TAMU BIOL 319 LAB Preface and Lab 1

Sagittal plane/section

divide the body or organ into right and left portions

Midsagittal plane/section

divides the body or organ into equal right and left sides

Frontal (coronal) plane/section

divides the body or organ into anterior and posterior portions

Transverse (cross section)

divides the body or organ into superior and inferior sides

Oblique

passes through the body or organ at an angle

Anatomical position

To stand erect with arms at the sides and palms of the hands turned forward

Superior (cranial)

toward the head end or upper part of a structure or the body; above

Inferior (caudal)

away from the head end or toward the lower part of a structure or the body; below

Anterior (ventral)

Nearer to or at the front of the body

Posterior (dorsal)

Nearer to or at the back of the body

Medial

Nearer to the midline of the body

Lateral

Further from the midline of the body

Intermediate

Between two structures

Ipsilateral

On the same side of the body as another structure

Contralateral

On the opposite side of the body as a structure

Proximal

Closer to the trunk or point of attachment

Distal

Farther from the trunk or point of attachment

Superficial

Toward or on surface of the body

Deep

Away from the surface of the body

Osteocyte

derived from osteoblasts- involved in bone maintenance

Osteoclast

Multinucleate cell that secretes acids and enzymes to dissolve bone matrix

Osteoblast

Derived from osteoprogenitor cells - secretes organic components of matrix

Osteoprogenitor cells

stem cells that differentiate into osteoblasts

Histology

study of tissues

epithelial tissue

tissue that lines and covers organs and internal passageways, creates boundaries between different environments, and forms glands; made up of sheet of cells (joined together via tight junctions and desmosomes)

Apical (free) surface

Surface of the cells that are exposed to the external environment or to an internal passage way or cavity; obtain nutrients by diffusion of substances from connective tissue that are underlying the epithelia

Simple epithelium

• Single layer of cells

• function: diffusion, absorption, filtration, and secretion

• at the free surface, microvilli on the epithelial cell membrane increase surface area for absorption

• goblet cells secrete mucus that coats the cell to protect epithelia at free surface

• cilia, small motile hair-like projections from the apical surface that sweep substances across the apical surface

Stratified epithelium

Composed of more than one layer of cells

• found in areas exposed to abrasions and friction (body surface and upper digestive tract)

• mostly for protection

• regenerate from basal cells that divide and move out to replace older cells near the apical border

• stratified squamous is most common

Regeneration of tissues

How easily the tissues can be regenerated; based on the rate of mitosis and the amount of blood supply

Examples of good to excellent regeneration of tissue

Epithelial tissue, bone, areolar tissue, dense irregular connective tissue, and blood forming tissue

Examples of moderate regeneration of tissue

Smooth muscle and dense regular connective tissue

Examples of weak regeneration of tissue

Skeletal muscle and cartilage

Example of none of almost no regeneration of tissue

Cardiac muscle tissue and (central nervous system) nervous tissue

Reasons why regeneration of tissue can be high

If the rate of mitosis is high and there is adequate or abundant blood supply

Avascular

No blood vessels or supply

Function: simple squamous epithelium

To allow passage of materials by diffusion and filtration in sites where protection is not important; secrets lubricating substances in serosae (tissue lining of a body cavity or outer lining of an organ)

Description: simple squamous epithelium

single layer of flattened cells with disc-shaped central nuclei and sparse cytoplasm; the simplest of the epithelia

Location: simple squamous epithelium

Kidney glomeruli, air sacs of lungs, lining of heart, blood vessels, lymphatic vessels, lining of ventral body cavity

Avelous

Air sack present in between linings of the simple squamous in the lung

Endothelium

type of simple squamous epithelia that:

provides a slick, friction-reducing lining in lymphatic vessels and in all hollow organs of the cardiovascular system

Mesothelium

type of simple squamous epithelia that:

the epithelium found in serous membranes lining the ventral body cavity and covering its organs

Description: simple cuboidal epithelium

single layer of cube-like cells with large, spherical central nuclei

Function: simple cuboidal epithelium

Secretion and absorption

Location: simple cuboidal epithelium

Kidney tubules; ducts and secretory portions of small glands; ovary surface

Lumen

pocket that lies in the center of a circle of simple cuboidal epithelium

Description: simple columnar epithelium

single layer of tall cells with round to oval nuclei; some cells bear microvilli on surface AND cilia; layer may contain mucus-secreting unicellular glands (goblet cells)

Function: simple columnar epithelium

absorption; secretion of mucus, enzymes, and other substances; ciliated type propels mucus (or reproductive cells) by ciliary action

Location: simple columnar epithelium

Nonciliated type lines most of the digestive tract (stomach to rectum), gallbladder, and excretory ducts of some glands; ciliated variety lines small bronchi, uterine tubes, and some regions of the uterus.

Goblet cells

secrete mucus

How simple columnar epithelium looks under the microscope

Almost looks like petals with nuclei near the inner rim; the goblet cells look like white pockets

Description: stratified squamous epithelium

thick membrane composed of several cell layers; basal cells are cuboidal or columnar and metabolically active; surface cells are flattened (squamous); in the keratinized type, the surface cells are full of keratin and dead; basal cells are active in mitosis and produce the cells of the more superficial layers

Function: stratified squamous epithelium

protects underlying tissues in areas subjected to abrasion

Location: stratified squamous epithelium

nonkeratinized type forms the moist linings of the esophagus, mouth, and vagina; keratinized variety forms the epidermis of the skin, a dry membrane

Basement membrane

Cells at the base of an epithelial layer are attached to this

Description: pseudostratified ciliated columnar epithelium

Single layer of cells of differing heights, some not reaching the free surface; nuclei seen at different levels; may contain mucus-secreting cells and bear cilia

Function: pseudostratified ciliated columnar epithelium

Secretion, particularly of mucus; propulsion of mucus by ciliary action

Location: pseudostratified ciliated columnar epithelium

Nonciliated type in male's sperm-carrying ducts and ducts of large glands; ciliated variety lines the trachea, most of the upper respiratory tract

Description: transitional epithelium

resembles both stratified squamous and stratified cuboidal; basal cells cuboidal or columnar; surface cells dome shaped or squamous-like, depending on degree of organ stretch

Function: transitional epithelium

stretches readily and permits distension of certain hollow organs (urinary organ by contained urine)

Location: transitional epithelium

lines the ureters, bladder, and part of the urethra

Connective tissue

made from mesenchyme; A body tissue (non-cellular) that provides support for the body and connects all of its parts (also protects, stores reserve energy, insulates the body, and transports substances throughout the body)

Fibroblasts

In connective tissue, stationary cells that secrete the proteins of the fibers.

• macrophages patrol these tissues and are mobilized during an infection or injury, migrate to the site of the disturbance, and phagocytize damaged tissue cells and microbes

Mast cells

Detect foreign microorganisms and initiate immune responses against them; release histamine that causes inflammatory response, but also secretes heparin, proteases, and other enzymes

Adipocytes

fat cells; contain vacuoles for storage of lipids, that make up most of the subcutaneous layer

Loose connective tissue

has an open network of protein fibers in a thick, syrupy ground substance and is divided into three groups

Dense connective tissue

Made up of two types of fibers: protein fibers assembled into thick bundles of collagen and elastic fibers with widely scattered cells

Dense regular connective tissue

Protein fibers in the matrix are arranged in parallel bands

Dense irregular connective tissue

fibers are interwoven; has fibers that run in many different directions and is found where tension is exerted from many different directions (capsules of joint and organs, dermis of skin, submucosa of the digestive tract)

What are the two types of fluid connective tissue?

blood and lymph

• blood contains red blood cells (erythrocytes) and white blood cells (leukocytes - which mediate immune responses and tissue response to injury)

What are the two types of supporting connective tissue?

bone and cartilage

• bone is composed predominantly of calcium phosphate salt (hydroxyapatite); supports and protects the body, provides cavities for synthesis of blood cells and storing fact

• bone is more rigid than cartilage because of more collagen fibers and hydroxyapatite

• unlike cartilage, bone is highly vascularized and innervated

• cartilage can withstand both compression and tension because it is tough and somewhat flexible

Perichondrium

surrounds all supporting connective tissue in cartilage and produces chondroblasts (which secrete fibers and the ground substance of cartilage matrix)

• cartilage receives nutrients by diffusion from perichondrium

• chondroblasts become trapped in the matrix called lacunae and turn into chondrocytes

What are the three types of cartilage?

hyaline, elastic, fibrocartilage

Which tissue has all 3 fibers present?

Areolar tissue

Description: Areolar Connective Tissue

gel-like matrix with all three fiber types; cells: fibroblasts, macrophages, mast cells, and some white blood cells; loose arrangement of fibers creating space for water and salt storage

Function: Areolar Connective Tissue

wraps and cushions organs; its macrophages phagocytize bacteria; plays important role in inflammation; holds and conveys tissue fluid

Location: Areolar Connective Tissue

Widely distributed under epithelia (skin) of body, e.g., forms lamina propria of mucous membranes; packages organs; surrounds capillaries.

Description: Adipose tissue

matrix as in areolar, but very sparse; closely packed adipocytes, or fat cells, have nucleus pushed to the side by large fat droplet

Function: Adipose tissue

provides reserve food fuel; insulates against heat loss; supports and protects organs

Location: Adipose tissue

under skin in subcutaneous tissue; around kidneys and eyeballs; within abdomen; in breasts; around heart and in bone marrow (serves as fuel for high energy demand organs)

Description: Reticular tissue

network of reticular fibers in a typical loose ground substance; reticular cells lie on the network

Function: Reticular tissue

fibers form a soft internal skeleton (stroma) that supports other cell types including white blood cells, mast cells, and macrophages

Location: Reticular tissue

lymphoid organs (lymph nodes, bone marrow, and spleen)

Description: Dense regular connective tissue

Primarily parallel collagen fibers; a few elastic fibers; major cell type is the fibroblast

Function: Dense regular connective tissue

attaches muscles to bones or to muscles; attaches bones to bones; withstands great tensile stress when pulling force is applied in one direction

Location: Dense regular connective tissue

Tendons (connect muscle to bone); most ligaments (connect bone to bone); aponeuroses

Description: Dense regular elastic tissue

Dense regular elastic tissue containing a high proportion of elastic fibers

Function: Dense regular elastic tissue

Allows recoil of tissue following stretching; maintains pulsatile flow of blood through arteries; aids passive recoil of lungs following respiration

Location: Dense regular elastic tissue

walls of large arteries; within certain ligaments associated with the vertebral column; within the walls of the bronchial tubes

Description: Blood

Red and white blood cells in fluid matrix

• erythrocytes: transport blood gases

• leukocytes: cells of the immune system and protect the body from infection

• thrombocytes: form a plug to reduce bleeding

Function: Blood

Transport of respiratory gases, nutrients, wastes and other substances

Location: Blood

contained within blood vessels

Description: Bone

hard, calcified matrix containing many collagen fibers; osteocytes lie in lacunae

Function: Bone

bone supports and protects (by enclosing); provides levers for the muscles to act on; stores calcium and other minerals and fat; marrow inside bones is the site for blood cell formation (hematopoiesis)

Location: Bone

bones

Lamellae

Concentric rings made up of groups of hollow tubes of bone matrix

Haversian canal

one of a network of tubes running through compact bone that contains blood vessels and nerves; center dark spot in the osteoblasts

Canaliculi

Hairlike canals that connect lacunae to each other and the central canal

Description: Hyaline cartilage

amorphous but firm matrix; collagen fibers form an imperceptible network; chondroblasts produce the matrix and when mature (chondrocytes) lie in lacunae

Function: Hyaline cartilage

supports and reinforces; serves as resilient cushion; resists compressive stress

Location: Hyaline cartilage

forms most of the embryonic skeleton; covers the ends of long bones in joint cavities; forms costal cartilages of the ribs; cartilages of the nose, trachea, and larynx