Tissues Of The Body, Homeostasis

Front 1

What are the four types of body tissue?

Back 1

Epithelial - covers, lines, forms glands
Connective - stores energy, transports, structural support for other tissues
Muscle - contraction, heart, skeletal
Neural - carries information in form of electrical impulses

Front 2

Epithelium includes

Back 2

epithelia (cells that line) and glands (produce fluid secretions)

Front 3

What are characteristics of epithelial tissue?

Back 3

1. cellularity - cells are bound together by cell junctions
2. polarity - exposed part of cell and inside part differ in membrane structure and function, ways in which organelles are distributed
3. attachment - base of epithelium bound to basal lamina
4. avascularity - obtain nutrients via diffusion or absorption
5. regeneration - cells are replaced through stem cell division

Front 4

What are the four functions of epithelial tissue?

Back 4

1. protection - against abrasion, dehydration, destruction
2. control permeability - hormones can affect transport of ions/nutrients through epithelial
3. provide sensation - i.e. neuroepithelium specialized to sense smell, taste, sight, equilibrium, hearing
4. produce secretions - glands secrete fluids for protection or to provide chemical messengers

Front 5

Specializations of epithelial tissues includes

Back 5

movement of fluids for protection
movement of fluids to control permeability
production of secretions

Front 6

An epithelial cell is divided into two functional regions:

Back 6

1. apical surface - exposed face
2. basolateral surface - base and sides

Front 7

Integrity of epithelia includes

Back 7

1. intracellular connections - cell adhesion molecules bind cell to basal lamina, hyaluronic acid binds adjacent cells
2. cell junctions

Front 8

List and describe the three different types of cell junctions.

Back 8

1. tight junctions - interlocking membrane proteins bind cells, prevent water/solutes from entering
2. gap junctions - cells are held together by connexons (membrane channel proteins) and beating of cilia
3. anchoring junctions - durable connections for stretching, bending, twisting, bound by proteoglycans and cell adhesion molecules, connected to cytoskeleton of cell, seen in superficial layers of skin belt desmosomes, button desmosomes, hemidesmosomes

Front 9

Describe simple epithelium.

Back 9

one layer of cells covers basal lumina
thin and fragile
line internal compartments and passageways
secretion or absorption occurs

Front 10

Describe stratified epithelium.

Back 10

several layers
surface of skin cell

shapes are squamous, cuboidal, columnar

squamous epithelia is thin, flat, and irrecular

Front 11

Describe simple squamous epithelia.

Back 11

located where absorption or diffusion takes place
or where a slippery surface is needed
most fragile in body
alveoli/lining of ventral body cavities (mesothelium)
lining of blood vessels

Front 12

Describe stratified squamous epithelia.

Back 12

located where mechanical stresses are severe
forms series of layers
surface of skin
lining of mouth
lining of anus if skin then contains keratin and is keratinized
water-resistant of non-keratinized then tough but will dry out (oral-cavity, vagina, anus, esophagus)

Front 13

Cuboidal epithelia resembles

Back 13

hexagonal boxes (appear square in cross sections)
simple cuboidal - occurs where secretion or absorption takes place (kidney tubules, pancreas, salivary glands)
stratified cuboidal - lines sweat gland ducts, large ducts of mammary glands
transitional - tolerates stretching, found in urinary bladder

Front 14

Columnar epithelia resembles

Back 14

hexagonal but are taller than cuboidal (appear rectangular in cross sections)
simple columnar - occurs where absorption or secretion takes place (small intestine) or protects against chemicals in stomach
pseudostratified columnar - appear to be stratified but are not since all cells contact basal lamina, lining of nasal cavity, trachea
stratified columnar - multiple layers, provides protection along anus, pharynx, urethra

Front 15

What is the difference between simple and stratified epithelia?

Back 15

simple - one layer
stratified - several layers, comes in shapes

Front 16

Distinguish between the two types of glands.

Back 16

endocrine - ductless. secretion released directly into interstitial fluid, hormones regulate or coordinate various tissues, pancreas, thyroid, pituitary
exocrine - have ducts. secretions discharged onto epithelial surface via ducts, sweat, mammary, salivary

Front 17

Describe the three types of secretions.

Back 17

serous - water enzyme-containing solution parotid salivary glands
mucous - mucin becomes mucous, sublingual salivary glands
mixed endocrine glands - serous and mucous

Front 18

Describe the structure of exocrine glands.

Back 18

unicellular (goblet cells, mucin)
multicellular secretory sheet is simplest form
mucin producing line of stomach
multicellular glands are described by:
1. shape of secretory portion (tubular, alveolar [blind pockets], acinar [chambers])
2. structure of duct, simple (no divisions), compound (divides before reaching gland cell)
3. relationship between duct and glandular, if tubular/acinar shares a duct it is called branched

Front 19

What is the function of connective tissue?

Back 19

connects epithelium/muscles/bones to rest of body
bones, fat, blood, cartilage
storage of energy
transport

Front 20

Define "matrix."

Back 20

extracellular fibers and ground substance

Front 21

How is connective tissue classified?

Back 21

1. connective tissue proper - contains extracellular fibers in a syrupy ground substance, adipose tissue, tendons, divided into loose and dense connective tissues, diverse cell population
2. fluid connective tissue (blood and lymph)
3. supporting connective tissue - cartilage and bone, matrix contains more densely packed fibers

Front 22

Describe the three types of connective tissue fibers.

Back 22

1. collagen - long and straight, flexible, strong tendons and ligaments
2. reticular - thinner than collagen and branches, form a network and can flex from many directions
3. elastic - contains protein elastin, after stretching returns to original shape

Front 23

What does ground substance do?

Back 23

fills spaces between cells and surrounds connective tissue fibers

Front 24

Describe loose connective tissue.

Back 24

main locations - everywhere that support must be combined with elasticity, ex. subcutaneous tissue
functions - support, reservoir for fluid and salts
description - fibers produced by fibroblast cells embedded in semifluid matrix and mixed with miscellaneous other cells

Front 25

Describe connective tissue.

Back 25

main locations - tendons, many ligaments, dermis of skin
functions - support, transmission of mechanical forces
description - collagen fibers may be regularly or irregularly arranged

Front 26

Describe elastic connective tissue.

Back 26

main locations - structures that must both expand and return to their original size, such as lung tissue and large arteries
function - confers elasticity
description - branching elastic fibers interspersed with fibroblasts

Front 27

Describe reticular connective tissue.

Back 27

main locations - framework of liver, lymph nodes, spleen
function - support
description - consists of interlacing reticular fibers

Front 28

Describe connective tissue proper.

Back 28

involved in maintenance/repair/energy, storage/defense tendons/ligaments

Front 29

____ secret hyaluronan and help make ground substance viscous
____ engulf pathogens and are scattered in matrix
____ are fat cells

Back 29

fibroblasts
macrophages
adipocytes

Front 30

____ are stem cells, respond to infection by dividing to produce fibroblasts or macrophages

Back 30

Mesenchymal cells

Front 31

_____ produce melanin and skin color.

Back 31

Melanocytes

Front 32

_____ release histamin and heparin, stimulate local inflammation

Back 32

Mast cells

Front 33

____ increase with tissue damage, some develop into antibodies

Back 33

Lymphocytes

Front 34

____ phagocytic blood cells, eosin/neutrophils

Back 34

Microphages

Front 35

Describe loose connective areolar tissue.

Back 35

open framework
made mostly of ground substance
forms a layer that separates skin from deeper structures

Front 36

Describe loose connective adipose tissue.

Back 36

made mainly of adipocytes, absorbs shock, insulator, lipid breakdown releases energy as heat, adipocytes deflate when nutrients are scarce but still remain, do not divide in adults but can be produced by mesenchymal cells

Front 37

What is the function of loose connective reticular tissue?

Back 37

support parenchyma (functional cells) of spleen/liver

Front 38

Dense connective tissue consists of

Back 38

mostly collagen fibers.

Front 39

Describe dense regular connective tissue.

Back 39

collagen is parallel and densely packed
tendons connect skeletal muscles to bones
ligaments connect one bone to another or stabilize organs
aponeurosis attaches broad flat muscles to another muscle or several bones

Front 40

Describe dense irregular connective tissue.

Back 40

no consistent pattern
subject to stresses from many directions
gives skin its strength
forms capsules around internal organs

Front 41

Describe fluid connective tissue.

Back 41

blood and lymph
plasma contains red blood cells, white blood cells, platelets
red blood cells (erythrocytes) transport oxygen/carbon dioxide
white blood cells (leukocytes) immune response
platelets clotting
lymph composed mainly of lymphocytes

Front 42

Supporting connective tissue is

Back 42

cartilage and bone.

Front 43

____ are the only cells in cartilage matrix and occupy chambers called cartilage lacunae.

Back 43

Chondrocytes

Front 44

____ in bone occupy lacunae.

Back 44

Osteocytes

Front 45

Describe the three types of cartilage.

Back 45

1. hyaline - most common, connections between ribs and sternum, articular joints, nasal, closely packed collagen
2. elastic - flexible, outer ear flap, epiglottis
3. fibrocartilage - dense interwoven collagen fibers, durable and tough, spinal vertebrae, between pubic bones of pelvis, fibrocartilage pads prevent contact between bones during movement

Front 46

Describe bone.

Back 46

vascular
receives nutrients through canaliculi sheated by periosterum which has a fibrous outer layer and a cellular inner layer which participates in appositional bone growth
also has an inner spongy bone and a hard outer compact bone (composed of osteons)

Front 47

Membranes consist of

Back 47

epithelial tissue and connective tissue combined.

Front 48

Mucous membranes

Back 48

line passageways and chambers that communicate with the exterior, line digestive, respiratory, reproductive, urinary tracts, lubricate

Front 49

Serous membranes function to

Back 49

line sealed subdivisions of body cavities.

Front 50

Membrane types include

Back 50

connective tissue framework
1. superficial fascia - just below skin
2. deep fascia consists of dense irregular connective tissue, ties organs together
3. subserous fascia - separates serous membranes from deep fascia

Front 51

List and describe the three types of muscle tissue.

Back 51

1.skeletal - large/long/slender, multinucleated, cells do not divide but stem cells produce new cells
2. cardiac - connections known as intercalated discs. small amount of division, pacemaker cells
3. smooth - located in walls of blood vessels, digestive and reproductive tracts, can divide, short and spindle-shaped, moves food/urine/reproductive secretions, controls diameter of respiratory passages, regulates diameter of blood vessels

Front 52

Describe neural tissue.

Back 52

specialized for conduction of electrical impulses
composed of neurons (dendrites, cell body, axons)
and neuroglia (supporting cells)
distribute information using action potentials and neurotransmitters
may synapse with muscle, organ, receptor, nerve, vessels

Front 53

Homeostasis is

Back 53

the maintenance of constant stable internal environment

Front 54

What are the types of homeostatic regulation?

Back 54

1. intrinsic - organ or organ system adjust to environmental change
2. extrinsic - nervous or endocrine, adjusts many systems at the same time

Front 55

The nervous system functions in homeostasis by

Back 55

directing specific responses.

Front 56

The endocrine system functions in homeostasis by

Back 56

releasing hormones.

homeostasis involves receptors, effectors, and a control center

Front 57

Describe positive and negative feedback.

Back 57

positive - designed to push limits outside of window
negative - hormone control, blood pressure, respiration, maintain within a window

Front 58

Describe negative feedback.

Back 58

primary mechanism to preserve homeostasis
thermoregulation in the body is controlled by the hypothalamus
temperature receptors in the body detect an increase, hypthalamus control-center receives information from receptors
effectors like the blood vessels dilate and sweat glands increase secretion

Front 59

Describe positive feedback.

Back 59

response that enhances change in original conditions
escalating cycle
ex. blood clotting

Front 60

Homeostasis involves several systems to regulate body temperature.
heat loss - ____
muscular - ____
cardiovascular - ___
nervous -_____

Back 60

integumentary
muscular
cardiovascular
nervous

Front 61

The integumentary system

Back 61

consists of skin and structures such as nail and hair. Protects the body, helps regulate body temperature, and receives stimuli such as pressure, pain, and temperature.

Front 62

Developmental biology is concerned with

Back 62

cells and development
division
differentiation
organogenesis
growth and death

Front 63

_______ is

Back 63

biochemically and structurally specific

Front 64

Define "gamete."

Back 64

mature sex cell, sperm/ovum, haploid at maturity

Front 65

Define:
telolicithal
yolk platelets
animal pole
vegetal pole

Back 65

many vertebrate eggs
storage packets of nutrients
nucleus
mostly yolk side of ovum

Front 66

The cortex is the

Back 66

region beneath plasma membrane of ovum containing cortical granules activated at fertilization.

Front 67

oviparous birth ____
viviparous birth ____

Back 67

comes from an egg
is live birth

Front 68

Define "zygote."

Back 68

fertilized egg
totipotent (gives rise to all cell types)

Front 69

List the primary germ layers.

Back 69

ectoderm, mesoderm, endoderm.

Front 70

Describe the three envelopes that surround the egg.

Back 70

Primary - next to plasma membrane, contains vitelline. membrane composed of fibrous proteins, called "zona pellucida" in mammals
Secondary - composed of follicle cells, help transfer nutrients to ovum, in mammals becomes "corona radiata"
Tertiary - outer shell of ovum in birds/reptiles

Front 71

Define morphogenesis.

Back 71

differentiated cells must become progressively organized

Front 72

List the steps of fertilization.

Back 72

1. Sperm capicitation - maturation in female reproductive tract
2. Attraction to ovum - motility increases as sperm approaches egg
3. acrosome reaction - Ca2+ ions signal acrosomal head to swell/burst, releasing proteolytic enzymes
4. cortical reaction - polyspermy prevented by hardening of vitellin envelope, again using Ca2+ signaling
5. Activation program - metabolic changes within egg (protein synthesis, aerobic respiration)

Front 73

Chart the division of the zygote.

Back 73

zygote -> morula -> blastula -> gastrula -> neurula

Front 74

Describe the morula, blastula, gastrula, neurula.

Back 74

morula - solid mass of cells
blastula - hollow ball of cells around an internal blastocoel cavity
gastrula - distinct endodermal tube formed (gastrocoel/primitive gut). onset of gastrulation marked by indentation
neurula - ectodermal/neural tube formed

Front 75

Describe differentation/gastrulation.

Back 75

distinct endodermal tube formed (primitive gut/gastrocoel)
onset of gastrulation marked by indentation
dorsal edge of indentation called dorsal lip of blastopore, which is an organizing site
surface cells flow to blastopore (opening to archenteron or primitive gut) to become endomesodermal cells

Front 76

Describe organogenesis/neurulation.

Back 76

neurulation - process of forming an ectodermal tube (neural tube)

Front 77

Describe human embryo division.

Back 77

1. morula - solid mass of cells as embryo travels down uterine for ~5 days
2. blastula stage starts after about 5 days, is nearing the uterus, and is ready for implantation
3. gastrulation - begins at end of the 1st week with the appearance of the hypoblast (which will become endoderm). continues to form the epiblast (later becoming the ectoderm) during the 2nd week and is completed during the 3rd week

Front 78

The purpose of gastrulation is to

Back 78

position the three embryonic germ layers: endoderm, ectoderm, and mesoderm.

Front 79

Ectoderm develops into

Back 79

the skin, nails, epithelium of the nose, mouth and anal canal, lens of eye, retina, nervous system

Front 80

Endoderm develops into the

Back 80

inner linings of digestive tract, as well as linings of the respiratory passages. forms many glands, such as the liver and pancreas

Front 81

Mesoderm forms the

Back 81

somites, notochord, mesenchyme, which give rise to the muscles, circulatory and excretory systems

Front 82

During gastrulation, embryonic cells migrate through an opening within the embryo known as the

Back 82

blastocoele, which disappears completely as the gastrula forms.

Front 83

The opening into the gastrula is known as the

Back 83

blastopore. The inner cavity caused by the infolding is the archenteron.

Front 84

During gastruation, ___ is derived from cells moving inward from the outer surface, ___ is derived from cells during gastrulation which end up between inner endodermal and outer ectodermal layers, and ____ is derived from outer cells covering the embryo.

Back 84

endoderm
mesoderm
ectoderm

Front 85

____ is an axis of organization and forms during gastrulation.

Back 85

Primitive streak.

Front 86

______ begins with the formation of a neural plate after ~18 days, giving rise to the spinal cord and brain. ____ are also created during neurulation. Neural crest cells migrate away from neural tube and give rise to various cell types, inc. pigment cells and neurons.

Back 86

Neurulation
Neural crest cells

Front 87

____ is necessary in order to induce neural plate formation.

Back 87

The notochord

Front 88

3 germ layers give rise to 4 ____.

Back 88

extra-embryonic membranes.

Front 89

List and name the functions of the four extra-embryonic membranes.

Back 89

1. chorion - outermost membrane of embryo
2. amnion - surrounds entire embryo, encloses amniotic fluid, moisture and cushioning
3. allantois - outgrowth of developing digestive tract, stores wastes
4. yolk sac - digests yolk making it available to embryo

Front 90

Gestation takes ___.
____ since last menstrual period.

Back 90

38 weeks.
40 weeks.

Front 91

_______ is the organ of exchange.
_______ connects fetus to placenta.

Back 91

Placenta
Umbilical cord

Front 92

Human chorionic gonadotropin (HCG)

Back 92

signals corpus luteum and is produced by the placenta. The corpus luteum releases estrogen and progesterone, which maintains pregnancy.

Front 93

Identical twins are called

Back 93

monozygotic.
2-cell embryo separates, giving rise to 2 complete organisms. Inner cell mass subdivides, forming 2 independent groups of developing cells.

Front 94

Fraternal twins are called

Back 94

dizygotic.
2 separate eggs are released simultaneously and are fertilized by different sperm.

Front 95

What is progeria (Hutchinson-Gilford syndrome)?

Back 95

rapid, pre-mature aging, avg. life expectancy of 13 years

Front 96

Apoptosis is

Back 96

programmed cell death.

Front 97

How does apoptosis differ from necrosis?

Back 97

apoptosis is programmed, controlled, regulated
necrosis - uncontrolled cell death, leads to lysis of cells