What is epithelial tissue?
a sheet of cells that covers a body surface or lines a body cavity
The _____ is not attached to surrounding tissue and is exposed to either the outside of the body or the cavity of an internal organ.
apical surface or "free" surface
The _______ is attached to the underlying connective tissue.
basal surface or "fixed" surface
Epithelia exhibit _________ due to their two surfaces.
What are myofilaments?
contractile proteins (actin and myosin) in muscle cells
Describe skeletal muscle tissue.
long, cylindrical, multinucleate cells with obvious striations
What is the function of skeletal muscle tissue?
voluntary movement; locomotion; manipulation of the environment; facial expression; voluntary control
What is the location of skeletal muscle?
attached to bones or skin
Describe cardiac muscle tissue.
Branching, striated, uninucleate cells interlocking at intercalated discs
What is the function of cardiac muscle tissue?
as it contracts, it propels blood into the circulation; involuntary control
Where is cardiac muscle located?
within the heart wall and septum
Describe smooth muscle tissue.
cells are spindle shaped with central nuclei; no striations; cells are arrange closely to form sheets
What is the function of smooth muscle tissue?
propel substances or objects (foodstuffs, urine, a baby) along internal passageways; involuntary control.
Where is smooth muscle tissue located?
mostly in the walls of hollow organs
wavelike contractions of the smooth muscle of the digestive tract that force food through the tube and waste toward the anus
What are neurons?
highly specialized nerve cells that generate and conduct nerve impulses
What are glial / neuroglial cells?
non-conducting cells that support, insulate, and protect neurons
What is skin?
layers of the cutaneous membrane
- epidermis (keratinized stratified squamous epithelium)
- dermis (connective tissue)
Membranes that line all body cavities that open to the outside of the body (hollow organs of digestive, respiratory, and urogenital tracts)
mucous membrane / mucosae
The epithelial sheet that lies directly over a layer of area connective tissue is called the _________.
Describe simple squamous epithelium:
single layer of flattened cells with disc-shaped central nuclei and sparse cytoplasm; the simplest of the epithelia
What is the function of simple squamous epithelium?
- allows for quick and easy exchange - filtration and diffusion of gases
Where is simple squamous epithelium found?
**where protection isn't important
- alveoli and kidney glomeruli
- lymphatic vessels
- mesothelium: lines the ventral cavity wall (serous membranes)
- endothelium that lines the cardiovascular system
Describe simple cuboidal epithelium.
single layer of cubelike cells with large, spherical central nuclei
What is the function of simple cuboidal epithelium?
- secretion and absorption
Where is simple cuboidal epithelium found?
- lines tubules and small ducts of glands (kidney, pancreas, salivary glands and ovary)
Describe simple columnar epithelium.
a single layer of tall cells with oval-shaped nuclei; some bear cilia, others may contain microvilli
What is the purpose of microvilli?
increase surface area for absorption
What is the purpose of cilia?
propulsion and motility
What is the function of simple columnar epithelium?
- secretion of mucus, enzymes, and other substances
- ciliated type propels mucus or reproductive cells by ciliary action
Where is simple columnar epithelium found?
- digestive tract (stomach, colon, galbladder)
- reproductive tract (fallopian tubes and some regions of the uterus)
Describe pseudostratified columnar epithelium
single layer of cells of differing heights, some not reaching the free surface; nuclei seen at different levels; cells rest on basement membrane; may contain mucus-secreting goblet cells and bear cilia
What is the function of pseudo stratified columnar epithelium?
- secretions protect, moisten and lubricate the throat and respiratory tract
Where is pseudo stratified columnar epithelium located?
- respiratory tract (bronchi, bronchioles, larynx, trachea)
Describe stratified squamous epithelium
thick membrane composed of several cell layers; basal cells are cuboidal or columnar and metabolically active; surface cells are flattened (squamous); in the keratinized type, the surface cells are full of keratin and dead; basal cells are active in mitos
What is the function of stratified squamous epithelium?
protects underlying tissues in areas subject to abrasion
Where is stratified squamous epithelium found?
- esophagus, mouth, and vagina (non-keratinized)
- epidermis of the skin (keratinized
Describe transitional epithelium.
resembles both stratified squamous and stratified cuboidal: basal cells are cuboidal or columnar, on the surface cells are dome shaped or squamouslike
What is the function of transitional epithelium?
stretch to permit distention
Where is transitional epithelium found?
- urinary bladder
- ureters and part of urethra
mesothelia lining pleural, pericardial, and peritoneal cavities
lines the lungs and inner surface of the chest
covers entire abdominal wall and envelopes the organs in abdomen
surrounds the heart and large vessels entering and leaving the heart
the simple squamous epithelium lining the heart, blood vessels, and lymphatic vessels
Capillaries consist exclusively of _________.
the simple squamous epithelium lining ventral body cavities and covering its organs
If simple squamous epithelium is the most delicate, why does it make up the mesothelium lining the pleural, pericardial, and peritoneal cavities?
it reduces friction, allows for easy filtration, exchange, and diffusion of gases
what is serosae?
lines glomerular capsules (Bowman's capsule)
Lines lymphatic vessels
nonkeratinized stratified squamous
nonkeratinized stratified squamous
nonkeratinized stratified squamous
forms the epidermis of the skin
keratinized stratified squamous
forms the walls of (the smaller) kidney tubules
forms the walls of ducts and secretory portions of small glands (pancreas, salivary glands)
forms the surface of the ovary
Lines most of the digestive tract (stomach to rectum and gallbladder)
non-ciliated simple columnar
lines uterine tubes and some regions of the uterus
ciliated simple columnar
what is the function of ciliated simple columnar epithelium?
to propel mucus or reproductive cells by ciliary action
lines the nasal cavity
pseudo-stratified ciliated columnar epithelium
lines the trachea and bronchi
pseudo-stratified ciliated columnar epithelium
the three primary germ layers of embryonic development
ectoderm, mesoderm, and endoderm
the 4 main classes of connective tissue
connective tissue proper, cartilage, bone, blood
All connective tissue arise from ________.
What is mesenchyme?
embryonic tissue that forms connective tissue, blood, and smooth muscles
immature, undifferentiated stem cells
connective tissue proper cells
fibroblasts, fibrocytes, adipocytes, leukocytes, macrophages, and mast cells
Fibroblasts in connective tissue proper become ________.
What are adipocytes?
fat cells - cells that store energy as fat
What are leukocytes?
white blood cells
What are mast cells?
cells that initiate local inflammatory responses against foreign microorganisms
Mast cells contain what chemicals?
heparin, histamine, and proteases
What is heparin?
What does histamine do?
What are proteases?
enzymes that break down proteins
all mature connective tissues except for bone cartilage and blood are...
connective tissue proper
two subclasses of connective tissue proper
loose connective tissue and dense connective tissue
loose connective tissue
areolar, adipose, reticular
dense connective tissue
dense regular, dense irregular, elastic
Fibroblasts are the predominant cell type in ________ connective tissue.
What is the function of areolar connective tissue?
- absorbs fluids during inflammation
- binds body parts together, but allows some free movement
Where is areolar connective tissue located?
it surrounds glands, nerves and small vessels. it also forms the basement membrane in subcutaneous tissue.
In reticular connective tissue, the _______ forms the internal supportive framework of lymphoid organs.
What is the function of reticular connective tissue?
Where is reticular connective tissue found?
liver, spleen, bone marrow, and lymph nodes
_________ connective tissue contains lipids and cholesterol.
What is the function of adipose tissue?
protects, insulates, and reserves energy fuel
What is brown fat?
adipose cells that contain abundant mitochondria that use the lipid fuels to generate heat
Chondrocytes live in small chambers called ________.
the most abundant cartilage in the body
Where is hyaline cartilage located?
articular, nasal and costal cartilage, trachea and larynx
What cartilage has a great tolerance to repetitive bending?
Where is elastic cartilage located?
external ear, epiglottis
Fibrocartilage is mostly made up of what?
Fibrocartilage is the ________ cartilage.
Where is fibrocartilage located?
intervertebral discs, pubic symphysis, menisci
menisci of the knee
articular ends of bones
tracheal ring cartilages and cartilage of the larynx
fascia of the dermis of skin
fibrous organ capsules
periosteum, perineurium, perimysium, and pericardium
What is the function of fibrous (dense) connective tissue?
Where is dense regular connective tissue found?
tendons, ligaments, aponeuroses
Where is dense irregular connective tissue found?
- fascia of the dermis of skin
- fibrous organ capsules
- joint capsules
- heart valves
Dense irregular CT contains more _________ than dense regular CT.
What is the jelly-like embryonic connective tissue of the umbilical cord?
What type of membrane consists of epithelium and connective tissue, and lines body cavities open to the exterior?
What type of membrane lines the thoracic walls and covers the lungs, and what is it called?
serous membrane called pleurae
What is pathology?
scientific study of changes in organs and tissues produced by disease
What is pus?
A collection of tissue fluid, bacteria, dead and dying tissue cells, white blood cells and macrophages in an inflamed area.
What is scurvy?
a nutritional deficiency caused by lack of adequate vitamin C needed to synthesize collagen
What are the signs and symptoms of scurvy?
blood vessel disruption, delay in wound healing, weakness of scar tissue, and loosening of teeth
What is VAC (vacuum-assisted closure)?
innovative healing process for open-skin wounds and skin ulcers; involves covering the wound with a special sponge, and then applying suction through the sponge
What is the outcome of skin stretching using VAC?
fibroblasts in the wound form more collagen tissue and new blood vessels proliferate, bringing more blood into the injured area, which also promotes healing
What is an adenoma?
any neoplasm of glandular epithelium, benign or malignant
What is the specific name for a malignant adenoma?
What is Marfan's syndrome?
genetic disorder that affects the body's connective tissue
What is keloid?
an abnormal hyperplastic proliferation of scar tissue usually due to surgeries or trauma
What are adhesions?
abnormal joining of tissues
What is a biopsy?
surgically removing a tissue sample and examining it microscopically
What is blood plasma?
nonliving fluid matrix of blood
What is dysplasia?
any abnormal change or development; as in the shape and size of cells
What is anaplasia?
reversion of cells to a more primitive or less differentiated state
the replacement of destroyed tissue with the same tissue
the replacement of destroyed tissue with fibrous connective "scar" tissue
What are the three main steps of tissue repair?
inflammation, organization, and permanent repair via regeneration and fibrosis
Why is blood considered a connective tissue?
it develops from mesenchyme and consists of blood cells surrounded by a nonliving fluid called blood plasma