Lectrure 2: Comprehensive APSC 3064: Animal Anatomy, Physiology, and Behavior

What is APSC 3064 about?

"Comparative aspects of companion and laboratory animals: anatomy, physiology, nutrition, genetics, and reproduction."

What behaviors are covered in APSC 3064?

"Normal behaviors and techniques of behavior modification."

What are considered companion and laboratory animals in this course?

"Dogs, cats, rabbits, guinea pigs, rats, mice, birds, etc."

Why is a glossary important in anatomy/physiology?

"It ensures accurate, consistent communication when describing structures and lesions."

What do anatomical terms save?

"Time and confusion by giving a shared reference system."

What is the classification of the dog?

"Domain: Eukaryota → Kingdom: Animalia → Phylum: Chordata → Class: Mammalia → Order: Carnivora → Family: Canidae → Genus: Canis → Species: C. lupus → Subspecies: C. l. familiaris."

What is the classification of the cat?

"Domain: Eukaryota → Kingdom: Animalia → Phylum: Chordata → Class: Mammalia → Order: Carnivora → Family: Felidae → Genus: Felis → Species: F. silvestris → Subspecies: F. s. catus."

What animals are lagomorphs?

"Hares, rabbits, pikas."

What is special about lagomorph incisors?

"Two pairs in the maxilla (peg teeth) and one pair in the mandible, with unpigmented enamel."

Do lagomorphs have maxillary fenestrations?

"Yes."

Do lagomorphs have a penis bone?

"No."

What animals are rodents?

"Mice, rats, guinea pigs."

What is special about rodent incisors?

"One pair in both jaws, with pigmented enamel only on the front surface."

Do rodents have a penis bone?

"Yes, called the baculum."

How many times were dogs domesticated?

"Twice — in Asia and in Europe/Near East."

What evidence supports multiple domestications of dogs?

"Genetic divide between European dogs (Newgrange, golden retriever) and Asian dogs (Shar Pei, Tibetan village dogs)."

What is the ancestor of domestic cats?

"The African wildcat (Felis silvestris lybica)."

When were cats domesticated?

"Around 10,000 years ago with the rise of agriculture in Africa/Middle East."

What cat adapted independently in China?

"The leopard cat (Prionailurus bengalensis)."

What modern breed came from leopard cat × domestic cat?

"The Bengal."

What is the human equivalent age of a 1-year-old dog or cat?

"15 years."

What about a 2-year-old dog or cat?

"24 years."

After 5 years

how do dogs/cats age?,"About +4-5 human years per pet year."

What is anatomy?

"The study of body parts (structure)."

What is physiology?

"The study of activities of the body (function)."

What is functional anatomy?

"The study of anatomy in relation to function, integrating microscopic and gross structures with physiology."

What is comparative anatomy?

"Study of body structures across species to understand evolutionary adaptations."

What is comparative physiology?

"Study of how vital processes differ across species, showing adaptation to specific needs."

How are structure and function related?

"If structure changes, function changes."

What determines pupil size at rest?

"Balance between parasympathetic (CN III constriction) and sympathetic (dilation)."

What is miosis?

"Pupil constriction."

What is mydriasis?

"Pupil dilation."

What is the pupillary light reflex (PLR)?

"A reflex where shining a bright light in one eye causes both pupils to constrict (direct and consensual response)."

What is the dazzle reflex?

"A blink response when a bright light is suddenly flashed, mediated by CN VII."

What is the afferent pathway of PLR?

"Retina → CN II → optic chiasm → optic tract → CN III nucleus."

What is the efferent pathway of PLR?

"CN III parasympathetic nucleus → orbital fissure → ciliary ganglion → pupillary constrictor muscles."

Why does the consensual/indirect PLR occur?

"Because some CN II fibers cross at the optic chiasm and synapse at the contralateral CN III nucleus."

What does the menace response test?

"Cortically mediated eyelid closure via CN II → thalamus → occipital cortex → motor cortex → CN VII."

Which reflex checks subcortical structures?

"Pupillary light reflex."

Which reflex checks cerebral cortex?

"Menace response."

What are tissues

organs, and systems?,"Groups of cells → tissues → organs → systems (common task)."

What are the four basic tissue types?

"Epithelial, connective, muscle, nervous."

What does epithelium cover and form?

"Body surface, body cavities, glands, structures like hair, hooves, horns."

How does epithelium receive nutrients?

"By diffusion from underlying connective tissue (no direct blood supply)."

What are the main types of epithelial cell arrangements?

"Simple (1 layer), stratified (2+ layers)."

What are the shapes of epithelial cells?

"Squamous (flat), cuboidal (equal height/width), columnar (taller than wide)."

What are examples of connective tissue?

"Loose connective tissue, fat, cartilage, bone, marrow, blood."

What is Ehlers-Danlos Syndrome (cutaneous asthenia)?

"A collagen defect causing fragile, stretchy, loose skin."

What are exocrine glands?

"Secrete outside body via ducts (saliva, digestive secretions, tears)."

What are endocrine glands?

"Secrete hormones into bloodstream."

What do directional terms provide?

"A common language to describe body structures."

Name common directional pairs.

"Cranial/Caudal, Dorsal/Ventral, Medial/Lateral, Superficial/Deep, Proximal/Distal."

What is the median plane?

"Divides the body into equal left/right halves."

What is the sagittal plane?

"Divides into left/right parts, not necessarily equal."

What is the transverse plane?

"Divides into cranial/caudal parts."

What is the horizontal (dorsal) plane?

"Divides into dorsal/ventral parts."

What does the dorsal cavity contain?

"Brain (cranial), spinal cord (vertebral)."

What does the ventral cavity contain?

"Thoracic, abdominal, pelvic cavities."

What is the peritoneum?

"Serous membrane lining abdominal cavity and covering organs."

What is ascites?

"Accumulation of >25 mL fluid in peritoneal cavity (clinical correlate)."

What is transudate?

"Fluid from hydrostatic imbalance; low protein/cells."

What is exudate?

"Fluid from increased vascular permeability; high protein/cells."

What percentage of neonatal body weight is skin + coat?

"~24% (12% in adults)."

What are main skin functions?

"Protection, barrier, flexibility, temp regulation, storage, pigmentation, immune defense, vitamin D production, sensation, excretion, health indicator."

Can cats and dogs synthesize Vitamin D efficiently?

"No — they must get it from diet."

What are the three skin layers?

"Epidermis, dermis, hypodermis (subcutis)."

What are epidermal appendages?

"Hair, sweat glands, sebaceous glands."

How thick is dog epidermis vs human epidermis?

"Dogs: 3-5 cells thick; Humans: 10-15 cells."

What are the two types of dog skin glands?

"Apocrine (pheromones, sealing epidermis) and merocrine (sweat, paws only)."

How much hair do dogs and cats produce annually?

"Dogs: 60-180 g/kg BW; Cats: 30-40 g/kg BW."

What types of hairs make up the coat?

"Primary (guard hairs), secondary (undercoat), and whiskers (tactile hairs)."

Which breeds have double coats?

"Huskies, German Shepherds, Akitas, Golden Retrievers, Labradors, Pomeranians."

Which breeds have single coats?

"Poodles, Terriers, Maltese, Bichon Frise, Shih Tzus, Border Collies."

Do all dogs shed?

"Yes, but degree varies. Poodles are "non-shedding" due to long hair cycle."

How does photoperiod affect shedding?

"Short days → winter coat; long days → shedding. Indoor animals shed year-round."

What is special about cat skin?

"Loose, especially on nape; aids in temp regulation and fighting protection."

What does failure to groom indicate in cats?

"Illness or health problem."