Whole Body Functioning Flashcards
distinguishing factors of passive transport
no energy required
always down a gradient
down what sort of gradients does passive transport occur?
concentration gradient (nutrients) electrical gradient (ions) pressure gradient (gases) electrochemical gradient (combined electro and concentration gradients)
types of passive transport
diffusion/osmosis
facilitated diffusion
what is diffusion/osmosis and what substances use it?
hydrophobic molecules, small uncharged polar molecules
directly across the membrane
occurs whenever there is a gradient
very fast over short distances
what is facilitated diffusion and what substances use it?
large uncharged polar molecules, ions
through a membrane channel or transporter (water through an aquaporin)
what does active transport require to work?
ATP (energy)
2 types of active transport
primary active transport
secondary active transport
what is primary active transport?
ATP used directly for the process
transports substances against their electrochemical gradient
creates electrochemical gradients
what is secondary active transport?
uses electrochemical gradients created by primary active transport
the movement of one substance down its gradient drives the movement of another substance against its gradient
what is bulk transport (flow)?
fast over long distances
all solutes and water move together in the same direction
requires pressure gradients
bulk transport in cells
occurs in organ systems to transport substances to and from cells
cell transport occurs through the cell membrane to transfer substances into cells, and wastes out of cells
how do bulk transport, diffusion & bulk flow work together in the digestive system?
bulk transport:
food bolus moves through stomach & intestines
diffusion:
nutrients & water diffuse -> from gut tube in epithelial cells -> into the blood
bulk flow:
blood flows through blood vessels
how do bulk flow & diffusion work together in the respiratory system?
bulk flow: air flows through airways to lungs diffusion: oxygen diffuses form lungs into blood carbon dioxide diffuses from blood into lungs bulk flow: blood flows through blood vessels
how do bulk flow & diffusion work together in blood?
bulk flow:
blood flows through the heart & blood vessels (cardiovascular system)
diffusion:
oxygen, nutrients, & water diffuse out of the blood, into cells
carbon dioxide & wastes diffuse out of cells, into blood
bulk flow:
blood flows through blood vessels
how do bulk flow & diffusion work together in the urinary system?
bulk flow:
blood flows through a ‘filter’ into the kidney tubules, creating pre-urine
diffusion:
nutrients, ions, wastes, toxins, and water diffuse across tubule cells, or flow to become urine
bulk flow:
blood flows through blood vessels
urine flows down into bladder, then out urethra
what is homeostasis (balance)?
a balanced internal environment
many variables need to be kept within a set range to ensure cells can function
homeostasis maintains what variables?
blood glucose (fuel for cells) blood pH (acidity affects protein functioning) blood osmolarity (needs to stay the same as inside cells so water doesn't move in/out of cells) blood pressure (ensure blood gets to all cells) blood temperature (affects protein functioning)
function and purpose of blood glucose
primary fuel to make ATP
cells also use other blood fuels (fatty acids, amino acids)
fuel from body storage (glycogen or fat) or from food & drink
function & purpose of blood fuel
muscle cells need fuel to make ATP
so muscles can contract and make the legs move
harder they work, more food they need
purpose & function of blood pH
measure of acidity
refers to the concentration of hydrogen ions in blood
food we eat & breathing rate affect acidity
muscle cells produce waste as they work
co2 & h+ wastes increase blood acidity
breathing increases to rid more co2
purpose & function of blood osmolarity
the ratio of solutes to water
plasma osmolarity must = ICF osmolarity or water moves in/out cells (affecting functionality)
food & fluid, environment & activity levels affect plasma osmolarity
increased blood osmolarity occurs when dehydrated
decreased blood osmolarity occurs when over-hydrated
purpose & function of blood pressure
mean arterial blood pressure (MABP) is the average blood pressure within all arteries
needs to be high enough to control flow
blood volume, heart rate & blood vessel width affect BP
extreme exercise & hydration state increases MABP
purpose & function of blood temp
optimum blood temp is 37˚C
hotter temp = protein damage
colder temp = processes slow/stop
food & fluid, hydration state, activity level & environment affect core temp
heat is produced when working muscle cells create & use ATP
heat loss through sweat, vasodilation, breathing
heat gain through shivering, vasoconstriction
2 types of control to maintain homeostasis
feedforward (preparation before) negative feedback (correction after)
example of feedforward
“I am going to watch his body language so I can anticipate when to jump”
example of negative feedback
“I jumped too late. need to jump earlier to get it”
components of negative feedback
stimulus
sensor
control centre
effector
stimulus function
something disturbs balance
variable goes out of range
sensor function
cells detect the change
control centre function
cells signal to effectors to correct the change
effector function
effector cells do something that will correct the change and restore homeostasis
