Anatomy: study of structure Physiology: study of function

Groups of cells with common s&f Four categories: 1.Epithelial a.Covers outside of body b.Lines organs & cavities b.Tight junctions ensure function as a barrier Butterfly 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 chemicals 1. Line respiratory & digestive tracts as mucous membranes

2. Connective tissue a. Bind & support other tissues b. 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. Adipose a. Stores fat b. Cushions & insulates 3. Fibrous connective a. Dense with collagen b. Tendons (m-b) & ligaments (b-b)

4. Cartilage a. Strong, flexible 5. Bone a. Mineralized connective tissue b. Osteoblasts: cell that deposit collagen matrix – mix with Ca, Mg, P ions & harden c. Deposited around center of nerves & blood vessels

6. Blood a. Matrix: plasma b. RBC, WBC, platelets

3. Nervous tissue a. Senses stimuli & transmits signals b. Nerve cell: neuron 4. Muscle tissue a. Long fibers that contract when stimulated by nerve impulses b. 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 O 2 used or CO 2 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)

Basal metabolic rate (BMR): rate when at rest, non-growing, no food (endothermic) Humans: kcal/day ( ) ( ) BMR for specific temp: standard metabolic rate (SMR) BMR and SMR affected by many factors