Multiple Choice Questions (MCQ) on Veterinary Anatomy and Histology (Part-4)

ANSWERS & EXPLANATIONS

1

a. (Zonula occludens)
-The intercellular junction which prevents the leakage of material from the lumen is Zonula occludens (Tight junctions).
-The intercellular junction which holds the cells firmly together, known as Zona adherens (Anchoring junctions)
The intercellular junction, which is communicating junctions, communicates two cells together, Nexus (gap junctions).

2.

a. (Heparin Sulphate)
Ground substance which is found in arteries - Heparin sulphate
Different layers of blood vessels wall:
Tunica intima: innermost layer, made up of endothelial and subendothelial cells
Tunica media: middle layer, made up of elastic fibers
Tunica adventitia: outer most layer, composed of nerves and tiny vessels.

Note:

Outer layer of tunica intima is Internal elastic membrane.
Layer of tunica intima from inside to outside:
Endothelium
Subendothelial layer
Internal Elastic membrane

3.

d. (Z line)
I band of skeletal muscles are interconnected by Z - line.
The light band are called I band (Isotropic band) and contains only Actin containing thin filaments while the dark band are called A band (Anisotropic band), contains both Actin containing Light filaments and Myosin containing Dark filament.
At the middle of the thin filament, there is dark line, called Z lines. Distance from one Z line to another is Z -line is Sarcomere (functional unit of myofibril Shorten when muscles contracts.
H -zone contains only Myosin filaments
M -line: Line present at middle of H -zone, also the middle line of Sarcomere unit.

4.

b. (Apocrine)
On the basis of mode of release of secretion, glands are of following types:
Merocrine: Release their secretion via Exocytosis, there is no cell damage. Salivary gland
Apocrine: Top of the cells are lost along with secretions. Mammary gland
Holocrine: Whole cell burst with secretion. Sebaceous glands

5.

a. (Dog)
-Stratum compactum, a layer rich in collagen fiber seen in the stomach of Carnivores.

6.

b. (Distal convoluted tubules)
Macula Densa is a region where Distal convoluted tubules touch the glomerulus, its functions are to sense sodium chloride concentration in the filtrate and activates tubuloglomerular feedback which adjust GFR to regulate the concentration of tubular sodium and chloride.

Parts of Nephron with their functions

Renal Corpuscles: Generates glomerular filtrate composed of water, ions and small molecules
Proximal convoluted tubule: Reabsorbs sodium, Chloride, potassium, water, glucose, amino acids, bicarbonates, Calcium and Phosphates; Secretes Ammonium and Creatinine
Thin descending loop of Henle reabsorbs water
Thin ascending loop of Henle: Reabsorbs sodium and Chloride
Thick ascending loop of Henle reabsorbs Ammonium, Sodium and Chloride
-Distal Convoluted tubules: Reabsorbs Sodium and Chloride
-Collecting Duct: Reabsorbs Sodium, Chloride and Water; Secretes Ammonium, Hydrogen ions and Potassium.

7.

b. (Type -II pneumocytes); Pulmonary surfactant is secretory product of Type -II pneumocytes.
The alveolar epithelium is composed of two types of cells: Type I pneumocytes and Type II pneumocytes. Type -I cell are are squamous cell and possess centrally placed nucleus and thin cytoplasm.
The type II pneumocytes are rounded in shape and project into lumen of the alveolus. Internally the alveolar surface is covered by a thin film of surfactants, which reduces surface tension of alveoli, produced by type II pneumocytes.

8.

c. (Thyroid gland)
Parafollicular cells or C cells are found in thyroid gland, secretes Calcitonin hormones.
Chief cells and Oxyphil cells are the cells found in Parathyroid gland where chief cells secrete Parathormone hormones and oxyphil cell’s function still unknown.
Spongiocytes and Chromaffin cells are mainly found Adrenal glands, where chromaffin cells produce Catecholamines (Epinephrine and Norepinephrine).

9.

a. (Rumen): Muscularis mucosa is absent in Rumen.

Histology of Ruminal Stomach

Rumen: The wall of rumen is composed of Tunica serosa( outermost covering composed of collagen and elastic fibers, covered by simple epithelium(mesothelium)), Tunica muscularis( composed of two layer of muscles fibers: inner- Circular and outer- Longitudinal in this layer nerve plexus and ganglia are present), Tunica submucosa (lamina propria- composed of collagen, elastic fibers and reticular fibers along with plenty of blood capillaries; muscularis mucosa and glands are absent) and Tunica mucosa(epithelium lined with stratified squamous epithelium, like epidermis of skin, it presents stratum corneum, stratum granulosum, stratum spinosum and stratum Basale) lined with from outside to inside.

Note

Reticulum: Same as rumen. (Muscularis mucosa is also absent in Reticulum.
Muscularis mucosa is present in Omasum and Abomasum.

10.

a. (Prostate gland)
Corpora amylacea (starch- like bodies) is a small hyaline mass found in the prostate gland (benign prostatic acini), nervous system, lungs and sometimes in other organ of body.

11.

b. (Ovary)
-Call -Exner bodies, giving a follicle- like appearance, are small eosinophilic fluid filled punched out spaces between granulosa cells, pathognomonic for granulosa cell tumors.

12.

b. (Radius)
Brachial region: Superior to the antebrachial region, consists of the upper arms (area between the shoulder and elbow joint). Bone included: Humerus
Antebrachial region: lies between the hands and elbow of the arms. Bone Included: Radius and Ulna.

13.

b. (Stifle joint); The fabella are seen in the dog in the stifle joint.
-The fabella is a sesamoid bone that is embedded in the lateral head of the gastrocnemius muscles and often articulates directly with the lateral femoral condyle.

14.

d. (Seventh)
-C7 is the largest cervical vertebra.
while C1 and C2 are smallest cervical vertebra.

15.

a. (10-22 days)

Animal	Day of Maternal recognition of Pregnancy	Day of attachment	MOlecule Involved
Cow	16-17	18-22	Bovine Trophoblast protein (Interferon- tau)-1
Mare	14 -16	36-38	Estrogen protein
Ewe	12-13	16	Ovine trophoblast protein-1
Doe	17	-	Caprine trophoblast protein -1
Sow	12	-	-

16.

a. (1st branchial arch); Mandible is derivatives of 1st branchial or Pharyngeal arch.
-Pharyngeal arches or branchial arches are mesenchymal condensation derived from neural crest cells majorly or intraembryonic mesoderm.
Derivatives of Branchial arches/ Pharyngeal arches

Branchial or Pharyngeal arches	Nerve of Arch	Muscles of Arch	Artery
1st Arch	Mandibular nerve	Mastication muscles; mylohyoid muscles; Anterior belly of digastric;tensor tympani and tensor palatini	maxillary artery
2nd Arch	Facial nerve	muscles of facial expression;posterior belly of digastric; Stapedius	stapedial artery
3rd Arch	Glossopharyngeal nerve	stylopharyngeus	common carotid artery
4th arch	superior laryngeal branch of Vagus nerve	muscles of pharynx	Arch of aota
6th arch	Recurrent laryngeal branch of Vagus nerve	Muscles of larynx except cricothyroid	Ductus arteriosus Pulmonary artery

17.

a. (Fowl); Single Occipital Condyle is present in Fowl.
Occipital is single cranial bone of skull, form superior and posterior aspect of skull and consists of three parts: Lateral mass, Basioccipital and Supraoccipital.
Lateral mass: It comprises of condyle, foramen magnum, paramastoid process, condyloid fossa, hypoglossal foramen and condyloid foramen. Condyle- oval elongated structure- two in number, includes foramen magnum between them in cattle. Foramen Magnum gives passage to spinal cord, and these condyles articulate with atlas behind.

18.

c. (Pulmonary trunk)
Conus arteriosus (Infundibulum) is a conical pouch formed from the upper and left angle of the right ventricle in the chordate heart, from where the pulmonary trunk arises.
Develops from bulbus cordis
-Defects in the infundibulum development can results in a heart condition, known as tetralogy of Fallot.

19.

a. (Horse)
Bicipital groove is subdivided by vertical ridge in Horse.
Some facts related to Humerus:
Prominent deltoid tuberosity is found in Horse.
Bicipital groove again divided by ridge in Horse.
-Nutrient foramina is in medial surface in Horse
Radial and olecranon fossa are communicated by a large supratrochlear foramen in dog.

20.

d. (Horse and Dog)
-Sigmoid flexure is absent in Horse and Dog.
Seminal vesicles and Bulbourethral glands are absent in dog.
-External urethral opening present at tips of the glans.
Abdominal testes are present in fowl.

21.

a. (5); Number of lobes of liver in Dog - 5 (left lateral, right lateral, left central, right central and caudate)
Number of lobes of in liver of ruminants - 4 lobes (left and right hepatic lobes, quadrate and caudate lobe.
- Horse - 3 (left lobe, Right lobe and middle lobe). Gall bladder is absent in case of horse.
- Pig- 4 main lobe (right lateral, right central and left lateral and left central) and one small caudate lobe.
- Fowl- 2 lobes (left and right).
- Rabbit- 5 lobes

Note:

Blood is supplied to liver by:
a. Portal vein (80%) - Functional supply
b. Hepatic artery (20%)- Nutritional supply

22.

a. (80%)
Out of total volume, Rumen occupies 80% of the abdominal cavity. Rumen is the largest compartment of ruminal stomach, almost occupies most part of left side and a small part of right half of the abdominal cavity.

Note:

Gradual changes of size of different compartments in different ages as follows:
Newborn - (Rumen+ Reticulum) * 2 = Abomasum
8th week- (Rumen + Reticulum) = Abomasum
12th week- 1/2 (Rumen+ Reticulum) = Abomasum

23.

c.( Schindylesis)
Schindylesis: It is an articulation in which two bones are joined by fitting the ridge of one bone into the groove of another. Also known as wedge and groove joint. Ex: Junction between Vomer and Sphenoid bone.

24.

a. (4th rib)
Brachiocephalic trunk originates from the arch of aorta at the level of 4th rib.
Heart is the cone- shaped organ situated at the ventral half of the middle mediastinum with the base directed upward and apex downward. The base extends from 3rd to 6th rib and placed about 10 to 12cm below the spine.
-The weight of an adult heart is about 0.4 to 0.5% of the total body weight.

25.

c. (Cauda equina)
At termination of vertebral canal, a lashes of long nerve roots attaches to spinal cord (which are horse- tail like in appearance) and are called cauda equina.
Most distal bulbous part of spinal cord - Conus medullaris
The filum Terminale is a fibrous band that extends from the conus medullaris to the periosteum of the coccyx, functions is to fixate, stabilize and buffer the distal spinal cord from normal and abnormal cephalic and caudal traction.

26.

d. (4th ventricle)
Pons is separated dorsally from cerebellum by 4th Ventricle and ventrally from medulla oblongata by inferior pontine sulcus.
The tentorium is the fold of duramater which separates cerebellum from cerebrum.

Note:

Behind the pons, a transverse band is present, called Corpus trapezoideum
Corpus callosum, located at interjunction of two cerebral hemispheres

27.

c. (Larynx, epiglottis)
Cavum laryngis is cavity of larynx and is closed during deglutition (Swallowing) by epiglottis to prevent food to enter into respiratory tract.

Note:

Vocal box of poultry (Fowl) - Syrinx (Caudal larynx)

28.

a. (Inguinal, broad)
In bitch, inguinal canal contains in addition to external pudic vessels and nerves and broad ligament of uterus.
Inguinal canals are the two passages in the anterior abdominal walls of animals which in males, conveys the spermatic cords and in females, the round ligament of uterus.

29.

a. (Left, Ox)
‘L’ shaped Cardiac notch is present in left lungs of Ox.
Some Facts related to Lungs:
Right lung of cattle has 4 lobes: Apical, Cardiac, Diaphragmatic and Accessory and intermediate while left lung of cattle has 3 lobes - Apical, Cardiac and Diaphragmatic.
Dog's right lung has 4 lobes: Apical, Cardiac, Diaphragmatic and Accessory while left lung of dog has 2 lobes - Apical and diaphragmatic
- Pig and rabbit right lung has 4 lobes: Apical, Cardiac, Diaphragmatic and Intermediate while left lung of pig has 2 lobes: Apico cardiac and diaphragmatic
Horse right lung have 3 lobes: Cranial, caudal and accessory while left lungs has two lobes - cranial and caudal

30.

d. (All)
Ribs of fowl(poultry) has following characteristics:
They are seven pairs in number
Absence of costal cartilage
-Each rib has a dorsal and a ventral segment. 1st two ribs do not extend upto the sternum.
-Each of the dorsal segment of 2nd to 6th ribs possesses a caudal extension, known as uncinate process which support the thoracic cage in a better way by overlapping the succeeding rib.

Note

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Since, it's a part -4, for MCQ on Veterinary Anatomy (part -3): Multiple Choice Questions on Veterinary Anatomy and Histology (Part-3) - Vet Lectures (veterinarylectures.com)

For MCQ on Veterinary Anatomy (Part-5): Multiple Choice Questions on Veterinary Anatomy and Histology (Part-5) - Vet Lectures (veterinarylectures.com)