M1-1 Cells and Tissues Vocab

Superior

“above,” “upper”

Adipose (fat) tissue

A type of connective tissue that stores fat, provides insulation, cushioning, and support for the body.

Adipocytes

Specialized fat cells that make up the adipose tissue and store energy in the form of lipid (fat) droplets.

Apical membrane

The surface of an epithelial cell that faces the lumen or external environment, often involved in absorption or secretion.

• has tiny finger-like projections (microvilli) that increase S.A. available for transport

Basal lamina/basement membrane

A thin layer of extracellular matrix that separates epithelial cells from underlying connective tissue, providing support and influencing cell behavior.

• ECM epithelial cells that make up this layer

• proteins that are secrete by epithelial cells and depostied on the basolateral surface

• a thin, protein‑rich layer of extracellular matrix that underlies the basal side of epithelial cells.

Basolateral membrane

The surface of an epithelial cell on the cell membrane that faces the extracellular fluid playing a role in cell communication and transport.

• may also have folds that increase the cell’s surface area

Caudal

“waist line”

Cell-cell junctions

Protein complexes which connect and hold cells together; connections of different cells in the body

Cell-matrix adhesions

Protein complexes which connect cells to the ECM

Ciliated epithelium

• Simple cuboidal/columnar

• apical surface (tissue surface facing lumen) covered with cilia that beats in coordinated rhythmic motion, moving fluid and particles across the tissue surface

ex. nose, trachea, upper airways

Chondrocytes

Specialized cells that produce and maintain the firm but flexible matrix of the cartilage in the body.

Columnar epithelium

A type of epithelial tissue characterized by high, column-like cells that are primarily involved in absorption and secretion, often found in the digestive tract and respiratory system.

• found in transporting, ciliated, and secretory epithelia

Connective tissue

The diverse, second major tissue type that supports, binds together, and protects tissues and organs of the body

• contains a loose widely scattered mesenchymal cells in the extensive ECM

• includes blood, support tissues for the skin and internal organs, cartilage and bone

Types of Connective Tissues

1. Loose connective tissue

2. Dense/Fibrous connective tissue

3. Supporting connective tissue

4. Blood

Cranial cavity

• relative term to describe the location of the “head of the body”

Cuboidal epithelium

• A type of epithelial tissue characterized by cube-shaped cells that are involved in secretion and absorption, commonly found in glandular tissues and the lining of kidney tubules.

• found in protective, transporting and ciliated epithelia

Dense connective tissue

• A type of connective tissue that is characterized by a high density of collagen fibers, providing strength and flexibility

• includes fibroblasts and densely packed ECM

• It is commonly found in tendons, ligaments, and the dermis of the skin.

Distal

“far from the body in extremity"”

Dorsal

• known as ‘posterior’

• “Back of the body”

Elastin

• A coiled, wavy protein fiber found in connective tissues that provides elasticity and resilience

• protein return to its original shape after stretching.

Endocrine gland

• A ductless gland that secretes products/hormones directly into the bloodstream to regulate various body functions such as metabolism, growth, and mood.

• ex. pituitary, thymus, thyroid, pineal

Endothelium

• most common type of epithelium

• simple squamous epithelium lining the heart and blood vessels

Epithelial tissues

• lines the external and internal surfaces of most organs

• any substance crossing the internal/external boundary crosses an epithelium

• organized by structure and function!!

Exchange epithelium

• contains simple squamous for efficient gas exchanges between cells and across the epithelium

• weak tight junctions

• lines lumen of blood vessels/capillaries

• can be fenestrated (pores in capillaries to allow smaller molecules than proteins to pass between two adjacent epithelial cells

Exocrine duct/gland

A gland that releases products through ducts into the external environment (outside of the body)

ex. sweat, sebaceous, salivary, liver, pancreas, mammary, and mucous

Extracellular matrix (ECM)

• The network of extracellular proteins surrounding the cells in tissues

• synthesized and secreted by the cells of a tissue

• these proteins provide cell attachment and resistance to compression

• associated with all cell types, but most abundant in connective tissue

Fenestrated capillaries

• large pores that allow high volumes of fluid to pass rapidly between the plasma and interstitial fluid

• primarily found in the kidney and the intestine

Fibroblasts

• A type of cell in connective tissue that secretes collagen-rich matrix, playing a crucial role in wound healing and maintaining the extracellular matrix.

• cells that secrete matrix proteins

• -blast: on a connective tissue name often indicates a cell that is either growing or actively secreting extracellular matrix

Frontal/coronal plane

A vertical plane that divides the body into anterior (ventral, front ) and posterior (dorsal, back)) sections.

Histology

Study of tissue structure and function

Homeostasis

Maintaining the internal body’s regulation within an finite range of normal values in response to a changing environment

• Variables under homeostatic control: temp, pH, osmolarity, water/oxygen levels, ions, hormones

• ALWAYS CHANGING AND AT DISEQUILIBRIUM; NOT STATIC

Inferior

“below”; “lower part of the body”

Lateral

“Side of the body”

Ligaments

• Connect one bone to another bone

• contain elastic fibers

• limited ability to stretch and provide stability to joints.

• elastin allow for shock absorbant

Loose connective tissue

• elastic tissues that underlie the skin and provide support for small glands

• very flexible with multiple cell types and fibers

• contains fibroblasts and loose ECM

• attaches epithelia to underlying tissues

• provides shape and structure to organs

Lumen

interior of any hollow organ that may be wholly or partially filled with air or fluid

ex. heart, lung, blood vessels, intestines

Medial

“Center of the body”

Mesenchymal cells

• widely scattered (loose unstructured) cells that secrete and modify the extensive ECM in connective tissues

Negative feedback

• the response opposes or removes the stimulus, shutting off the response loop

• stabilize the regulated variable and helps the system maintain homeostasis

Osteoblasts

Specialized cells synthesize and deposit matrix, stimulating bone formation

Pelvic cavity

• apart of one of the 3 main body cavities: abdominopelvic cavity

• beneath the abdominal cavity and bounded by the pelvic bones

• contains organs such as the female reproductive systems, urinary bladder, and the lower digestive tract/the terminal portion of the large intestine

Positive feedback

• the response further amplifies the stimulus rather decreasing or removing it, sending the variable farther from the set point

• response increases in the same direction as the stimulus

Posterior

Dorsal; “Back of the body”

Proximal

“Close to the central body in proximity”

Protective epithelium

• found on the outer skin/integumentary system

• Stratified bottom cuboidal layers to stratified top squamous

• outer skin cells are constantly being replaced

• prevent exchange between internal and external environments and provide protection

• strong tight junctions to keep water in and pathogens out

• found on the skin, lining of cavities that open to the environment (digestive/respiratory tract)

Sagittal plane

A vertical plane that divides the body into left and right sections.

Secretory epithelium

• composed of epithelial cells that produce a substance and secrete it into the internal/external environment

• contains to types of glands: exocrine and endocrine glands

Simple Epithelium

• A single layer of cells

• It is typically found lining internal organs and body cavities.

Squamous epithelium

• A type of epithelium made up of flat, squashed cells that allow for rapid diffusion and filtration.

• It is commonly found in areas such as the alveoli of the lungs and the lining of blood vessels.

Stratified epithelium

• many epithelial layers

• It is commonly found in areas subject to abrasion, such as the skin and the lining of the mouth.

Tendons

• Connective tissues that attach muscles to bones.

• They are strong and resistant to pulling force

• lack elastin so cannot stretch

• not stretchy so muscles can contract → move bones

transporting epithelium

• actively and selectively import/export solutes (nongaseous materials; ions and nutrients) between the internal and external environment

• lines the hollow tubes of digestive system and kidney (where lumens open into the external environment)

• simple cuboidal/columnar NOT STRATIFIED

• No free exchange; strong tight junctions

• contains microvilli - increase surface area for absorption

transverse/cross-sectional plane

A hortizonal division section providing a view of internal organs or structures

• superior vs inferior

Ventral

• known as the anterior

• “front of the body”