AHS 131 Lecture Exam 2

What does epithelial tissue do?

covers exposed tissues;

lines internal passageways;

forms glands

what are characteristics of epithelial tissue?

cellularity, polarity, attachment, avascularity, regeneration

what are functions of epithelial tissue?

provide physical protection, control permeability, provide sensation, produce specialized secretions

stratified squamous

the type/shape of epithelial tissue that skin is made of

transitional epithelium

type of epithelium that tolerates repeated cycles of stretching and recoiling and returns to its previous shape without damage; found in the bladder

tight junctions

cell junctions that cannot withstand stretching; the lipid portions of two plasma membranes are tightly bound together by interlocking membrane proteins

gap junctions

cell junctions that have tunnels between cells (connexons) for intercellular communication

connexon

a protein channel in a gap junction that links adjacent cells

desmosomes

cell junctions found where tissues are stretched

hemi-desmosomes

Attaches cell to basal layer of epithelium

endocrine glands

ductless glands that secrete hormones into the bloodstream

exocrine glands

ducted glands that release secretion on the surface of epithelium

what does connective tissue do?

fills internal spaces;

supports other tissues; stores energy

what are characteristics of connective tissue?

Specialized cells

Solid extracellular protein fibers

Fluid extracellular ground substance

what are functions of connective tissue?

structural framework;

transports fluids;

protect delicate organs;

supporting, surrounding, and interconnecting tissue;

stores energy reserves (fat);

defending body from invading organisms

fibroblast

most common type of connective tissue cell; produces matrix

mesenchymal cell

connective stem cells that turn themselves into what's needed (differentiate)

mast cell

connective tissue cell that produces and releases histamines

macrophage

connective tissue cell that cleans things up; "eats" pathogens

adipocyte

Connective tissue cell specialized for the synthesis and storage of fat as triglycerides.

melanocyte

connective tissue cell that creates melanin (skin pigment)

collagen fibers

connective tissue fibers that are very strong and flexible; the thickest and most common connective tissue fiber

elastic fibers

connective tissue fibers that stretch to about 150% of their resting length

reticular fibers

connective tissue fibers responsible for supporting and strengthening; make up framework of organs; are made of women fibers (storm)

cartilage

gel-type ground substance of "gummy bear" consistency; for shock absorption and protection

hyaline cartilage

Most common type of cartilage; it is found on the ends of long bones, ribs, and nose

chondroitin sulfate

provides support and adhesiveness in cartilage, bone, skin, and blood vessels; makes cartilage gel-like

perichondrium

"around the cartilage" membrane

elastin

highly elastic protein in connective tissue and allows many tissues in the body to resume their shape after stretching or contracting

diffusion

how does cartilage and epithelial tissue get nutrients?

Lacuna (cartilage)

A cavity or depression in cartilage that are occupied by chondrocytes

interstitial growth

cartilage growth from within (density)

appositional growth

gradually increases the size of cartilage by adding to its outer surface (length/size); growth of the perichondrium

chondroblast

immature chondrocyte whose purpose is to build cartilage

18

what percentage of body weight does bone make up?

functions of bone

support, storage of minerals and lipids, blood cell production, protection, leverage

calcium (calcium phosphate)

one of the two main compounds of bone; makes bones hard and brittle

collagen

one of the two main compounds of bone; provides strength and flexibility

osteocyte

mature bone cell

osteoprogenitor cells

stem cells that produce osteoblasts

osteoblast

immature bone cell that builds bone

osteoclast

cell that breaks down bone to release stored minerals

diaphysis

shaft of a long bone

epiphysis

expanded end of a long bone

metaphysis

where diaphysis and epiphysis meet; important for growth

compact

type of bone structure that makes up the outside of bone

spongey (trabecular)

type of bone structure that makes up the inside of bone

medullary cavity

center of a long bone that store marrow

osteon

basic functional unit of bone; also known as a Haversian system

Haversian canal

hollow central canal of bone that contains blood vessels and often nerves

lacuna (bone)

A cavity or depression in bone that are occupied by osteocytes, located between lamellae in compact bone.

concentric lamellae

extracellular matrix in bone found within the osteon

interstitial lamellae

extracellular matrix in bone that fill spaces between osteons

parallel

how are osteons arranged compared to the long bone?

canaliculi

canals that allow for communication between superficial and deep osteocytes

canals of Volkman

transverse canals through which blood vessels perforate bone

periosteum

tough fibers membrane encapsulating bones

endosteum

periosteum that lines Haversian canals and canals of Volkman

endochondral ossification

the turning of bone from within the cartilage

diaphysis

what is the primary ossification center?

osteoclasts

what forms the medullary cavity during ossification?

epiphysis

what is the secondary ossification center?

articular cartilage

cartilage that remains at the end of bone

epiphyseal cartilage

cartilage in the metaphysis also known as growth plate

chondroblast (bone growth)

what type of activity is there on the epiphysis side during puberty/ bone growth?

osteoblast (bone growth)

what type of activity is there on the diaphysis side during puberty/ bone growth?

epiphyseal line

this is formed when there is so much osteoblast activity that the epiphysis and the diaphysis fuse; its presence indicated that bone growth has finished

intramembranous (ossification)

growth of flat bones that occurs in the dermis

nutrient vessels

the largest and most important skeletal blood vessels; enters the diaphysis through the nutrient foramen

metaphyseal vessels

vessels that supply blood to the metaphysis

periosteal vessels

vessels that supply blood to superficial osteons of compact bone and migrates to the epiphysis

calcitriol

hormone that's produced by the kidneys;

promotes calcium absorption by the intestines

growth hormone (GH)

hormone that's produced by the pituitary gland;

stimulates osteoblast activity

thyroxine

hormone that's produced by the thyroid gland;

stimulates osteoblast activity

sex hormone

hormones produced by either the ovaries or testes;

stimulate osteoblast activity

calcitonin

hormone produced by the thyroid gland;

decreases osteoclast activity and increases the release of calcium by the kidneys

[when there's too much calcium in the body]

parathyroid hormone (PTH)

hormone produced by the parathyroid gland;

increases osteoclast activity and decreases the release of calcium by the kidneys

[when there's not enough calcium in the body]

osteopenia

non-pathological decrease of bone density over time

8, 3

about what percentage of bone mass do women and men (respectively) lose every decade?

osteoporosis

severe osteopenia caused by decreased circulating hormones

osteomalacia

bone softening as a result of a vitamin D deficiency

rickets

osteomalacia in children; can cause sever bow-leggedness

gigantism

overproduction of growth hormone before puberty

acromegaly

gigantism that occurs in adult years

marfan's syndrome

metabolic disorder caused by the lack of certain chemical connective tissue making that tissue weak;

usually can be seen by the lack of proportion

stratum corneum

thickest and upper most layer of the epidermis; accumulates yellow/orange pigment called carotene

stratum lucidem

layer of the epidermis that's most prominent in palms and soles of feet; the layer in which keratohyalin is converted to eleidein

stratum granulosum

the darkest layer of the epidermis; contains cells that produce keratohyalin for more structure

stratum spinosum

layer of the epidermis that contains desmosome, which are cells with thickened interconnected membranes

stratum basale (germinativum)

deepest layer of the epidermis; contain melanocytes that protect from UV light and give pigment to the skin

papillary

superficial layer of the dermis; creates finger prints and has Meissner Corpuscles

papillae (dermis)

tissue folds caused by elastic and collagen fibers that create finger prints

Meissener Corpuscles

corpuscles in the papillary layer of the dermis that sense light touch

reticular

deep layer of the dermis; contains Pacinian Corpuscles

Pacinian Corpuscles

corpuscles in the reticular layer of the dermis that sense deep pressure

holocrine exocrine glands

a type of sebaceous gland where the cells rupture sebum into the duct of the gland

apocrine

sweat glands found in the groin, nipples, and axillae;

they secrete thick sweat that creates body odor

merocrine (eccrine)

sweat glands that respond to a rise in body temperature; thin sweat secreted contains electrolytes, protein, and other compounds

terminal

type of hair: thick and heavy, found on the scalp, eyebrows, and eyelashes

intermediate

type of hair: heavier on the arms, legs, and pubic region