Topic 4 = Histology
Voluntary
Conscious control over skeletal muscles. Found attached to bones.
Endocrine
Have no ducts; secrete hormones directly into blood
Mast cells
Secrete heparin to inhibit clotting. Secrete histamine to dilate blood vessels.
Striated muscular tissue
Alternating dark and light bands
Axon (nerve fiber)
Sends outgoing signals to other cells, Can be more than a meter long
Adipose tissue function
energy storage, insulation, protective padding
pseudostratisifed columnar epithelial tissue location
lines nasal cavity, trachea, bronchi, male reproductive ducts
dense irregular tissue function
multidirectional tensile strength
Dendrites
multiple short, branched processes, receive signals from other cells, transmit messages to neurosome
Apocrine
musky smell, in axillary and genital region
desmosomes
patch that links a cell to a neighboring cell. ties into the cytoskeletal system
necrosis
pathological tissue death due to trauma toxins or infections
apoptosis
programmed cell death, normal cellular process
Hypertrophy
enlargement of preexisting cells
areolar tissue function
"packing peanuts," stores fluids, immune surveillance
What is the outer embryotic tissue called?
Ectoderm
Areolar tissue location
underlies most epithelial, surrounds blood vessels, nerves, and visceral organs
stem cells
undifferentiated cells, can divide repeatedly, can produce one or more cell types,
Elastic tissue location
walls of large arteries, vocal cords
phase 3 of wound healing
week 1-6 proliferation, pulls the wound closed
phase 4 of wound healing
week 6 to 2 years remodeling, final proper tissue
what is meant by stratified
2 or more layers of cells
Recticular
A supporting mesh in soft tissues such as liver, bone marrow, and the tissues and organs of the lymphatic system
Hemidesmosomes
Anchor epithelial cells to a basement membrane
Elastic
Are extracellular components of higher vertebrates and confer elasticity and resilience to numerous tissues and organs such as large blood vessels, lungs, and skin
When looking at the stratified tissues, which cell layer determines the name, basal or apical?
By the shape of the most apical layer of cells, closets to the free space.
Unicellular
Can be exocrine or endocrine.
Multicellular
Capsule, stroma, parenchyma.
Chondrocytes
Cartilage cells that are trapped in lacunae (cavities).
Glands
Cell or organ that secretes substances for use elsewhere in the body or releases them for elimination from the body
Holocrine
Cells accumulate a product until they "burst" Secrete a mixture of cell fragments and synthesized substances Examples: oil glands of scalp and skin, and glands of eyelids
UnStriated muscular tissue
Cells are elongated, cells are not branched.
What is the inner embryotic tissue called?
Endoderm
Keratinized and nonkeratinized Stratified squamous Location
Epidermis, Tongue, oral mucosa, esophagus, and vagina
Involuntary
Found in the walls of internal organs.
Proteoglycans
Gigantic molecules (core protein plus GAGs) shaped like bottle brushes. Form gravy-like colliods that hold tissues together.
cell body (neurosoma)
Houses nucleus and other organelles, controls protein synthesis
where would you find stem cells
In the basal layer of the epidermis
Serous membrane (serosa)
Internal membrane. Function- Produces serous fluid that arises the blood.
Mucous membrane (mucosa)
Lines passages that open to the external environment (example: digestive tract). Sublayers: epithelium, lamina propria (areolar tissue), muscularis mucosa (smooth muscle). Function- Absorptive,secretory, and protective functions.
Exocrine
Maintain their contact with surface of epithelium by way of a duct.
What is the middle embryotic tissue called?
Mesoderm
Macrophages
Phagocytize foreign material and activate immune system.
Fibroblast
Produce fibers and ground substance of matrix.
secretion
Product useful to the body.
Neuroglia (or glial cells)
Protect and assist neurons,"Housekeepers" of nervous system, *More numerous than neurons*
Stratified squamous (keratinized and nonkeratinized)- function
Protection against microorganisms from invading underlying tissue and/or protection against water loss
Adhesive glycoproteins
Protein-carbohydrate complexes. Bind component tissue together
Cutaneous membrane (The skin)
Relatively dry layer serves protection.
Glycosaminoglycans
Responsible for stiffness of cartilage.
Adipocytes
Store triglycerides (fat molecules)
skeletal muscle tissue
Striated, multinucleated, voluntary
Plasma cell
Synthesize antibodies(proteins)
Collagen
The fiber in the extracellular matrix of connective tissues characterized by being elongated and made up of collagen glycoproteins.
Osteocytes
They allow for nutrients and transfer between cells through gap functions.
excretion
Waste product.
Leukocytes
White blood cells.
transitional epithelium function
allows the organ to stretch; protects underlying tissue
what is the basement membrane
basal lamina and reticular lamina
what are the four stages of wound healing?
bleeding, inflammation, proliferation, remodeling
bone tissue location
bones
metaplasia
changing from one type of mature tissue to another
Hormones
chemical messengers that stimulate cells elsewhere in the body
epithelial tissue characteristics
closely packed cells, covers body surfaces and lines body cavities, have a free upper surface, avascular, usually nourished by underlying connective tissue, have a high rate of mitosis
phase 1 of wound healing
day 1-3 hemostosis
phase 2 of wound healing
day 3-20 inflammation, new framework for blood vessel growth
dense irregular tissue location
deep part of the dermis, fibrous capsules of organs and joints, fibrous sheaths of bones, nerves, and many cartilages
Neurons (nerve cells)
detect stimuli, respond quickly, and transmit coded information rapidly to other cells
Elastic cartilage location
ear, epiglottis
elastic tissue function
elasticity
does the endocrine or exocrine system secrete directly into the bloodstream?
endocrine
stratified squamous epithelium location
epidermis (heavily keratinized); oral cavity, esophagus, vagina (non-keratinized)
the 4 classes of tissues
epithelial, connective, muscle, nervous
does the endocrine or exocrine system use ducts
exocrine
matrix
fluid/gel-like, mesh of reticular fibers
hyperplasia
growth through cell multiplication
blood connective tissue location
heart and blood vessels
Adipose tissue location
hypodermis, surround organs, yellow bone marrow, fatty deposits
Fibrocartilage location
intervertebral discs, some joints, pubis symphysis
smooth muscle tissue
invoulintary, not striated, fusiform, large nucleus, smaller than the other 2 muscle tissues
Simple Cuboidal epithelial tissue Location
kidney tubules, small ducts and glands
Simple Columnar epithelial tissue Location
lines the digestive tract, uterus, uterine tubules, small bronchi, ducts of large glands
Simple squamous epithelial tissue location
lines the heart and blood cells, air sacs of lungs, serous membranes
Transitional epithelial Location
lines the urinary bladder, ureters, urethra
merocrine or eccrine glands
located over entire body; empty on the skins surface, temperature regulation
what is meant by pseudostratified
looks multilayered, but all cells touch basement membrane
Reticular tissue location
lymph nodes, spleen, thymus, bone marrow
bone tissue function
mineral storage, protects organs, attachment sites for muscles
Hyaline cartilage location
most of respiratory tree, articular cartilage, nose, costal cartilage, developing bone
simple columnar function
often have microvilli to increase surface area or cilia to create a current
what is meant by simple
one layer of cells
gap junctions
pore made up of 6 transmembrane proteins. allow ions, nutrients and other small molecules to move between the cells
epithelial tissue common functions
protect deeper tissues from injury and infections, produce and release chemical secretions, excrete wastes, absorb chemicals including nutrients, selectively filter substances, sense stimuli
stratified squamous epithelium function
protection of underlying tissues from abrasion; slows water loss
elastic cartilage function
provides support, very flexible
Hyaline cartilage function
provides supportive framework
Dense regular connective tissue function
provides unidirectional tensile strength
simple squamous function
rapid diffusion, secrets serous fluid
tight junctions
seals off intercellular space making it difficult for substances to pass between cells. forces materials to travel through the cell = acts as a cell
pseudostratisifed columnar epithelial tissue function
secretes and moves mucus via cilia
simple cuboidal function
secretion and absorption
fibrocartilage function
shock absorption
atrophy
shrinkage of a tissue through a loss in cell size or number
nervous tissue common functions
specialized for communication by electrical and chemical signals, Changes in voltage result in rapid transmission of signals to other cells
cardiac muscle tissue
striated, intercalated discs, one huge centrally located nuceli, voluntary
reticular tissue function
supportive framework for lymphatic organs
Dense regular connective tissue location
tendons, ligaments
blood connective tissue function
transports nutrients, hormones, gases, waste, etc.
tissue sections
transverse, longitudinal, oblique
connective tissue common functions
•Connecting organs—tendons and ligaments •Support—bones and cartilage •Physical protection—cranium, ribs, sternum •Immune protection—white blood cells attack foreign invaders •Movement—bones provide lever system •Storage—fat, calcium,phosphorus •Heat production—metabolism of brown fat in infants •Transport—blood
connective tissue characteristics
•Diverse, abundant type of tissue •Lots of space and material (matrix) outside of the cells •Most cells are not in direct contact with each other •Highly variable vascularity •Loose connective tissues have many blood vessels •Cartilage has few or no blood vessels
muscular tissue characteristics
•Elongated cells that are specialized to contract in response to stimulation •Changes in voltage result in contraction, shortening of the cell •Three types of muscle: skeletal, cardiac, and smooth
Muscular Tissue: common functions
•Primary job is to exert physical force on other tissues and organs •Creates movements involved in body and limb movement, digestion, waste elimination, breathing, speech, and blood circulation •Important source of body heat