Quick Review on Veterinary Anatomy

Vetnepal Review Note 2019-03-15

TERMINOLOGY

Acetabulum is present in pelvic girdle
Aponeurosis is fusion of muscle with muscle (May with bone sometimes)
Appendicular means bone of limbs
Axial skeleton means Bones of skull, vertiveral column, and ribs and sternum
Bulbus glandis is present in the penis of dog
Caudal indicates the structure being described is closer to the tail
Clavicle is absent in cattle and horse
Coccygeal vertebrae in the rabbit are very small.
Coracoid bone is found in fowl.
Cotyloid cavity is present in pelvic girdle
Cranial means the structure is closer to the head of the animal.
Dorsal means the structure is closer to the top side (back) of the animal.
Furculum known as fowl clavicle
Furculum: clavical of fowl
Glenoid cavity present in scapula
humerus is hollow in fowl
Ilium is the largest of the three. It articulates with the sacrum.
Ischium is the most posterior and forms the posterior part of the floor of the pelvis.
Lateral indicates the structure is farther away from the midline.
Male cat has an os penis
Maxilla the largest bone in the facial group
Medial means the structure is closer to the midline of the limb, trunk, or head.
Navicular bone is a small bone at the back of the last joint
Olecranon process is proximal end of the ulna
Ovulation bursa is present in the ovaries of bitch
Ovulation fossa is present in ovaries of mare.
Pubis is the smallest of the three bones and forms the anterior floor of the pelvis.
pygostyle is present in fowl
Pygostyle last few caudal vertebra fuses to form a pointed projection.
Rostral means the structure is closer to the nose, and caudal means the structure is closer to the back of the head.
Sigmoid flexure is absent in penis of horse and dog.
Spongy bones is also known as cancellous bone
Tendon link bone with muscle
Ventral means the structure is closer to the bottom side (belly) of the animal
Volkman’s canal is also found in the compact bone
The patella is the knee cap. It is found in the hind limb at the knee joint
Dermis; the physically tough/strong component of skin.
Tendon; attaches muscle to bone (called aponeurosis when sheet-like)
Ligament; attaches bone to bone
Fascia; collagenous fibrous tissue that hold the body together
Superficial fascia: subcutaneous tissue between skin & muscles/bone
Epimysium: fascia covering the surface of a muscle
Perimysium: around muscle fascicles
Endomysium: within muscle fascicles
Cytology: the branch of biology that studies the structure, function, multiplication, and life history of cells.
Histology: the study, esp. the microscopic study, of the tissues of an animal.

ANATOMY OF MALE AMD FEMALE REPRODUCTIVE ORGANS

Male Reproductive Organs: Male reproductive tract=Primary + Secondary + Accessory sex organs

Primary sex organs – 2 testes
Secondary sex organs – Epididymis, vasa differentia, penis, Scrotum etc
Accessory sex organs: Prostate gland (1), Seminal vesicles (2), Bulbo-urethral gland (2)

Scrotum: It is the pendulous bag-like sac or pouch holding the testes.
Testes: They are round or oval in shape (average size is 5 x 3 x 3 cubic inches). Right one is slightly larger and is little more active than the left one. Wall of the seminiferous tubules consists of 2 types of cells;
Epididymis (Pairs): It is constituted of three parts – Head (Caput), body (Corpus) and tail (Cauda). It may be (33-35) m/110-118 feet long and longer in boar. Functions: Transportation: (7-9 days), Concentration: (mostly caput), Maturation: (Corpus), Storage: (in tail)
Vas deferens (Pairs): It consists of two parts- duct and ampulla. It is mainly meant for the transportation of sperm cells and is responsible for the active contraction of the muscle during copulation and involves Ejaculation.
Penis: It is the male organ of copulation. In bull 3 feet long and 1 inch diameter. Sigmoid flexure (Bull & Boar) is the S shaped curving of the penis between the legs that shortens the length during relaxation.
Seminal vesicles/Vesicular glands: (2): It is also the produce of fructose - a source of energy for the sperm cells.
Prostate glands: (1): It secretes the accessory fluid to clean and lubricate the urethra during pre-copulation period.
Bulbourethral glands: It is also known as the Cowper's glands It clean and lubricate the urethra in the preparation to the process of ejaculation.
Prepuce: It is the sheath that surrounds the glans penis as the invagination of the skin

Germ cell: Produce spermatozoa -Semen (Spermatozoa + seminal fluid)
Sertoli cells: Called mother sperm cell & produce sperm head

Female Reproductive System

Ovaries (Pairs): Its average size is 1.25 x 0.75 x 1.5 cubic inches. Right one is slightly larger and is little more active than the left one. In each ovary there are as much as 75,000 follicles
Oviduct/fallopian tube/ovarian tube: This is zigzag tube and they are suspended in the broad ligament. Their size is 4.0 inches in length (20-25) cm. Ovarian end is called infundibulum
Uterus: The total length of the uterus is 15 inches, the body being 2 inches and the remaining is the length of each horn. The diameter of the horn on an average is 1 inch. It works as the incubator for the fertilized ovum and also supplies the nutrients (Uterine milk) to the embryo. Non-pregnant uterus is in pelvic cavity and pregnant is in abdominal cavity
Cervix: On an average, it is 4 inches long and 1 inch diameter
Vagina: Its size is 8 inches long and the average diameter 2 inches.
Vulva: These are two in number and called as the outer lips of the libia of the urogenital system.

JOINTS

Immovable once the animal has reached maturity i.e. bones of the skull and the midline joint of the pelvic girdle.
Slightly moveable like the joints between the vertebrae but most joints allow free movement and have a typical structure with a fluid filled cavity this kind of joint is called a synovial joint
Ligaments The joint is held together by bundles of white fibrous tissue
Cartilage a fibrous that also reduces friction and some joints, e.g. the knee
Gliding movement e.g. between the ankle and wrist bones
Hinge joints the joints at the elbow, knee and fingers
Pivots the axis vertebra on the atlas vertebra
Ball and socket joints, like those at the shoulder and hip, allow the greatest range of movement

CLASSIFICATION OF JOINTS

Fibrous joints - immobile joints: Three types are recognized:

Suture: bones of the skull
Gomphosis: tooth in an alveolus,
Syndesmosis: bones joined by ligaments, e.g., [radius & ulna] and [tibia & fibula]

Cartilaginous joints - immobile joints, united by cartilage, ossify with age. Two types are recognized:

Symphysis: (grow together) e.g. pelvic symphysis; mandibular symphysis; (also, intervertebral disk)
Synchondrosis = hyaline cartilage union, e.g. physis

Synovial joints: Two types are recognized:

Simple joint = formed by two bones, e.g., shoulder joint
Compound joint = formed by more than two bones, e.g. elbow joint, carpal joint

Joints located

The stifle joint: between the femur and the tibia on the hind limb.
The elbow joint: between the humerus, radius and ulna on the forelimb.
The hock joint: between the tarsals and metatarsals on the hind limb.
The hip joint: between the pelvis and the femur.

COMMON Names of Joints

The joint between the femur and the tibia on the hind leg is our knee but the stifle in animals.
Our ankle joint (between the tarsal’s and metatarsals) is the hock in animals
Our knuckle joint (between the metacarpals or metatarsals and the phalanges) is the fetlock in the horse.
The “knee” on the horse is equivalent to our wrist (i.e. on the front limb between the radius and metacarpals)

JOINTS OF FORE LIMB

Shoulder: Scapula and Humerus- Ball and socket joint
Elbow: Humerus and Radius and ulna - Hinge joint
Carpal (Knee): Radius- ulna, carpal and metacarpal - Hinge joint
Fetlock: Metacarpal and 1st phalanx - Hinge joint
Pastern: 1st phalanx and 2nd phalanx -Hinge joint
Coffin: 2nd phalanx and 3rd phalanx - Hinge joint

JOINTS OF HIND LIMB

Hip: Hip bone and femur - Ball and socket/ spheroid joint
Stifle: Femur and tibia - Gliding
Hock: Tibia, tarsal and metatarsal - Gliding
Fetlock: Metatarsal and 1st phalanx - Hinge (movement in one plane)
Pastern: 1st phalanx and 2nd phalanx - Hinge
Coffin: 2nd phalanx and 3 rd phalanx - Hinge

Bone in Body

Vertebrae support the body and protect the spinal cord.
Cervical vertebrae in the neck,
Thoracic vertebrae in the chest region which articulate with the ribs,
Lumbar vertebrae in the loin region,
Sacral vertebrae fused to the pelvis to form the sacrum and tail or coccygeal vertebrae
Skull protects the brain and sense organs.
Cranium forms a solid box enclosing the brain.
Mandible forms the lower jaw
Forelimb consists of the humerus, radius, ulna, carpals, metacarpals and phalanges. It moves against or articulates with the scapula at the shoulder joint
Hind limb consists of the femur, patella, tibia, fibula, tarsals, metatarsals and digits. It moves against or articulates with the pelvis at the hip joint.
Bones articulate against each other at joints
Compact bones in the shaft of long bones give them their strength.
Spongy bone at the ends reduces weight. Bone growth occurs at the growth plate
Periosteum: outer surface of bone covered by membrane

BONES CATEGORIES

Long bones like the femur, radius and finger bones
Short bones like the ones of the wrist and ankle
Irregular bones like the vertebrae
Flat bones like the shoulder blade and bones of the skull
Pneumatic bones like Humerus of fowl
Keel bone: sternum of fowl
Sesamoid bones which include bones like the patella or kneecap that develop in tendons
Visceral bones that develop in the soft tissue of the Os penis of the dog and the cow’s Os cordis, Os opticus in fowl, Os rostrale in pigs.
Heterotopic bones — os penis [dog], os cardis [cattle]

Types of bone cell: @ Mature cells: Ostseocytes, @ Immature cells: Osteoblasts, Osteoclasts.

Movement

Abduction: the moving of a part away from the median plane.
Adduction: the moving of a part toward the median plane.
Extension: the lengthening of a part by increasing the angle between bones, straightening the limb, digit, or spine.
Flexion: the movement of one bone on another so that the angle between them is reduced.
Pronation: medial rotation so that the palmar or plantar surface of the paw faces ventrally.
Rotation: the movement of a part around its long axis (action of the radius when using a screwdriver).
Supination: lateral rotation of the paw so that the palmer or plantar surface faces medially or dorsally.

PLANES OF THE BODY

Median plane: Divides the head, body, or limb longitudinally into equal right and left halves.
Sagittal plane: Passes through the head, body, or limb parallel to the median plane.
Transverse plane: Cut across the head, body, or limb at a right angle to its long axis, or across the long axis of an organ or a part.
Ventral: Lie towards the belly or the corresponding surface of the head and tail.
Cranial: Lie towards the head.
Rostral: Towards the muzzle.
Lateral: Lie towards the side of the animal.
Proximal: Structures that lie toward junction with the body
Distal: Structures that lie at a greater distance from the junction
Palmar: (Palm of the hand) in the fore limb
Plantar: (Sole of the foot) in the hind limb

STUDY OF SYSTEM

Bone/Joint - Osteology, Muscles - Myology, Visceral organs of different system - Splanchnology, Heart and Blood vessels - Angelology, Nervous system - Neurology, Organs of special senses - Anesthesiology

VERTEBRAL Formula -Cervical-Thoracic-Lumber-Sacrum-Coccygeal

Cattle = C7T13L6S5C015-25, •Dog = C7T13L6S3C018-22
Pig = C7T15L7S3C018-26, •Horse = C7T18L7S4C016-25
Sheep/Goat = C7T18L6-7S4C016-18, •Fowl = C14T7(L+S)14C04-9

The second cervical vertebrae are known as Axis.· The first cervical vertebrae are known as Atlas.

NUMBER OF BONES FOUND IN SKELETON

Animals	Skull	Vertebra	Ribs and sternum	Fore limb	Hind limb	Visceral bone	total
Cattle	32	51	26+1	24*2	24*2	2	208
Horse	32	51	36+1	20*2	20*2	-	200
Dog	32	51	26+1+1	45*2	45*2	1	291
Pig	30	52	28-30+1	40*2	40*2	1	274
Rabbit	34	46	24-26+1+2	31*2	29*2	-	229
Fowl	40	41	14+1+1	13*2	21*2	2	167

CRANIAL NERVES

I = Olfactory = Sensory
II = Optic - Sensory
III = Oculomotor - Motor
IV = Trochlear - Motor
V = Trigeminal - Motor
VI = Abducent -Motor
VII = Facial - Mixed
VIII = Vestibulo-cochlear - Sensory
IX = Glossopharyngeal - Mixed
X = Vagus - Mixed
XI = Accessory - Motor
XII = Hypoglossal - Motor

DENTAL formula of common Animals

Cattle: Deciduous (Temporary) Teeth, Calves have a total of 20 deciduous teeth.

There are no deciduous molars and deciduous premolar 1 is not present.

The dental formula for the deciduous teeth follows:

Incisors (I),Canine teeth (C)
Premolars (P) ‘Molars (M)

Deciduous teeth: 2(Di 0/4, Dc 0/0, Dp 3/3) = 20 deciduous teeth

MUSCLE

There are three types of muscle:

Skeletal muscle or "voluntary muscle" is anchored by tendons (or by aponeuroses at a few places) to bone and is used to effect skeletal movement such as locomotion and in maintaining posture.
Smooth muscle or "involuntary muscle" is found within the walls of organs and structures such as the esophagus, stomach, intestines, bronchi, uterus, urethra, bladder, blood vessels, and the arrector pili in the skin (in which it controls erection of body hair). Unlike skeletal muscle, smooth muscle is not under conscious control.
Cardiac muscle is also an "involuntary muscle" but is more akin in structure to skeletal muscle, and is found only in the heart.

Tongue = striated muscle; covered by mucosa, featuring papillae & taste buds

TYPES OF PAPILLAE

Fungiform, vallate, & foliate — have taste buds
Filliform, conical — are mechanical (cat tongue has spines)

MUSCLES OF TONGUE

Intrinsic — forms tongue proper (curls, groove, bend, etc. the tongue)
Extrinsic — move tongue relative to bone:
Genioglossus — protracts tongue
Hyoglossus — retracts tongue
Styloglossus —retracts tongue
Lyssa = cylindrical fibrous tissue enveloping fat & muscle

SALIVERY GLANDS: Saliva moistens food to facilitate swallowing & contains amylase (not in carnivore or cattle)

Parotid — duct goes to upper buccal vestibule.
Zygomatic [carnivores] — ducts go to upper buccal vestibule.
Mandibular — duct goes to sublingual caruncle
Sublingual: — duct goes to sublingual caruncle
Polystomatic gland — multiple ducts into oral cavity proper
Buccal — prominent in the cat, caudal to last lower molar
Diffuse glandular tissue in cheeks, lips, tongue, & soft palate

The tooth related terms with their descriptions

Enamel- Hardest substance in the body; covers the tooth
Dentine- Found under the enamel of the tooth
Incisors- Chisel-shaped teeth at the front of the mouth
Dental formula- The way in which the number of the different kinds of teeth of mammals can be expressed
Diastema- A space in the mouth of rodents and herbivores where the canines would normally be
Open rooted- These teeth keep growing through the life of the animal. (E.g. in rodents).
Premolars and molars- These teeth are used for grinding food
Canines- Long cone shaped teeth, well developed in carnivores, form tusks in male pigs (boars)
Carnassial teeth- These teeth are found in carnivores. They are formed from premolars and molars and are used for shearing flesh

The ratio of the length of small intestine to large intestine is about 4:1

SHAPE OF SPLEEN OF DIFFERENT ANIMALS:- Ox: Elongated oval shaped, Sheep: Oyster-shaped, Pig: Elongated tongue shaped, Horse: Flat and sickle shaped

SHAPE OF THE KIDDNEY:- Cattle: Lobulated, Horse: Heart shaped, Pig: Bean shaped, Sheep/goat: Bean shaped, Chicken: Lobulated