Unit 2: Ch 5 (Histology) Flashcards
Glands*
- Description
- Parts
- Components
- Types
- Function: Move/secrete substances
- Parts: Stroma & parenchyma
- Components: Capsule & septa or trabeculae (further categorized into lobes/lobules or globule/globules
-
Types:
- Endocrine glands
- Exocrine glands
- Some organs have both endocrine and exocrine functions (ie liver, gonads, pancreas)
-blasts
Immature cell
-cyte(s)
Mature cell
Adherens junction*
[review lecture audio]
- A protein complex located at the junction between epithelial cells, which are subjected to stretching and pulling, yet require tight contact between them so they can function as a single unit
- An element of the cell-cell junction in which cadherin receptors bridge the neighboring plasma membranes via their homophilic interactions.
- Cadherins associate with cytoplasmic proteins called catenins, which in turn bind to cytoskeletal components, such as actin filaments and microtubules
Adhesive Glycoproteins
- Bind tissue components together
- Mark paths that guide migrating embryonic cells to their destinations in a tissue
Adipose Tissue*
- Cells
- Blood supply
- Functions
- Locations
- Cells:
- Adipocytes
- Filled with triglycerides
- Blood Supply: Vascular
- Functions
- Contributes to body contours
- Anchors and cushions organs
- Provides thermal insulation (white/yellow & brown fat)
- Locations
- Subcutaneous fat beneath the skin
- Examples: Breast, heart surface, mesenteries, surrounding organs such as kidneys & eyes
- Notes
- Nucleus always found on the periphery of the cell; pressed against the plasma membrane
Apocrine Secretion
- Bud their secretions off through the plasma membrane producing extracellular membrane-bound vesicles
- The apical portion of the secretory cell of the gland pinches off and enters the lumen
- Found primarily in the breast of lactating mammals (i.e. the mammary glands are apocrine glands)
Areolar Tissue Functions
- Binds epithelial cells to deeper tissues
- Allows passage of nerves and blood vessels through to other tissues
- Arena for immune defense
Areolar Tissue*
- Description
- Cells
- Fibers
- Blood supply
- The most common, plentiful, and diverse tissue
- Nearly every epithelium rests on a layer of areolar tissue, whose blood vessels provide the epithelium with nutrition, waste removal, and a supply of leukocytes
- Cells: All 6 types
- Fibers
- All 3 types
- Random directions
- Blood supply: Vascular
Biopsy
The removal and microscopic examination of a sample of living tissue
Blood*
- Components
- Blood supply
- Functions
- Components
- Collectively called formed elements
- Erythrocytes / Red blood cells (RBCs)
- Leukocytes / White blood cells (WBCs)
- Blood platelets
- Doesn’t exhibit fibers, except when it clots
- Collectively called formed elements
- Blood supply: Vascular
- Functions
- Transports cells & dissolved matter through blood vessels
Bone Types*
- Spongy bone (internal portion of bone)
- Compact bone (hard & strong with calcium and phosphate molecules)
Brown Fat*
- Mainly in fetuses, infants, and children
- Concentrated in fat pads in the shoulders, upper back, and around the kidneys
- Stores lipids in the form of multiple globules rather than one large globule
- Notes
- Color comes from the abundance of blood vessels and enzymes in its mitochondria
- Mitochondria oxidative pathway is not linked to ATP synthesis
- Oxidized fat energy is released as heat
- Hibernating animals accumulate brown fat in preparation for winter
Cartilage*
- Description
- Cells
- Fibers
- Blood supply
- Functions
- Locations
- Start as chondroblasts that become trapped in lacunae, and then become chondrocytes surrounded by perichondrium _(_only in hyaline and elastic cartilage)
- Matrix is rich in chondroitin sulfate
- Surrounded by perichondrium (only the hyaline & elastic fibers)
- Cells
- Chondroblasts
- Chondrocytes
- Fibers
- Hyaline
- Collagen
- Fibrocartilage
- Blood supply
- Avascular
- Functions
- Provide shape and support
- Examples: ear, nose, thyroid cartilage (adam’s apple)
- Locations
- Fetal bones, ears, intervertebral discs, places of flexibility
- Notes
- Chondrocytes takes longer to heal because it is avascular, meaning that it relies upon diffusion for blood supply
Cell Junctions*
- Description
- Functions
- Types
- The connection between one cell and another
- Enable cells to resist stress, communicate with each other, and control the movement of substances through tissues
- Types
- Tight junction (structural junction)
- Adherens (structural junction)
- Desmosomes (structural junction)
- Hemidesmosomes (structural junction)
- Gap junction (communicating junction)
Chondro-
Cartilage
Collagen fibers*
- Description
- Appearance
- Most abundant protein in the body
- Appearance
- Thicker than elastic fibers
- Glistening white appearance, often called white fibers
- Function
- Form the fibers of many connective tissues in places such as the dermis, tendons, and bones
- Important for the functionality of strength (the thicker it is, the stronger it is)
- Resist stretching
- Base of gelatin, leather, and glue
Compact Bone*
- Cells
- Components
- Functions
- Locations
- Cells
- Osteoblasts/osteocytes
- Lacunae
- Structure
- Osteon: functional unit of a compact bone
- Periosteum
- Cells and matrix surround vertically oriented blood vessels in long bones
- Canaliculi: allows for communication/transportation of messages and physically connect osteocytes
- Components
- Calcium & phosphate molecules
- Functions
- Allows for communication and transportation of messages
- Physically connects osteocytes
- Locations: Surrounds spongy bone
Cells found in the connective tissues*
- Adipocytes: Fat cells that provide insulation, shock absorption, and energy storage
- Fibroblasts: Create fibers of extracellular matrix
- Leukocytes: White blood cells (immunity/protection)
- Macrophages: Performs phagocytosis
- Mast cells: Release histamines
- Plasma cells: Antibodies and immunity
Fibers that form the connective tissues*
- Fiber Types
- Ground substance/extracellular matrix
- Collagen fibers: strength
- Elastic fibers: Thin; allow for movement in tissue (ie heart and lung expansion)
- Reticular fibers: lymphatic & immune systems
Connective Tissue Functions*
- Binding of organs
- Support
- Physical protection
- Immune protection
- Movement
- Storage
- Heat production
- Transport
Connective Tissue Ground Substance
- Absorbs compressive forces and, like the styrofoam packing in a shipping carton, protects the more delicate cells from mechanical injury
- Usually has a gelatinous to rubbery consistency resulting from 3 classes of large molecules:
- Glycosaminoglycans
- Proteoglycans
- Adhesive glycoproteins
Connective tissue types*
- Loose Connective Tissue
- Areolar
- Reticular
- Dense Connective Tissue
- Dense regular
- Dense irregular
- Notes
- The anatomical difference between the two types is how much space is between the cells
- The difference between dense tissue is how the collagen fibers are arranged in a plane
Connective Tissue*
- Description
- Types
- Parts
- Most abundant, widely distributed, and histologically variable of the primary tissues
- Connective tissue types
- Fibrous tissue
- Loose connective tissue
- Areolar
- Reticular
- Dense connective tissue
- Dense regular
- Dense irregular
- Loose connective tissue
- Adipose tissue
- Cartilage
- Bone
- Spongy
- Compact/Dense
- Blood
- Fibrous tissue
- Parts
- Cells
- Matrix (aka extracellular matrix)
Cutaneous Membrane
- The largest membrane of the body; the skin
- Stratified squamous epithelium (epidermis - keratinized) that rests on a layer of connective tissue (dermis)
Dense Irregular Connective Tissue*
- Cells
- Fibers
- Blood supply
- Functions
- Locations
- Cells
- Few visible
- Located in 3 planes
- Fibers
- Collagen
- Randomly arranged
- Blood supply
- Vascular
- Scarce
- Functions
- Withstands unpredictable stresses
- Locations
- Skin
- Around viscera such as liver, kidney, spleen
- Fibrous sheaths around cartilages and bones
Dense Regular Connective Tissue*
- Cells
- Fibers
- Blood supply
- Functions
- Locations
- Cells
- Fibroblasts (compressed in the nuclei)
- Fibers
- Elastic
- Collagen
- Parallel; wavy-like pattern
- Blood supply
- Scarce blood vessels (results in slow healing)
- Functions
- Ligaments tightly bind bones together and resist stress
- Tendons attach muscle to bone and transfer muscular tension to bones
- Locations
- Tendons
- Ligaments
Desmosomes
- Functions
- Locations
- Functions
- Serve to keep cells from pulling apart and enable tissues to resist mechanical stress
- A patch that holds cells together somewhat like the snap on a pair of jeans
- Cannot prevent substances from passing around them and going between the cells
- Locations
- Common in the epidermis, the epithelium of the uterine cervix
- Notes
- Not continuous
- The basal cells of epithelium are similarly linked to the underlying basement membrane by half-desmosomes called hemidesmosomes
Anatomical & physiological differences between keratinized and nonkeratinized epithelia*
- Anatomical
- Presence or lack of keratin
- Physical
- Nonkeratinized have living cells throughout
- Keratinized are superficial layers that contain dead cells