Exam #2 Flashcards
What are the two main types of epithelial tissue? Where are they located?
covering and lining epithelia (on external & internal surfaces)
glandular epithelia (secretory tissue in glands)
define tissue
a group of cells that serve a function
what is cell polarity in epithelial tissue?
apical (upper, free) & basal (lower, attached)
apical – microvilli (intestinal lining) or cilia (trachea lining)
basal – noncellular lamina of glycoprotein
is epithelial tissue closely/loosely packed cells? what junctions?
closely packed
tight junctions and desmosomes
what does vascular / avascular mean?
vascular: with veins, with blood supply
avascular: no veins, no blood supply
does epithelial tissue have a low or high rate of regeneration?
epithelial has a high rate of regeneration
in what order do you name epithelial tissue?
layer, name
e.g. simple squamous
describe simple squamous epithelium
single layer of flattened cells
what is the function of simple squamous epithelium?
allows passage of materials by diffusion & filtration where protection isn’t important
secretes lube in serosae (ventral body cavity lining)
where can you find simple squamous epithelium?
kidneys
air sacs of lungs
lining of heart
blood vessels
lymphatic vessels
lining of ventral body cavity (serosae)
describe simple cuboid epithelium
single layer of cube-like cells
what is the function of simple cuboid epithelium?
secretion & absorbtion
where can you find simple cuboid epithelium?
kidney tubules
ducts and secretory portions of small glands
describe simple columnar epithelium
single layer of tall cells
might have cilia
might contain mucus secreting unicellular glands
what is the function of simple columnar epithelium?
absorption
secretion of mucus
where can you find simple columnar epithelium?
digestive tract
gallbladder
describe pseudostratified columnar epithelium
single layer of cells where not all of them reach the free surface (top)
what is the function of pseudostratified columnar epithelium?
secretion, especially mucus
where can you find pseudostratified columnar epithelium?
upper respiratory tract
trachea
describe stratified squamous epithelium
thick membrane composed of several dead cell layers
keratin
what is the function of stratified squamous epithelium?
protects underlying tissues in areas subjected to abrasion
where can you find stratified squamous epithelium?
epidermis of the skin
what does a goblet cell do?
generates mucin, which makes mucous
what are the two types of glands?
endocrine: no ducts (eg. hormones released into ECF)
exocrine: ducts (e.g. sweat, mucous)
describe transitional epithelium
looks like stratified squamous and stratified cuboidal
surface cells dome/flatten depending on the organ stretching
what is the function of transitional epithelium?
accommodate fluctuation of volume of the liquid in an organ
where can you find transitional epithelium?
urinary bladder
uterus
what is the cutaneous membrane?
the skin that covers the surface of the body
what is the muceous membrane?
lines the organ cavity that are open to the exterior
e.g. lungs and esophagus
what are serous membranes?
line body cavities closed to the exterior
secrete a lubricating fluid which reduces friction from muscle movement
what is a gland?
one or more cells that makes and secretes an aqueous fluid
site of product release
what is the function of muscle tissue?
allows for movement in the body
what composes muscle tissue?
made of muscle fibers/cells and protein fibers (actin and myosin)
ID skeletal muscle: type, shape, nuclei #, absent/present striations, voluntary/involuntary function, and location
long, cylindrical
multinucleate
striations present
voluntary control - facial expression, manipulation of environment
skeletal muscles, attached to bones or skin
ID cardiac muscle: type, shape, nuclei #, absent/present striations, voluntary/involuntary function, and location
branching
uninucleate
striations present
involuntary control - propels blood to circulate as it contracts
the walls of the heart
ID smooth muscle: type, shape, nuclei #, absent/present striations, voluntary/involuntary function, and location
spindle-shaped
uninucleate
striations not present
involuntary control - propels substances or objects along internal passageways
walls of hollow organs
what’s the function of glial cells?
surround and support neurons
maintain homeostasis, form myelin
what causes MS (multiple sclerosis)
degeneration of myelin sheath
what is the function of the myelin sheath?
insulates and enables communication through the axon of a neuron
what is the function of nervous tissue neurons?
communication between cells through sensory input
what are the two major cell types of nervous tissue neurons?
glial cells – surround and support neurons, maintain homeostasis, form myelin
neurons – process and transmit information electrically
what is the function of dendrites?
carry information toward the cell body
what is the function of axons?
carry information away from the cell body
describe organs
structures consisting of multiple tissue types
organized to perform a specific function
describe organ systems
groups of organs performing related functions
what are the major regions of skin?
epidermis – superficial region
dermis – middle region
hypodermis – deepest region
describe epidermis: cell type, cells, vascular/nonvascular
keratinized stratified squamous epithelium cells
keratinocytes – produce fibrous protein keratin
melanocytes – produce melanin pigment (10-15% in lower epidermis)
avascular
How long does it take for an epidermal cell to move from the bottom layer to the top layer?
2 weeks
Briefly describe how epidermal cells are regenerated
cuboidal cells undergo mitosis at the base
new cells are pushed and flattened toward the surface
new epidermal cells produce keratin
cells die on the outermost layer filled with keratin
what pigments contribute to skin color?
melanin – yellow/red-brown to black. produced in melanocytes
carotene – yellow to orange, most obvious in palms and soles
hemoglobin – pinkish hue
describe dermis
strong, flexible connective tissue
supplies nourishment to epidermis
vascular
oil and sweat glands
hair follicles
fat tissue
nerves
connective tissue
what are the layers of the epidermis?
stratum corneum – dead cells filled with keratin
stratum granulosum – flattened cells w/ deteriorating organelles
stratum spinosum – cells contain thick bundles of intermediate filaments made of pre-keratin
stratum basale – cells are actively mitotic stem cells
what is the superficial layer of the dermis called? describe it
papillary layer
blood supply
areolar connective tissue with collagen, elastic fibers, and blood vessels
forms fingerprints
what is the deep layer of the dermis called? describe it
reticular layer
dense irregular tissue
contains 80% thickness of dermis
collagen fibers, strength and resiliency
elastic fibers, stretch-recoil properties
hair follicles
associated with stretch marks
what is the subcutaneous layer?
in the hypodermis
loose connective tissue packed with adipose cells
stabilizes position of skin
what are the different needle injection sites?
transdermal 0.05mL (allergy shot)
subcutaneous 1.00mL (insulin, heparin)
intramuscular (steroids)
what is the function of hair?
protection
thermoregulation
sensory
which gland produces oil/wax?
sebaceous
associated with hair follicles
maintains pliability of skin
which gland produces sweat?
suderiferous
maintains body temp
which gland secretes milk?
mammary glands
which gland is found in your ear and produces wax?
ceruminous
what are the functions of skin?
protection
temperature regulation
sensation
chemical compound storage
excretion of waste
synthesis of compounds
what is the vascular phenomena that happens when you sweat and need to conserve heat
vasodialation – when sweating to lose heat
vasoconstriction – when cold and to preserve heat
what is the ABCD rule? ***
asymmetry – two sides of the area don’t match
border – has indentations
color – black/brown/tan/red/blue
diameter – larger than 6mm ( > pencil eraser)
what are the degrees of burns?
1° – redness, epidermis
2° – blistering, dermis
3° – all three layers, no pain
what is skin pathology?
study of disease state of tissue on the cellular level
what causes wrinkles on the skin?
loss/degeneration of collagen and elastin (w/ aging)
what are the subclasses of connective tissue?
loose connective tissue:
- areolar
- adipose
- reticular
dense connective tissue:
- regular
- irregular
- elastic
what are the subclasses of cartilage?
- hyaline
- elastic
- fibrocartilage
what are the subclasses for bone tissue?
- compact bone
- spongey bone
what is the tissue of origin for connective tissue?
mesenchyme
does connective tissue have varying degrees of vascularity?
yes
what separates cells in connective tissue?
extracellular matrix (ground substance and fibers)
-blasts are cells which…
are mitotically active and secretory (young)
-cytes are cells which…
are matured cells
what are the types of fibers and their function?
collagen (white fibers)
- most abundant
- strongest
- provides tensile strength
elastic
- long, thin elastin fibers
- allow stretching
reticular
- short, fine, branched
- collagenous fibers
what is ground substance?
a medium for solutes to diffuse between blood capillaries and cells
name the three main types of connective tissue
fibrous
supportive
fluid
what are the fibrotic connective tissues?
loose: fascia, adipose fiberscells
what does fibrous connective tissue do?
covers and allows organs to expand
where are osteocytes located?
in the lacuna
what promotes bones health?
nutrition - provides important constituents (e.g. calcium)
exercise - adapt to stress
hormones - build and maintain density
what is the optimal blood calcium level?
8.5-11 mg/dl
what is the purpose of regulation of bone growth by mechanical stress?
strengthen bone
what is the purpose of regulation of bone growth by hormonal feedback?
maintain calcium homeostasis
what is osteomyelitis?
inflammation of bone and surrounding muscle
what is osteoporosis?
reduction in bone mass, chemical composition remains normal
what is gigantism?
excess of growth hormone before epiphyseal plates are ossified
what is osteomalacia (rickets)?
reduction in bone mass, chemical composition is abnormal
what is the difference between osteoporosis and osteomalacia?
osteoporosis has normal chemical composition
osteomalacia has abnormal chemical composition
what is acromegaly?
excessive growth hormone after epiphyseal plates are ossified
what is pituitary dwarfism?
deficit of growth hormone
What is bone?
matrix of collagen and calcium phosphate crystals
where are osteocytes?
found in lacunae in concentric rings
what is contained by the central canal in bones?
blood vessels and nerves
what are the tiny canals that link lacunae with one another and the central canal?
canaliculi
what is the fluid connective tissue made of?
fluid matrix (plasma)
- red blood cells
- white blood cells
- platelets
what do red blood cells do?
carry oxygen
what do white blood cells do?
immunity, fight infection
what do platelets do?
clot blood
what is osseous tissue?
dense and supportive connective tissue
produces solid matrix of calcium deposits
around collagen fibers
what is the most common cartilage?
hyalin
what are the four types of cells that make up bones?
osteocytes
osteoblasts
osteoclasts
osteogenic
function of an osteocyte?
maintain bone tissue
function of an osteoblast?
forms bone matrix
builds bone and becomes osteocyte
function of osteogenic cells?
stem cells
function of osteoclast?
breaks down bone (resorbs)
how do osteoblasts turn into osteocytes? *
osteoblasts get trapped in calcified bone matrix, calcify, and turn into osteocytes.
structure of dense matrix of bone tissue?
deposits of calcium salts
osteocytes within lacunae around blood vessels
function of canaliculi & volksman canal?
form pathways for blood vessels
exchange nutrients and wastes
function of periosteum
extra reinforcement wherever tendons attach
covers outer surfaces of bones
consists of out fibrous and inner cellular layers
function of endosteum?
to prevent the bone from becoming unnecessarily thick, osteoclasts resorb the bone from the endosteal side
covers inside surface of bones
consists of only inner cellular layer
how many layers does the endosteum have?
one
how many layers does the periosteum have?
two layers
cellular - inner
fibrous - outer
what is the function of tendons?
attach muscle to bone
what is an osteon?
the basic unit of compact bone
what is a circumferential lammellae?
lamellae wrapped around long bone
binds osteons together
does spongy bone have osteons?
no, osteons are only found in long bone
what the matrix of the matrix of spongy bone called?
trabeculae
does the trabeculae have blood vessels?
no, the trabeculae is avascular
what is the space between the trabeculae filled with? what’s its purpose?
red bone marrow
has blood vessels
forms red blood cells
supplies nutrients to osteocytes
where is yellow marrow found? what’s its function?
found in some bones, spongy bone hold yellow marrow
it stores fat
does spongy bone have central canals?
no, and it doesn’t have osteons
when do bones in humans stop growing?
25 years
what is osteogenesis?
bone formation
what is ossification?
the process of replacing other tissues with bone
what is calcification? when does it happen?
the depositing of calcium salts
during bone ossification
what are the two main forms of ossification?
endochondral ossification - cartilage/long bone
intramembranous ossification - skull bones/flat bone
what is the spongy bone in the skull called?
diploé
what are the four steps of growing long bone? where does it occur?
within epiphyseal plate
- proliferation chondroblasts -> chondrocytes
- hypertrophic growth
- calcification to form osteoblasts
- completion of ossification
what would cause premature closure of the growth plate?
irregular estrogen or lack of growth hormone
describe bone nutrition / blood supply to bones *
- nutrient artery & vein
- single pair of large blood vessels
- enter the diaphysis through the nutrient foramen - metaphyseal vessels
- supply the epiphyseal cartilage
- where bone growth occurs
- growth plate - periosteal vessels
- blood to superficial osteons
- secondary ossification occurs
what is the process of bone remodeling?
bone continually remodels, recycles, and replaces
osteoblast activity outpaces osteoclast activity and bones become larger and thicker as a child grows
as the body ages, osteoclast activity outpaces osteoblast activity resulting in fragile bones
what is bone homeostasis?
osteoclast and osteoblast activity dynamically at balance
remodeling is the process of creating new bone and removing old bone
what is the function of the PTH (parathyroid hormone)?
PTH causes the body to put more calcium into the blood
what is the function of calcitonin?
opposes PTH activity
what are the steps of endochondral ossification?
- osteoblasts secrete bone
- degeneration of catilage
- vascular invasion
- brings in nutrients and cells
- epiphyseal plate forms
- growth of long bone
how do fractures occur?
when force on bone is greater than the force the bone can withstand
what’s the difference between open/closed fractures?
simple closed fractures don’t break the skin while open compound fractures do
what is granulation tissue? *
indicator of how well something is healing
function of caniculae
connects nutrients from canal to the cells
what cells make up skin?
kerinocytes
what are the four main tissue types?
epithelial tissue (covering and lining & glandular)
connective tissue (loose and fibrous)
nervous tissue (neurons and glial)
muscle tissue (skeletal, cardiac, and smooth)
what is a desmosome?
junction, by which two adjacent cells are attached
what is a tight junction?
junction where there’s no gap between two cells that would normally be there otherwise
what causes wrinkles?
loss of collagen and elastin
what are the type, shape, nuclei #, absent/present striations, voluntary/involuntary function, and location of each muscle
skeletal:
- long, cylindrical
- multinucleate
- striations present
- voluntary control - facial expression, manipulation of environment
- skeletal muscles, attached to bones or skin
smooth muscle:
- spindle-shaped
- uninucleate
- striations not present
- involuntary control - propels substances or objects along internal passageways
- walls of hollow organs
cardiac muscle:
- branching
- uninucleate
- striations present
- involuntary control - propels blood to circulate as it contracts
- the walls of the heart
