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Physiology & Histology - Exam 1
Fall 2012
207
Veterinary Medicine
Graduate
08/28/2012

Additional Veterinary Medicine Flashcards

 


 

Cards

Term
Charasteristics of the basement membrane
Definition

Selectively permeable

 

Rich in glycoproteins

 

Collagen meshwork

Term
What does Hematoxylin stain, color and structures
Definition
Blue - nucleus, nucleolus, polysacs, ribosomes
Term
What does Eosin stain, color and structure
Definition

Red

 

Acidophilic

 

cytoplasm, elastic fibers, collagen, secretory vesicles

Term
What cell produces extracellular fibers?
Definition
Fibroblasts
Term
Are Mesenchyme cells pluripotent or totipotent?
Definition
Pluripotent - Has the ability to give rise to any of the three germ layers (ectoderm, mesoderm, endoderm)
Term

What is this?

 

[image]

 

 

Definition
Nerve - ya heeeeard
Term
What cells make up the sheath in a nerve cell in the CNS?
Definition
oligodendrocytes
Term
What cells make up the sheath in the PNS?
Definition
Schwann cells
Term
What is a ganglion?
Definition
Collecton of neuronal cell bodies
Term
What are the 3 parts of the basement membrane?
Definition

1) Lamina Lucida - anchors basement membrane to epithelial cell

 

2) Lamina Densa - selectively permeable membrane

 

3) Lamina Fibroreticularis - Anchors basement membrane to underlying CT

Term
Name the 7 types of epithelium 
Definition

[image]

 

Term
Where can endothelium be found?
Definition
Lining cardiovascular system, it is simple squamous epithelium
Term
Where can mesothelium be found?
Definition
Lining body cavities and organs, it is simple squamous epithelium
Term
Main function of simple cuboidal cells?
Definition
Secretion and absoprtion
Term

[image]

 

What epithelial cell type is this?

 

Name one place this can be found

Definition

Simple columnar epithelium

 

Gall Bladder

Term
Where can simple columnar be found?
Definition
Stomach, intestines, gall bladder, uterus and glands
Term

[image]

 

What epithelial cell type is this?

Definition

Pseudostratified ciliated columnar epithelium with goblet cells

 

 

Term
What is the function of transitional cells?
Definition
Expansion - think bladder
Term

[image]

 

Name the layers

Definition

C - Stratum Corneum

 

G - Stratum Granulosum

 

S - Stratum Spinosum

 

B - Stratum Basale

Term
What is the difference between Corneum and Corium?
Definition

Corneum is the outer most layer of the epidermis

 

Corium is Latin for dermis

Term
Do exocrine or endocrine glands have excretory ducts?
Definition
Exocrine, fucking duh
Term
Where can Merocrine glands be found on dogs?
Definition
On the digital pads
Term

[image]

 

What type of gland is this?

 

Apocrine, Merocrine or Holocrine

Definition
Apocrine
Term

[image]

 

Name all three gland types by product produced

Definition

[image]

 

Serous, Mixed (w/ serous demilune pointed out) and Mucous

Term

[image]

 

What is the arrow pointing to?

Definition
Sabaceous gland
Term
What is Axial Periodicity?
Definition
Collagen fibers overlap about 1/4 of their length, crosslinking the fibers and making them appear striated in the microscope
Term
What does GAG stand for?
Definition
Gylcosaminoglycans
Term
Describe Type 1 collagen
Definition
Large fibers - Loose & Dense CT, bone and fibrocartilage
Term
Describe Type 2 collagen
Definition

Hyaline and elastic cartilage

 

Can be found in the vitreous humour of the eye

Term
Describe Type 3 collagen
Definition
Reticular CT - Bone marrow, lymphatic tissue
Term
Describe Type 4 collagen
Definition
Sheet-like mesh - think basement membrane
Term
Is elastin basophilic of acidophilic?
Definition
Acidophilic... the pink shit
Term
What is ground substance, and what does it generally consist of?
Definition

All of the space between CT fibers and cells

 

It is an amorphous aqeous gel-like solution, containing water and GAGs (glycosaminoglycans)

Term
What does a proteoglycan consist of?
Definition
A "core protein" that has been glycosylated with one or more covalently attached GAGs (glycosaminoglycans)
Term
What force do GAGs help resist?
Definition
Compression
Term
Does collagen bind water?
Definition

Ha! idiot. No.

 

The proteoglycan aggregate (GAGs attached to Hyaluronic acid) bind water and resist compression force....what an idiot.

Term
Where can dense regular CT be found?
Definition

Tendon, ligament and cornea

 

Dense CT does not have a good blood supply

Term
Where can reticular CT be found?
Definition
Bone and Lymphnodes
Term
What is a chondroblast?
Definition
A cell that is actively producing a cartilage matrix, and has not yet surrounded itself in a lacuna 
Term
What is a chondrocyte?
Definition
A mature cartilage cell that has surrounded itself in a lacuna
Term
Name the multinucleated cell that is involved in the reabsorption (eat) cartilage
Definition

Chondroclast

 

[image]

Term
Define perichondrium
Definition

Mesenchymal cells that lie adjacent to cartilage. 

 

These cells will eventually become committed to making cartilage (They will eventually become chondroblasts...duh!)

Term
what is interstitial growth?
Definition

Growth from within - refers to the ability of chondrocytes to undergo mitosis

 

Only occurs in young growing animals

Term
What is appositional growth?
Definition
Growth in layers, this occurs from the perichondrium - mitosis of chondroblasts
Term

[image]

 

Name the type of cartilage

Definition
Elastic, Fibrous, Hyaline
Term
Is the corium of the hoof insensitive?
Definition

No...

 

<3

Term
The Stratum externum is also known as what?
Definition
Periople, which is produced by the perioplic epidermis
Term
The laminar epidermis produces what part of the strat?
Definition

Stratum internum, also known as the stratum lamellatum

 

The stratum internum also produces the "white line"

 

 

Term
The coronary corium underlies the coronary epidermis, what does the coronary epidermis make?
Definition
Stratum medium - the hoof wall
Term
perioplic epidermis creates what?
Definition
Stratum externum - also known as the periople
Term
[image]
Definition

1 - Perioplic corium

 

2 - Stratum medium

 

3 - Sole corium

Term
[image]
Definition

Top to bottom:

 

- Coronary corium

 

- Stratum Externum (periople)

 

- Laminar corium

Term
[image]
Definition

1 - sole epidermis

 

2 - White line

 

3 - Stratum lamellatum

Term
What is the metaphysis on a bone?
Definition
The metaphysis is the wider portion of a long adjacent to the growth plate
Term
Describe the epiphysis
Definition
The rounded edge of a long bone
Term
Where is the diaphysis located?
Definition
The main long shaft (ha! Get it?) of a long bone
Term
Describe periosteum
Definition

The membrane that surrounds all bones, except the joints of long bones. 

 

It consists of DENSE IRREGULAR CT with a fibrous outer layer (contains fibroblasts) and a osteogenic inner layer (contains progenitor cells)

Term
What resides in the Medullary cavity?
Definition
Red bone marrow, spicules, blood and fat
Term
Define Anastamosis
Definition
Refers to the reconnection of two things. Two branched blood vessels coming together as one... <3
Term
[image]
Definition
Osteonal canal
Term
Where is the endosteum located?
Definition

Lines the medullary cavity, where bone marrow and shit lives

 

It is the CT in the osteon

 

[image]

Term

[image]

 

What is the blue arrow pointing to?

Definition
Reversal line
Term
What does Calcitonin counter?
Definition
PTH
Term
Vitamin D's target organs
Definition

Small itestines

 

Kidney

 

Bone

Term
Vitamin D's affect on kidney?
Definition

Increased Ca reabsorption

 

Increased phosphate reabsorption

 

Inhibits Hydroxylation (Introducing hydroxyl group to organic compound, -OH group you, duh!)

Term
Where is articular cartilage located on bone?
Definition
[image]
Term

[image]

 

Are these active or inactive osteoblasts?

Definition
Inactive, they take on a flattened appearance.
Term
What is trabecular bone also known as?
Definition
Spongy bone - form a spider web like appearance in the medullary cavity, epiphysis and metaphysis
Term
Is the cartilagenous growth plate of a young animal highly vascular?
Definition

Hell no. That shit be Avascular.

 

The growth plate prevents metaphyseal blood supply from anastomosing with blood supply from the epiphysis. 

Term
Describe a slipped epiphysis
Definition
Epiphysis slips off the metaphysis of a young animal. If the arteries are severed, this will cause the epiphysis to die, and the bone will stop forming/growing/getting love from blood
Term
How does blood get into the medullary cavity?
Definition
Through nutrient arteries
Term
[image]
Definition

Active osteoblasts take on a columnar appearance

 

Osteocytes in their lacuna

Term
Describe woven bone
Definition

Woven bone is immature or fibrous bone, that is why it can be sectioned easily

 

The matrix is usually eosinophilic

Term
where can woven bone be found?
Definition

Developing areas

 

fracture repair sites

 

bone cancer

 

-If woven bone is found in an adult, it usually represents some pathologic issue

Term
What is lamellar bone?
Definition

Adult bones! hahaha bone.

 

- it is highly organized in layers

 

- generally organized around blood vessels

Term
What is the predominant bone configuration in the medullary cavity and the epiphysis?
Definition

Trabecular bone

 

Also known as Cancellous bone

 

Also know as fucking spongy bone

 

 

Term
What is dense bone also known as?
Definition

Cortical bone or compact bone

 

- This is typically found in the diaphysis

Term
Describe what interstitial bone is
Definition
portions of bone that do not appear to be associate with an osteonal canal, but like magic... they really are
Term
What is circumfrential bone, and what is the difference between inner and outer circumferential bone?
Definition

Bone layers that are added by appositional growth

 

- Outer circumferential bone is contributed by the periosteum

 

- Inner circumferential bone is added by the endosteum

Term
Describe intramembranous ossification, do bones formed this way bear weight? 
Definition

- Mesenchymal cells will clump together and commit to becoming osteoblasts. These cells will begin creating woven bone, which will eventually be replaced by mature bone.

 

- Bones formed in this manner are generally non-weight bearing (flat bones of the skull & Clavicle)

Term

[image]

 

Eermahgerd! WTF kind of ossification is this?

Definition
Intramembranous ossification - That dark pink thing is a spicule
Term
What is endochondral ossification
Definition

Mesenchymal cells aggregate and commit to a chondroblast lineage. These cells secrete a cartilage scaffold that grows both interstitially and appositionally. This is eventually replaced with woven bone, and then lamellar bone. 

 

Found in the long bones. get it?

Term
Cartilage in the bone begins to calcify in the central part of the diaphysis, the first blood vessels that invade this newly calcified region are called what?
Definition
Periosteal bud - the vessels also contain macrophages and mesenchymal cells (which will begin to secrete woven bone)
Term

[image]

 

 

The black arrow is pointing to a primary ossification center. The Hyaline cartilage on the epiphysis of this bone will eventually turn into what?

Definition
Articular cartilage
Term
What are the 4 zones of the growth plate?
Definition

Reverse zone - abuts the epiphysis and contains cells that produce cartilage

 

Growing zone - where chondrocytes are actively dividing

 

Hytrophied zone - where the cells begin to expand, this is the weakest of all zones and where fractures commonly occur

 

Calcified zone - where the matrix begins to calcify

Term
What does the boney collar do?
Definition

Contributes to the diaphysis and metaphysis by appositional growth. 

 

Think of your arm (cartilage) in a long sleeve shirt (Bony collar), your shirt dictates the diameter your arm can grow

Term

Very early in development, the connective tissue of the potential joint cavity undergoes a process called _______ where there is selective cell death that results in the joint space. 

Definition
Cavication
Term
What is the predominant cell type found in loose CT?
Definition
Fibroblasts
Term
Where can dense irregular CT be found?
Definition

Dermis

 

Capsules of many organs

Term
Where are the four place dense regular CT can be found?
Definition

Tendons

 

ligaments

 

aponeuroses

 

cornea

Term

[image]

 

 

Wtf are these things?

Definition

1 - Loose CT

 

2 - Dense irregular CT

 

3 - Dense regular CT

Term
How can you view reticular CT?
Definition
With silver stain... and a microscrope. 
Term
Reticular fibers are predominant where?
Definition
Bone marrow and Lymphnodes
Term
Fibroblasts wedged between elastic CT often take what shape?
Definition

S or curved shaped

 

[image]

Term
What cell type is on the peripheal edge of most adenomeres (functional unit of salivary gland) and are contractile
Definition
Myoepithelial cells - thought to force secretory product into and out of th duct system
Term
Does appositional growth require a perichondrium?
Definition
Yes.. boom
Term
Characteristics of territorial matrix
Definition

matrix immediately surrounding the lacunae

 

increased water binding capacity

 

easily maintained by the chondrocyte

Term
One place where hyaline cartilage lacks a perichondrium
Definition
Joint surfaces
Term
What are some characteristics of smooth muscle?
Definition

No striations

 

short spindle shaped cells

 

centrally located nucleus

 

involuntary (ANS)

Term
Is smooth muscle very eosinophilic?
Definition
Hell yes. The pink stuff
Term

[image]

 

WTF are these?

Definition

Smooth muscle on the left

 

Dense regular CT on the right

Term
Where can smooth muscle be found?
Definition

Blood vessels

 

Walls of viscera

 

Capsule of spleen

 

Skin

 

Pupil

Term
Characteristics of Cardiac muscle
Definition

Striated

 

Cells branch

 

Intercalated discs

 

Single central nucleus

 

Involuntary (ANS)

Term
Skeletal muscle characteristics
Definition

Voluntary

 

Striated

 

Can be very long

 

multi-nucleated

Term
What are the contractile proteins of muscle?
Definition
Actin & myosin
Term
The region of the sarcomere that only contains myosin is labeled as what
Definition
H band
Term
What is Actin comprised of?
Definition

2 strands of globular actin protein and 2 linear strands of tropomyosin protein wound together as a helix. Globular troponin proteins are attached intermittently.

 

[image]

Term
Describe Epimysium, Perimysium, Endomysium
Definition

Epimysium - Fascia, external covering of muscles

 

Perimysium - Sheath that wraps muscle bundles

 

Endomysium - Sheath that covers individual muscle fibers

 

[image]

Term
Is Na+ or K+ higher in concentration on the inside of the cell, normally
Definition
K+
Term
What is an osteoid?
Definition
osteoid is the unmineralized, organic portion of the bone matrix that forms prior to the maturation of bone tissue.
Term
What ion channels are always open and determine resting membrane potential (very superficial question, let's not over think and go overboard here.)
Definition
Leak channels for k+
Term
Describe saltatory conduction
Definition
Propagation of action potentials along myelinated axons from one node of Ranvier to the next node, increasing the conduction velocity of action potentials without needing to increase the diameter of an axon.
Term
Generator potential amplitude depends on what?
Definition
Generator potential amplitude depends on the intensity of the stimulus (stretch-activated ion channel)
Term
A membrane potential of +40mV is polarized or depolarized?
Definition
Depolarized
Term
The vast majority of synapses in the CNS are what type of synapses?
Definition
Chemical synapses
Term
What happens when an action potential arrives at an axon terminal?
Definition
The depolarization opens Ca+ voltage gated channels. The influx of Ca+ causes synaptic vesicles to fuse with the plasma membrane of the axon terminal
Term
What are the inhibatory neurotransmitters?
Definition
GABA (Gamma amino butyric acid) and Glycine
Term
Name 3 excitatory neurotransmitters
Definition

Acetylcholine

 

Glutamate

 

Serotonin

 

Epinepherine

 

Nor-epnpherine

 

Dopamine

 

opaties

 

Adderall, crack, meth, cocaine, speed, Justine, your mom

 

 

Term
Generally how big is an RBC?
Definition
~7microns
Term
Describe what an inactive nucleus looks like
Definition
Dark, condense nuclei due to coiled chromatin - more heterochromatin, less cell activity
Term
Describe grey mater in the CNS
Definition
Clusters of neuronal cell bodies within the butterfly structure
Term
Describe Neuropil
Definition
Any area in the nervous systemcomposed of mostly unmyelinated axonsdendrites and glial cell processes that forms a synaptically dense region containing a relatively low number of cell bodies.
Term
Define Nissl Substance
Definition
eER and Ribosomes - large granular bodies found in neurons and assit in the formation of NT production
Term
Where can myoepithelial cells be found and what is their general function
Definition
Found in glandular epithelium as a thin layer above the basement membrane but generally beneath the lumenal cells. These may be positive for alpha smooth muscle actinand can contract and expel the secretions of exocrine glands. They are found in the sweat glandmammary glandlacrimal gland, and salivary gland
Term
What is Parenchyma & Stroma
Definition

Parenchyma - functional tissue of the organ

 

Stroma - supporting CT structure where the parenchyma sits

Term
What does Cathepsin G do?
Definition
Protease - causes pruritis by attacking laminin, proteoglycans, collagen. Increased inflammation when released from damaged keratinocytes, furthering pruritis
Term
What is the startum basale?
Definition
actively dividing layer of epidermis - sits on basement membrane, cuboidal/columnar cells and basophilic
Term
What is the stratum corneum comprised of?
Definition
Dead keratinocytes
Term
Where do melanocytes originate from?
Definition

Pigment cells that originate from neural crest (ectroderm)

 

[image]

Term
What converts tyrosine to melanin
Definition
Tyrosinase - contained in the melanosome within menalocytes
Term
What are melanophages?
Definition
Any cell that phagocytosizes a melanosome - like a keratinocyte
Term
What are Langerham cells?
Definition
Aid in contact hypersensitivity (immunological function)
Term
What are Merkel Cells?
Definition

Located in the Stratum Basale and play a role in sensory

 

From The Wiki:

oval receptor cells found in the skin of vertebrates that have synaptic contacts with somatosensory afferents. They are associated with the sense of light touch discrimination of shapes and textures. They can turn malignant and form the skin tumor known as Merkel cell carcinoma.

Term
What is the approximate epidermal cell renewal time in dogs?
Definition
22 days
Term
How can you increase skin absorption?
Definition

Increase moisture

 

Elevating temp.

 

Removing sebum

 

Increasing med. concentration

 

Slightly damage the skin

Term
Where is pruritis elicited from?
Definition
epidermis, dermis and conjunctiva (lines the inside of eye lids)
Term
What part of the skin provides blood and nutrients to hair follicles?
Definition
Dermal papilla
Term
Define anagen, catagen and telogen hair cycles
Definition

Anagen - period of growth (~3 months transition from telogen)

 

Catagen - brief period of growth, growth stops and changes from active to stopped growth

 

Telogen - long rest period - follicle atrophy

Term
What is reticular CT?
Definition

Modified fibroblasts - very delicate strand of collagen fibers and are less robust tham fibers found in the skin or tendons. 

 

They are important in anchoring small blood vessels and nerve twigs to the surrounding tissue

Term
Why is brown adipose "brown"
Definition
lobulated and a lot of mitochondria present
Term
Describe Hyaline cartilage and where it can be found
Definition

Smooth, no fibers present and an amorphous matrix

 

Can be found in Bones, joint surfaces, growth plate, articular surfaces, growing bones, trachea, support system of hollow tubular organs

Term
Weight bearing bones are first formed by which type of cartilaginous scaffold?
Definition
Hyaline bitches!
Term
Can fibrocartilage have normal growth/repair after being damaged?
Definition
No, lacks perichondrium
Term
What are Joint Mice?
Definition
Small fibrous, cartilaginous, or bony loose bodies in the synovial cavity of a joint.
Term
What is the repair potential for Hyaline, Elastic and fibrous cartilage?
Definition

Hyaline (Non-articular) - Good in young, fair in adults

 

Hyaline (Articular) - Good in young, Very poor in adults

 

Elastic - Good in young, Poor in adults

 

Fibrocartilage - Fair in young, very poor in adults

 

Basically, you're fucked once you grow up.

Term
What are canliculi
Definition
Cell projections that allow cell-cell communication and transport of CA/minserals between osteocytes
Term
When does osteolysis occur?
Definition
When there is a short demand for Ca - demineralize matrix around lacuna for day to day Ca regulation
Term
What is the H-band?
Definition
Region in the middle of the sarcomere that only contains myosin
Term
What attaches to the perichondral ring after the growth plate closes?
Definition
Remains for the life of the animal - tedon, ligament and joint capsule attachment point
Term
What is contained in the I-band?
Definition

Region containing only Action

 

Refracts light (isotropic)

Term
What is contained in the A-Band
Definition

The entire myosin filament along with the actin

 

Does not let light pass through (anisotropic)

 

[image]

Term

Which bands decrease during muscle contraction?

 

A, I or H?

Definition
I and H bands... 
Term
What are astrocytes?
Definition

Adhere to neurons and capillaries and assist in removal of excess ions and neurotransmitters. They also assist in exchange of nutrients. These are the cells that help form the so-called blood- brain barrier.

Term
What are microglia?
Definition

"tiny cells" that function in repair (phagocytosis), probably of monocytic origin

 

Wiki:

Microglia are a type of glial cell that are the resident macrophages of thebrain and spinal cord, and thus act as the first and main form of active immune defense in the central nervous system (CNS). 

Term
What are ependymal cells?
Definition
Cells that line CNS cavities, such as the ventricles and the central spinal canal. Ciliated, cuboidal to columnar cells that assist in production of cerebrospinal fluid (CSF).
Term
Is CT present in the PNS or CNS?
Definition
PNS
Term
What is the Axon Hillock?
Definition
Site where axon attaches to the cell body, and generally the place where action potential is generated
Term
What are Telodendria?
Definition

the end parts of the axon that will form a synapse (connection) with the next neuron or muscle.

Term
What are pseudounipolar neurons?
Definition
Generally associated with sensory neurons. The cell body is situated between long arms of the axon. The dendrites are located at one end of the axon rather than on the cell body
Term
What are the 4 types neuroglia (support cells) of the CNS?
Definition

Oligodendricytes - form myelin sheath

 

Astrocytes - removal of NT and exchange nutrients

 

Microglia - Tiny cells that perform phagocytosis

 

Ependymal cells - line CNS cavities assist in CSF production

Term
What types of neuroglia are associated with the PNS?
Definition

Schwann cells - Myelin sheath

 

Satellite cells - cells that support the neuron in ganglia

Term
What is a muscle fascicle?
Definition
Bundle of muscle fibers surrounded by perimysium
Term
What is the sarcolemma?
Definition
It is the cell membrane of a muscle cell
Term
What is the purpose of T-tubules?
Definition

They are a membrane system that is an extension of the sacrolemma, and extend deep into each muscle cell. 

 

The T-tubules contact a sub region of the sarcoplasmic reticulum (SR) called the terminal cisternae

 

The T-tubules will convey electrical signals to the SR to control the release of calcium and begin muscle contraction

Term
What is the difference between fenestrated cisternae and terminal cisternae?
Definition

Terminal Cisternae are sites of calcium release into the sarcoplasm

 

Fenestrated Cisternae are sites of calcium reuptake, also where calcium pumps are concentrated

Term
Once ACh is released from the neuromuscular junction, what happens?
Definition

Transmembrane channels in the sacrolemma open and lead to depolarization of the muscle fiber

 

That action potential is propagated across the sacrolemma, to the T-tubule system and to the Sarcoplasmic reticulum

 

Calcium is released from the terminal cisternae

Term
When Ca2+ enters smooth muscle cell, what does it bind to?
Definition

Calmodulin which activates a myosin light chain kinase.

 

Myosin gets phosphorylated and binds to actin. Myosin and bind and rebind to actin as long as it is phosphorylated

Term
What is the role of the sarcoplasmic reticulum?
Definition
To release, sequester and pump calcium ions.
Term
A positive charge in the gap between the T-tubule and the SR signal the DHP (dihydropyridine receptor) to do what?
Definition
Open the Ryanodine receptor and release calcium from the SR
Term
What two molecules are released from the myosin head that cause it to undergo a conformational change and tug on the thin filament?
Definition
ADP and Pi
Term
What's one difference between skeletal and cardiac muscle concerning excitation contraction coupling?
Definition
Cardiac muscle requires extracellular Calcium whereas skeletal muscle does not. 
Term
Describe Ca2+ induced Ca2+ released
Definition

In cardiac muscle the T-tubule membrane contains voltage regulated Ca2+ channels known as DHP (dihydropyridine) receptors

 

Positive charge depolarizes the DHP receptor and allows Ca2+ to enter the SR

 

Ca2+ binds to Ryanodine receptors

 

Ryanodine receptors are also Ca2+ channels and release Ca2+ from the SR into the cytoplasm

 

Ca2+ then binds to the troponin complex to initiate the sliding filament process

Term
Which muscle types is troponin found in?
Definition

Troponin is a Ca2+ binding protein in muscle fibers and it is found in skeletal and cardiac muscle

 

NOT in smooth muscle

Term
Smooth muscle relaxation requires what enzyme?
Definition
MLCP - Myosin light chain phosphatase to remove the phosphate from the myosin light chain which causes the myosin head to change conformation and can no longer reach the binding site on the thin filament
Term
What is G actin?
Definition

Globular actin. 1 single ball of actin that combines to create F actin

 

[image]

Term
What comprises a full thin filament (actin)
Definition

F actin bound by tropomyosin, which is complexed over by troponin

 

[image]

Term
Describe the steps involved in muscle contraction
Definition
[image]
Term
What makes up the CNS
Definition

Brain, brainste, and spinal cord

 

 

Term
Where do neuronal cell bodies exist?
Definition
In the grey matter
Term
Is participation of the cortex required for reflex actions?
Definition
Negative ghost rider
Term
Do sensory neurons have their ganglia inside or outside of the CNS
Definition
Outside
Term
What is the difference between efferent and afferent 
Definition

Efferent - Carry nerve impulses away from the CNS

 

Afferent - Carry impulses toward the CNS

Term
What does the medulla control?
Definition
Involuntary functions suchs as breathing, heart rate and blood pressure
Term
What does the hypothalamus control?
Definition
Body Temp, hunger, thirst, fatigue, sleep and circadian cycles
Term
Where about is the origin of sympathetic nerves in dogs and cats?
Definition
T1 - L4&5
Term
What do myenteric and submucosal plexuses control?
Definition

Myenteric -  The myenteric plexus is the major nerve supply to the gastrointestinal tract and controls GI tract motility.


SubmucosalThis plexus lies in the submucous coat of the intestine; it also contains ganglia from which nerve fibers pass to the muscularis mucosae and to the mucous membrane. The nerve bundles of the submucous plexus are finer than those of the myenteric plexus. Its function is to innervate cells in the epithelial layer and the smooth muscle of the muscularis mucosae.

Term
What role do Chromaffin cells play?
Definition

Located in the medulla of adrenal glands, they release Catecholemines, nor-epinepherine and epinepherine into systemic circulation, instead of to adjacent cells/organs

 

Stimulated by sympathetic preganglionic neurons

Term
The effect of NTs are dictated by what?
Definition
The receptors they act on
Term
What inactivates ACh?
Definition
AChE - Acetylcholinesterase
Term
nAChR is a ligand gated ion channel that is excitatory or inhibitory?
Definition
Excitatory
Term
mAChR (muscarinic) is a G-protein linked receptor that is stimulatory or inhibitory?
Definition
Both! Ha! Sucker. Avery questioned that ass. 
Term
Describe M2 and M3 receptors, and the paradoxial effect of M3
Definition

M2The M2 muscarinic receptors are located in the heart, where they act to slow the heart rate down to normal sinus rhythm after stimulatory actions of the sympathetic nervous system, by slowing the speed of depolarization.


M3 Located in the smooth muscles of the blood vessels, as well as in the lungs. With respect to vasculature, activation of M3 on vascular endothelial cells causes increased synthesis of nitric oxide, which diffuses to adjacent vascular smooth muscle cells and causes their relaxation, thereby explaining the paradoxical effect of parasympathomimetics on vascular tone and bronchiolar tone.

Term
What is Cholinergic?
Definition
cholinergic refers to acetylcholine in the neurological sense. The parasympathetic nervous system, which uses acetylcholine almost exclusively to send its messages, is said to be almost entirely cholinergic
Term
What are Alpha1 receptors excitatory to?
Definition
Smooth muscle, gut, vessels, erector pili and GI sphincters
Term
Alpha2 receptors inhibit what?
Definition

presynaptic neuron, or parasympathetic neurons

 

-self regulatory to prevent over-activation of synapse through inhibition of pre synaptic membrane

 

- Receptor on parasympathetic neuron activated through spympathetic NT (norepinephrine) to inhibit parasympathetic action, initiate sympathetic action

Term
Beta 1 Adrenergic receptors are excitatory to what?
Definition
Cardiac muscle and conductile tissue
Term
Beta 2 excite or inhibit smooth muscle?
Definition

Inhibit

 

- relaxation during sympathetic drive to increase airway diameter

Term
Describe Homer's syndrome in a dog/cat
Definition

Loss of sympathetic input to ocular structures

 

- Mitotic pupil - loss of tone to pupilary dialator

 

- Enophthalmos - loss of tone to periorbita (eye sits too far back) and 3rd eyelid protrudes

 

- Ptosis - loss of tone to m. levator palpeprae superioris, dropping or falling of upper eye lid

Term
What is the typical NT released from parasympathetic postganglionic ending?
Definition
ACh
Term
The typical NT released from sympathetic postganglionic ends
Definition
NE - norepinephrine
Term
Are alpha2 receptors found pre or post symaptically?
Definition
Pre
Term
Where are M3 receptors found?
Definition

Found on SM and glands where their effects are primarily exitatory

 

Also found on endothelial cells where stimulation of these endothelial receptors produce nitric oxide which acts on adjacent muscle to produce vasodilation

Term
Where are M2 receptors found?
Definition
SA & AV nodes of the heart, inhibition of target tissue with increased activity of K+ channels
Term
What is a lytic, pharmacologically
Definition

Antagonist, blocker

 

competitively binds with receptors preventing the actual NT from binding

Term
What would a parasympathomimetic do?
Definition
Produce effect of parasympathetic stimulation of an organ
Term
What would an alpha1 blocker produce?
Definition
peripheral vasdilation but limited dilation of coronary arteries
Term
Describe skeletal, cardiac and smooth muscle contraction
Definition

Skeletal muscle - Action potential (AP) reaches axon terminal. ACh is released and positive charge enters muscle fiber. AP propagates down T-Tubule and contacts the Terminal Cisternae which released Ca2+ from the SR to the cytoplasm. Ca2+ binds troponin which moves tropomyosin and allows Myosin head to bind to Actin filament

 

Cardiac Muscle - Ca2+ induces Ca2+ release. T-Tubule contains DHP receptors. When AP reaches the DHP receptors, they open and release Ca2+. That binds to Ryanodine which releases Ca2+ from the SR to the cytoplasm. The Ca2+ binds troponin like skeletal muscle. SR also contain Ca2+ pumps to remove Ca2+



Smooth muscle - AP generated by stretch-activated channels or NT's on the smooth muscle. Calmodulin binds Ca2+ and activates Myosin light chain kinase (MLCK). This phosphorylates the myosin light chain and causes a conformational change in the myosin head. Myosin light chain phosphatase (MLCP) releases the phosphate from the myosin head to relax the muscle.  

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