anatomy: study of structure physiology: study of function
TRANSCRIPT
• Groups of cells with common s&f• Four categories:
1. Epitheliala. Covers outside of bodyb. Lines organs & cavitiesb. Tight junctions ensure
function as a barrierButterfly children
d. Criteria for epithelial tissue: # cell layers & shape of cells 1. Simple epithelium: single layer of cells
2. Stratified epithelium: multiple tiers
3. Shape: cuboidal (cube), columnar (bricks on end), squamous (flat)
e. Glandular epithelia: absorb & secrete chemicals1. Line respiratory & digestive tracts as mucous membranes
2. Connective tissuea. Bind & support other tissuesb. Sparse population of cells scattered through ECM
c. Three kinds• Collagenous fibers• Elastic• Reticular
d. Connective tissue in vertebrates:1. Loose connective
a. Binds epithelia to tissues, holding organs in place – has two main cells types scattered throughout
1. Fibroblasts: secrete proteins of extracellular fibers
2. Macrophages: engulf bacteria & dead cells
2. Adiposea. Stores fatb. Cushions &
insulates3. Fibrous connective
a. Dense with collagen b. Tendons (m-b) & ligaments (b-b)
4. Cartilagea. Strong, flexible
5. Bonea. Mineralized connective
tissueb. Osteoblasts: cell that
deposit collagen matrix – mix with Ca, Mg, P ions & harden
c. Deposited around center of nerves & blood vessels
3. Nervous tissuea. Senses stimuli & transmits signalsb. Nerve cell: neuron
4. Muscle tissuea. Long fibers that contract when stimulated by nerve impulsesb. Three types: skeletal, cardiac, smooth
• Organization of tissue layers into organs• Organs suspended by sheets of tissue: mesenteries•Thoracic cavity (heart & lungs) separated from abdominal cavity by diaphragm
• Organs work as organ systems
• B.P. affects interaction with environment•All cells must be in “water”•Direct vs indirect contact•Aquatic vs terrestrial
• Internal envi: interstitial fluid•Nutrient & gas exchange•Helps maintain constant internal envi
• Depends on feedback mechanisms•1) Negative feedback• Change in variable triggers the control mechanisms to counteract further change in the same direction• Ex: body temperature
•2) Positive feedback•Change is amplified, not reversed•Ex: childbirth
• Requires great deal of energy to maintain
• 1.Tropism= movement in the direction of stimulus determines direction of response •Towards the stimulus = positive tropism, •Away from the stimulus = negative tropism
2.Photoperiodic response=sensing time of day via a photoreceptor protein to determine flowering
3.Vernalisation= exposing seeds or seedlings to low temperatures to hasten plant development and flowering
• 4.Gas/Water Exchange= carbon dioxide and water vapor moving through stomates (transpiration)•Controlled by guard cells
• How organisms maintain body systems• Food “fuel” (ATP)• ATP powers life at all levels & releases heat• Biosynthesis: storage, growth, gamete production (need ATP)
•Metabolic rate: amount of energy an animal uses in a given time•Measured by rate of heat loss or amount of O2 used or CO2 made by cell resp.•Endothermic: bodies warmed by heat generated by metabolism (birds, mammals)
•Ectothermic: bodies warmed by environment (reptiles, fish, amphibians, insects)•Amount of energy to maintain a gram of body weight inversely proportional to body size•Mouse 20x more cal/g than elephant (Sci. don’t know why)