Quiz 4 TISSUES Flashcards
TISSUE
- homogenous group of cells with a similar structure and function which work together as a unit
- differ greatly in size, shape, composition and nature ranging from fluid blood to compact bone
- this vast difference is the sum of two variables: CELL TYPE & EXTRACELLULAR FLUID (ECM)
Extracellular Fluid
- fluid rich in proteins that serve to connect and aid communication with neighboring cells
- produced by the very cells it surrounds, and together with any endogenous matter it comprises the interstitial space
- in essence, the inside and outside of a cell determines the tissue type
Cell Differentiation
- we start as one cell
- two cells each carrying half the genetic code for a human being unite into one (fertilization)
- DNA merges, copies are made, and the one cells begins to divide
- eventually, we are 75+ trillion cells forming our unique anatomic and physiological self
Potency
- we start out totipotent
- within a few days of fertilization CELL DIFFERENTIATION begins and our cells are now pluripotent
- as cell division continues, differentiation continues and we are born with cells that are multipoint and fully differentiated cells
Totipotent
Pluripotent
Multipotent
Fully Differentiated
Totipotent: the first cell has the potential to express any and all of our genes (Zygote)
FIRST DIFFERENTIATION (Blastocyst and Trophoblast)
Pluripotent (Fetus, embryonic)
Multipotent: some potential to still differentiate into many cell types (Infant, adult)
Fully Differentiated: no potential for producing anything but an exact replica of itself (can not be a stem cell)
4 basic tissue types
Epithelial
Connective
Nervous
Muscular
Epithelial Tissue: Unifying Concepts
- Avascular: does not have blood supply to actual tissue itself, blood to surrounding tissue
- Innervated: has a nerve supply
- Labile: changeable (e.g. callous on foot)
- Includes linings, coverings, barriers, and glands
- Forms sheets (prevents stuff from leaking out, eases diffusion)
Asymmetry (upside/downside; inside/out)- Luminal Surface: not in contact with other cells and may be smooth, villous, or ciliated
- Basal Surface: anchored to underlying cells via a basement membrane
- Named by their architectural design
- squamous, cuboidal, columnar, transitional
- simple, stratified, pseudostratified
Epithelial Tissue: Functions
vary among the different types of epithelial tissue, and include: protection, absorption, excretion, secretion
Epithelial Tissue: Glands
- specialized secretion forming epithelial cells
Anatomy: Unicellular (mucus: goblet cells)
Multicellular (sweat, milk, enzymes, bile, waste)
Type: Endocrine: secrete into circulation (hormones)
Exocrine: secrete into a hollow structure for eventual excretion (Serious: watery, protein rich; Mucous: thick, carb rich; Sebaceous: oily, lipid rich)
Mechanism:
Merocrine, Apocrine, Holocrine
Merocrine, Apocrine, and Holocrine (mechanism of glands)
Merocrine: no cellular damage with secretion
Apocrine: part of cell membrane and some cytoplasm pinched off with secretion
Holocrine: total cell death with secretion
Apoptosis & Necrosis
Apoptosis: programmed cell death (DNA)
Necrosis: caused by factors external to the cell or tissue such as toxins, infection, physical trauma, lack of nutrients, etc.
Connective Tissue: Unifying Concepts
- vascular, innervated, labile, everywhere
- includes cells and a protein matrix secreted by the cells (vast ECM)
- includes all of our support/connecting structures
Connective Tissue: Function
vary among the different CT types, and include:
storage, support, protection, transport
Connective Tissue: Types
CT Proper:
- Loose CT: areolar, adipose
- Dense CT (dense regular: tendons, ligaments; dense irregular: capsules and membranes surrounding various organs)
Specialized CT:
- blood, bone, cartilage, lymph, elastic CT
Nervous Tissue: Unifying Concepts
- permanent, excitable
- dependent on ion gradients, specifically Na, K, Ca
- includes brain, spinal chord, and nerves
Nervous Tissue: Functions
communicate via neurotransmitters at the cell junction
Muscle Tissue: Unifying Concepts
- stable/permanent, excitable, contractile
- dependent on ion gradients, specifically Na, K, Ca
Muscle Tissue: Functions
movement through contraction
Muscle Tissue: Types
- Skeletal: attaches to bone, gross movement, voluntary
- Smooth: in tubes and hollow organs, transport, involuntary
- Cardiac: bulk of the heart, heartbeat, involuntary
MEMBRANES (Epithelial)
Mucous membrane: line entry/exit ways (GI, GU, respiratory)
- secreted mucus for immune function and protection
Serous membrane: line closed cavities (thoracic/abdominal) & attach to organs
- pleurae, peritoneum, serous pericardium
- secrete serous fluid for lubrication
MEMBRANES (Connective)
Synovial membrane: inner surface of all synovial joints
Meningeal membrane: protects/insulates brain and spinal chord
Other: fascia, periosteum, fibrous pericardium
Atrophy
waste away, decrease in cell size (usually part of apoptosis)
Hypertrophy
increase in cell size
Hyperplasia
proliferation of cells, overgrowth of cells
Dysplasia
abnormal development
Metaplasia
a change in the type of adult cells in a tissue to a form abnormal for that tissue
Neoplasm (tumor)
is an abnormal growth of tissue, and when also forming a mass is commonly referred to as a tumor
Cancer
is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body?
Metastasis
When cancer spreads from the part of the body where it started (its primary site) to other parts of the body
