Learning Objectives-Exam 1 Flashcards
describe the physiologic functions of the epidermis (4)
primary protection/physical barrier against microbes, chemicals, toxins, and impacts via formation of the cornified envelope. production of antimicrobial substances, and permanent shedding of corneocytes; is also the primary envelope to contain water, electrolytes, and macromolecules
describe the physiologic functions of the dermis (3)
blood supply, immune protection, anchors epidermis
describe the physiologic functions of the hypodermis/subcutis
anchors the dermis to underlying muscle and bone
describe basic anatomy of the ear and how ear canal, middle, and inner ear relate to each other
- pinna: outer shell, can palpate
- ventral canal connects pinna to horizontal canal (palpation and otoscopy)
- tympanic membrane leads to bony septum leads to inner ear (ventral to middle ear); need to sedate to look at
- middle ear leads to auditory tube
(can only evaluate inner ear and middle ear via CT and MRI)
contrast feline ear to canine ear
In felines, septum bulla (felines have not dogs) almost completely separates tympanic cavity into two compartments (ventromedial and dorsolateral) but this separation is incomplete and not as prominent in canines
describe how the ear canal, middle ear, ad inner ear relate to each other
- pinna: visible from outside and can palpate; elastic cartilage; sweat and sebaceous glands
- vertical canal: should feel pliable and not painful upon palpation
- typmanum: pars tensa, pars flaccida, manubrium of malleus
- pars tensa= thin shiny sheet on ear drum
-manubrium= give conical shape
-pars flaccida= not taut like tensa and hold up membrane - inner ear is embedded in bones, contains
-vestibular organ: semi-circular ducts, balance
-cochlea: hearing
-both above communicate with middle ear through membrane-covered windows - middle ear: boney hollow structure; holds the air-filled tympanic cavity
define the healthy ear and skin microbiome (5)
- the collection of microbes that naturally live on our bodies
- in a constant state of flux
- composition varies based on species, between individuals of the same species, and depending on body site of the same individual
- influenced by many factors
- shifts in our natural microbiome can be caused by inflammation
if a dog’s natural ear microbiome is chronically shifted, what can result?
they can have chronic otitis due to persistent inflammation; allergic dogs have a tendency to develop bacterial otitis; body responds to allergens with inflammation, making a more suitable environment for infection
what are internal impacts to the skin? (2) what can they result in?
- malnutrition
- lack of essential fatty acids
these can cause epidermal lipid deficiency/disturbance and lead to scaling and poor barrier function
what are external impacts to the skin? (3) what can they result in?
- excessive washing
- chemicals
- wet/dry environment
can weaken epidermal barrier, leading to increased scaling and increased transepidermal water loss
describe the process of keratinization (4)
- proliferation/adhesion
- production of additional keratin filaments; beginning of synthesis of lipid-containing lamellar bodies
- progressive flattening of cells, keratin filaments get progressively packed into large, insoluble polymers with the help of filaggrin
- keratinocytes are terminally differentiated, coated by lipids, separated by proteases, and constantly shed
list the phases of the hair follicle cycle (go to hair follicle brainscape and study further too!)
- anagen (growth phase)
- catagen (regression phase)
- telogen (resting phase)
- exogen + anagen
explain the basic anatomy of hooves
keratinized portion of hoof is composed of wall, sole, frog
wall: stratum externum (tubular and intertubular horn), stratum medium (tubular and intertubular horn), stratum internum (lamella), laminar corium (dermis, where primary and secondary epidermal and dermal laminae interdigitate)
sole: similar to tubular and intertubular regions of wall, but softer than wall, has white line
frog: similar to sole but underlying papillae are shorter and frog is softer than sole
contrast integument anatomy of nails, hooves, and horns across species
horses: hoof; wall, sole, frog
ruminants and swine: claws; wall, sole, bulbs (no frog); walls only have primary epidermal and dermal laminae, no secondary
carnivores: claws; wall and sole
explain basic anatomy of horns and nails
- horn is keratinized portion (hard keratin; doesn’t slough off)
- underlying dermis (corium)
- hypodermis may or may not be present; modified to form digital cushion and digital pad
- bones and associated structures of bones
Name, list, and identify the bones related to forelimb (small and large animals).
Name, list, identify, and recognize the bones that make up specific joints of the forelimb (small and large animals).
see other brainscapes for this
Define cutis and subcutis and relate to gross anatomy
cutis: superficial dermis + underlying dermis
subcutis: hypodermis (where sub Q fluids are deposited)
both are outermost layers of the skin
Distinguish between the strata of the epidermis and the layers of the dermis. Describe their interdigitation.
epidermis:
1. stratum corneum: outermost; layers of flat cornified/keratinized. cells lacking a nucleus and organelles; varies in thickness based on abrasion
2. stratum lucidum: clear layer, inconsistent and rare squamous cell layer; found only in very thick epidermal regions
3. stratum granulosum: flattened cells that contain keratohyalin granules (present in soft keratin but NOT in hard keratin)
4. stratum spinosum: prickle cell layer; thick in regions with no hair, thin in regions with hair
5. stratum basale: proliferation and attachment layer; adjacent to dermis; cell division occurs here
dermis/corium: network of collagen, elastic, reticular fibers
1. papillary layer: loose irregular CT; most superficial layers; interdigitates with s. basale via dermal papillae
2. reticular layer: dense irregular CT; deepest and thickest layer; many large bundles of collagenous fibers
Distinguish between keratinocytes and non-keratinocytes
keratinocytes: most numerous cell type of epidermis; maturation process is kertinization
non-keratinocytes: include melanocytes (produce pigment, cytocrine secretion), intraepidermal macrophages/Langerhan’s cells (dendritic cells in upper stratum spinosum), and tactile epithelioid cells/Merkel cells (sensory mechanoreceptors in basement membrane of s. basale)
Distinguish between the layers of the hair
hair is subdivided into shaft, root, and hair bulb; shaft has 3 layers
1. cuticle: outermost single layer of overlapping (shingle-like) keratinized cells
2. cortex: densely packed keratinized cells that contain pigment granules
3. medulla: center of hair, loosely arranged cuboidal or flattened cells
distinguish between the layers of the hair follicle (6)
- internal epithelial root sheath: innermost layer next to hair root/stratum corneum of hair follicle
- external epithelial root sheath: strata basale and spinosum of hair follicle
- glassy membrane: basement membrane of follicle epithelium
- dermal root sheath and dermal papilla: CT enclosure of hair follicle; root sheath continuous with papilla that projects into underside/base of bulb; made of collagen and elastic fibers, blood vessels, nerves
- hair matrix: dividing cells (s. basale) overlying dermal papilla, product the hard keratin = hair
- arrector pili muscle: smooth muscle, innervated by ANS; spans dermal root sheath of follicle and papillary layer of dermis; elevates hair and expresses sebaceous glands located between follicle and muscle mass
Distinguish between sebaceous and sudoriferous glands and know their modes of secretion/what they produce
sebaceous glands: alveolar, holocrine secretion, secrete sebum; secrete product into hair follicle or directly onto skin surface
sweat glands/sudoriferous glands: produce sudor/sweat; vary greatly in appearance and secretory product; utilize merocrine and apocrine secretion; include mammary glands, anal glands
Determine the type of cartilage that supports the pinna
elastic cartilage
Define cerumen and list the glands that contribute to its formation
cerumen: the combo of sebaceous and ceruminous gland secretions known as ear wax; ceruminous glands are simple coiled tubular apocrine sweat glands of inner surface of ear pinna and external auditory canal
what are the 3 glands of the eyelids? name the products of each
Miebomian/tarsal glands: meibum (polar and nonpolar lipids)
Zeiss: sebaceous glamds
Moll: aprocrine sweat glands
Determine why Meibomian glands are also called tarsal glands
located in the tarsal palate
Define anal sacs and relate to gross anatomy
- paired cutaneous diverticula that open into anal canal at anocutaneous junction
- ducts and sacs are lined by stratified squamous epithelium
- cats have both apocrine and sebaceous but dogs only have apocrine glands
List the basic integumentary glands that empty into the anal sacs of dogs v. cats
cats have both apocrine and sebaceous but dogs only have apocrine glands
Determine which basic integumentary gland that circumanal glands are derived from, and whether they are present in both the dog and the cat
circumanal glands are modified sebaceous glands located circumferentially around anus; frequent site of canine tumors in intact males and females; not present in felines
What type of glands are mammary glands?
modified sweat glands; compound tubuloalveolar
What type of epithelium lines mammary gland ducts?
varies from simple cuboidal epithelium in the smaller ducts to stratified cuboidal epithelium surrounded by increasing amounts of CT as ducts become progressively larger
What are the exocrine modes of secretion of mammary glands?
lipids are released via apocrine
proteins are released via merocrine
so milk is released by both apocrine and merocrine secretion
How do mammary glands respond to hormonal stimulation for milk letdown?
myoepithelial cells contract in response to oxytocin to force milk into the duct system = milk letdown
Distinguish between the different types of adult CT proper
- loose/areolar CT: always irregular; cells are fibroblasts; contain all 3 collagen fibers but type I is most visible
- dense CT: irregular and regular;
-dense irregular: cells are fibroblasts, contain all 3 fibers, but Type I most visible and large bundles than loose
-dense regular: collagenous and elastic; cells are fibroblasts; all 3 fibers; type I most visible in collagenous and elastic most dominant in elastic - reticular CT: reticular cells and their fibers concentrated to a mesh-like framework for soft organs like bone marrow, spleen, liver, endocrine glands; cells are reticular cells; fibers are reticular fibers
- adipose tissue: cells are adipocytes; fibers are a delicate network of collagen and reticular fibers
-white adipose: white fat; found throughout body and varies in abundance based on BCS; single chamber (unilocular)
-brown adipose: multi-chambered (multi-locular); less abundant; location is regional
what is embryonic CT? describe
also called mesenchyme; the CT of the developing embryo; cells are mesenchymal cells and are pluripotent; all three fibers present but are fine and not highly visible
Distinguish between the different types of cartilage
- hyaline cartilage: found in most bone-forming sites, articular surfaces, resp airways, larynx and nose; cells are chondrocytes inside lacunae which can revert back to condroblasts to divide and form cells nests; type II collagen; territorial (more basophilic) and interterritorial matrix organization (less basophilic); HAS perichondrium EXCEPT at articular surfaces (articular cartilage)
- elastic cartilage: external ear and external auditory canal, auditory tube, portions of laryngeal and epiglottic cartilages; cells are condrocytes within frequent isogenous groups; matrix is identical to hyaline but also has elastic fibers; HAS PERICHONDRIUM
- fibrocartilage/fibrous cartilage: in intervertebral discs and attachments of certain tendons and ligaments; joint menisci; pubic symphysis, plus regions of transition between fibrous CT and hyaline cartilage; cells are small chondrocytes in lacunae; matrix has type I collagen fibers in herringbone pattern; NO PERICHONDRIUM
list the growth patterns of cartilage
chondroblasts divide and synth matrix in response to hormones or bone repair; 2 types of growth
1. interstitial growth: growth within inside; chondroblasts divide and secrete matrix around and between daughter cells
2. appositional growth: growth upon outside; chondroblasts within perichondrium secrete matrix onto cartilage surface
Define intramembranous and endochondral bone formation and relate these to the formation of the diaphysis and epiphyses
intramembranous: mesenchymal cells differentiate into osteoblasts, which produce pre-bone matrix (osteoid) that becomes calcified; common method for flat bone formation (marrow space but not marrow cavity)
endochondral: mesenchymal cells differentiate into chondrocytes that form a hyaline cartilage model of future bone; cartilage model is digested and replaced with bone tissue; common method for long bone formation (have a marrow cavity);
diaphysis is primary center of ossification; like a turtle neck/bony collar at diaphysis; bone around outside cuts off cartilage inside so it dies and calcifies, sending signals for repair to bring in vessels and osteoblasts, which lay down bone and grow towards metaphysis
Understand how bone grows in width
growth in width occurs by simple appositional growth on outer bone surface as diaphyseal diameter increases and so does diameter of marrow cavity via existing bone resorption
Demonstrate an understanding of how long bones grow in length by labeling the zones of the epiphyseal cartilage
this all occurs at the epiphyseal cartilage (physis or epiphyseal plate)
1. zone of resting cartilage/reserve zone: anchors growth plate to epiphysis; cells appear inactive
2. zone of proliferation: cells arranged in rows or columns (pancakes); actively dividing chondrocytes
3. zone of hypertrophy/maturation: maturing chondrocytes are increasing in size
4. zone of calcification/ossification: cartilage “walls” around hypertrophied chondrocytes calcify; cartilage “floors and ceilings” between chondrocytes are resorbed by incoming osteoclasts, brought in by invading capillaries
Know the location of the metaphysis
the wide portion of long bones; located between diaphysis and epiphysis (where the funnel/angle of epiphysis stops)
Understand why articular cartilage of a synovial joint is not covered by a perichondrium
synovial fluid provides nutrients so do not need vascular perichondrium to bring nutrients
Label the basic components of a neuron (dendrites, cell body, nucleus, nucleolus, Nissl substance, axon hillock, and axon)
go over histo slides
what are the 2 glial cells of the PNS?
- ganglionic gliocytes (satellite cells)
- neurolemmocytes (Schwann cells)
describe ganglionic gliocytes/satellite cells of the PNS
form a protective capsule around neuron cell bodies in cranial and spinal nerve (sensory) ganglia
what are the 4 glial cells of the CNS?
- astrocytes/astroglial cells
- oligodendrocytes/oligodendroglia
- microglia
- ependymal cells
describe astrocytes (3)
- ID’d by their large euchromatic nuclei (larges of all glial cells but not as large ar interneurons!)
- located in both white and grey matter
- of their many important functions, contribute to the blood brain barrier
describe oligodendrocytes (3)
- ID’d by their round euchromatic nuclei with thick nuclear envelope (eyeliner)
- in white matter: forms myelin sheaths but myelinates multiple axons
- in grey matter: serves are a perineuronal satellite cell, providing support to nearby neurons
describe microglia (2)
- small, heterochromatic, cigar-shaped nucleus on sagittal section surrounded by scant cytoplasm
- macrophages of the CNS
describe ependymal cells
specialized neuroglial cells that line the central canal of the spinal cord and the 4 ventricles of the brain
Distinguish between the layers of the meninges
- dura mater: thick outermost dense regular to irregular CT and thick collagen bundles with elastic fibers with blood and lymphatic vessels and nerves; two laminae in the skull
- arachnoid: arachnoid membrane of fibrocytes with arachnoid trabeculae that extend and act as a framework for suarachnoid space (where CSF flows)
- pia mater: tightly adherent to surface of brain and spinal cord; highly vascular, surrounds all small vessels traveling in sulci and fissures to penetrate and supply the nervous tissue
List the components of the blood-brain barrier
- a filter that regulates the movement of molecules from blood to the brain (function)
- endothelial cells of the brain capillaries have occluding/tight junctions and continuous basement membranes, additionally surrounded by/fortified by the foot processes of the astrocytes
Distinguish between the CT layers of peripheral nerve
- endoneurium: strands of collagenous fibers and CT matrix that occupy space between individual, adjacent nerve fibers (axons)
- perineurium: CT fibers arranged chiefly longitudinally interposed between bundles of nerve fibers (fascicles)
- epineurium: thicker layers of longitudianlly arranged collagen and matrix surrounding nerve trunks (around groups of fascicles)
Distinguish between the cells of bone
osteoblasts: cover inner and outer surfaces of bone; NOT in lacunae
osteocytes: within lacunae; embedded in matrix; have cytoplasmic processes called canaliculi
osteoclasts: multinucleated giant cells (lysosomal enzymes digest organic matrix; organic acids dissolve mineralized inorganic matrix)
Distinguish between woven and lamellar bone
woven: NO HAVERSIAN SYSTEMS; cells and fibers arranged irregularly due to rapid formation; found in developing bone and fracture repair sites and will be replaced by lamellar bone
lamellar bone: HAS HAVERSIAN SYSTEMS; formed slowly by remodeling woven bone precursor; cells and fibers arranged in organized layers (lamellae); comprises most of adult skeleton
Be able to label the components of an osteon (Haversian system)
go to histology slides and be able to recognize:
1. central canal (Haversian canal): at center of osteon
2. lamellae: concentric layers of bone matrix
3. osteocytes: reside in lacuae at regular intervals between lamallae
4. lacunae: houses osteocyte
5. canaliculi: connect adjacent lacunae
6. peforating/Volkman’s canals: interconnect longitudinally arranged central canals with each other and medullary cavity of bone
7. interstitial lamellae: orphan fragments of partially degraded osteons
8. inner circumferential lamellae: arranged in circular pattern around marrow cavity; covered by endosteum and smooth inner surface of bone
9. outer circumferential lamellae: smooth outer surface of bone and covered by perichondrium
Distinguish between endomysium, perimysium, and epimysium of skeletal muscle
epimysium: dense irregular CT; the deep fascia on the surface of skeletal muscle
perimysium: CT septa surrounding muscle fascicles
endomysium: thin collagenous septa surrounding individual myofibers
Distinguish between the grey and white matter of the spinal cord
histology lab
Distinguish between myelinated, unmyelinated, and mixed nerve fascicles in tissue sections
histology labs
Label a three-neuron spinal-reflex arc and relate this to the spinal cord in transverse section
diagram from nerve lab; be able to label sensory (in dorsal root ganglion), motor (coming from ventral root), and interneurons (within ventral horn)
Distinguish between the nucleus/nucleolus and dendrite/axon hillock in a large neuron
histology labs
Distinguish between sensory and motor ganglia
sensory: unipolar
motor: multipolar
Interpret the selective distribution of ions across the neuronal axon and skeletal muscle cell membranes that are important in establishing membrane polarity
sodium: more extracellular; wants to move into cell (+1)
potassium: more intracellular; moves out of cell (+1)
chloride: more extracellular; wants to move into cell (-1)
calcium: almost none intracellular; big, wants to move into cell (+2)
unequal distribution of ions across membrane causes by selective permeability of membrane
List the major ion channels that contribute to the selective permeability of the neuronal and skeletal muscle membrane
- sodium potassium ATPase establishes concentration gradient; but too slow to contribute to real time changes in membrane potential
- leaky sodium channels: allow slow depolarization of membrane until threshold is reached
- voltage-gated sodium channels: fly open when threshold is reached; allow for action potential propagation; inactivated/blocked to allow for absolute refractory period
- potassium channels: allow for relative refractory period (harder to depolarize to threshold)
Interpret and predict differences in membrane permeability that occur at resting membrane potential, during the action potential, and membrane repolarization
resting potential: membrane leaky to sodium, slowly depolarizing to threshold
action potential: VG sodium channels fly open once threshold is reached, allowing for propagation of AP; absolute refractory period and relative refractory period by blocking sodium channels and opening potassium channels
membrane repolarization: leaky sodium channels open again
Interpret and predict the actions and interactions of calcium, myosin, troponin, and ATP during muscle contraction
- calcium binds to troponin, causing a conformational change in tropomyosin, exposing myosin head binding sites on actin
- myosin head binds to a site and ADP is released
- stored energy is released, causing myosin head to change conformation, resulting in power stroke as thin and thick filaments slide past each other
- ATP binds to myosin, causing it to release from actin
- ATP is hydrolyzed to ADP + Pi, resulting in myosin head changing conformation (re-cocking)
- if calcium is still binding troponin AND myosin head binding sites on actin are still exposed, cycle repeats
- if action potentials cease, calcium is rapidly pumped back into sarcoplasmic reticulum
how many ATP used per power stroke?
1; binds to myosin to allow myosin to release from actin
Name, list, and predict the major steps from the generation of the action potential in the motor neuron to skeletal muscle contraction.
- motor neuron transmits the action potential to the neuromuscular junction
- calcium entry voltage-gated channels open
- acetylcholine is released at the neuromuscular junction
- sodium enters cell through VG channels
- local current between depolarized end plate of axon and adjacent muscle plasma membrane is established
- muscle fiber action potential is initiated
- propagated action potential in muscle plasma membrane
- DHP receptor is voltage sensitive and activated by passing AP; has a calcium channel that allows calcium to enter the muscle cell after release from sarcoplasmic reticulum
- calcium from sarcoplasmic reticulum will bind to troponin, beginning power stroke process
Recognize that acetylcholine is the major neurotransmitter at the neuromuscular junction
major neurotransmitter at NMJ: acetylcholine
major receptor at neuromuscular junction: nicotinic receptors
Assess, deduce, infer, and interpret loss of function associated with fractures
Associate developmental abnormalities in bones to dysfunction
Name, list, and recognize radiographical planes and views
Identify bony prominences and features associated with origin and insertion of muscles, tendon, ligaments, and other structures
Assess, infer, and interpret changes in function of muscles or joints based on observed abnormalities (forelimb) (EX: fractures)
Identify and locate major points of origins and insertions of major extrinsic and intrinsic muscles of the forelimb
List, identify, and locate shoulder, brachial, and antebrachial muscles
Deduce, decipher, infer, and interpret loss of specific muscle function to loss of action (extension/flexion) of specific joints
Identify, locate, and understand the relationship between superficial and deep digital flexor tendons
Identify, locate, and describe unique tendons of forelimb and related structures for specific species – STAY apparatus (equine and bovine)
Holladay lecture 6
Identify, list, and locate major vessels of the forelimb – arteries and veins
Identify major arteries and their branches to major muscles and regions of the forelimb
Identify major forelimb nerves
Identify the cutaneous autonomous zones associated with forelimb nerves
radial nerve: dorsal arm and all digits but most lateral digit
ulnar nerve: palmar arm and most lateral digit
musculocutaneous nerve: medial arm
axillary: armpit
Assess, deduce, infer, and interpret loss of function associated with loss of innervation
Identify, locate, and assess sites of joints, ligaments, and pouches.
Compare equine with other species
Identify, locate, and assess sites of diagnostic nerve blocks in equine
Which type of cartilage lines the articular surfaces of bones that form a synovial joint?
hyaline cartilage (specifically called articular cartilage here)
Which type of cartilage looks like dense irregular CT because it is predominantly composed of type I collagen fiber bundles?
fibrocartilage
Which type of cartilage does NOT have a perichondrium?
fibrocartilage
What is NOT present in the extracellular matrix of elastic cartilage?
reticular fibers
Collagenous tendons & ligaments and elastic ligaments are classified what connective tissue (CT) proper categories?
dense regular CT
Which type of connective tissue (CT) typically has the MOST amount of ground substance?
mesenchyme (embryonic CT)
What are typically the components of the ground substance of connective tissue (CT)?
GAGs, proteoglycans, ions, metabolites, water
The tendons and ligaments that you see during your gross anatomy dissections are composed of which type of connective tissue (CT) proper?
dense regular
When you “clean” (remove connective tissue) from the surface of skeletal muscle during the gross anatomy dissection labs, you are removing a layer of CT that separates the muscle from other tissues in the area. This tissue allows the muscle to move independently. What is the name of this CT layer?
epimysium
What is true concerning the long bone of a young, growing animal?
Both the compact & cancellous bone start out as woven (immature) bone and are converted to lamellar (mature) bone.
You dissect the radial nerve in the gross anatomy lab all the way up to where it is near the vertebral column, where it is called a spinal nerve; this is BEFORE it divides into dorsal & ventral roots. What TRUE about this spinal nerve?
It is composed of BOTH motor (efferent) axons & sensory (afferent) axons.
The long head of the triceps originates from the caudal border of the scapula. Because of this it can ?
extend the shoulder joint (and flex elbow joint)
The radial nerve innervates the triceps. If the radial is nerve in a dog is damaged before it enters the triceps on the medial surface of the brachium, can this dog still bear weight on this leg?
no
A dog seems to have cut the axillary nerve completely. Do you expect this dog to still be able to flex the shoulder?
yes
Which of the following muscles that are innervated by the radial nerve and thoracodorsal nerve can help a dog flex the shoulder?
latissimus dorsi
A cat got into an accident and broke the distal end of the humerus. The radiograph taken after the accident shows that the fracture is right along the supracondylar foramen. Which of the following muscles may not work in the affected limb?
flexor carpi radialis
A horse had an accident jumping a barbed wire fence and cut its radial nerve as it exits underneath the lateral head of the triceps on the lateral distal aspect of the brachia. Which of the following will be expected in this horse?
the horse will be knuckling on the affected limb
