Lesson 2 Flashcards
characteristics of epithelial cells (5)
- cellularity and specialized contacts (membranes/special junctions)
- polarity - apical (top) and basal (bottom)
- supported by connective tissue (attached to basement membrane)
- avascularity (no blood vessels/nutrients need to diffuse to the epithelial tissue)
- regeneration (replacement of cells lost due to friction)
epithelia is classified by two criteria:
- basis of arrangement
- or number of layers, as simple as 1 layer or stratified with multiple layers - cell shape
- such as squamous (flat), cuboidal, columnar
simple squamous epithelium: function
allows materials to pass by diffusion and filtration in sites where protection is not important; secretes lubricating substances in serosae
simple squamous epithelium: location
kidney glomeruli, air sacks of the lungs, lining of the heart, blood vessels, lymphatic vessels, lining of ventral body cavity (serosae)
simple cuboidal epithelium: function
secretion and absorption
simple cuboidal epithelium: location
kidney tubules, ducts and secretory portions of small glands, ovary surface
simple columnar epithelium: function
absorption, secretion of mucus, enzymes, and other substances, ciliated type propels mucus (or reproductive cells) by ciliary action
pseudostratified columnar epithelium: function
secretes substances, particularly mucus; propulsion of mucus by ciliary action
simple columnar epithelium: location
nonciliated type lines most of the digestive tract (stomach to rectum), gallbladder, and excretory ducts of some glands
ciliated variety lines small bronchi, uterine tubes, and some regions of the uterus
stratified squamous epithelium: function
protects underlying tissues in areas subjected to abrasion
stratified squamous epithelium: location
nonkeratinized forms the moist linings of the esophagus, mouth, and vagina
keratinized forms the epidermis of the skin, a dry membrane
stratified cuboidal epithelium: function
protection
stratified cuboidal epithelium: location
largest ducts of the sweat glands, mammary glands, and salivary glands
stratified columnar epithelium: location
rare in the body
small amounts in the male urethra and in large ducts of some glands
transitional epithelium: function
stretches readily and permits distension of urinary organs by contained urine
transitional epithelium: location
lines the ureters, urinary bladder, and part of the urethra
connective tissue characteristics (3)
- usually have rich blood supply
- composed of many cell types
- has nonliving material (aka extracellular matrix) found between cells
- the matrix is produced by cells and is composed of- ground substance: interstitial fluid, cell adhesion proteins, and proteoglycans
- fibers: collagen, elastic, and reticular fibers
connective tissue functions (3)
- protect tissues/organs
- support tissues/organs
- bind together other tissues
Mesenchyme
embryonic connective tissue
- differentiates to yield all adult connective tissues
loose connective tissue: areolar - function
cuchions/protects the body
loose connective tissue: adipose - function
fat
insulates body and is for food storage
loose connective tissue: reticular
fine collagen fibers
dense connective tissue - loaction: elastic
bronchial tubes, large arteries
dense connective tissue: regular
in tendons and ligaments
dense connective tissue - loaction: irregular
in dermis of the skin, submucosa of digestive tract
embryonic connective tissue: function
gives rise to all other connective tissue types
embryonic connective tissue: location
primarily in the embryo
connective tissue proper - loose connective tissue - areolar: function (4)
wraps and cushions organs
its macrophages phagocytize bacteria
plays an important role in inflammation
holds and conveys tissue fluid
connective tissue proper - loose connective tissue - areolar: location (3)
widely distributed under epithelia of the body, e.g. forma lamina propria of mucous membranes
packages organs
surrounds capillaries
connective tissue proper - loose connective tissue - adipose: function (3)
provides reserve fuel
insulates against heat loss
supports and protects organs
connective tissue proper - loose connective tissue - adipose: location
under the skin
around kidneys and eyes
within abdomen
in breasts
connective tissue proper - loose connective tissue - reticular: function
fibers form a soft internal skeleton (stroma) that supports other cell types, including white blood cells, mast cells, and macrophages
connective tissue proper - loose connective tissue - reticular: location
lymphoid organs
lymphoid nodes, bone marrow, and spleen
connective tissue proper - dense connective tissue - dense regular: function (3)
attaches muscles to bones or to muscles
attaches bones to bones
withstands great tensile stress when pulling force is applied in one direction
connective tissue proper - dense connective tissue - dense regular: location
tendons, most ligaments, aponeuroses
connective tissue proper - dense connective tissue - dense irregular: function
able to withstand tension exerted in many directions
provides structural strength
connective tissue proper - dense connective tissue - dense irregular: location
fibrous capsules of organs and joints
dermis of the skin
submucosa of digestive tract
connective tissue proper - dense connective tissue - elastic: function
allows for recoil of tissue following stretching
maintains pulsatile flow of blood through arteries
aids passive recoil of lungs following inspiration
connective tissue proper - dense connective tissue - elastic: location
walls of large arteries
within certain ligaments associated with the vertebral column
within the walls of the bronchial tubes
types of connective tissue (4)
- connective tissue proper
- cartilage
- bone
- blood
cartilage - hyaline: function
supports and reinforces
serves as resilient cushion
resists compressive stress
cartilage - hyaline: location
forms most of the embryonic skeleton
covers the ends of long bones in joint cavities
forms costal cartilages of the ribs
cartilages of the nose, trachea, and larynx
cartilage - elastic: function
maintains the shape of a structure white allowing great flexibility
cartilage - elastic: location
supports the external ear (auricle) and the epiglottis
cartilage - fibrocartilage: function
tensile strength with the ability to absorb compressive shock
cartilage - fibrocartilage: location
intervertebral discs
pubic symphysis
discs of knee joint
connective tissue - bone: function
supports and protects (by enclosing)
provides levers for the muscles to act on
stores calcium and other minerals and fat
marrow inside bones is the site for blood cell formation
connective tissue - blood: function
transport of respiratory gases, nutrients, wastes, and other substances
connective tissue - blood: location
contained within blood vessels
three types of muscle tissue
skeletal, cardiac, smooth
skeletal muscle
voluntary muscle that is striated in appearance
cardiac muscle
involuntary muscle found in the heart
smooth muscle
involuntary visceral muscle that lines the walls of hollow organs
muscle - skeletal: function
voluntary movement
locomotion
manipulation of the environment
facial expressions
voluntary control
muscle - skeletal: location
in skeletal muscles attached to bones, occasionally to skin
muscle - cardiac: function
as it contracts, it propels blood into circulation
involuntary control
muscle - cardiac: location
walls of the heart
muscle - smooth: function
propels substances or objects (foodstuff, urine, a baby) along internal passageways
involuntary control
muscle - smooth: location
mostly in the walls of hollow organs
nervous tissue: function
transmit electrical signals from sensory receptors and to effectors (muscles and glands)
supporting cells support and protect neurons
nervous tissue: location
brain, spinal cord, and nerves
functions of the skin (5)
- protect against mechanical/chemical damage and bacterial invasion
- insulate against heat/cold, dissipates heat
- cushions body tissue
- prevent water loss/excretes wastes (urea, salts, water)
- site for vitamin D synthesis
the skin is composed of two main layers
epidermis
dermis
the epidermis consists of _____ major layers
five
what are the five major layers of the epidermis?
- stratum corneum
- stratum lucidum
- stratum granulosum
- stratum spinosum
- stratum basale
stratum corneum
first layer of skin
outermost layer (20-30 cells thick), accounts for bulk of the epidermal thickness
essentially flat membranous sacs filled with keratin
glycolipids in extracellular space
stratum lucidum
very thin, clear, layer that exists in thick skin and NOT present in thin skin
(second layer of thick skin)
stratum granulosum
layer 3 in thick skin, layer 2 in thin skin
thin layer containing granules that provide waterproofing and support
generally 1-5 layers
organelles are deteriorating
full of lamellar granules (release lipids) and keratohyaline granules
stratum spinosum
layer 4 of thick skin, layer 3 of thin skin
several cells thick, cells in lower layer is able to get nutrients and undergo cell division
keratinocytes joined by desmosomes
cells contain thick bundles of intermediate filaments made of pre-keratin
stratum basale
5th layer of epithelium
innermost layer, single cell thickness, cells undergo mitotic division
newly formed cells become part of the more superficial layers
dermis
connective tissue region
hypodermis/superficial fascia is composed of primarily of adipose tissue and lies underneath the dermis
how many layers does the dermis have?
two
what are the layers of the dermis?
papillary and reticular
papillary layer
superficial layer composed of areolar connective tissue
pain receptors (free nerve endings) and Meissner’s corpuscles (touch receptors found in hairless skin) are located here
reticular layer
deepest layer composed of dense, irregular connective tissue containing many arteries and veins, sweat and sebaceous glands, and Pacinian corpuscles (pressure receptors)
what is skin color dependent on? (3)
melanin, carotene, and oxygenation of the blood
what could changes in skin color indicate? (5)
- hypertension: flushed skin
- anemia: pale skin
- asphyxiation/lung disease: cyanosis, bluish skin
- liver disease: jaundice, yellow skin
- Addison’s disease: hyposecretion from adrenal cortex, bronze skin
since the epidermis lacks blood vessels, nutrients/wastes are received/removed by diffusion to blood supply from the _____
dermis
In bedridden patients, the blood supply to the skin is restricted causing what to occur?
skin cell death and can result in bedsores (decubitus ulcers)
what is the inner core of hair called?
medulla
what surrounds the medulla in a hair follicle?
the cortex
what covers the cortex of the hair follicle?
the cuticle
what is hair within the follicle called?
the root
what is hair emerging from the scalp called?
shaft
What type of tissue is this?
simple squamous epithelium
What type of tissue is this?
simple cuboidal epithelium
What type of tissue is this?
simple columnar epithelium
What type of tissue is this?
pseudostratified columnar epithelium
What type of tissue is this?
stratified squamous epithelium
What type of tissue is this?
stratified cuboidal epithelium
What type of tissue is this?
stratified columnar epithelium
What type of tissue is this?
transitional epithelium
What type of tissue is this?
embryonic connective tissues - mesenchyme
What type of tissue is this?
connective tissue proper - loose connective tissue - areolar
What type of tissue is this?
connective tissue proper - loose connective tissue - adipose
What type of tissue is this?
connective tissue proper - loose connective tissue - reticular
What type of tissue is this?
connective tissue proper - dense connective tissue - dense regular
What type of tissue is this?
connective tissue proper - dense connective tissue - dense irregular
What type of tissue is this?
connective tissue proper - dense connective tissue - elastic
What type of tissue is this?
cartilage - hyaline
What type of tissue is this?
cartilage - elastic
What type of tissue is this?
cartilage - fibrocartilage
What type of tissue is this?
bone - osseous tissue
What type of tissue is this?
connective tissue - blood
What type of tissue is this?
skeletal muscle
What type of tissue is this?
cardiac muscle
What type of tissue is this?
smooth muscle
What type of tissue is this?
nervous tissue
Label this figure.
Label this figure.