part 5

Anatomy

Skin

  • Dermis

    • Deeper layer of the skin (not on the surface)

    • Composed of connective tissue

  • Polood (Possibly "Blood")

  • Lymph

    • Dogs and cats have a primary hair follicle.

    • This single pore is shared by 5-20 secondary hair.

Factors Influencing Hair Growth

  • Photoperiod

  • Ambient temperature

  • Nutrition

  • Hormones

  • Genetics

  • General health

Skeletal System

  • Functions:

    • Protection

    • Support

    • Attachment sites for muscles

  • Cats:

    • 245 bones

  • Dogs:

    • 319 bones

Skull

Cats

  • Large eye sockets

  • Large eyes

  • Jaw Structure:

    • Three major types:

    • Dolichocephalic

      • Narrow skull base

      • Elongated muzzle

      • Long neck

    • Mesocephalic

      • Medium ratio of skull base width to muzzle length

    • Brachycephalic

      • Broad skull base and short muzzle

Dogs

  • Teeth:

    • 28 teeth as puppies

    • 42 teeth as adults

  • Mandible and Maxilla:

    • Cats:

    • 26 teeth as kittens

    • 30 teeth as adults

Teeth

  • Carnassial teeth:

    • Fourth upper premolar and first lower molar

    • Function for ripping and tearing food

    • Fit together like scissors

  • Loss of Baby Teeth:

    • Timeline for when they lose their baby teeth not included in transcript.

Vertebral Column

  • Regions:

    • Cervical

    • Thoracic

    • Lumbar

    • Coccygeal

  • Formula:

    • 7 cervical: 13 thoracic: 7 lumbar: 3 sacral and 0-23 coccygeal

  • Purpose:

    • Provide support

    • Provide stability

    • Provide protection

  • Sacral vertebrae fuse to form the Sacrum.

  • All vertebrae protect the spinal cord.

  • Attachment Sites:

    • Attachment site for muscles for locomotion and respiration.

  • Notable Vertebrae:

    • C1: Atlas

    • C2: Axis

  • Atlanto-occipital Joint:

    • Connects the skull to the spine.

Forelimb

  • Bones:

    • Scapula

    • Humerus

    • Radius / Ulna

    • Carpus

    • Metacarpals

    • Phalanges (P1, P2, P3)

    • P3 produces the claw.

Hindlimb

  • Bones:

    • Pelvis

    • Sacrum, ilium, pubis, and acetabular bones

    • Femur and acetabular articulation creates the ball-and-socket joint.

    • Note: Often abnormal in dogs with hip deformities.

    • Other Bones:

    • Tibia

    • Fibula

    • Tarsus

    • Metatarsals

    • Phalanges

  • Joints:

    • The joint between the lower femur and tibia is the stifle (knee).

Hind Limb Details

  • Patella (Knee Cap):

    • Embedded in tendons and ligaments.

  • Phalanges in Cats:

    • 5 on front

    • 4 on back

    • Polydactyly (more than five) is inherited and dominant.

  • Functions of Claws:

    • Necessary for traction, digging, climbing, and hunting.

    • Ligament from P2 to P3:

    • At rest, the claw is sheathed in the skin.

    • When extended, the ligament is rigid and unsheathes the claw.

  • Phalanges in Dogs:

    • 4 functional digits on each foot and a dewclaw.

    • Many breeds do not have dewclaws on the hind legs.

    • Many breeds recommend that dewclaws be removed as close to birth as possible.

    • Dogs need claws for traction and digging.

Muscular System

  • Functions:

    • Muscles contribute to the outward appearance of the animal.

    • Essential for movement, circulation, posture, digestion, breathing, and many other functions.