Lecture 2 - Tissue Types Flashcards
what are the four basic tissue types?
- epithelium
- connective tissue
- muscle
- nerve
what are the four main functions of epithelial tissue?
- forms barriers (b/w inside and outside world, and between compartments within the body)
- covers exposed body surfaces
- lines organs, body cavities, and tubes
- forms all glands of the body
what are the four main functions of connective tissue?
- links tissues and organs together
- provides structure and metabolic support
- stores energy
- forms the immune system
what are the three main functions of muscle tissue?
- specialized for contraction
- generates force to: produce motion and move substances
- maintain body temperature
what are the two main functions of nervous tissue?
- receives, processes, and integrates signals from within the body and from the external environment
- generates and transmits impulses that control and integrate the various functions of the body
what does it mean for a tissue to be continuous?
similar cells (look, size, shape) are all lined up with tight jxns between them
- continuous
- avascular but richly innervated
- rest on basal lamina
- little extracellular matrix (ECM)
- polarized
- high regeneration
these are all characteristics of what type of tissue?
epithelia
what does it mean for cells to be polarized?
- organelles are not homogeneous
- apical and basolateral surfaces differ
basement membranes are formed from:
ECM from epithelium (basil lamina) + ECM from connective tissue (reticular lamina)
how are epithelia classified?
epithelia are named based on:
1) number of layers of cells
2) shape of cells in outermost (apical) layer
type of epithelia comprised of a single layer of flat cells
simple squamous epithelium
where is simple squamous epithelium found?
- lines body cavities (mesothelium)
- lines heart chambers and blood vessels (endothelium)
- lines sites of gas exchange in the lungs
what are the functions of simple squamous epithelium?
- secretes lubricating substance (reduces friction)
- controls vessel permeability
- allows material to pass by diffusion
type of epithelia comprised of a single layer of cells where height equals width
simple cuboidal epithelium
where is simple cuboidal epithelium found?
- in glands and their ducts
- lines portions of the kidney (tubules)
what is the function of simple cuboidal epithelium?
where secretion and absorption occurs
type of epithelia comprised of a single layer of cells that are taller than they are wide
simple columnar epithelium
where is simple columnar epithelium found?
lines the digestive tract
what is the function of simple columnar epithelium?
provides absorption and protection, can secrete mucus and enzymes
type of epithelia comprised of a single layer of epithelia of different sizes (all cells touch the basal lamina but not all may reach luminal/apical surface)
pseudostratified columnar epithelium
where is pseudostratified columnar epithelium found?
the respiratory tract
what is the function of pseudostratified columnar epithelium?
protection, secrection of mucus, and motility
type of epithelia comprised of multiple layers of cells with the outermost layer being thin and flattened
stratified squamous epithelium
where is stratified squamous epithelium found?
where mechanical stresses are severe
- outer layers of skin (keratinized)
- lines oral cavity, esophagus, anus, and vagina
what is the function of stratified squamous epithelium?
prevents skin from drying out, provides protection against abrasion, pathogens, and chemicals
type of epithelia with two or three layers of cells with the outermost layer of cells of equal height and width
stratified cuboidal epithelium
where is stratified cuboidal epithelium found?
in ducts of sweat glands and mammary glands
what is the function of stratified cuboidal epithelium?
involved in secretion
type of epithelia with 2+ layers of cells, height of outer layer of cells greater than width
stratified columnar epithelium
where is stratified columnar epithelium found?
intermediate locations in humans (reproductive ducts)
what is the function of stratified columnar epithelium?
involved in changes of function to organ systems
type of epithelia with multiple layers of cells (outermost layers being dome shaped) that change in appearance with stretching
transitional epithelium
where is transitional epithelium found?
the urinary tract
what is the function of transitional epithelium?
expansion and protection
all glands are composed of what type of cells?
epithelial cells
glands that release secretions through ducts onto epithelial surfaces
exocrine glands
glands that lack ducts and secrete hormones into the blood
endocrine glands
how are exocrine glands formed?
1) epithelial cells grow into underlying connective tissue
2) secretory cells remain connected to the surface by a duct
how are endocrin glands formed?
1) epithelial cells grow into underlying connective tissue
2) connecting cells disappear
3) secretions released into blood vessels
- cells dispersed in abundant ECM
- provides structural and metabolic support to other tissues and organs
- link different tissues together
- link tissues and organs together to generate overall body form
- aid with wound repair
- protects body against infection
these are all characteristics of what type of tissue?
connective tissue
what are the three classes of connective tissue?
proper, fluid, and supportive
how are the different types of connective tissue classified?
based on:
- specific cell types
- types of fibres
- density of fibres
type of connective tissue with many types of cells and extra-cellular fibres in a syrupy ground substance
proper CT
type of connective tissue with a distinctive population of cells suspended in a watery matrix containing dissolved proteins
fluid CT
type of connective tissue with a more homogenous population of cells and matrix contains closely packed fibres
supporting CT
secrete ECM and can produce different fibre types
fibroblasts
hydrated gel which provides compression strength
ground substance
collagen, elastic, and reticular are all types of:
fibres
stores lipid reserves, energy storage
adipocytes
ingest debris and function in immune response
macrophages
what are the five basic structures of proper connective tissue?
- fibroblasts
- ground substance
- fibres
- adipocytes
- macrophages
cells that are found in a developing embryo and is the origin of all connective tissue - they remain as stem cells in adult tissue
mesenchyme
what is the function of loose connective tissue?
fills spaces between organs, provide cushioning and support
what are the three types of loose connective tissue?
- areolar
- adipose
- reticular
the most common and least specialized connective tissue which has an open framework (w/ ground substance and elastic fibres)
areolar connective tissue
what is the function of areolar connective tissue?
links together tissues and organs (encompasses organs), and is often found with epithelium
type of connective tissues that forms deposits in specific areas of the body (commonly known as fat tissue)
adipose connective tissue
what is the function of adipose CT?
functions in padding, insulation, and energy storage
type of connective tissue that forms the stroma for hemopoietic tissues (spleen and bone marrow) and lymphoid structures and organs
reticular connective tissue
what is the function of reticular connective tissue?
forms soft tissue “skeletons”, supportive structure
type of connective tissue with relatively little ground substance and few cells compared to other CT
dense connective tissue
what are the two types of dense connective tissue?
regular and irregular
type of connective tissue where fibres are aligned in one direction
dense regular
where is dense regular connective tissue found?
forms tendons and ligaments
what is the function of dense regular connective tissue?
provides attachment, conducts pull of muscles, reduces friction, holds bones in place
type of connective tissue where fibres are unaligned and run at a variety of angle
dense irregular connective tissue
where is dense irregular connective tissue found?
dermis of skin, organ capsules, sheaths around bones, muscles, and nerves
what is the function of dense irregular tissue?
provides strength and resistance to forces in multiple directions, prevents overexpansion of organs
what are the four main types of membranes?
- mucus
- serous
- cutaneous
- synovial
what two tissue types make up membranes?
epithelium and connective tissue
what are the two types of fluid connective tissue?
blood and lymph
what is blood made of?
various blood cells (rbcs, wbcs, platelets) and plasma (dilute proteins which forms the fluid matrix)
what is lymph made of?
lymph fluid (proteins + excess interstitial fluid) and lymphocytes
type of connective tissue that consists of cartilage and bone
supporting connective tissue
what is the function of supporting connective tissue?
support and protection of soft tissues in the body and body framework
- elongated cells
- specialized to contract
- generates force
these are all characteristics of what type of tissue?
muscle tissue
what are the three main types of muscle tissue?
skeletal, cardiac, and smooth
- cylindrical
- multinucleated
- striated
- powerful but easily fatigued
- attaches to bone
- involved in voluntary contractions
these are all characteristics of what type of muscle tissue?
skeletal muscle
- striated
- mononucleate (central nucleus)
- branching fibres with intercalated discs
- specialized for continuous and rhythmic beating
- involved in involuntary contractions
these are all characteristics of what type of muscle tissue?
cardiac muscle
- spindle shaped
- mononucleate (central nucleus)
- non-striated
- slow, sustained contractions
- associated with viscera
- involved in involuntary contractions
these are all characteristics of what type of muscle tissue?
smooth muscle
- contains large cells with elongated processes
- contains smaller cells which support, protect, and provide framework for large cells
- receives, processes and integrates signals from within the body and the external environment
- generates and transmits impulses which control and integrate the various functions of the body
these are all characteristics of what type of tissue?
nervous tissue
what are the four main components of neurons?
- cell body
- dendrites
- axon
- presynaptic terminals
nerve cells and muscle cells interact at the:
neuromuscular junctions
sensory information being carried to the CNS travels along the:
dorsal root
motor information being carried away from the CNS travels along the:
ventral root
most axons in the CNS and PNS are insulated by:
myelin sheaths
where are myelin sheaths produced?
glials cells:
- oligodendrocytes (CNS)
- schwann cells (PNS)
what is the purpose of myelin sheaths?
protection of axon and increases conduction velocity
what are the four main types of supporting cells in the CNS?
- astrocytes
- oligodendrocytes
- ependymal cells
- microglia
function as the physical support, metabolic and ionic homeostasis, and protection of the CNS
astrocytes
produce myelin sheaths in the CNS
oligodendrocytes
produces cerebrospinal fluid
ependymal cells
functions as macrophages in the CNS
microglia