lec 1- animal form and function Flashcards
what are the key traits of an animal?
multicellularity (cells that lack cell walls), heterotrophy (obtain necessary carbon compounds from other organisms), and Motility (move under their own power at some point in their life cycle)
what is a tissue?
a group of similar cells that work together as a unit to perform the same function
what are the four types of tissues?
connective tissue, nervous tissue, muscle tissue, and epithelial tissue
what is connective tissue?
consists of cells loosely arranged in a liquid, jelly like, or solid matrix. They make their own matrix
what are the four types of connective tissue
Loose connective tissue (fibrous proteins in a soft matrix, eg. fat tissue)
Dense connective tissue (contains a matrix dominated by tough collagen, eg. tendons and ligaments)
Supporting connective tissue (has a firm extracellular matrix, eg. bone and cartilage)
Fluid connective tissue (cells surrounded by a liquid matrix, eg. blood)
what is nervous tissue?
nervous tissue consists of nerve cells, or neurons, and several types of supporting cells
why are neurons excitable cells?
because they have a plasma membrane with a charge that changes over time
what is a neuron made of?
Neurons consist of a cell body, short branching dendrites which transmit electrical signals from adjacent cells to neuron body, and a long axon which carry electrical signals from the cell body to other cells
what is muscle tissue?
consists of cells that contract, converting chemical energy to movement, they are also excitable like neurons
what are the three types of muscle tissue?
skeletal muscle (attach to bones, long cells), cardiac muscle (makes up the walls of the heart, branched cells), and smooth muscle (lines the walls of the digestive tract and blood vessels, tapered cells)
what is epithelial tissue?
consists of tissue that cover the outside of the body, line the surfaces of organs and form glands
what is an organ?
an organ is a structure that serves a specialized function and consists of several tissue
what is a gland?
A gland is a group of cells that secrete specific molecules or solution
what is epethelia?
Epithelia provide protection and act as gatekeepers for the selective movement of water and nutrients across their inner and outer surface
what is the function of the apical side of the epithelial tissue?
Apical side of epithelial tissue lines the organs and secrete mucus
what is the function of the basolateral side of the epithelial tissue?
Basolateral side of epithelial tissue cement the apical to the basil lamina
how long do epithelial cells last for?
Epithelial cells have a lifespan of 2 to 3 days
what happens when a cell gets larger?
As a cell gets larger its volume increases much faster than its surface area does
what are the adaptation to increase surface area?
flattening, folding, branching
what does a larger surface area result in?
More surface area results in more absorption and more heat loss
what are endotherms, ectotherms, homeotherms, and poikilotherms?
Endotherms- produce adequate heat to warm its own tissue
Ectotherms- relies on heat gained from the environment
Homeotherms- keep their body temperature constant
Poikilotherms- allow their body temperature to change depending on the environmental conditions
what is the type of thermoregulation strategies humans use
endothermic homeotherms
what is torpor?
Torpor is a temporary drop in body temperature
what is hibernation?
Hibernation is a longer drop in body temperature
what is the differences between endotherms and ectotherms?
Endotherms have a higher metabolic rate, hence being more active but requires more energy. Ectotherms have a lower metabolic rate, which results in being less active, but it makes it so more energy can be used to support reproduction
why is heat exchange important?
Heat exchange is important because overheating can cause denaturing of proteins, high temperature can lead to water loss, and low temperature can slow down enzyme function and energy production
what are the mechanisms of heat exchange?
Conduction- transfer of heat between solid to solid
Convection- transfer of heat between gas or liquid to solid
Radiation- transfer of heat between two bodies not done physically
Evaporation- phase exchange from water to gas
what is thermal conductivity
High thermal conductivity means quicker flow of heat, meaning high thermal conductivity equals feeling hotter.
what is insulation?
a layer of air/water/tissue that decreases heat loss
what is Allen’s and Bermann’s rule?
Allens rule= animals in cold climates display shorter limbs due to less folds conserving heat
Bermanns rule= animals in cold climates are larger because they have smaller surface area/volume ratio conserving heat
how does heat exchange conserve heat?
by using countercurrent heat exchangers which has small gradients along their entire length
