Chapter 3: Histology Flashcards
What are the 4 major categories of tissues in the body?
Epithelial
Connective
Muscle
Nervous
What is a zygote?
a single fertilized cell that all multicellular organisms begin life as
What are the 3 primitive germ layers?
Ectoderm
Mesoderm
Endoderm
Ectoderm
primarily develops into the epidermis (top layer of skin), epidermal derivatives (glands, hair, nails), entire nervous system (brain, spinal cord, nerves) and neural components of the endocrine tissue (adrenal gland and posterior pituitary)
-Epithelial and nervous tissue
Mesoderm
primarily develops into internal epithelial structures (lining of body cavities, cardiovascular, urinary, reproductive, and lymphatic system) entire muscular system, (skeletal, smooth and cardiac muscle), endocrine structures, and connective tissue developing into the skeletal system
-Epithelial, connective, and muscle tissue
Endoderm
primarily develops into epithelial glandular derivatives of the digestive, respiratory, urinary, reproductive, and endocrine systems.
-Epithelial tissue
What are the 5 characteristics of epithelial tissue?
- Cellularity- cells tightly bound
- Polarity- one surface is attached and one is exposed
- Attachment- cells are firmly attached
- Regeneration- cells are damaged and replaced rapidly
- Avascular- does not contain blood vessels.
What are the 4 types of cellular arrangement of epithelial tissue?
Simple- single layer of cells
Stratified- multiple layers of cells
Pseudostratified- cells firmly attached to the basement membrane, but because of varied nucleus locations, it appears multi-layered.
Transitional- cells vary in shape and size depending on degree of tissue stretch, large and round cells…
What are the 3 types of cell shape for epithelial tissue?
Squamous- cells are thin, flat, and irregular in shape
Cuboidal- cube-shaped cells
Columnar- cylindrical shaped, tall cells
What are the 2 types of epithelial stratified squamous tissues?
Unkeratinized- no smooth layer at the edge (vagina)/oesophagus
Keratinized- smooth layer on the edge (skin)
what are the 5 characteristics of connective tissue?
- No cellularity- cells are not closely associated
- No polarity- all cells contained within body, no cellular surface exposed
- No attachment- cells are not attached to other tissue
- Slow regeneration- cells are not damaged easily, so division and regeneration is slow
- Vascular- they have blood vessels (except cartilage)
Proper connective tissue
wide variety of cell types and protein fibers in a thick semi-fluid ground substance
characterized into loose and dense proper CT according to concentration of protein fibers
3 types of loose CT proper
a. Areolar CT “space”, widely spaced (cushion, support, mobility)
b. Adipose CT “fat” closely associated cells (heat, energy reserve, protect, cushion)
c. Reticular CT “web” (support soft tissues) fibers coursing around organ cells
3 types of dense CT proper
a. dense regular CT (strong attachment in one direction), stabilization.
b. dense irregular CT (strong attachment in multiple directions)
c. Elastic CT (elasticity) elastic fibers allows tissue to stretch and rebound shape
What is lacunae?
spaces within the matrix housing the osteocytes.
Glandular epithelia
A type of tissue that lines certain internal organs and makes and releases substances in the body, such as mucous, digestive juices, and other fluids.
Exocrine glands
function and 3 types?
release secretions directly onto body’s external and internal body spaces
3 types:
a) Holocrine glands
b) Merocrine (eccrine) glands
c) apocrine glands
Holocrine glands
secrete their contents through process of cell lysis.
releases its secretions by disintegrating the whole cell So the entire cell breaks down to release what’s called sebum
associated with hair follicles
Merocrine (eccrine) glands
most common type of exocrine gland
secretes contents through process of exocytosis without causing any damage or loss in the secretory cel
sweat, salivary, gastric glands
Apocrine glands
secrete contents through process of exocytosis, allows large volumes of secretion without cell death.
secrete their secretions in the form of pinched-off buds or vesicles
Mammary glands and ceruminous (ear) glands
Basement membrane
glycoprotein secretion functioning to attach cells to the underlying tissue
Mesenchymal cells
embryonic connective tissue; pluripotent cells
Extracellular matrix
extra-cellular substance consisting of the ground substance and protein fibers
Ground substance
solution surrounding the cellular and fibrous components of connective tissue
Fibroblast
Connective tissue cell responsible for secreting large amounts of protein into the extracellular matrix
What are the 2 types of supportive connective tissue?
Cartilage
Bone (osseous tissue)
What are the 3 types of cartilage?
Hyaline
fibrocartilage
Elastic
What are the 2 types of bone (osseous tissue)?
Compact bone (dense)
Spongy bone
Hyaline cartilage
Characteristics and function
most abundant and weakest cartilage
tough but somewhat flexible
thin groups of collagen fibers
Fx: reduces friction, provides stiff but somewhat flexible support and protection
Elastic cartilage
Characteristics and function
Most flexible, large amount of elastic fibers
support and flexibility
Fx: support and maintain shape
Fibrocartilage
Characteristics and function
strongest cartilage
interwoven, thick collagen fibers
Fx: resist compression, prevent bone to bone contact, limit joint motion
Compact bone (dense bone)
-contains few spaces between bony matrix
-forms outer wall of bones
-arrangement of matrix and osseous cells
-have lamella, lacuna, central canal, canaliculi, osteoctyes, and a calcified matrix
Central canal
forms center of osteon or haversion system.
open space in bony matrix allowing passage of blood vessels & nerves,
supply blood to active osteocytes
Lamellae
rings of bony matrix around central canal and resident blood vessels
Canaliculi
small canals connecting osteocytes within lacunae to central blood vessels
allows for better diffusion and access to nutrients
Perforating (Volkmann’s) canal
communicating canals connecting adjacent central canals, allowing blood flow between adjacent osteons
What are the 4 types of bone cells?
- Osteoprogenitor cells “bone”
-unspecialized bone cell that can become active - Osteoblasts “bud or germ”
-active bone matrix forming cells
-produces osteoid which calcifies to hard bone - Osteoctye “cell”
-mature bone cells derived from osteoblast
-maintenance of surrounding osseous tissue - Osteoclast “break”
-breakdown of matrix, re absorption of osseous tissue
spongy bone
Characteristics & function (Fx)
-forms core of most bones and ends of long bones
-composed of lattice of interlocking beams/struts of bony matrix
-retrieve nutrients directly from surrounding blood
Bony beams are called Trabecula (spongy appearance)
Spaces between trabecula filled with blood forming cells comprise the red bone marrow
fluid connective tissue
Characteristics & function (Fx)
comprised of blood and lymph
copious amounts of extracellular fluid containing specialized cells
carry metabolic products, nutrients, respiratory gases, chemical messengers, functional proteins, and waste products to all body cells
Simple squamous ET
Characteristics & function (Fx)
single layer of flat, thin, irregular shaped cells
lining blood vessels, body cavities, portions of kidney tubules
Fx: protection, allowing diffusion (absorption and secretion)
Stratified squamous ET
Characteristics & function (Fx)
multiple layers of flattened cells
Keratinized or unkeritanized (Depending on presence of waterproofing keratin protein)
covering skin, lining mouth, throat, anus, vagina, esophagus
Fx: protection: physical, chemical, infections
Simple cuboidal ET
Characteristics & function (Fx)
single layer of cube shaped cells
round, centered nuclei
no intercellular space
in glands, kidney tubules, liver, thyroid
Fx: protection, secretion, absorption
Simple columnar ET
Characteristics & function (Fx)
single layer of column shaped cells
no intercellular space
tall nuclei, located at basal end of cell
Lining intestine, stomach, gallbladder
Fx: protection, secretion, absorption
Pseudostratified columnar (ciliated) ET
Characteristics & function (Fx)
single layer of columnar cells
oval nuclei at various levels within cell, layered/striated appearance.
often have cilia on surface
lining trachea, nasal passages, bronchi
Fx: secretion, movement of surface molecules (protection)
Transitional ET
Characteristics & function (Fx)
multiple layers of cells of varying shapes
cell shape depends on stretch of tissue
lining urinary bladder, renal pelvis, ureters
Fx: allowing tissue expansion/recoil without damage to epithelium or restricting organ function (stretching)
Areolar CT (loose CT proper)
Characteristics & function (Fx)
widely spaced cells, fills spaces between structures for support and protection
Fx: cushion, support, allowing mobilityy
Adipose CT (loose CT proper)
Characteristics & function (Fx)
closely associated cells, appear hollow
Fx: reduce heat loss, protect, cushion, energy reserve
Reticular CT (loose CT proper)
Characteristics & function (Fx)
composed of numerous reticular fibers coursing around organ cells
Fx: provide supportive framework for soft tissues
Dense regular CT
Characteristics & function (Fx)
Uniformly arranged collagen fibers
forms tendons, ligaments, and aponeuroses
Fx: provides strong attachment and stabilization
Dense irregular CT
Characteristics & function (Fx)
non-uniformly arranged protein fibers
in dermis of skin, sheath covering bones (periosteum), and capsule around various organs
Fx: provides strength to resist force applied in various directions
Elastic CT (dense)
Characteristics & function (Fx)
large quantities of elastic fibers
Fx: cushion, elasticity (Stretching)
Identify this
Fibrocartilage
Identify this
Hyaline cartilage
Identify this
Elastic Connective Tissue (CT)
identify this
Elastic Cartilage CT
Identify this
Compact bone (ground)
Identify this
Reticular CT (loose proper CT)
Identify this
Dense regular CT (dense proper)
Identify this
Dense irregular CT (dense proper)
Identify this
Adipose CT (loose proper)
Identify this
Areolar CT (loose proper)
Identify this
Transitional ET
Identify this
Pseudostratified ciliated columnar ET
Identify this
Simple columnar ET
Identify this
Keratinized stratified squamous ET
Identify this
Simple cuboidal ET
The three major components of connective tissues are :
cells, ground substance, and protein fibers.
Which tissues are found as coverings and linings in the body?
Epithelial
The epithelial tissue made of a single layer of long rectangular cells, often found in areas where absorption and secretion are important is:
simple columnar
identify this
simple cuboidal ET
Identify this
simple squamous ET
Identify this
stratified squamous ET
Identify this
Adipose CT
Identify this
Areolar CT
The bone cells responsible for the active secretion of bone matrix are:
osteoblasts
the bony matrix is hardened by the addition of calcium phosphate and calcium hydroxide minerals collectively called:
hydroxyapatite
Unspecialized bone cells derived from mesenchymal cells, which have potential to develop into active bone matrix secreting cells (osteoblasts) are called :
osteoprogenitor cells
What is the structural and functional unit of compact bone?
Osteons
the concentric rings of matrix around the central canal are:
lamellae
the small spaces which house mature osteocytes
lacunae
the bony struts or “little beams” which comprise the lattice of spongy bone are:
trabeculae
small communicating canals connecting osteocytes within lacunae to central blood vessels are:
canaliculi
The serous membrane lining the surface of the lung is the ______________
visceral pleura
cardiac muscle cells are connected to each other with specialized cell junctions that connect the cytoplasm of adjacent cells. These junctions are called ______________
gap junctions
_______ bone does not have a canal.
spongy
bone cells responsible for secreting bony matrix, actively building new bone tissue are called __________
osteoblasts
both cartilage and bone cells reside in small spaces within their matrix called :
lacunae
Identify both structures
- compact bone CT
- central canal
identify
elastic cartilage CT
Identify
Dense regular CT
Identify
Reticular CT
Identify
Adipose CT
Identify
Areolar CT
Identify
Transitional ET
Identify
unkeratinized stratified squamous ET
