Animal form and function 1 Flashcards
Physiology
the whole natural history or natural sciences (the study of the functions of organisms)
Anatomy
the study of the structure of organisms
Functional Anatomy
function correlates with structure in the tissue of animals
Tissue
integrated group of cells with a common structure and function
Four main types of Tissues
- Epithelial
- Connective
- Muscle
- Nervous
Epithelial tissue is..
sheet of tightly packed cells lining organs and cavities
Epithelial Functions
- barrier- protecting against injury, microorganisms, fluid loss
- exchange surface
- absorption or secretion of chemical solution
Epithelial Types
is based on the number of cell layers and shape of cells
Epithelial Types - number of cell layers
- simple; single layer
- stratified; multiple tiers
- pseudostratified; single layer that appears stratified
Epithelial Types- shape of cell
- cuboidal; like dice
- columnar; like bricks on end
- squamous; flat like tiles
Connective Tissue- cells and extracellular matrix
-cells- sparse population
- matrix- web of fibres embedded in uniform foundation
: collagenous fibres- collagen, non-elastic
: elastic fibers- elastin, rubbery quality
: reticular fibres- collagen, thin and branched, tightly woven
Connective Tissue- main function
to bind and support other tissue
Connective Tissue Types
for each type, the structure correlates with its special function
Loose Connective Tissue
- all 3 types of fibres, lossly woven
- binds epithelia to tissues, packing material
- cells; fibroblasts and macrophages
Fibrous connective tissue
- collagenous fibres; defense
- parrallel fibre bundles-> ^ non-elastic strength
- in tendons and ligaments
Adipose tissue
- store fat, pads and insulates
- loose connective tissue
Cartilage
- flexible support (nose, ears)
- abundance of collagenous fibres in rubbery matrix
- cells; chondrocytes
Bone
- make up skeleton supporting the body of most vertebrates
- mineralized connective tissue (calcium, magnesium, phosphate)
- cells; osteoblasts and osteocytes
Blood
- extensive extracellular matrix
- matrix- liquid called plasma
- cells; erythrocytes and leukocytes also platelets (cell fragments)
Muscle tissue
is the most abundant tissue in most animals
Muscle tissue Function
muscle fibres contract when stimulated by nerve impulses
Muscle tissue types; Striated
- responsible for voluntary movement
eg. skeletal muscle
Muscle tissue types; smooth
- lacks striation
eg. in intestines
Muscle tissue types; cardiac
- striated, but cells branched
- forms contractile wall of the heart
Nervous tissue Functions
sense stimuli and transmit signals from one part of the animal to another
Nervous tissue cells (neurons and glia)
neurons- functional units of nervous tissue, transmit nerve impulses
glia- support neurons metabolically, structurally, and functionally
Organs
specialized centres of the body functions composed of several different types of tissue
Organ systems
group of organs that work together in performing vital body functions
Signalling by hormones
- slow
- effect often long lasting
- limited to cells that have the receptor for the signal
Signalling by neurons
-very fast
- brief signal
- limited to cells that connect by specialized junctions to an axon that transmits an impulse
AND
if the junction is a chemical synapse, have the receptor for the neurotransmitters
Internal environment for vertebrates
interstitial fluid
Homeostasis
is the maintenance of a relatively stable internal environment despite changing external conditions
(homeo= sameness, stasis= standing still)
How is homeostasis achieved?
by complex coordination of processes via chemical and or electrical signalling
Regulator
uses mechanisms of homeostasis to moderate internal change in the face of external fluctuations eg. endotherms thermoregulate
Conformer
allows some conditions within its body to vary with certain external changes eg. spider crabs osmoconform
Osmoregulation
management of the body’s water content and solute composition
71% of earth surface is covered by what types of water ?
- mostly seawater
- total fresh water <1% or 0.01% of sea water
Seawater contains
- 3.5% salt
- sodium and chloride
- magnesium, sulfate, calcium
Fresh water contains
-<0.1 to > 10 mosm/L of salt
Osmosis
diffusion of water across a selectively permeable membrane
Molarity
- moles of solute/ volume L
- 1M substance = MW of substance in grams/L
Osmolarity
- osmoles of solute particles/ volume L
- 1 osmole = 1 mole of osmotically active particles
Osmolality
osmoles of solute/ kg
Hyperosmotic side
- higher solute concentration
- lower free water concentration
Hypoosomotic side
- lower solute concentration
- higher free water concentration
Isoomotic with medium
body fluids= same osmotic pressure as medium
Hyperosmotic
osmotic concentration higher than medium
Hypoosomotic
osmotic concentration lower than medium
Osmoconformer
animal that does not actively adjust its internal osmolarity becuz its isoosmotic with its environment
Osmoregulator
- animals whose body fluid has a different osmolarity than that of the environment
- animals that live in hypoosmotic environment must discharge excess water
- animals that live in hyperosmotic environment must take in water
- expend energy to control its internal osmolarity
How is water balanced in freshwater ?
- Osoregulators
- gain water by osmosis and food
- lose salt by diffusion and in urine
- regain salt in food and by active uptake from surroundings
- excrete large amounts of diluted urine
How is water balanced in the ocean? (Invertebrates)
- osmoconformers
- total osmolarity= seawater
- individual solute no seawater
- > conform to osmolarity of ocean, but regulate internal ionic composition
How is water balanced in the ocean? (Vertebrates)
- Osmoregulator
- lose water by osmosis
- gain water and salt in food and drinking seawater
- dispose of salt by active transport out of gills and in urine
- produce small quantities of urine
Stenohaline
organism that cannot tolerate substantial changes in external osmolarity (stenos= narrow, close and halos= salt)
Euryhaline
organism that can tolerate substantial changes in external osmolaroty (eurys= wide, broad)
Water balance and waste disposal depends on ?
transport epithelia
Transport epithelium
- layers of specialized cells that regulate solute movement
- ability to move specific solutes in controlled amounts in particular directions ***
- cells joined by tight junctions
- arranged into tubular networks with extensive
Anhydrobiosis
(life without water)
- ability to survive in dormant state when an organism’s habitat dries up
Osmotic balance on land large problem = Desiccation
- adaptations that reduce water loss are key to surivial on land
- water loss reduced by.. body coverings, nocturnal habit, drinking and eating moist food, using metabolic water
Kangaroo rat
- fur for insulation
- remains cool in burrows during day
- seed eater, derived water from seeds
- concentrates urine and dehydrates feces
- condenses respiratory moisture in nasal passages
