Vet Tech 1 Unit 1

Microscopic Anatomy

seen with a microscope (tissue, cells, etc)

Macroscopic Anatomy

seen with the unaided eye (organs, muscles, bones, etc)

Regional Anatomy

pertains to specific region (ex. forelimb anatomy)

Systemic Anatomy

pertains to body system (endocrine system)

Sagittal plane

left and right- offset, not necessarily equal

Median Plane

specific plane that divides the body into equal left and right parts

Transverse Plane

cranial and caudal, dorsal and ventral

Ventral (sternal) recumbence (DV)

dorsoventral view on radiographs

Dorsal recumbence (VD)

ventrodorsal view on radiographs

Right lateral recumbence

right lateral view in radiographs

Left lateral recumbence

left lateral view in radiographs

Cranial

towards head

Caudal

towards tail

Rostral

towards nose

Dorsal

toward the back

Ventral

Toward the belly

Dorsum

along back of animal

Medial

towards median plane

Lateral

away from median plane

Superficial

external

Deep

internal

Proximal

towards dorsal plane

Distal

away from dorsal plane

Palmar

palm of hand

Plantar

sole of foot

Withers

top of scapula where neck meets trunk of body

Barrel

pertaining to the trunk (body)

Flank

side of the body between the ribs and ilium

Brisket

Area at the base of the neck between the front legs that covers the cranial end of the sternum

Brachium

arm

Antebrachium

forearm

Poll

very top of head between ears

Muzzle

the projecting part of the face, including the nose and mouth, of an animal such as a dog or horse.

Tailhead

Dorsal part of the base of the tail

Stifle

knee (carpus)

Hock

ankle (tarsus)

Cannon

fore, hind

Fetlock

area of the limb between the pastern and the cannon

Pastern

area of the limb between the fetlock and hoof

Dorsal Cavity

central nervous system (cranial and spinal cavity)

Ventral Cavity

viscera of the thorax and abdomen (what's in the trunk)

*visceral pain = organ pain, broad pain

- divided by diaphragm into cranial thoracic cavity and caudal abdominal cavity

- animals without diaphragm = coelomic cavity (coelom)

Cranial Thoracic Cavity

- thorax

- Organs: heart, lungs, blood vessels, esophagus, trachea

- Pleura: thin sac lining chest

- inflammation: pleuritis/pleurisy

Caudal Abdominal Cavity (Peritoneal Cavity)

- Organs: digestive organs, reproductive organs, urinary organs, blood vessels

Peritoneum: thin sac lining abdomen

- Inflammation: peritonitis

Cells

- basic functional units of life

- Interdependent: cannot live alone

- Carry out functions such as contraction (muscle cells), absorb nutrients (intestinal cells), transport oxygen (red blood cells)

Tissue

- groups of specialized cells

- entire body is divided into 4 groups: Epithelial tissue, connective tissue, muscle tissue, nervous tissue

Organs

- groups of tissues that work together

- can be single structures like the brain or heart, or paired structures like eyes or lungs

Systems

- groups of organs that are involved in a common set of activities

- Ex) digestive system: mouth, salivary glands, esophagus, stomach, intestine, pancreas, liver; obtain food, digest food, absorb nutrients

Health

state of normal anatomy and physiology

Disease

results from abnormal anatomy or physiology

Homeostasis

- maintenance of dynamic equilibrium

- activity, energy, and work

- balance of various structures, functions, and properties

Examples of Cell Functions

- growth

- metabolism

- development

- reproduction

- adaptation

- respiration

- homeostasis

- obtain energy from food

- influenced by external stimuli

Prokaryotic Cells

lack a nucleus ("before nucleus")

Eukaryotic Cells

- distinct nucleus

- DNA combined with protein to form chromosomes, surrounded by a nuclear envelope

- found in all multi-cellular organisms today

Limitations on Cell Size

- Surface area to cytoplasm ratio comes down to nutrition requirements; smaller cells have an advantage

- Governing ability of the nucleus --> cell size/activity dictates number of nuclei

Mammalian Cell Anatomy

3 common structures:

- Plasmalemma- cell membrane

- cytoplasm

- nucleus

Cell Membrane

Flexible, elastic phospholipid bilayer

- controls passage of substances into/out of cell

- maintains receptors for attachment of ligands

- receptor waits to be triggered by ligand

Flagella and Cilia

- energetic, motile "hairs"

- extensions of the plasma membrane; made of microtubules and originate from basal bodies

Cilia

large numbers on exposed surfaces of certain cells

- synchronous, wave-like motion

- move fluid, mucus, debris

Flagella

move cells through fluid

- propel cell forward via undulations

- usually occur singly

- significantly longer than cilia

- ex) sperm cells

Caveolae

- "Little caves"

- pinch off and migrate into cell to form vesicle

- endocytosis, transcytosis, contact signaling

Cytoplasm

- inner substance of the cell (excludes nucleus and genetic material)

- principal components: cytosol, cytoskeleton, organelles

Cytosol

- viscous fluid of the cell

- comprised of dissolved electrolytes, amino acids, simple sugars, and proteins (mostly enzymes)

Cytoskeleton

- provides cell shape/support

- enables cell to move

- provides direction for metabolic activity

- anchors organelles

fiber types: microtubules, intermediate fibers, microfilaments, microtrabeculae

Microtubules

thickest cables or "railroad tracks" for organelle movement; also make up cilia and flagella- necessary for cell division- pair of tubulins that form a spiral chain

Intermediate Fibers

ropelike fibers with high tensile strength- resist forces pulling on the cell

Microfilaments

located near the cell surface, arranged in bundles and meshworks- composed of actin so with the motor protein (myosin), it's involved in cell division- permanent in muscle cells as myofibrils

Microtrabeculae

lattice that connects larger cytoskeletal elements, suspends free ribosomes, gives cytosol its jam-like consistency

Centrosome

region of cytoplasm near nucleus; build and breakdown microtubules

Centrioles

- small hollow cylinders composed of 9 triplets of microtubules

- duplicate in preparation for cell division (become spindle apparatus)

Mitochondria

- cellular respiration --> energy (powerhouse)

- divides by fission if energy demands increase

- contain DNA, RNA, and enzymes

- matrix contains enzymes, calcium ions, etc

- inner membrane folded for more surface area = increased production of energy

Ribosomes

- most common and smallest or organelles

- synthesize proteins

- two globular subunits: protein and ribosomal RNA (rRNA)

Ribosome Subunits

- small subunit attaches to mRNA

- large subunit provides exit for protein as it's formed

Ribosome Locations

- protein intended for intracellular use: ribosomes throughout cytoplasm

- protein intended for cellular export or for use in the plasma membrane: ribosomes attached to endoplasmic reticulum

Endoplasmic Reticulum (ER)

2 types: (both have a membrane that is continuous with the nuclear membrane)

1) Rough ER- ribosomes on surface, protein production

2) Smooth ER- synthesis and storage of lipids/steroids, eliminates drugs, breaks down glycogen to glucose (in liver)

Golgi Apparatus

- act as modification, packaging, and distribution center for molecules destined for secretion or for intracellular use (packages in vesicles and delivers to surface); vesicles

- polysaccharide synthesis

Lysosomes

- specialized vesicles formed by golgi apparatus

- functions include breakdown of molecules/debris within vesicles, autolysis ("self destruction"), breakdown extracellular material

Apoptosis

programmed cell death (normal) leading to release of organelles in membrane-bound apoptotic bodies

Proteasomes

- breakdown and removal of unwanted protein in the cell; one protein at a time

Peroxisomes

- membranous sacs containing peroxidases, catalases

- formed by fission of vesicles, or by pinching off of ER

- functions: detoxification, remove free radicals to prevent interference with proteins, lipids, and nucleic acids

Vaults

- transportation pods for molecules to/from nucleus

- made of protein and vRNA

Inclusions

- packaged units of metabolic products or substances the cell engulfed

- granules, vacuoles, vesicles, lipid droplets, fat globules

Nucleus

- largest organelle in the cell

- primary functions: maintain DNA, control cellular activity through protein synthesis

Nucleus Components

- nuclear envelope or membrane

- nucleoplasm: gel-like substances similar to cytoplasm

- chromatin

- nucleolus (nucleoli if multiple)

Nuclear Envelope

- 2 lipid bilayers; nuclear pores 10% of surface

- outer layer: continuous with ER, studded with ribosomes

DNA and RNA

- genetic information

- chains of nucleotides: nitrogenous base (DNA- adenine, cytosine, guanine, thymine; RNA- uracil instead of thymine), 5 carbon sugar, deoxyribose vs ribose, phosphate group

Chromatin

- light or dark fibers in nucleoplasm

- DNA + histones = nucleosome

- extended chromatin: uncoiled, active in protein synthesis

- chromosomes: condensed, during cell division

- histones: globular proteins that expose different genes at different times (gene regulation), 8 per DNA strand

Nucleoli

- making rRNA

- 1+ per nucleus

- dark-staining spherical area

- functions: ribosomal subunits made here, contain DNA to govern synthesis of rRNA

Sensible Water Loss

- you can cense it and measure it

- typical routes of excretion: urination, sweat, defecation

Insensible Water Loss

- you cannot sense or measure it

- other routes: transepidermal diffusion, respiratory loss

Body Fluids

- intracellular fluids

- extracellular fluids: interstitial fluids, intravascular fluid, lymphatic fluid, body cavities

Solutes in the Body

- ions (electrolytes): anions (Ca, sulfate), cations (Na, K), acids (H), bases (hydroxyl ion)

Electrolyte (Ion) Concentrations

intracellular fluid

- highest concentrations: K+, Mg2+

extracellular fluid

- highest concentrations: Na+, Cl-

Acidity

- more free H+ ions in a solution, greater the acidity

- pure water pH=7 (neutral)

- gastric acid=pH below 7

- more H+ ions

*more acidic = lower pH

Alkalinity

- more free OH- ions in a solution, more basic or alkaline

- bleach pH>7

-blood=pH of 7.4

*more basic = higher pH

Electrolyte Concentrations and pH

homeostasis for normal vital functions

- transmission of nerve impulses

- muscle contraction

- respiration

supported with IV fluids in sick patients

Osmolality

- measurement of solute concentration in fluid (per mass basis; higher osmolality = higher concentration of solutes = greater pull of water)

- Osmolarity: solute concentration in fluid (per volume basis)

Isotonic Fluids/Compartments

- osmolality between two compartments

- all fluid compartments in body are isotonic when at equilibrium

- water can pass freely

- isotonic fluid - fluid osmolarity = blood osmolarity

- Iso means same!

Isotonic Fluids

- ringer's solution

- LRS

- Normosol-R

- Plasmalyte

- 0.9% NaCl

Hypotonic Fluid Therapy

- osmolality of fluid is less than that of blood

- cytoplasm of the cell is more concentrated than the ECF

- water flows into the cell = swelling, breakage

- ex) 0.45% NaCl

Hypertonic Fluid Therapy

- osmolality of fluid is greater than that of blood

- extracellular fluid is more concentrated than the cytoplasm

- water shifts into extracellular space = cell shrinks/shrivels

- ex) 3%, 5%, 7.2% NaCl

- 10% dextrose