs); Birds (30-33pairs).
Branches of the spinal nerves: (Dorsal Branch- which supplies to epaxial muscles (muscles around vertebral column and skin); Ventral branch -which supplies to the hypoaxial muscles (muscles and skin ventral to the transverse process of vertebral column. Also supplies to fore and hind limb by forming brachial and lumbosacral plexus.
Note: Brachial plexus is formed by anastomoses of ventral branches of last 3 cervical and 1st one ( in goat and sheep) or 1st and 2nd (Cattle, horse, dog) ventral branches of thoracic spinal nerves, supply all the structure of forelimb, and lateral wall of thorax and abdomen of animals. Branches of Brachial Plexus: (10 nerves): Suprascapular nerve, subscapular nerve, Musculocutaneous nerve, pectoral nerve, Axillary nerve, Radial nerve, Median and ulnar nerve, thoracodorsal nerve, long thoracic nerve, lateral thoracic nerve.
Lumbosacral plexus: formed by anastomoses of ventral branch of last 3 lumbar spinal nerve and 1st 2 sacral nerves, supply blood to hindlimbs, consists of (8 nerves): Cranial and caudal gluteal nerve; Caudal cutaneous femoral nerve; pudendal nerve; caudal rectal nerve; sciatic nerve; tibial nerve; fibular nerve.

3.

a. (Rib)
Example of elongated bone - Rib

Classification of bones on the basis of shapes:

Long bone: Long hollow cylindrical type, weight bearing bone found in limbs. Ex: Femur and Humerus
Short bone: Carpals and metacarpals, tarsal, metatarsal are example of short bones.
Flat bones: Scapula and some cranial bones of skull
Irregular bones: Vertebrae
Pneumatic bone: Humerus of Fowl
Sesamoid bone: Non weight bearing, small seeds like bones. Ex: Patella
Visceral bones: Found in viscera of some animals. Ex: Os penis on Dog; Os cardis in ruminant; Os opticus in fowl; Os Phrenic in camel

4.

b. (Trochlea)

Terminology related to Veterinary Anatomy:

-Spine: Elongated elevation on bone surface; Protuberance: Bony projection of nodular shape; Sulci: Elongated depression on bony surface; Foramen: Perforation in bone for passage of vessel; Process: A general term for prominence on bone; cleft: Fissure in a bone; Facet: Small flate or undulating articular surface; Lamina: Thin plate like structure
Fossa: Depression on bony surface Caput/head: Convex articular structure
Trochlea: Pully like articular surface Condyle: Knuckle shaped pair articular surface
Epicondyle: Small non - articular projection along condyle Fovea: Very small pitted articular surface
Cornu: Curved horn like process Hamulus: Hook like process ‘ Tuberosity: Large round projection Tubercle: Small projection
Trochanter: Very large prominence line: Faint elongated elevation
Tubercle: Small projection crest: Sharp and rough elevation

5.

b. (Clavicle)
Collar bone of Shoulder - Clavicle ( S-shaped long bone) .
Pectoral girdle ( Shoulder girdle) consists of 3 major bones: Scapula,Clavicle and coracoid.
Major Structures present in Scapula - Acromian process, Glenoid cavity, Coracoid process.
-Acromian process is absent in horse.
-Coracoid process is absent in dog
-Acromian process is rudimentary and Glenoid notch absent in pig
-Metacromian process is present in rabbit
In fowl, Two clavicle bones are fused, known as Forcula (also known as Wish bone).

6.

c. (Cingulum membri thoraci)
The NAV (Nomina Anatomica Veterinaria) is an standardized nomenclature, made by World Association of Veterinary Anatomists (WAVA).

The following principles, which agrees to a large extent with those of the NA, have served as a guide in the work:

-Aside from a very limited number of exceptions, Each anatomical concept should be designated by a single term.
-Each term should be in Latin in the official list, but the anatomist of each country are free to translate the official latin terms into the language of instruction.
-Structures that are closely related topographically should have similar names. For example: Arteria femoralis, Vena femoralis, Nervus femoralis etc.
-Differentiating adjectives should generally be opposites, as major and minor, superficialis and profundus
-Terms derived from proper names should not be used.

7.

a. (Humerus)
Humerus is the bone of the Arm region.
-Humerus is a long bone, situated obliquely downward and backwards, form shoulder joint above with scapula, and elbow joint below with radius and ulna
The cylindrical shaft is twisted and present four surfaces- Anterior, Posterior, Medial and lateral.
-Major structures found in Humerus: Teres tubercle ( At middle of medial surface, there is turbercle for insertion of teres major and latissimus dorsi muscles); Deltoid tuberosity (Between anterior and lateral surface, there is border, known as crest of humerus, At middle of the crest of humerus, there is a prominence for insertion of deltoid muscles, termed deltoid tuberosity); Nutrient foramen ( situated at the distal third of the posterior surface); Bicipital groove ( proximal end of humerus); Radial fossa ( articulate with radial bone); Olecranon fossa ( articulates with olecranon process of ulna.
Prominent deltoid tuberosity - Horse; Supratrochlear foramen ( Radial and Olecranon fossa communicates with this foramen), present in Dog And Pig; Rabbit; Pneumatic Humerus present in Fowl.

8.

b.( 2 )
-Digits are the composed of first phalanx, second phalanx and third phalanx.
-In ruminant ( sheep, Cattle, and goat), there are 4 digits in each foreleg, namely 2nd, 3rd, 4th and 5th, out of which only 3rd and 4th are functional, 2nd and 5th are rudimentary, represented only by small dewclaws at the back of fetlock joint.
-In ox, 1st and 5th metatarsal are absent, 3rd and 4th well developed, bearing digits. 2nd one just quardrilateral plate like.
-In horse, 1st and 5th are absent, 3rd well developed carry digits, second and fouth much reduced.
-In pig, 1st absent, 3rd and 4th well developed carries digits, second and fifth - somewhat reduced, and carry accessory digits.
-In fowl, 4 metatarsal are present, 1st one is small, 2nd 3rd and 4th - elongated and carries chief digits.

9.

a. (Deltoideus)
Lateral surface of Scapula give attachment to Deltoideus muscles.
-Scapula is flat triangular bone situated at the cranio lateral aspect of thorax, directed downward and forward, extends from 3th to 4th thoracic spine to distal end of 1st rib, possess 2 surfaces, 3 angles and 3 borders.
The lateral surface is divided into 2 unequal halves by spines in ratio 1:3. Upper part- supraspinous fossa accomodates supraspinous muscles and inferior one is infraspinous fossa, accomodates infraspinous muscles. spine is broad and bent backward at middle to attach trapezius muscles, this spine terminates below into a pointed projection, acromian process where deltoid muscles originates.
The medial surface has shallow fossa at middle, called subscapular fossa, accomodates subscapular muscles. On the upper part of this surface, cranially and caudally, there are 2 rough triangular area for attachment of serratus cervis and serratus thoracis muscles respectively.

Note:

Biceps brachii muscles originates from tuber scapulae or supra glenoid tubercle (situated at cranial aspect of glenoid cavity); Coraco- brachialis muscles originate from coracoid process.

10.

c. (Trochlea)
Distal extremity of femur consist Trochlea
Femur is cylindrical and largest long bone, directed obliquely downward and forward, articulates with hip bone above to form hip joint and with tibia, fibula and patella below to form stifle joint. It has body and two ends. Body is cylindrical in middle and have 3 sides below. Lateral medial and anterior surface are smooth and continous, covered by quadriceps muscles while medial surface is not smooth.
Special structures present in Femur: Lesser trochanter (situated to the upper part of medial border of posterior surface, there is rough depressor in trochanter for illiacas and psoas major muscles); Distally to this medial border, there is rough prominence, medial supracondyloid crest, from this, medial head of gastrocnemius muscles originates; Fovea capitis femoris ( small depression at head of femur; Greater trochanter is a large tuberosity, situated at lateral aspect of anterior end; Trochanteric ridge connect greater and lesser trochanter; Trochanteric fossa is an elclosed depression between trochanteric ridge and head.
Distal end consists of Condyle and Trochlea

Some Facts:

-Third trochanter ( extra prominence in upper part of lateral border) present in Horse
-Supracondyloid fossa absent in dog
-Only greater trochanter is present in fowl .

11.

d. (7)
Number of carpal bones present in dog.
Carpal are the short bones arranged in two rows ( Promixal and distal) between the radius and ulna above and metacarpal below.
In cattle: (6); P(4 - Radial( Scaphoid), Intermediate (Semilunar), Ulnar(Cunciform) and Accessory (Pisiform); D( 2- 2nd and 3rd fused( Os magnum), 4th ( Unciform))
In horse: (7); P(4- radial, intermediate, ulnar, accessory) D( 2nd, 3rd and 4th); 1st carpal is in the form of small nodules
In Dog: (7); P(3- radial and intermediate fused, ulnar and accessory) D( 4- 1st, 2nd , 3rd and 4th)
In Pig: ( 8); P( 4- radial, Intermediate, ulnar and accessory) D( 4- 1st, 2nd, 3rd and 4th)
In Rabbit: (8); P (3- radial, intermediate and ulnar) D( 5 - 1st 2nd 3rd 4th and 5th)
In Fowl: (2 ) P - radial and ulnar carpal; while distal row fused with metacarpal

12.

b. (Ischium)
Pelvic girdle or bony pelvis is formed by right and left hip bones (Os coxae), sacrum and one or two coccygeal verterbra.
Each hip bone consists of Ilium, Ischium and Pubis, these bones joins together to form large acetabular cavity, which articulates with head of femur. Hip bone of one side join to other at pelvic symphysis.
Ilium: Triangular, flat bone situated at craniolateral aspect of pelvis, has 2 surface (gluteal and pelvic surface), 3 angles (External angle - tuber coxae; Internal angle - tuber sacrale; and distal (cotyloid) angle is expanded and join with corresponding angle of pubis and ischium to form cotyloid cavity ( Acetabulum) articulate with head of femur.
Ischium: Quadrilateral plate, situated behind the pubis, and form most part of pelvic floor, having 2 surface (Dorsal or pelvic surface and ventral surface), 4 borders ( anterior border- Forms posterior border of obturator foramen),posterior border( meet posterior border of other side of ischium bone, form ischial arch, medial border form ischium symphysis, ventrally at middle of symphysis, there is prominence, ventral tubercle) 4 angle ( Anterointernal, Anteroexternal (forms cotyloid cavity);Posteriointernal and posterioexternal (trifid ischial tuberosity) referred as pin Bone.
Pubis: Triangular shaped, having 2 surface, 3 border and 3 angles.

13.

b. (Stifle joint)
-The patella is seen in dog in the Stifle joint.
Types of joints:
Immobile joint/Synarthrosis/Fibrous joint- Suture in skull
Slightly movable/ Amphiarthrosis/ cartilaginous joints- Intervertebral disc, Ribs, pelvis
Freely movable/ Diarthrosis/ Synovial joint- Ball and socket - hips and shoulder/ Hinge- Knee and Elbow/ Pivot - Base of head at neck/ saddle- Base of fingers/ Ellipsoid or Condyloid- wrist/ Gliding - Metatarsal and phalanges
Shoulder joint- joint between scapula and humerus; Elbow joint - joint between humerus and radius and ulna ;carpal/wrist joint- joint between carpal, metacarpal and radius and ulna ; metacarpal and phalanges- fetlock ; 1st and 2nd phalanx- pastern ; 2nd and 3rd phalanx- coffin
Hip joint- joint between pelvic girdle and femur; Stifle/Knee joint: Joint between femur, tibia fibula and patella; Hock joint/Ankle joint- Joint of tibia and fibula/tarsal and metatarsal; Fetlock - joint between metatarsal and 1st phalanx, pastern - joint between 1st and 2nd phalanx; coffin- joint between 2nd and 3rd phalanx.

14.

b. (third )
Example of typical cervical vertebra- Third cervical vertebra
A typical vertebra has body, Arch and Processes (Supraspinous process, Transverse process and Cranial and caudal articular process).
A Atypical cervical vertebra - 1st, 2nd, sixth and seventh.

Vertebral Formula of different Domestic Animals

Species	Cervical	Thoracic	Lumbar	Sacral	Coccygeal
cattle	7	13	6	5	15-25
Horse	7	18	6	5	16-22
Dog	7	13	7	3	18-25
pig	7	14-15	6-7	4	18-24
Fowl	14	7	lumbosacral -14	4-9

15.

a. (Dog)
Haemal arches are present in the coccygeal vertebra of dog.
Haemal arch ( also known as Chevron) is a bony arch on the ventral side of a tail vertebra of vertebrate, provides protection for the median coccygeal artery, which encloses by arch.
Fovea dentis, a depression at the caudal part of the floor of the atlas, articulate with odontoid process of axis. Fossa atlantis- ventral surface of wing of atlas is concave and termed fossa atlantis.

16.

b. (9 pairs)
-Number of pairs of sternal ribs present in dog - 9 pairs
Ribs is curved elongated bone arranged one after another from either of the vertebral column and forms the thoracic cage. A typical rib has head at proximal end, shaft and costal cartilage at distal end. There are 3 types of ribs - Sternal or true rib (Ribs that connected to sternum directly through their own costal cartilage; Asternal rib or false rib joins the sternum through costal cartilage that connected to preceding costal cartilage; Floating ribs are either single or in pairs at the end of series which are not connected with sternum directly or indirectly.
In cattle - 13pairs of ribs, out of which first 8 pairs are sternal and rest 5 pairs are asternal
In horse - 18 pairs of rib, out of which first 8 pairs are sternal and rest 10 pairs are asternal
In Dog- 13 pairs of ribs. out of which first 9 pairs are sternal and 4 are asternal
In Pig- 14-15 pairs of ribs, out of which first 7 pairs are sternal, and rest 7-8 pairs are asternal. last rib is small and floating. 1st rib has a prismatic body.
In fowl- 7 pairs of ribs.

Note:

Uncinate process are present in ribs of fowl.

17.

a.(Occipital bone)
Foramen Magnum is present in Occipital bone.
Skull is the skeleton of head, comprises of two parts- Cranium that encloses brain and Facial Bones. Bones of Skull - Occipital, Sphenoid, Ethmoid - single; Interparietal, Parietal, Frontal and Temporal - Paired; Facial bone: Lacrimal, malar, maxilla, premaxilla, palatine, nasal, pterygoid, turbinate- paired and vomer - single
-Foraman magnum, paramastoid process, condyloid fossa, condyloid foramen, hypoglossal foramen, Mastoid foramen, External occipital protuberance - found in occipital bone
-Pituitary fossa (Sella turcica), Foramen ovale, Foramen orbitorolundum, Optic foramen - Sphenoid bone
-Cribiform plate - Ethmoid bone; Lacrimal fossa - lacrimal bone; Zygomatic process/ frontal process - malar bone;
Infraorbital foramen - maxilla while supraorbital foramen - Frontal bone

Note:

Largest sinuses present in Horse - Maxillary sinus

18.

d. (Sartorius)
muscle present in medial aspect of thigh region - Sartorius
Muscles of lateral aspect of thigh: Tensor fascialata; superficial gluteus; middle gluteus; deep gluteus; biceps femoris; semitendinosus ( @GBST)
Muscles of the medial aspect of thigh: Sartorius, Gracialis, pectineus, Adductor, Semimembranosus , Quadratus femoris, Obturator internus, Obturator externus, Gemellus
Muscles of Anterior aspect of thigh: Quadriceps femoris; Articular genu
Muscles of anterolateral aspect of Thigh: Complex ( peroneus tertius, medial digital extensor, common digital extensor); lateral digital extensor, Peroneus longus, Tibialis anticus, Extensor bravis.
Muscles of postero- medial aspect of thigh: Gastrocnemius, soleus, superficial and deep digital flexor, popliteus

19.

b. (Rectus abdominis) - Prepubic tendon is the insertion of Rectus abdominis muscles

Muscles of Abdomen:

Muscles	Description	Origin	Insertion
Obliquus Abdominis Externus	Extensive muscles of lateral abdominal wall, it’s fibres are directed downward and backward.	Lateral surface of ribs from 5th intercostal space and lumbodorsal fascia	linea alba and prepubic tendon
Obliquus Abdominis Internus	located below the externus muscles, fibres are directed forward and downward	Tuber coxae, pauparts ligaments, and lumbo dorsal fascia	Linea alba and prepubic tendon few ribs and cartilage
Transverse Abdominis	inner muscles, fibres are directed transversely downwards	Transverse process of lumbar vertebra and some asternal cartilage	linea alba and xiphoid cartilage
Rectus Abdominis	elongated flat muscles, extends from sternus to pubis along floor of abdominal cavity	Lateral and ventral surface of sternum	Pubic and linea alba

Note:

Cremaster muscles are the muscles which covers testicles, originates from pubic tubercle and inserts into tunica vaginalis

20.

b. (Retractor costae)

Muscles of back thorax and sub lumbar regions:

longissimus dorsi - longissimus costarum - levator costarum
Multifiedus dorsi - Serratus dorsalis anticus -Serratus dorsaslis posticus external
Intercostal - Internal intercostal - Retractor costarum
Rectus thotracis - Transversus thoracis - latissimus dorsi
Serratus thoracis - psoas major - Psoas minor
Iliacus - Quadratus lumborum - inter Transversales lumborum

21.

c. (Malaris)
Malaris is not mastication muscles.

Muscles of Mastication

Masseter
Lateral Pterygoid
-Temporal
Digastric
Mylohyoid
Temporalis
Medial pterygoid

22.

b. (Mylohyoideus)
Muscles of the hyoid apparatus - Mylohyoideus

Muscles of the hyoid apparatus

-Mylohyoideus
geniohyoideus
Sternohyoideus
thyrohoid

Muscles of the tongue

genioglossus; Hyoglossus; Styloglossus

Muscles of the Soft palate and pharynx

Palatinus
tensor veli palatini
Levator veli palatine

23.

d. (Sternothyrohyoideus)
The muscles of larynx are divided into 2 groups:

a. Extrinsic muscles:

Extrinsic muscles which produce the movement of the hyoid bone. These are the infrahyoid (Sternohyoid, omohyoid, sternothyroid, thyrohyoid) and suprahyoid (stylohyoid, digastric, mylohyoid, geniohyoid)

b. Intrinsic muscles:

Muscles which move the vocal cords in order to produce speech sounds. They are adductor (lateral cricoarytenoid, transverse arytenoid), abductor (posterior cricoarytenoid), sphincters (transverse arytenoid, oblique arytenoid, aryepiglottic), muscles that tense the vocal cord and muscles that relax the vocal cord ( Thyroarytenoid, vocalis).

24.

b. (Right)
-Sub sinosal groove seen on right surface of the heart.

Surfaces and borders of heart

There are 5 surfaces and 5 borders of heart.
5 border of heart - (@RAILS)- Right border (right atrium), Apex border( left ventricle), Inferior border (right ventricle and left ventricle), left border(left atrium and left ventricle) and superior border(Right atrium and Left atrium);; 5 surfaces of heart (@APRIL)- Anterior surface(Right Auricle and Ventricle and left Auricle and Ventricle), Posterior surface( Right atrium and right ventricle), right surface( right atrium), inferior surface (Diaphragmatic surface)(left and right ventricle), left surface (left atrium and ventricle).
On the surface of heart, there are series of groove, called sulci, each sulci contains coronary blood vessels and variable amount of fat. Sulci marks the external boundaries between 2 chambers of the heart.
Coronary sulcus/arterioventricular sulcus: marks the external boundaries between atria and ventricle
-Interventricular sulci: Marks the boundary between right and left ventricles:
a. Anterior Interventricular sulcus: on the anterior surface
b. posterior Interventricular sulcus: On the posterior surface.

25.

a. (Right atrium)
The coronary sinus present in Right atrium, bring deoxygenated blood from heart.
Two coronary arteries (right and left) arises from aorta supplies to the oxygenated blood to heart while coronary sinus bring deoxygenated blood from heart and pour into Right atrium for oxygenation.

26.

b. (3 )
Number of papillary muscles in right ventricles is 3 while in left ventricles is 2.
Papillary muscles are the muscles located in ventricles of heart, attach to the cusps of the arterioventricular valves ( known as mitral and tricuspid valve) via chordae tendinae and contracts to prevent inversion or prolapse of these valve on systole ( ventricular contraction).

27.

c. (Fowl)
Vena cava receives deoxygenated blood from different parts of body via different vein and pour it into right atrium. Normally superior vena cava receive deoxygenated blood upper parts of body of heart while inferior vena cava brings deoxygenated blood from the lower parts of body.
Fowl has two anterior vena cava.

28.

c. (Vertebral)
The artery does not arises from thoracic aorta - vertebral artery
Aorta arises from base of left ventricles, having 3 parts: Ascending Aorta; Arch of aorta; Descending Aorta.
Ascending Aorta gives two branches: Left and right carotid artery;
Arch of aorta gives 3 branches - brachiocephalic trunk, left common carotid artery(internal and external carotid artery), left subclavian artery, further brachiocephalic trunk gives right common carotid artery ( further gives internal and external carotid artery) and right subclavian artery)
Descending aorta haves 3 parts - Thoracic part, Abdominal parts and terminal parts ( two branches of Common iliac artery);
Arteries arises from Thoracic aorta: ( Bronchial; Oesophageal; intercostal; phrenic)
Arteries arises from abdominal aorta: (celiac; phrenic; splenic; left ruminal, hepatic, left gastric artery)

29.

b. (Camel)
Os- phrenic is visceral bone present in diaphragm of camel
in penis of dog, Os- penis is visceral bone
Visceral bone present in heart of cattle - Os -cardis
Os- opticus is visceral bone present in eyes of fowl

30.

a. (Posterior Vena cava)
-largest venous trunk in the body - Posterior vena cava
Posterior vena cava receive deoxygenated blood from the posterior part of body and pour into right atrium
Anterior vena cava receives deoxygenated blood from anterior part of body and pour into right atrium
Portal vein is blood vessel that carries blood from the GI tract, gallbladder, pancreas and Spleen to the liver
-Vena azygos is a single vein drains blood from the dorsal walls of the left side of the thoracic and abdominal cavity and opens independently to the heart.