Classification of Tissues Flashcards
Cells group together with one another based on similar structure and function
Tissues
The study of tissue is called
Histology
What are the four basic types of tissues?
epithelium, connective, muscular, nervous
Tissue that lines and covers surfaces.
Epithelium
Tissue that protects, supports, and binds together
Connective tissue
Tissue that produces movement
Muscular tissue
Tissue that receives stimuli and conduct impulses
Nervous tissue
What are the purposes of epithelium?
protection, absorption, excretion, secretion, filtration, and sensory reception
Epithelium is arranged so there is one free surface (____________) and one attached surface (_____________)
apical surface, basal surface
Cells in epithelium fit closely together side by side and sometimes atop each other to form sheets of cells. These sheets are held together by ______________.
specialized junctions
Epithelium is supported by ___________ tissue.
connective
Attachment to a layer of connective tissue at the basal surface forms a layer called the _________________, an adhesive layer formed by secretions from the epithelial cells and the connective tissue cells.
basement membrane
Epithelium is ________, meaning it typically lacks its own blood supply.
avascular
It is the most abundant and widely distributed tissue type found in the human body.
Connective tissue
Connective tissues tend to be very __________ (have a rich blood supply).
vascular
Exceptions in connective tissues that are vascular are ____________, __________, __________.
tendons, ligaments, cartilage
Connective tissues contain a large amount of non-living material referred to as the _________.
matrix
Matrix in connective tissue is composed of __________and ___________.
ground substance, fibers
The body is protected externally by one of its largest organs called
skin or integument
The skin is formed by three distinctive layers.
epidermis, dermis, and hypodermis
This is the outer layer of the skin.
epidermis
This is the middle layer of the skin.
dermis
This is the subcuntaneous layer and the innermost layer of the skin.
hypodermis
Layer of skin that is composed of keratinized stratified squamous epithelium
Epidermis
The epidermis is arranged into five layers:
Stratum corneum
Stratum lucidum
Stratum granulosum
Stratum spinosum
Stratum basale
outermost layer of flattened, dead cells
Stratum corneum
thin, translucent layer found only in thick areas of the skin
Stratum lucidum
names for the abundance of granules present. Upper boundary of this layer is where cells begin to die
Stratum granulosum-
layer where cells divide rapidly. Usually one of the thicker layers of the epidermis.
Stratum spinosum
the lowest layer of the skin. Attached to the dermis where it forms a basement membrane. Cells are constantly dividing to produce new cells
Stratum basale
Layer of skin that is composed of dense irregular connective tissue.
Dermis
projections or ridges that arise from the dermis that serve as attachment points for the epidermis
Dermal papillae
The layer of the skin that is composed of adipose tissue.
Hypodermis
produces sweat (mixture of water, salts, and urea) that acts to cool the body.
Eccrine gland
produce sebum (oil) to help keep the skin soft and pliable.
Sebaceous gland
It is associated with pain sensation; located in near dermal papillae
Free nerve endings
touch receptors- associated with tactility; located in near dermal papillae
Meissner’s corpuscle
pressure receptors; located deep within dermis at the boundary of the dermis and hypodermis.
Pacinian corpuscle
muscle that pulls up hair follicle leading to goose flesh or “goose bumps”
Arrector pili
It means a portion of an organism that is capable of developing or growing into a new part or a new whole
germ or germinate
A germ layer is a collection of cells that are formed during ______________ or during the phases of reproductive development.
embryogenesis
When the male sperm cell unites with the female egg cell this creates a fertilized egg cell, also called a ____________.
zygote
Immediately after this time, the rapid process of cell multiplication begins, as 2 cells become 4, become 8, and onward, until a hollow ball of cells called the _____________ is generated
blastula
From the blastula comes the _________, which is like is a hollow horseshoe-shaped structure that has the start of three distinct cell layers
gastrula
Finally, there is the formation of the __________ (also called the yolk sac) upon which the three primary germ layers can be located.
embryo
Humans are _________-, that is, they have a body that is derived from three embryonic cell layers
triploblastic
What are the three primary germ layers?
endoderm, mesoderm, and ectoderm
It is found in the innermost potion of the embryo.
Endoderm
It is found in the middle potion of the embryo.
Mesoderm
It is found in the outermost potion of the embryo.
Ectoderm
Most of this epithelial tissue is comprised of cells, with very little extracellular material; this is what the term ‘___________’ refers to.
cellularity
Types of attachments in epithelial tissues
- Tight Junctions
- Desmosomes
- Hemidesmosomes
- Gap Junctions
fibrous attachments to neighboring cells at the apical end of the exposed cell layer. It is like a zip-lock seal that goes all the way around the top end of the tissue. Its role is to restrict the passage of unwanted substances (e.g., bacteria or fungi) into the body in between adjacent cells
Tight Junctions
These are also fibrous (collagen) attachments to neighboring cells, but these are located at the basal end of the cell layer, near basement membrane. These are more like ‘spot-welds’, they do not go around the entire cell continuously but are more sporadically located. Their role is to provide mechanical support during distention of the tissue, so cells remain attached to each other at the basal end.
Desmosomes
fibrous attachments of basal epithelial cells to the underlying basement membrane. Their role is to anchor these deepest basal cells to the basement membrane.
Hemidesmosomes
These are little protein channels that provide an open conduit from one neighboring cell to another. This allows for cell to cell communication via ions or other substances.
Gap Junctions
What are the two layers of basement membrane?
basal lamina and reticular lamina
What are the two layers of basal lamina?
lamina lucida and lamina densa
basement membrane that is made by epithelia tissue
basal lamina
basement membrane that is made by the connective tissue
reticular lamina
the clear layer of basal lamina, which is closer to the epithelium
lamina lucida
the dense layer of basal lamina, which is closer to the connective tissue
lamina densa
Epithelium that is found in glands that secrete substances.
Glandular Epithelia
What are the two types of glands that secrete substances?
Endocrine and exocrine
gland that secretes hormones directly into body fluids, usually blood.
Endocrine
gland that secretes products by way of duct onto an exposed surface.
Exocrine
secretion of exocrine glands by exocytosis (of vesicles), cell stays intact
Merocrine
Mode of secretion of exocrine glands wherein exocytosis of thicker, lipid-rich product (tip of the gland is shed).
Apocrine
mode of secretion of exocrine glands wherein vesicles accumulate and the entire cell is shed as a product.
Holocrine
