Anatomy Module 1

Anterior (Ventral)

front of body

Posterior (dorsal)

back of body

Superior

above

Inferior

below

Cranial

above (towards the head)

Caudal

Below (towards tail)

Medial

Closer to midline

Lateral

away from the midline

Proximal

Closer to the point of attachment/origin

Distal

farther from the origin of a body part or the point of attachment

superficial

near the surface

Deep

away from the surface

Histology

studies the microscopic structure of tissue

Histo= tissue

logy= the study of

Light Microscopy

light beam focused on specimen (magnified)

-stain applied to visualized

Electron Microscopy

high resolution + magnification

Transmission Electron Microscopy

beam of e- focused on sample

(absorbed/scattered by specimen's parts to form image on photographic plate)

**black and white image

Scanning Electron Microscopy

for visualization of sample surface (e- bounced off the surface)

ex. dental plaque

Microvilli

apical specialization on certain cells

Preparation of Tissue (LM)

1. Smear

2. Sectional Method

Smear

ex. blood, bone marrow, cervical cells, sputum, pus

Sectional Method

Thin piece of tissue on slides

**multi-step process to prepare

Steps for Sectional Method

1. Fixation

2. Embedding

3. Sectioning

4. Mounting

5. Staining

Fixation

Treatment to tissue to stop post-mortem alternations

-helps maintain normal tissue architecture

**most r flash-freezed (quick + easy, but not for long-term study)

Embedding

To prepare tissue for slicing/manipulation

-encased in rigid block of supporting medium

(dehydrates tissue so becomes smaller than living tissue)

Examples of Embedding Medium

Paraffin, plastic, gel

Sectioning

Cut specimen into thin slices (5 microns)

**plane of section dramatically affect appearance of structures

Mounting

Tissue is mounted onto slide (allows for further studies)

Staining

to create color contrast to visualize structure elements

Basic Stain

Stains nuclei

-positively charged --> stains negatively charged cellular components

ex. hematoxylin (dark blue/purple)

Acidic Stain

Stains cytoplasm

-negatively charged so stains positively charged parts

ex. eosin (light pink/orange)

Basophilic

cells that like or attracted to BASIC stains

Acidophilic/ Eosinophilic

cells that like ACIDIC stains

Organs

Made up of 2 components: parenchyma (functional cells) + stroma (supportive framework/connective tissue)

Periodic Acid-Schiff (PAS stain)

Colorful (magneta color)

-shows structures rich in carbohydrates (ex. glycogen)

Gram's Stain

Differentiate 2 bacteria based on different cell wall structure

-Gram positive= violet

-Gram negatuve= pink/red

Tichrome Stain

Specialized stain that shows fibrous components of extracellular matrix from muscle/epithelium

-nuclei= black

Muscle/blood cells/cytoplasm/fibrin= red

-collagen/mucin= blue

Elastic Stain

Elastic fibers will turn black/brown

Silver Stain

reticular fibers (stroma) stain black

Myelin Stain

fatty sheath that covers nerve axons to increase speed of conductance

-stains dark/black

Immunohistochemistry

Localization of specific antigens in tissue by the use of labeled antibodies

-antibody will bind to antigen

-fluorescent second antibodies will bind to antibody to give color