Review of Histology (P) Flashcards
What is tissue?
It is a grp of cells w/ similar structure and function
What is histology?
It is the study of tissue structure
What are the 4 basic tissue types?
1) Epithelial tissue
2) Connective tissue
3) Muscle tissue
4) Nervous (Neural tissue)
What are the characteristics of epithelial tissue?
1) It also forms glands
2) It is also found throughout the body covering tissues
What is the classification of epithelia based on number of layers and its corresponding cell shape?
Number of Layers: Cell Shape
Simple (1 layer): Squamous; Cuboidal; Columnar
Pseudostratified (a modified form of simple epithelium): Columnar
Stratified (more than 1 layer): Squamous; Keratinized;
Nonkeratinized (moist)
Transitional (a type of stratified epithelium): Roughly cuboidal to columnar when not stretched and squamous like when stretched
*What is simple squamous epithelium?
What is the purpose of simple squamous epithelium?
To prevent abrasion bet organs
How can simple squamous epithelium prevent abrasion bet organs?
By covering them and by secreting a lubricating fluid
*What is simple cuboidal epithelium?
*What is simple columnar epithelium?
What is pseudostratified columnar epithelium?
It is a modified simple columnar w/c appears to have more than 1 layer
What is the function of pseudostratified columnar epithelium and what is the action of this function?
Secretes mucus that covers its free surface
What are the characteristics of stratified cuboidal epithelium?
1) It is composed of 2 or more layers of cuboidal cells
2) It is relatively rare
3) It is found in sweat gland ducts, ovarian follicular cells, and salivary glands
What are the characteristics of stratified columnar epithelium?
1) It is also rare
2) It consists of more than 1 layer of epithelial cells, but only the surface is columnar
3) It is found in ducts in the breast, larynx, and portions of the male urethra
What is transitional epithelium?
It is a special type of stratified epithelium that can be stretched
*What is the characteristic of transitional epithelium?
*It has umbrella cells (dome cells) on the surface
What is the characteristic of connective tissue?
It is characterized by a large amt of extracellular mat separating the cells
What are the 3 components of the extracellular matrix of connective tissue?
1) Protein fibers
2) Ground substance consist of non-fibrous protein
3) Fluid
What are the 3 types of protein fibers (in connective tissue)?
1) Collagen fibers
2) Reticular fibers
3) Elastic fibers
What is ground substance (in connective tissue)?
It is the bg where the cells and protein fibers are seen
What is the characteristic of the ground substance (in connective tissue)?
It is made up of proteoglycans
How are connective tissue cells named?
They are named accdg to their functions
What are the connective tissue cells that are named accdg to their functions?
1) Blast: produces the matrix
2) Cyte: maintains the matrix
3) Clast: destroys the matrix
Provide exs of connective tissue cells that are named accdg to their functions
Osteoblast, osteocyte, osteoclast, fibroblast, and fibrocyte
What is the action of embryonic connective tissue?
It gives rise to 6 major connective tissue types
What is the action of extracellular matrix?
It determines the function of each connective tissue type
What are the diff classifications of connective tissues?
Loose (areolar) connective tissue
Adipose tissue
Dense connective tissue
A) Dense collagenous connective tissue
a) Collagen fibers arranged in the same direction
b) Collagen fibers arranged in many directions
B) Dense elastic connective tissue
a) Elastic fibers arranged in the same direction
b) Elastic fibers arranged in many directions
Cartilage
A) Hyaline cartilage
B) Fibrocartilage
C) Elastic cartilage
Bone
Blood
What are the characteristics of loose (areolar) connective tissue?
1) Extracellular matrix is composed mostly of collagen fibers and few elastic fibers
2) It is loosely distributed throughout the body
3) Basement membrane often rests in loose connective tissue
4) It is widely distributed throughout the body; substance on w/c epithelial basement membranes rest; packing bet glands, muscles, and nerves. Attaches the skin to underlying tissues
5) In terms of its structure, it is a fine network of fibers (mostly collagen fibers w/ a few elastic fibers) w/ spaces bet the fibers. Fibroblasts, macrophages, and lymphocytes are located in the spaces
What are the functions of loose (areolar) connective tissue?
1) It fills spaces bet glands, muscles, and nerves
2) Loose packing, support, and nourishment for the structures w/ w/c it is associated
What are the characteristics of adipose tissue?
1) It has very little extracellular matrix composed of collagen and elastic fibers
2) The cells are large and closely packed together, and appear empty under light microscope
- > each cell is filled w/ lipids
3) It is a connective tissue w/ special properties
4) In terms of structure, it has a little extracellular matrix surrounding cells. The adipocytes, or fat cells, are so full of lipid that the cytoplasm is pushed to the periphery of the cell
5) This is located predominantly in subcutaneous areas, mesenteries, renal pelves, around kidneys, attached to the surface of the colon, mammary glands, and in loose connective tissue that penetrates into spaces and crevices
What are the functions of adipose tissue?
1) Packing mat
2) Thermal insulator
3) Energy storage
4) Protection of organs against injury from being bumped or jarred
What is the other term for adipocytes?
Fat cells
What is the characteristic of dense connective tissue?
It is composed of densely packed fibers produced by fibroblasts
What are the 2 major categories of dense connective tissue?
1) Dense Collagenous Connective Tissue
2) Dense Elastic Connective Tissue
What are the characteristics of cartilage?
1) It is composed of chondrocytes located within spaces called lacunae, on a collagenous matrix
2) It heals slowly due to lack of direct blood supply
What is the purpose of collagen in the matrix?
To provide flexibility and strength
What is the proteoglycans in the ground substance and what is its purpose?
It is the substance that provide resilience
What are the characteristics of hyaline cartilage?
1) In terms of structure, collagen fibers are small and evenly dispensed in the matrix, making the matrix appear transparent. The cartilage cells, or chondrocytes, are found in spaces, or lacunae, within the firm but flexible matrix
2) In terms of location, growing long bones, cartilage rings of the respiratory system, costal cartilage of ribs, nasal cartilages, articulating surface of bones, and the embryonic skeleton
What are the functions of hyaline cartilage?
1) It allows the growth of long bones
2) It provides rigidity w/ some flexibility in the trachea, bronchi, ribs, and nose
3) It forms rugged, smooth, yet somewhat flexible articulating surfaces
4) It forms the embryonic skeleton
What are the characteristics of fibrocartilage?
1) In terms of structure, collagenous fibers similar to those in hyaline cartilage; the fibers are more numerous than in other cartilages and are arranged in thick bundles
2) In terms of location, intervertebral disks, symphysis pubis, articular disks (e.g. knees and temporomandibular [jaw] joints)
What are the functions of fibrocartilage?
1) It is somewhat flexible and capable of withstanding considerable pressure
2) It connects structures subjected to great pressure
What are the characteristics of elastic cartilage?
1) In terms of structure, it is similar to hyaline cartilage, but matrix also contains elastin fibers
2) It is located in the external ears, epiglottis, and auditory tubes
What is the function of elastic cartilage?
It provides rigidity w/ even more flexibility than hyaline cartilage because elastic fibers return to their original shape after being stretched
What are the characteristics of bone?
1) It is a hard connective tissue composed of living cells on a mineralized matrix
2) It has osteocytes that are located within lacunae
What are the 2 types of bone?
1) Compact bone
2) Cancellous bone (spongy)
What are the characteristics of bone?
1) In terms of structure, it is hard, and the bony matrix predominates; many osteocytes (not seen in the bone preparation) are located within lacunae; the matrix is organized into layers called lamellae
2) In terms of location, it is present in all bones in the body
What are the functions of the bone?
1) It provides strength and support
2) It protects internal organs such as the brain
3) It also provides attachment sites for muscles and ligaments
4) The joints of bones allow movements
What are the characteristics of blood?
1) It is a unique connective tissue because the matrix is liquid
2) In terms of structure, the blood cells and a fluid matrix
3) In terms of location, it is located within the blood vessels; WBCs frequently leave the blood vessels and enter the interstitial spaces
What are the functions of blood?
1) It transport O2, CO2, hormones, nutrients, waste products, and other substances
2) It protects the body from infections and is involved in temp regulation
What is the main characteristic of muscle tissue?
Its main characteristic is its ability to contract, making movement possible
The contraction by muscle tissue is brought by what?
It is brought about by contractile protein within the myocyte
What is the relationship bet the length of each myocyte to its diameter?
*The length of each myocyte is greater than its diameter = muscle fibers
What are the 3 types of muscle?
1) Skeletal muscle
2) Cardiac muscle
3) Smooth muscle
What are the characteristics of skeletal muscle in terms of:
1) Location
2) Cell shape
3) Nucleus
4) Special features
5) Striations
6) Autorhythmic
7) Control
1) Attached to bone
2) Long, cylindrical
3) Multiple, peripheral
4) NA
5) Yes
6) No
7) Voluntary
What are the characteristics of cardiac muscle in terms of:
1) Location
2) Cell shape
3) Nucleus
4) Special features
5) Striations
6) Autorhythmic
7) Control
1) Heart
2) Branched
3) Usually single, central
4) Intercalated disks
5) Yes
6) Yes
7) Involuntary
What are the characteristics of smooth muscle in terms of:
1) Location
2) Cell shape
3) Nucleus
4) Special features
5) Striations
6) Autorhythmic
7) Control
1) Wall of hollow organs, blood vessels, and glands
2) Spindle-shaped
3) Single, central
4) Cell-cell attachments
5) No
6) Yes
7) Involuntary
What is the function of skeletal muscle?
To move the whole body
What is the function of cardiac muscle?
Heart contraction to propel blood through the body
What is the function of smooth muscle?
Compression of organs, ducts, tubes, etc.
What are the functions of blood?
1) It transports O2, CO2, hormones, nutrients, waste products, and other substances
2) It protects the body from infectious
What are the characteristics of skeletal muscle?
1) It is a form of muscle tissue
2) In terms of structure, skeletal muscle cells or fibers appear striated (banded); cells are large, long, and cylindrical, w/ many nuclei located at the periphery
3) In terms of location, it attaches to the bone or connective tissue
What is the function of skeletal muscle?
For movement of the body (under voluntary control)
What are the characteristics of cardiac muscle?
1) It is a form of muscle tissue
2) In terms of structure, cardiac muscle cells are cylindrical and striated and have a simple, centrally located nucleus; they are branched and connected to 1 another by intercalated disks, w/c contain gap junctions
3) In terms of location, it is located in the heart
What is the function of cardiac muscle?
It pumps the blood (under involuntary control)
What are the characteristics of smooth muscle?
1) It is a form of muscle tissue
2) In terms of structure, smooth muscles cells are tapered at each end, are not striated, and have a single nucleus
3) In terms of location, it is located in hollow organs such as the stomach and intestine
What are the functions of smooth muscle?
1) It regulates the size of organs
2) It forces fluid through tubes
3) It controls the amt of light entering the eye
4) It produces “goose flesh” in the skin
- > all of these functions are done under involuntary control
What are the characteristics of nervous tissue?
1) It forms the brain, spinal cord, and nerves
2) It has the ability to communicate via electrical signals called action portentials
3) It is composed of neurons supporting cells
What are the 3 major parts of neurons?
1) Cell body
2) Dendrites
3) Axons
What are the supporting cells of neuroglia?
1) Astrocytes
2) Microglia
3) Oligodendroglia
4) Ependymal cells
5) Satellite cells
6) Schwann cells
Where is neuroglia found?
1) CNS
2) PNS
What does the CNS contain?
1) Astrocytes
2) Ependymal cells
3) Oligodendrocytes
4) Microglia
What does the PNS contain?
1) Satellite cells
2) Schwann cells
What are the functions of astrocytes?
1) It maintains the blood brain barrier
2) It provides structural support
3) It regulates ion, nutrient, and dissolved gas concentrations
4) It absorbs and recycle neurotransmitters
5) It forms scar tissue after injury
What are the functions of ependymal cells?
1) It lines ventricles (brain) and central canal (spinal cord)
2) It assists in producing, circulating, and monitoring CSF
What are the functions of oligodendrocytes?
1) It myelinates CNS axons
2) It provides structural framework
What are the functions of microglia?
1) It removes cell debris, wastes, and pathogens via phagocytosis
What are the functions of satellite cells?
1) It surrounds neuron cell bodies in ganglia
2) It regulates O2, CO2, nutrient, and neurotransmitter lvls around neurons in ganglia
What are the functions of Schwann cells?
1) It surrounds all axons in PNS
2) It is responsible for myelination of peripheral axons
3) It participates in the repair process after injury
