Block 2 Flashcards
Fascia of fibrous connective tissue that surrounds entire muscle
Epimysium
Small bundle or cluster of muscle fibers
Fascicle
Connective tissue extensions from the epimysium that surround each fascicle
Perimysium
Connective tissue extensions from the perimysium that surround the muscle fibers and are attached to the sarcolemma
Endomysium
Composed of linear series of repeating sarcomeres
Myofibril
Responsible for muscle contraction. Composed of thick and thin filaments
Myofilaments
Thin cell membrane, enclosing a skeletal muscle fiber cell
Sarcolemma
What is a special feature of the sarcolemma?
Invaginates into the sarcoplasm of the muscle cell, forming T-tubules
What is a muscle fiber made up of?
Bundle of myofibril, sarcomere and type 1 and 2 fibers
What are the type 1 fibers?
Red
What are the type 2 fibers?
White
What is the basic contractile unit of striated muscle fibers?
Sarcomere
Where are the sarcomere found?
Between the Z lines
What gives muscles the striated pattern?
Sarcomere
What are the components of thin filaments?
Actin, Troponin complex, Tropomyosin
What are the components of thick filaments?
Myosin (multiple molecules of myosin make up the thick filament)
Describe the structure of Myosin
Tail of intertwined helices and 2 globular heads
What is the role of the globular heads of Myosin?
To bind ATP and actin
What functions as an ATPase enzyme?
Myosin
Appx. 500 myosin heads of thick myosin filament form what?
Cross bridges
Myosin heads of thick filament form cross bridges that interact with actin to do what?
Shorten the sarcomere
What are the subunits of Troponin?
TnC, TnI, TnT
What provides myofibrils with large amounts of energy allowing for muscle contraction?
Mitochondria
What fibers have more numbers of mitochondria?
Slow twitch (red)
What organelle is responsible for regulating calcium storage, release and uptake?
Sarcoplasmic Reticulum
What organelle allows for rapid transfer of action potentials to the interior fiber?
T-Tubules
T-tubules play an important role in what?
Regulating cellular calcium concentration
What are the smallest functional units of a muscle?
Sarcomere
What two proteins are found in the sarcomere?
Myosin and actin
What must happen before muscle contraction begins?
Myosin heads bind with ATP
What fibers are found to have higher numbers of mitochondria?
Slow-Twitch (red)
What fibers are found to have larger sarcoplasmic reticulum?
Fast Contracting (White)
What initiates muscle action?
Nerve impulse
When an action potential occurs, what is released?
Stored Calcium ions
What actions allow the myosin head to bind to active sites on the actin filament?
When Calcium binds with troponin, the tropomyosin molecules are lifted off the active sites of the actin filament, allowing the myosin head to bind.
What provides energy for muscle action?
When the myosin head binds to ATP- ATPase on the myosin head splits the ATP into a usable energy source
What happens when myosin binds with actin?
The myosin head tilts and pulls the actin filament so they slide across each other. This results in muscle contraction.
When does muscle action end?
When calcium is pumped out of the sarcoplasm to the SR for storage.
What are type 1 (Red) muscle fibers?
Type 1 fibers have high aerobic endurance and are suited to low-intensity endurance activities
What are type 2 (White) muscle fibers?
Type 2 fibers are better for anaerobic or explosive exercises.
What muscle fibers are found to be rich in mitochondria?
Type 1
A muscle that has slow contractile speed allowing for slow prolonged activity would have what type fibers?
Type 1 (Red)
What fibers are mixed oxidative-glycolytic fibers?
Type IIa
These muscle fibers have moderate aerobic capacity and fatigue resistance
Type IIa
What are the features of Type IIa muscle fibers?
Moderate aerobic/oxidative capacity
Moderate fatigue resistance
Fast contractile speed
Highly developed SR
Mixed oxidative-glycolytic fiber
What fibers are glyolytic fibers?
Type IIb
Which of the following is/are NOT a feature of Type IIb fibers?
High anaerobic/glycolytic capacity
High motor unit strength
Fast contractile speed
Highly developed SR
Slow contractile speed
High Fatigue resistance
Slow contractile speed and high fatigue resistance are NOT features of type II b
What class of muscles are responsible for movement?
Agonists
What prevents overstretching of agonist mucsles?
Antagonist
What assists the agonists and fine tunes direction of movement?
Synergists
What happens in concentric muscle action?
The muscle shortens
What happens in static muscle action?
The muscle length is unchanged
What happens in eccentric muscle action?
The muscle lengthens
What are the “stem cells” located in skeletal muscles?
Satellite cells
What are the cells involved in muscle growth and repair?
Satellite cells
What cells become activated when a muscle is injured?
Satellite cells
What is formed when satellite cells are activated after muscle injury?
New muscle fibers or myofibers
What is the primary function of Myostatin?
Regulate muscle growth and development
What is inhibited with myostatin?
It inhibits the proliferation and differentiation of muscle cells
Myostatin is produced and secreted by what cells?
Skeletal muscle cells
Where does smooth muscle receive its nerve signals from?
Autonomic nervous system (sympathetic and parasympathetic)
Smooth muscle can be divided into what two categories?
Single Unit (visceral)
Multi-Unit
Where is Single Unit smooth muscle typically found?
GI tract, bile duct, ureters, uterus, many blood vessels
Where is Multi Unit smooth muscle typically found?
Ciliary and iris muscles of the eye, base of hair follicles, smaller airways to lungs, walls of large blood vessels
In what type of smooth muscle does each fiber contract independently?
Multi-Unit
In what type of smooth muscle do the fibers work together as one unit?
Single Unit
What type of smooth muscle would you find where very small, fine movements are needed?
Multi Unit
Although smooth muscle contains thick and thin filaments, what do they NOT contain?
Myofibrils or sarcomere
What are the actin filaments of smooth muscle attached to?
Dense bodies (analogous to the Z-discs of striated muscle)
What configuration allows myosin to pull actin filament in opposite directions, in smooth muscle?
Side-polar cross-bridges
One side bend in one direction and the other side bends in the opposite (Think Chinese finger trap! When you pull in opposite directions it “flattens out”/pulls tight)
Once smooth muscle is initiated, low energy is needed to keep the tonic contraction, which can last for hours or even days. What is an example of this?
Maintaining blood pressures
What is different about the SR in smooth muscle compared to skeletal?
It is only slightly developed
What is the major source of Ca2+ for smooth muscle contraction?
Extra cellular fluid
What is not present in all smooth muscle fibers, but when it is, is found near the cell membrane?
Sarcoplasmic Reticulum
What feature is believed to excite calcium release from the SR in smooth muscle?
Caveolae
What structure in smooth muscle is similar to that of T-tubes from skeletal muscle?
Caveolae
If the SR is more extensive in smooth muscle, what is the result?
More rapid contractions
What do smooth muscles use Calmodulin for?
As a calcium binding protein to regulate contraction process (rather than troponin as in skeletal muscle)
What is the result of activated calmodulin?
It activates enzyme MLCK which phosphorylates specific regions of Myosin
What happens to phosphorylated myosin?
It binds to actin, forming a cross-bridge allowing muscles to contract
What happens when the ion calcium concentration is reduced?
Myosin phosphatase removes the phosphate from the myosin light chain, causing muscle relaxation
Found in the cytoplasm, Dense bodies serve as what?
Anchoring points for actin filament
The arrangement of actin, myosin and dense bodies allow for what in smooth muscle?
Coordinated contraction and relaxation of the muscle
What cells make up the myocardium?
Cardiomyocytes or cardiocytes
Cardiac muscle contains a less developed….
Sarcoplasmic reticulum
What are the similarities between cardiac and skeletal muscle?
Fibers are striated
Myofibrils are made up of actin and myosin
Similar organization of sarcomere
T-tubes also release calcium
What are some differences in cardiac muscle compared to skeletal?
Cardiac muscles:
Contraction is involuntary
Fibers are shorter and branched
Usually uninucleated
Interconnected by intercalated discs
Generate their own action potential (pacemaker fibers)
Cardiac action potential is NOT initiated by nervous activity, instead, it is generated by what?
Pacemaker cells
Pacemaker cells have what kind of action potential?
Automatic
Where are pacemaker cells found?
Sinoatrial node of right atrium
Cardiac muscle is a function synctium. What does this mean?
It means the cells function together; they are electrically connected to each other through intercalated discs
Cardiac muscle fibers remain separated as distinct cells with their respective sarcolemma. So how are they connected?
Via intercalated discs
What muscle has single multinucleated fibers during embryonic development?
Skeletal muscle (morphological syncytium)
Dark, dense cross-band found in the end of each myocardial disc
Intercalated disc
What structure is continuous with the sarcolemma and contains important cell-cell junctions
Intercalated discs
What cell-cell junction provides mechanical strength and stability?
Desmosome
What are the functions of the gap junction?
Allow diffusion of ions and to allow action potential to travel easily from one cell to the next
What accounts for the striations in cardiac muscle?
Organized arrangement of actin and myosin filaments
Smooth muscles differ from skeletal and cardiac muscles in that they lack what?
Smooth muscle lacks myofibrils
What is the role of tropomyosin in skeletal muscle contraction?
It covers the binding sites on actin, preventing myosin binding
What is the role of calcium ions in skeletal muscle contraction?
Binding to troponin, allowing actin-myosin interaction
How do T-tubules contribute to the excitation contraction coupling process in skeletal muscle cells?
By transmitting action potentials
Which connective tissue layer surrounds the entire skeletal muscle, enclosing all the muscle fascicles?
Epimysium
Four cell layers that make up the epidermis
- Stratum corneum
- Stratum granulosum
- Stratum spinosum
- Stratum basale
What layer of skin contains layers of keratinocytes and dead cells still connected by desmosomes?
Stratum corneum
What layer of skin has high keratin content and is where flattening of the cells occurs?
Stratum granulosum
In this layer of skin, cells are joined by desmosomes providing mechanical strength.
Stratum spinosum
What layer of skin contains the stem cells?
Stratum basale
In what layer do we find dendritic cells?
Stratum spinosum
In what layer do we find melanocytes?
Stratum basale
Where would we see a thicker, more prominent stratum corneum?
Hairless, thick skin (ie. pawpads)
What are the 4 cells of the epidermis?
- Keratinocytes
- Melanocytes
- Langerhans Cells
- Merkel’s cells
What are the most prominent cells in the epidermis?
Keratinocytes
What are the 3 functions of keratinocytes?
- Produce keratin- major structural protein for epidermis
- Contribute to formation of the epidermal water barrier
- Makes up majority of structure of the skin, hair and nails
In what skin layer does cell division occur?
Basal layer (stratum basale)
What are the intermediate keratin filaments?
Tonofilaments
What layers of skin does tonofilament synthesis occur?
Stratum basale and stratum spinosum
Extended response/Concept
Explain Keratin synthesis and the formation of the epidermal water barrier.
- Cell division occurs in the stratum basale where cells begin to synthesize tonofilaments. (intermediate keratin filaments)
*Cells are then pushed to the stratum spinosum where tonofilament synthesis continues and cells begin to produce keratohyalin granules which help convert granular cells to cornified (keratinization) and lamellar bodies. - Cells are pushed into the stratum granulosum and continue to stratum corneum.
*Lamellar bodies are discharged by exocytosis into spaces between the SG and SC.
*Lamellar bodies and the lipid envelope create an epidermal water barrier.
Where does synthesis of melanocytes begin?
It begins in the premelanosomes from the amino acid Tryosine
What skin type will see faster lysosome degradation?
Light skin
What are the two forms of melanin pigments?
Eumelanin -> brownish black
Pheomelanin -> Reddish yellow
Why does exposure to UV light accelerate the rate of melanin production?
As a way to protect the skin
Where we do find Langerhans cells?
Stratum spinosum
Who are the first line defenders, also playing a role in antigen presentation?
Langerhans Cells
What cells are antigen presenting cells?
Dendritic cells
Where are Merkel’s cells found?
Stratum basale
Where are Merkel’s cells most abundant?
Where sensor perception is acute, such as fingertips
What are the cells of the dermis?
- Fibroblasts (primary cells)
- Macrophages
- Leukocytes
- Mast cells
Strong and flexible connective tissue composed by cells and collagen fibers
Dermis
Tissues derived from the epidermis extend into the dermis and give rise to what?
Sweat glands, sebaceous glands, papillae from hair and feathers
What nerve endings are found only in hairless skin?
Meissner (touch receptors)
What nerve endings have deep pressure receptors for mechanical and vibratory pressure?
Pacini
What nerve endings are only found in haired skin?
Hair follicle sensor (tactile hairs)
What nerve endings respond to mechanical displacement of adjacent collagen fibers?
Ruffini
Cells in what layer would produce new hair follicles in the invent of skin injury?
Stratum basale
Hair follicles are formed by invaginations of what layers?
The epidermis and dermis
What region of the hair bulb produces new daughter cells that are pushed towards the surface?
The matrix
Single layer of dead, scale-like keratinocytes
Cuticle
Several layers of dead keratinocytes containing hard keratin
Cortex
Dead loosely keratinized cells
Medulla
Smooth muscle associated to the hair bulb and anchored to the outer layer of the dermis. (Sympathetic innervated)
Piloerector muscle
Hair follicles have cycles of activity… List them in order and what they are associated with.
Anagen (growth) to Catagen (regression) to Telogen (resting) to Exogen (shedding)
What are the two types of feathers?
Flight
Covert (down)
What is the flat part of the feather?
Vane
What does the vane consist of?
Barbs that are at angles of 45 degrees
Hooklets are present where?
Only on the barbules of one side of the barb on feathers
The barbules of down feathers lack what?
Hooklets
Feathers from the same feather follicle can have what?
Different pigmentation
What are the glands of the skin?
Sebaceous glands
Sweat glands
Mammary glands
This duct opens into a hair follicle and/or pore on the skin surface
Sebaceous gland
What is the composition of sebaceous glands?
Detached, degraded epithelial cells as well as lipids and proteins
What is the function of sebaceous glands?
Lubrication of skin, water impermeability, inhibition of bacterial growth
There are no sebaceous glands associated with feathers. _________ glands in waterfowl are used for preening/water proofing feathers.
Uropygial glands
What are the two types of sweat glands?
Eccrine and Apocrine
What sweat glands are common in primates?
Eccrine glands
Where do eccrine glands open?
In the pores at the skin surface
Where are Na+ and Cl- reabsorbed in skin?
Eccrine glands
What glands are common in domestic animals?
Apocrine
Where do apocrine glands open?
Into the hair follicle
Odoriferous secretion composed of fatty acids and protein come from what glands?
Apocrine
What are the milk producing units?
Alveoli (acini)
What are clusters of alveoli?
Lobuli
What are clusters of Lobuli?
Lobi
What cells are involved in milk ejection?
Myoepithelial cells
Nutrient and water required for milk production diffuse from ________ ___________ and enter into the __________ ______
blood capillaries, epithelial cells
What are examples of cornified epidermal structures?
Hooves, claws, horns, claws, beaks, shells, scales
Horny hoof wall is formed by what?
Keratinization of the cells in the coronary band, recently produced horn is pushed downward as new horn is being formed.
At the coronary band, the _____ of the skin is continuous with the _____ of the hoof.
Dermis, Dermis
What hairs provide the smooth appearance, lie close against skin, and promote rain runoff?
Guard hairs
How do guard hairs develop?
The follicle develops from an ectodermal bud, the distal end of the bud forms a bulbous enlargement indented by mesenchymal papillar to form primitive hair follicle.
Long tail hairs of cattle
Fetlock tufts of horses
Feather of tail and limbs of certain breeds of dogs
These are examples of what?
Guard hairs
What hairs provide the soft undercoat?
Wool hairs
These hairs are shorter, more numerous than guard hairs and are concealed between the guard hair
Wool hairs
These hairs are substantially thicker and generally protrude beyond the neighboring guard hairs
Tactile hair
These hairs can reach deep into the SQ or even superficial muscles
Tactile hair
These hairs are characterized by the presence of venous sinus filled with blood and located between inner and outer layers of dermal sheath
Tactile hairs
Follicles of these types of hair appear early in development, before those of the coat hairs.
Tactile hairs
Structure that has thick epidermal covering, dermis, and SQ cushion or pulvinus
Torus/Tori (foot pad)
What is the difference between digitigrade and plantigrade?
Digitigrade - such as dogs- don’t walk on the “soles” of their feet as much as their “digits”
Plantigrade - such as bears - put their weight mainly on the sole of their foot.
Ruminants and pigs have a digital pad called what?
Bulb- located in the hoof
Horses have digital pads called what?
Frog- located in the hoof
What are the three parts of the horse hoof?
Wall, Sole and associated pad (horny structure; corresponds with digital bulb or digital pad)
Strongly curved portion of the equine hoof that has sides that are sharply inflected to form bars
The wall
Space between the bars of an equine hoof
The frog
The part of the horse hoof that contacts the ground
Frog
The sole horn that fills the ground surface between the wall and the frog is a junction known as what?
The White Line
What is the band of soft horn that lies over the external surface of the wall near the junction of the skin?
Periople
What structure widens the back of the hoof, where it covers the bulbs of the heel and part of the frog?
Periople
Descends with the wall and dries to a protective glossy layer
Periople
What bonds the claw to the dorsal border of the bone?
Longitudinal interdigitations between the dermal and epidermal laminae
What make up the CNS?
Brain and spinal cord
What make up the PNS?
Spinal and cranial nerves
What is the role of the CNS?
The interpret incoming sensory information and issue instructions based on past experience and current conditions
What is the role of the PNS?
To carry impulses from the sensory receptors to the CNS and from the CNS to effectors
Afferent division (AKA sensory component) conducts impulses ________ the spinal cord and brain
Toward
Efferent division (AKA motor component) of the PNS conveys impulses ______ from the brain and spinal cord
Away
Afferent and Efferent are further subdivided into what?
Somatic and Visceral sytems
What system is concerned with both sensory and motor functions that determine relationship of the organism to the outside world?
Somatic
This system includes detection of stimuli in the skin, tissues of limb and trunk as well as behavioral actions
Somatic system
The somatic system can also be referred to as what?
The voluntary system
This system is concerned with sensory and motor functions that relate to the internal viscera
Visceral system
The motor component of the visceral peripheral nervous system is also referred to as what?
Autonomic system
Regulation of BP, HR, and the control of glandular activity and digestive process are controlled by what nervous system?
The Visceral (or Autonomic) nervous system
The Autonomic nervous system consists of what?
Sympathetic and parasympathetic systems
Visceral efferent fibers of the sympathetic division leave the CNS via the spinal nerves in the ___________ regions of the spinal cord
Thoracolumbar regions
The visceral efferent fibers of the parasympathetic division are found in a small group of cranial nerves and in spinal nerves of the ______ region of the spinal cord
Sacral region
The sympathetic division is responsible for what responses?
Flight or Fight
The parasympathetic division is responsible for what responses?
Conserving energy
Promotes housekeeping functions during rest.
What are the basic elements of the nervous system?
Neurons
Thin branching extensions of the cell body that conduct nerve impulses towards the cell body
Dendrites
A single branch (in most neurons) which conducts nerves away from the cell body?
Axon
What does gray matter of the brain contain?
Cell bodies of motor and association neurons
What does white matter of the brain contain?
Myelinated axons
All spinal nerves are ________ nerves, but not all cranial nerves are.
Mixed
What part of the brain controls coordination and fine tuning of movement?
Cerebellum
What part of the brain is the conscious perception of sensory input and initiation of conscious movement?
Cerebrum
What is the relay center for the brain, it filters sensory input and allows us to concentrate?
Brain stem (midprain, pons and medulla oblongota)
What is the corpus callosum responsible for?
Enabling communication between hemispheres
Reflexes do not require _______ input and does not imply consciousness.
Cerebral
Response requires _______ awareness
Cortical
What are the 5 elements of reflex arc?
- Receptor
- Sensory neuron
- Integration center
- Motor neuron
- Effector
What are somatic reflexes?
They include all reflexes that stimulate skeletal muscle
What are autonomic reflexes?
They regulate the activity of smooth muscle, heart and glands. I.e. Digestion, elimination, blood pressure and sweating
Sensory (afferent) Nerves, Motor (efferent) nerves and Mixed nerves are based on what?
The direction of the nerve impulse
What are the 4 types of basic tissue that make up the organs of the body?
Epithelial
Connective
Muscular
Nervous
What are the three types of epithelium?
Lining (surface) epithelia
Glandular epithelia
Special epithelia
Where would you find lining epithelia?
Body surfaces, lining of luminal organs, tubular structures, body cavities
What is the function of glandular epithelia?
To synthesize, store and release various products
What type of epithelia contain sensory nerve endings?
Special epithelia
Where would you find special epithelia?
Skin, ears, tongue (nose and eyes but w/ modified neurons)
What are some characteristics of epithelium?
Supported by connective tissue
Avascular
Basement membrane
Cells are cohesive
Cells are polarized
Epithelium that is composed of flat, elongated cells, with a round to oval nucleus- often centrally located.
Simple Squamous Epithelium
Where would simple squamous epithelium be found?
Lining of body cavities (mesothelium), alveolar walls in lungs, inner lining of blood vessels and lymphatic vessels (called the endothelium)
What type of epithelium has tall, narrow cells with an oval nucleus located near the base?
Simple Columnar Epithelium
What kind of epithelium would you find lining the luminal surface of the stomach, SI, LI and gall bladder?
Simple columnar
What kind of epithelium would you see lining the oviduct?
Simple columnar ciliated
What type of epithelium is composed of a single layer of irregularly shaped and sized cells?
Pseudostratified
In what kind of epithelium would all cells touch the basement membrane but not all reach the apical surface?
Pseudostratified
Where would you find pseudostratified epithelium?
Nasal cavity and upper respiratory tract
What complication can be seen with a lack or absence of cilia?
Chronic respiratory infections
What epithelium is composed of several layers of cells?
Stratified Squamous Epithelium
What are the two types of squamous epithelium?
Keratinized (cornified)
Non-keratinized
What type of epithelium is found in the dental pad of ruminants?
Stratified Squamous, Keratinized
Transitional epithelium is also called what?
Urothelium
What type of epithelium would you find lining the urinary bladder?
Transitional (Urothelium) epithelium
What makes Urothelium unique?
Superficial cells have specialized plasma membranes providing an osmotic barrier between urine and tissue fluids
In transitional epithelium, if the superficial cells are cuboidal with a dome shaped surface what does that indicate?
An empty bladder
In transitional epithelium, if the epithelium appears flattened and more like stratified squamous, what does that indicate?
A full bladder
Where are stem cells located?
Stratum basale (basal cell layer)
What are the criteria used to classify glandular epithelium?
Number of cells in the gland
Shape of duct and secretory units (adenomeres)
Type of product
Mode of secretion
Where are unicellular glands found?
Epithelial lining and glands of intestine as well as in the epithelial lining of the respiratory tract
What is an example of a unicellular gland?
Goblet cell
What gives the goblet cell it’s unique shape?
The presence of abundant mucinogen granuls in the apical part of the cell
Where might you see goblet cells?
Simple columnar epithelium of the colon
What are the three types of multicellular glands?
Tubular
Acinar
Alveolar
What type of gland would you find in sweat glands, stomach glands or intestinal glands?
Tubular gland
What kind of gland is pie-shaped?
Acinar
What type of gland would you find in the small lumen (pancreas and salivary glands)?
Acinar
What gland provides a larger luminal space?
Alveolar
Where would you find alveolar glands?
Mammary glands, prostate, sebaceous glands
What shape corresponds to a rounded secretory unit?
Acinar
What shape corresponds to a bigger luminal space?
Alveolar
What is the parenchyma?
The collective secretory units and ducts of a compound gland
The connective tissue elements comprise what?
The stroma
Large glands are divided into _______ which are further divided into _______
Lobes, lobules
What is an example of cerumen?
Ear wax
What is the secretion of modified sweat glands in the external auditory canal?
Cerumen
What is sebum?
Oily secretion from the sebaceous glands
A gland that produces both mucous and serous secretion is called mixed. What is an example of this?
Saliva
What are the components of connective tissue?
Cells, Fibers, Ground substance (interstitial fluid)
What are some characteristics of connective tissue?
Supports epithelia
Vascularized
Cells lack polarity
Less cohesive
No basement membrane
What are some functions of connective tissue?
Joins tissues together
Gives form, subdivides organs
Physical support of body
Thermoregulation
Nutrition and storage (adipose)
Defense and repair mechanisms
What are the two types of cells of connective tissue?
Resident and transient
What are the 3 types of fibers in connective tissue?
Collagen, elastic, reticular
What are the two types of ground substance in connective tissue?
Macromolecules and interstitial fluid
What is the most numerous cell population in connective tissue?
Fibroblasts
What type of cells are fibroblasts?
Resident cells
What synthesizes the fibers of connective tissue?
Fibroblasts
What are examples of resident cells?
Reticular cells, Fibroblasts, Adipocytes, Macrophages, Mast cells
What type of cells would you find in lymph nodes, liver, spleen, that would not be subjected to high mechanical stress?
Reticular cells
What cells serve as scaffolding to the parenchyma of various organs?
Reticular cells
What cells specialize in depositing lipids?
Adipocytes
What are the two types of adipocytes?
Multiocular (brown)
Uniocular (white)
Where would you see multiocular adipocytes?
Newborns and hibernating animals
What is the resident phagocyte cell of connective tissue?
Macrophage
What are the macrophages in the liver? And the bone?
Kupffer cells (liver)
Osteoclasts (bone)
What cells are filled with basophilic granules?
Mast cells
What cells are involved in inflammatory and allergic reactions?
Mast cells
What does degranulation (activation) of mast cells cause?
Release of histamine and other chemical mediators that trigger symptoms of allergy
What is an example of transient connective tissue cells?
White blood cells
(Neutrophils, eosinophils, basophils, lymphocytes)
What are the most numerous fibers of connective tissue?
Collagen fiber
What are some characteristics of collagen fiber?
White, very high tensile strength, very strong, can only stretch 5% of initial length
What is the most abundant protein in the body?
Collagen
What cells synthesize collagen?
FIbroblasts, chondroblasts, osteoblasts, odontoblasts…etc (basically anything ending in -blast)
What is formed in the fibroblast and transported out of the cell to be assembled into collagen fibrils?
Procollagen
What is an important cofactor in collagen synthesis?
Vitamin C
Found in 90% of body’s collagen, skin, bone, dentin, tendons, fibrocartilage; resists tensile forces
Type 1 collagen
Found in cartilage, resists compression
Type 2 collagen
Reticular fibers found in the stroma of expandable organs
Type 3 collagen
Basal lamina of the epithelia
Type 4 collagen
FIber found in aorta, arteries, lungs, vocal cords, dermis, ear pinna, epiglottis…
Elastic fibers
Individual, branching, anastomosing fibers
Elastic fibers
What fibers are stained by silver and serve as scaffolding to cells or cell groups of various organs?
Reticular fibers
What substance is produced by resident cells?
Ground substance
Composed of glycosaminoglycans (GAGs)
Ground substance
What link to core proteins to make proteoglycans?
GAGs
Properties of these molecules allow for binding of water, resisting compressive forces, cell adhesion to fibers, cell migration, barrier to bacterial/venom penetration
Ground substance
A solution of nutrients and dissolved gases derived from plasma
Interstitial fluid
Bathes the cells, fibers and ground substance, and aids in removing waste
Interstitial fluid
A decrease in skin turgor is what?
A LATE sign in dehydration
What are important in fluid movement and prevention of edema?
Lymphatics
True or false
Interstitial (tissue) fluid is visible on slides
False - NOT visible on slides
Adipocytes produce _____ which has regulatory effects on body fat.
Leptin
Leptin levels are proportional to what?
Body fat
What signals the brain (satiety center) that the body has had enough to eat?
Leptin
What occurs when adipocytes outnumber other cell types?
Adipose tissue
What is the endocrine function of white adipose tissue?
Hormone “leptin” secretion
What are the main functions of White adipose tissue?
Energy storage
Insulation
Leptin secretion
What is the main function of brown adipose tissue?
Heat generation
What part of the ear captures air vibrations and directs them towards the tympanic membrane?
External ear
The auricle (pinna) and ear canal (vertical and horizontal part) are the parts of what portion of the ear?
The external ear
Sound modulation is a function of what portion of the ear?
Middle ear
This part of the ear is located in the tympanic part of the temporal bone of skull
Middle ear
What are the 3 auditory ossicles?
Malleus
Incus
Stapes
What connects the tympanic membrane to the oval window?
The 3 auditory ossicles
Through what structure does the pharynx communicate with the middle ear?
Auditory tube
The pharynx and auditory tube ensure what?
That the air pressure inside the middle ear is equal to the outside air pressure
Where is the inner ear housed?
Deep inside the temporal bone
What nerve is found in the inner ear?
CN VIII (Vestibulocochlear nerve)
What comprises the inner ear?
Cochlea (organ for hearing)
Vestibular apparatus (organ for balance)
Utricle
Saccule
What are the 3 tunics of the eye?
Fibrous Tunic
Vascular Tunic
Nervous Tunic
What tunic houses the sclera and cornea?
Fibrous tunic
What tunic houses the iris, ciliary body, and choroid?
Vascular tunic
What tunic houses the pigmented layer and neural layer?
Nervous tunic
What structure is responsible for structural integrity of the eye?
Sclera
What structure of the eye allows light to enter the eye?
Cornea
What structure in the eye modulates the amount of light?
Iris
What structure of the eye modulates vision focus?
Ciliary body
What structure in the eye provides blood supply and innervation?
Choroid
What tunic reacts to light stimuli and outputs nerve impulses for the brain to be interpreted as images?
Nervous tunic
What is the transparent anterior 1/4 of the eye?
Cornea
What is the opaque posterior 3/4 of the eye?
Sclera
Where is the tapetum lucidum found?
In the choroid
Dorsal part of the eye that reflects light, is avascular and reflects in iridescence
Tapetum lucidum
Which portion of the eye is suspended between the cornea and lens?
Iris
Which portion of the nervous tunic of the eye has no photoreceptors?
Anterior, thinner pigmented layer
What is responsible for the “blind spot”?
Optic disk of the nervous tunic (retina) where axons emerge from the eye bulb
What muscles change the shape of the lens for focusing?
Ciliary muscles
What intrinsic muscles of the eye are poorly developed in domestic animals?
Ciliary muscles
What are the intrinsic muscles of the eye?
Ciliary and pupillary
What type of muscles of the eye are under voluntary control?
Extrinsic muscles (4 rectus and 2 oblique)
The space between the cornea and lens is divided into what 2 chambers?
Anterior and Posterior chamber
What chamber does NOT communicate with anterior compartment?
Vitreous chamber
What eye chamber is from the cornea to the iris?
Anterior
What eye chamber is from the iris to the lens?
Posterior
What chamber contains the aqueous humor?
Anterior and Posterior chamber
Concave fold of palpebral conjunctiva that protrudes from the medial angle of the eye
Third eyelid (plica semilunaris)
What supports the third eyelid?
T-shaped cartilage
Gland of the eye located dorso-lateral to eye, secretes serous fluid
Lacrimal gland
What is the flow for tears/gland secretion?
Lacrimal gland secretes serous fluid, then secretion flows over cornea then passes through lacrimal puncta and into lacrimal canaliculi and then drains into nasolacrimal duct
What is located in the caudal region of the nasal cavity?
Olfactory mucosa
What covers thin scrolls of ethmoidal bone?
Olfactory mucosa
This nerve is made up of numerous axons that rise in the olfactory mucosa and pass through cribiform foramina to olfactory bulbs
Olfactory nerve
Where are taste buds located on the tongue?
Vallate
Foliate
Fungiform papillae
What CN is found on the caudal 1/3 of the tongue?
IX (Glossopharyngeal)
What CN is sensory from the rostral 2/3 of the tongue?
Lingual nerve (Touch- trigeminal nerve CN V and taste- facial CN VII)
What do canine’s have since they have an incomplete orbit?
Orbital ligament
