topic 4a Flashcards
endotherm
produced most of their heat through metabolic reactions.
ectotherms
derive most of their heat from the environment (reptiles, amphibians, invertebrates and most fish)
name the connective tissues
loose conective lissue (adipose)
dense connective tissue (tendons, ligaments)
speacialised connective tissue (cartilage, bones, fat, blood, lymph)
types of cell communication
direct, synaptic, parancrine. endocrine
types of hormones
steroid
peptide
animno acid
three principle of negative feeback loops
sensor, control centre (hypothalamus) and effector
direct communication
ions flow from each cell by gap junctions (cardiac cells)
endocrine communication
chemicals secreted through the bloodstream, (insulin)
paracrine communication
chemicals released by cells diffuse through extracellular fluid, effects are short - local hormones (prostaglandins)
synaptic communication
chemicals released by cells diffuse through extracellular fluid, transmits electrical signals to each cell (neurotransmitters) (nervous system)
peptide hormone
melatonin - made of many amino acid chain they also bind to receptors on the cell surface as they are not lipid soluble
steroid hormone
synthesised from cholesterol they are lipid soluble so they can diffuse through plasma membranes, they bind to receptor cells inside target cells. (testosterone, oestrogen, progesterone.)
amino acid hormone
(insulin) 2 or more chains of amino acids , which cannot diffuse through the bilayer, they must bind to receptors on the cell surface.
homeostasis
maintainece of a contast internal enviroment
what are the two feedback loops in homeostasis
negative (conteract the change and positive (amplify the change)
