Exam 1 Terms Flashcards
Anatomy
Study of the internal and external structures of animals the physical relations between body parts
Physiology
Study of “how” living organisms perform their vital functions
Mechanism
The process by which a function is accomplished in an organism.
- step by step list or diagram of “how”
Domestic animal
Animals that humans have domesticated for their use as a source of food and raw materials, labor, and companionship
Mammal
Warm-blooded (homeothermic) higher vertebrates that nourish their young with milk secreted by mammary glands, and have skin usually covered with hair.
- most domestic animals are mammals
Herbivore
Animals that eat plants
Ruminant herbivore
Plant eaters with multi-chambered stomachs
- Cattle, sheep goats
Bovine
Cattle
Ovine
Sheep
Caprine
Goats
Non-ruminant herbivore
Plant eaters with single-chambered stomachs
- horses
Equine
Horses
Carnivore
Animals that eat other animals (meat)
Feline
Cat
Canine
Dog
Omnivore
Animals that eat both plants and meat
- pigs
- humans
Porcine
Swine, pigs
Histology
Microscopic study of tissues
Muscle tissue
Tissue that is specialized in contractions to initiate and perform various types of movements within the animal
Nervous tissue
Tissue that conducts impulses between parts of the body to accomplish physiological communication
Epithelial tissue
Tissue that covers body surface, lines body cavities, and forms glands
Connective tissue
Tissue that supports and binds other tissues, gives form and strength to organs, serve for protection and leverage, store energy, and transport materials throughout the body and prevent infections
Fibroblasts
Large flat cells that appear tappered at the ends. They produce the fibers and ground substance that forms the matrix of connective tissues
Ground substance
The area of connective tissue that looks clear or empty under a microscope. It is made up of glycosaminoglycans, proteoglycans, and glycoproteins.
- can be gelatinous, liquid (in blood plasma), or solid (in bone and cartilage)
Collagen fibers
long, fairly straight, and unbranched fibers made of collagen (protein) which reinforces the strength of tissues
Elastic fibers
Branched and wavy fibers that contain elastin (protein). These fibers give connective tissue the property of elasticity
Reticular fibers
Thin fibers that form the branched netlike interwoven framework of soft organs like the liver and spleen
Elastic connective tissue
Contain an abundance of kinked elastic fibers that regain their original shape after being stretched.
- Produced by fibroblasts.
- Locations: elastic arteries, ligamentum nuchae
Collagenous (white fibrous) connective tissue
Tissue in which there is a greater proportion of white inelastic fibers than of elastic fibers.
Dense regular white fibrous connective tissue
Collagen fibers are arranged in parallel bundles, forming cords, which gives the tissue considerable strength in one dimension.
- Location: tendons, ligaments
Dense irregular white fibrous connective tissue
Collagen fibers are arranged in thick mat & going in all directions, which gives the tissue strength int all directions
- Location: dermis of the skin, capsules that surround organs
Areolar (loose) connective tissue
Contains combos of collagenous, reticular, and elastic fibers that are loosely arranged. Found where protective cushioning and flexibility is needed
- Produced by widely dispersed fibroblasts
- Location: hypodermis of skin, lamina propria of digestive organs
Reticular connective tissue
Contain loosely arranged interlaced network of reticular fibers.
- Produced by fibroblasts
- Location: form the framework of soft organs like the liver, spleen and lymph nodes during embryonic and fetal developent
Adipose connective tissue
Composed of a loose array of collagen fibers with adipocytes (fat cells) deposited within.
- Produced by adipocytes
Adipocytes
Modified fibroblasts that take up fat for storage as inclusions within the cytoplasm. The nucleus gets pushed to the side of the adipocytes by the large fat inclusions.
White fat
Most common type of fat. Used for energy storage and cushioning of organs. Found widely distributed throughout animal
Brown fat
Used to produce heat for young animals and animals awakening from hibernation. Found primarily in fat deposits between shoulder blades (interscapular)
Cartilage
Specialized type of connective tissue that is firmer than fibrous connective tissues but softer than bone.
- Produced by chondrocytes (cartilage cells)
Hyaline cartilage
Transparent or clear cartilage that can form a smooth surface to reduce friction
- Location: glass-like covering of bone within joints, epiphyseal cartilage of long bones, costal cartilages of ribs, tracheal rings
Fibrocartilage
Mixture of cartilage and collagen fibers that forms a semi-elastic cushion of great strength
Elastic cartilage
Mixture of cartilage and elastic fibers
- Location: external ear, larynx
Blood
A suspension of cells in an extracellular fluid (ECF) called plasma that circulates in the cardiovascular system
Bone
Composed of cells and non-cellular material
Ligamentum nuchae
A strong band elastic connective tissue that supports the head, particularly important in cattle and horses
External Environment
The external environment consists of the atmosphere surrounding the animal and also includes the lumen
Internal Environment
Environment inside of animal’s body
Cytosol (ICF)
Fluid component of cytoplasm
Total Body Water (TBW)
60% of an organism’s mass is fluid. Actual % will vary from 50-70% depending on the amount of adipose tissue
Intracellular Fluid (ICF)
Fluid located inside cells. Accounts for 40% of the animal’s body weight. (1/2 TBW)
Intracellular fluid volume (ICF; liters) = 0.4 x weight of animal (kg)
Extracellular Fluid (ECF)
Fluid found outside of cells. Accounts for 20% of the animal’s body weight (1/3 TBW)
Extracellular fluid volume (ECF; liters) = 0.2 x weight of animal (kg)
Blood Plasma
Fluid component of blood, which circulates in the cardiovascular system. Plasma is blood minus the blood cells.
- Plasma is 5% of the animal’s body weight.
Plasma volume (liters) = 0.05 x weight of animal (kg)
- Alternatively, plasma volume can be calculated as 25% of ECF volume. Plasma volume (liters) = 0.25 x ECF volume (liters)
Interstitial fluid (IF)
Fluid found between cells in tissues
- Interstitial fluid 15% of the animal’s body weight. IF volume (IF; liters) = 0.15 x weight of animal (kg)
- Alternatively, IF volume can be calculated as 75% of ECF volume. IF volume (liters) = 0.75 x ECF volume (liters)
Transcellular fluid compartment
A third body fluid compartment that includes cerebrospinal fluid, pleural fluid, peritoneal fluid, synovial fluids, intraocular fluids (aqueous and vitreous humor) and digestive fluids.
Transcapillary exchange
Solutes (and water) in the plasma move from the plasma into the interstitial fluid (IF) by crossing the capillary walls using a process called transcapillary exchange.
Epithelial tissues
- Exchange
- Secretion
- Secretory epithelium
- Exchange epithelium
- Transporting epithelium
- Protective epithelium
- Ciliated epithelium
Apical (luminal or lumenal) surface
Free surface facing the lumen that can interact with lumenal contents of a hollow organ
Serial (basal) surface
Surface attached to basement membrane, which is the non-cellular layer of adhesive material that glues the epithelial cells to underlying connective tissue
Lateral Surface
Surface between adjacent epithelial cells
- The basal and lateral surfaces often have similar characteristics and are collectively referred to as the “basolateral surface”
Tight junctions (zonula occludens)
“Collars”; ribbon-like thickening of plasma membrane just below apical surface of epithelial cells that goes completely around periphery of cells (lateral surface)
FXN: anchor plasma membranes of neighboring cells together in a manner that restricts movement of water or dissolved materials (solutes) into the space between cells
Adherents junctions (belt desmosomes, zonula adherens)
Collar-like membrane thickening made up of actin microfilaments
FXN: Adherens junctions tightly bind plasma membrane of cells to neighboring adjacent cells
Desmosomes (button desmosomes; macula adherens)
“Spot welds”, localized thickenings of adjacent plasma membranes that are anchored to intermediate filaments of the cytoskeleton
FXN: hold adjacent cells together
Hemidesmosomes
Spot welds that anchor cells to underlying basement membrane
Gap junctions
Pore-like structures that serve as sites of communication between adjacent epithelial cells. These pores permit exchange of molecules and ions between neighboring cells
FXN: link neighboring cells metabolically and electrically by allowing molecules and ions with a molecular weight
Simple epithelium
Single layer of epithelial cells that is usually well adapted to allow exchanges (diffusion ad filtration) of molecules and ions
Stratified epithelium
Multiple layers (2 or more) of epithelial cells that are often involved in protective functions
Squamous epithelium
Flat plate-like cells
Simple squamous epithelium
Single layer of flat plate-like cells
Stratified squamous epithelium
Multiple layers of flat plate-like cells
Cuboidal epithelium
Cells are roughly equal in size in all dimensions like a cube
Simple cuboidal epithelium
Single layer of cube-shaped cells
Stratified cuboidal epithelium
Multiple layers of cube-shaped cells
Columnar Epithelium
Cells are cylindrical in shape
Simple columnar epithelium
Single layer of columnar cells, which can be ciliates or nonciliated
Stratified columnar epithelium
Multiple layers of cylindrical shaped cells
Psuedostratified columnar epithelium
Composed of single layer of columnar cells of different lengths that gives the epithelium the false appearance of being stratified
Protective epithelium
Composed of stratified squamous epithelial cells that are tightly held together by desmosomes. This type of epithelium serves to protect exposed surfaces and to prevent exchanges between the internal and external environment
EX: epidermis of the skin, lining of the mouth, pharynx, esophagus, vagina, and urethra
Exchange epithelium
Composed of very thin, simple squamous cells that allow gases (CO2 and O2) to pass through rapidly. Gaps and pores between these epithelial cells allow ions and molecules (smaller than proteins) to pass.
Endothelium
Simple squamous epithelial cells that line the inside of all blood vessels, which are considered to be an exchange epithelium
Transporting epithelium
Composed of simple columnar or cuboidal epithelial cells with tight tight junctions that prevent movement of solutes between the cells. These cells allow selective transport of no gaseous materials, like nutrients and ions, between the internal and external environment using specialized transcellular mechanisms.
Ciliated epithelium
Composed of non-transporting cuboidal glandular cells that synthesize and release secretory products into the external environment or into the interstitial fluid (IF)
Gland
A structure, formed by secretory epithelial cells, that secretes substances for use elsewhere in the body or releases them for elimination from the body
Exocrine gland
Secrete their products through ducts into body cavities or onto body surfaces
Endocrine glands
Secrete their products (hormones) into interstitial fluid (IF) around the secretory cells. Usually, secreted products then diffuse into capillaries and are carried in the bloodstream to their target cells
Integument
Skin is the largest organ in the body
Epidermis
Outer, thinner layer of skin
A stratified squamous protective equipment consisting of three types of cells
Dermis
True skin - inner thicker layer of skin
Keratinocytes
- Principal structural cell of the epidermis
- > 90% of the cells found in the epidermis
- These cells produce a fibrous protein called keratin, which is the “water-proofing” and toughening protein in the skin
Melanocytes
Pigment (melanin) producing cells that contribute to skin and hair color. There are different types of melanin, which produce different colors of skin and hair
Langerhans cell
Function in immune protection within skin
Stratum basale (Germinativum)
Single layer of columnar cells found just above dermis. These are the only epidermal cells that are capable of undergoing mitosis (cell division)
Stratum Spinosum (spiny layer)
Composed of 8 to 10 layers of irregularly shaped cells with prominent desmosomes
Stratum Granulosum
Consists of spindle-shaped cells that possess granules containing keratohyalin, which is a precursor needed for keratin formation. Cells in this layer are starting to degenerate and have high levels of lysosomes and degenerating nuclei.
Stratum Lucidens (clear layer)
Found in a non-hairy areas of thick skin in humans, but not found in animals. This stratum is composed of three to five layers of dead, flattened keratinocytes of the stratum lucidum do not feature distinct boundaries and are filled with eleidin, an intermediate form of keratin.
Stratum Corneum (horny layer)
Consists in most areas of the skin of many layers of flattened cells with no nuclei. This stratum consists of mostly keratin.
Hypodermis
Areolor (loose) CT found under the dermis.
Hair follicle
Develop as an ingrowth of epithelial cells (keratinocytes) of the epidermis into the dermis.
- ingrowth becomes the “hair follicle” from which a hair shaft will emerge.
Compound hair follicle
- dogs, cats, sheep, and goats have compound hair follicles that produce two types of hairs
Primary or Guard hair
Long stiff hair in center of follicle
Secondary hairs or undercoat
Shorter fine hairs approx 3 to 15 per follicle
Arrector pilorum muscle
Bundle of smooth muscle fibers that extend at approx 45 degree angle from the deep portion of hair follicle up to epidermis. When these muscles contract, hair straightens up at 90 degree angle to the surface of the skin
Sebaceous gland
Secrete sebum (oil) for skin and hair
Sweat (sudoriferous) gland
Found over entire body of domestic animals (low density in hogs and carnivores)
Two Types:
- Merocrine
- Apocrine
Cornification
The conversion of squamous epithelial cells (keratinocytes) of the skin into hardened keratinized (horny) material
- fingernails, horns, hooves, claws, chestnuts, ergots
Solvent
The liquid in which chemicals are dissolved
- water in living organisms
- need polar covalent bonds
Solute
Substances that are dissolved in a solvent
- chemical
Solution
The combination of solute(s) dissolved in a solvent
Solubility
The degree to which a chemical dissolves in a solvent
Hydrophilic (lipophobic)
“Water loving” (or fat hating)
- Chemicals that dissolve easily in water –> electrolytes, charged molecules, uncharged molecules with polar covalent bonds
Hydrophobic (lipophilic)
“Water hating” (or fat loving)
- molecules that do not dissolve in water
- contain nonpolar covalent bonds
Amphiphilic or amphipathic
Molecules that contain BOTH a charged or polar (hydrophilic) group and a nonpolar (hydrophobic) group
Phospholipids
Amphiphilic molecules that form a fluid phospholipid bilayer in aqueous solutions
Cholesterol
An important structural component of lipid bilayer.
- hydrophobic and inserts into the hydrophobic region of the membrane
- the single polar hydroxyl group orients near the hydrophilic heads of the phospholipids
Glycosphingolipids (GSL)
Amphiphilic molecules that structurally resemble phospholipids with the main difference being that the phosphate-containing head group is replaced with carbohydrate group
Passive transport
Membrane transport processes that do not require any direct energy expenditure of cellular energy (ATP)
Active transport
Membrane transport process that require the expenditure of cellular energy usually in the form of ATP
Adenosine Triphosphate (ATP)
The most common high energy compound used to accomplish work in cells
Fluid Mosaic Model
Biological membranes are made up of a fluid lipid bilayer into which the integral membrane proteins are inserted
- membrane proteins then float in the fluid lipid bilayer allowing them to freely diffuse within the membrane
Diffusion
A passive process
- the distribution of a chemical substance in a solvent becomes equally concentrated
- ours down a solutes concentration gradient
- high solute concentration to low solute concentration
Open channel
Simply pools formed by transmembrane proteins that are open all the time
- leak channels
Gated channels
channels in the membrane that contain gates that ca be opened and closed in response to certain types of physiological stimuli
Voltage-gated channels
Channels whose molecular conformation (opened or closed) responds to changes in the electrical potential across the cell membrane
Ligand-gated channels
Channels whose molecular conformation (opened or closed) responds to the binding of a specific chemical (ligand)
Ligand
Term used to describe any molecule that binds to a protein
Mechanically-gated channels
Channels whose molecular conformations responds to physical stimuli like stretching of the membrane
Facilitated diffusion
Passive transport process that operates down the concentration gradient but requires a carried protein instead of a channel
Osmolarity
Concentration of a solution determined by multiplying the molarity of the solution by the number of particles that the chemical dissociates into when dissolved in water
Osmosis
Diffusion of water
- passive movement of water across a selectively permeable membrane
Tonicity
Characteristic of a solution defined by the response of cells when immersed in that solution
Isotonic solution
Solution in which cells do not shrink or swell
- approx 300 mOsm
Hypotonic solution
Hypertonic solution
Water moves from inside the cell into the surrounding solution causing the cells to shrink (crenated)
- >300 mOsm
Primary active transport
Active transport in which the energy for transport is derived directly from hydrolysis of ATP
Secondary active transport
Active transport in which the energy for transport is derived secondarily from energy that has been stored in the form of a concentration gradient across a membrane
- requires primary active transport to create necessary conditions
Uniporter
Moves a single solute from one side of the membrane to the other side
- in one direction
Symporters
Transfer two (or more) solutes across the membrane in the same direction
Antiporters
Transfer two (or more) solutes across the membrane in opposite directions
Vestibular transport
Form of active transport used to move large molecules and particulates across the membrane
Exocytosis
Process in which intracellular vesicles fuse with the plasma membrane to release the vesicles contents to the outside of the cell or to display membrane proteins or lipids on the cell’s surface
Endocytosis
Process by which a cell brings molecules into the cell in vesicles formed by invagination of the plasma membrane. Vesicles containing extracellular materials form at the inner surface of the plasma membrane and are then brought into the cell
Phagocytosis
“Cell eating”
Involves the ingestion of large substances or particles, such as microorganisms or dead cells, via large vesicles called phagosomes
Pinocytes
“Cell drinking”
Involves ingest ions of ECF and solutes via small pinocytotic vesicles
Receptor-mediated Endocytosis (RME)
Occurs when the binding of a ligand to a receptor triggers the Endocytosis of the resulting ligand-receptor complex
Transepithelial transport
Chemical substances have to move all the way across an epithelium instead of just across a single membrane
Transcellular route
When chemicals move across both membranes of the epithelial cells
Paracellular route
When chemicals move between the epithelial cells
- dependent upon tight junctions
Transcytosis
Various macromolecules are transported across the interior of a cell
Homeostasis
Maintenance of a relatively constant state of an animal’s “Internal Environment”
Dynamic equilibrium
Changes induce other changes in order to remain the same
Reflex pathway
Control pathways that involve sensing changes in an animal’s internal environment, integrating (evaluating) the sensory information, and responding appropriately to the change
- Nervous system, Endocrine system, Neuroendorcine control
Response loop
The portion of a reflex pathway beginning with the stimulus and ending with the response of the effectors (or target cells)
Feedback loop
Portion of a reflex pathway where the induced response feeds back and influences the response loop of control pathway
Stimulus
The disturbance or change that activates the pathway
Sensor or receptor
Cells that sense the stimulus or change
Afferent (towards) path
When the sensor is stimulated, it will notify the integration center of the change by sending a signal along the afferent path
Integration (control) center
Center that receives incoming signals and compares them to the setpoint for a particular factor
Efferent (away from) path
When deviation from setpoint is detected, the integration center will send out a signal along an efferent path to an effector
Effector
Target cell/tissue that carry out the response and bring about a change
Negative feedback loop
- Used to maintain homeostasis
- A stimulus (environmental change) is met by a response that reverses (negates) the trend or direction of the stimulus
Positive feedback loop
- Not involved in maintaining homeostasis
- A stimulus is met by a response that reinforces the trend of the stimulus instead of reversing it
Osmotic pressure
The minimum pressure which needs to be applied to a solution to prevent the inward flow of water across a semipermeable membrane.
It is also defined as the measure of the tendency of a solution to take in water by osmosis.
Hydrostatic pressure
The pressure exerted by a fluid at equilibrium at a given point within the fluid, due to the force of gravity.
