Chpt Two PP II

signal transduction

vitally important for communication and to control cell growth; includes autocrine, paracrine, endocrine, synaptic signaling

autocrine

cell releases chemical into extracellular fluid that affects its own activity

paracrine

signaling acts on nearby cells

endocrine

when signal affects cell behavior w/i entire organism

synaptic signaling

neurotransmitters released from neurons to act on neighboring cells

signaling receptors

proteins that receive messages and make cells respond

signaling molecule

ligand that binds to messenger and sends messages; includes neurotransmitters, hormones, growth factors

phases of cell cycle

G0, G1, S, G2, M

phase 1: G0

state of inactivity; no more cell division

phase 2: G1

growth, longest phase, produce extra organelles and porteins

phase 3: S

synthesis, DNA replication

phase 4: G2

growth, prep for mitosis, microtubule production

phase 5: M

mitosis, active cell division

metabolism

process by which fats, proteins, and carbohydrates are where food we eat are converted to energy

catabolism

large and small molecules broken down to release energy

anabolism

uses energy to build smaller molecules into large molecules

junctions

structure that hold cells together

tight junctions

seal spaces between cells and prevent leakage

adhering junction

connect neighboring cells and help tissues maintain shape

gap junctions

help small molecules and ions pass directly between cells

extracellular matrix

material that fills spaces between cells, made of polysaccharides and proteins

collagen

provides strength in structure in the extracellular matrix

elastin

allows tissue to stretch and return to original shape

tissue

cells w similar embryonic origin or function are often organized into larger functional units

categories of body tissues

epithelial, connective, muscle, nervous

epithelial tissue

covers body’s outer surface and lines internal closed cavities; form secretory portion of glands and ducts

types of epithelial tissue

squamous, cuboidal, columnar, simple, stratified, pseudostratified

squamous epithelial tissue

collecting tubules of kidney, covering of ovaries

cuboidal epithelial tissue

lining of intestine and gallbladder

columnar epithelial tissue

skin

simple epithelial tissue

lining of blood vessels, alveoli

stratified epithelial tissue

mucous membranes, bladder

pseudostratified epithelial tissue

pituitary gland, thyroid gland

connective tissue

most common tissue in body; connects and supports tissue

proper connective tissue

loose, adipose, reticular, and dense connective tissue

specialized connective tissue

cartilage, bone, blood cells

muscle tissue

contraction of blood vessels and visceral organs, moves skeletal structures, pumps blood thru heart

skeletal muscle tissue

most abundant

cardiac muscle tissue

main part of heart

smooth muscle tissue

involuntary muscle bc its activity is spontaneous or stimulated by ANS

nervous tissue

provides means for controlling body function and for sensing/moving abt the environment

neurons

function in communication

neuroglial cells

support neurons; hold together neurons and allow them to function

afferent neurons

carry nerve impulses from sensory stimuli to CNS

efferent neurons

motor neurons that carry neural impulses away from CNS and to body

cerebral atrophy

reduction in size of cells in cerebrum of brain

cardiac hypertrophy

increased cardiac muscle mass; increased workload, functional demand

acromegaly

condition of cellular hyperplasia caused by excessive hormonal stimulation that leads to excessive growth