Organism Respond To Changes In Their Internal And External Environments Flashcards
Give two examples of effectors
Muscles or glands
What is a neurone?
Specialised cell that transmits electrical impulses
Define tropism
Give two examples of tropisms
Explain taxes
Directional movement, towards (positive) or away (negative) from a stimulus
Explain kineses
Random movement in response to a stimulus (non-directional)
What type of receptor is the Pacinian corpuscle?p
A mechanoreceptor
Describe the basic structure of the Pacinian corpuscle
A sensory neurone with nodes of ranviers and wrapped in layers called lamellae
How is a generator potential formed from the stimulus of a Pacinian corpuscle?
When the pacinian corpuscle is stimulated the lamellae are deformed and press on the sensory ending
Outline what happens in a simple reflex arc
Give the advantages of the reflex arc
Name the two photoreceptors and state where they are located
Rods and cones in the eyes
What is the difference between the location of Rods and Cones in the retina?
Compare and contrast rods and cone cells
Rods:
Only process black and white
Potential only produced when rhodopsin is broken down
Detect light at low intensities
Low visual acuity (cannot distinguish between separate light sources)
Cones:
Process coloured images
Three types which contain iodopsin pigments (red,green,blue) which are all absorbed at different wavelengths
One cone cell connects to a bipolar cell
Can respond to high light intensity
Define myogenic
State the two nodes and the location of them within the heart
SAN- located in the right atrium and is known as pacemaker
AVN- located near border of right and left ventricle within the atria
What is the role of a chemoreceptor?
What is the role of the pressure receptor?
What is the autonomic nervous system?
Describe the structure of a neurone
Define resting potential.
What forms an electrical charge?
Explain the role if the nucleas
Explain the role of the dendrites
Explain the role of the cell membrane
Explain the role of the soma
What are schwann cells for?
Explain the use of the nodes of ranvier
Explain the role of the axon
Explain how an action potential is reached
(Use of diagrams)
What is depolarisation?
What is repolarisation?
Explain the refractory period
Explain the all or nothing principle
What are the factors effecting speed of conduction?
How does temperature affect the speed of conduction?
How does myelination affect the speed of conduction?
How does axon diameter affect conduction?
Where are synapses found?
Name the features on a synapse
What are the features of synaptic transmission?
What are excitatory neurotransmitters?
What are inhibitory transmission?
Explain spatial summation
Explain temporal summation
Define homeostasis
What are the three factors that affect homeostasis?
How does temperature and pH affect homeostasis?
How does water potential affect homeostasis?
How does glucose concentration affect homeostasis?
What is negative feedback?
What is the chain order of negative feedback?
Define osmoregulation
What is the role of the hypothalamus in osmoregulation?
What is the role of the posterior pituitary gland in osmoregulation?
What is the purpose of Antidiuretic hormone(ADH)?
List the names of the components in the nephron that makes up it’s structure
What is the glomerulus?
List the components of the glomerulus filterate
List and then state how much of each components in the filterate is reabsorbed by the PCT
What is the function of the loop of  Henle?
How is the gradient of sodium ions in the medulla maintained?
What are the two limbs in the loop of Henle?
Why and how do they differ from each other?
In which parts of the nephron is water reabsorbed?
What are the factors that influence blood glucose concentration?
Define glycogenesis
What is the role of glycogenesis in the liver?
Define glycogenolysis
What is the role of glycogenolysis in the liver?
Define gluconeogenesis
What is the role of gluconeogenesis in the liver?
What is insulin and where is it found?
How does insulin help to control the glucose concentration in our blood?
What is glucagon and where is it found?
How does glucagon help to control the glucose concentration in our blood?
Is the role of insulin to increase or decrease the concentration of glucose?
Is the role of glucagon to increase or decrease the concentration of glucose?
What is adrenaline and where is it released from?
What is the role of adrenaline?
Describe the second messenger model of adrenaline and glucagon action
Define diabetes
What are the two health conditions that diabetes could cause and when do they happen?
State the difference between type 1 diabetes and type 2 diabetes
What are the differences in the ways we treat individuals with type 1 vs. type 2 diabetes?
What causes you to have type 1 diabetes?
What causes you to have type 2 diabetes?
What is IAA?
What are sensory receptors?
What is the role of the SAN?
What is the role of the AVN?
What receptor detects high blood pressure and what is the effect it produces?
What receptor detects low blood pressure and what is the effect it produces?
What receptor detects high blood O2 and what is the effect it produces?
What receptor detects low blood O2 and what is the effect it produces?
Describe the structure of the neuromuscular junction
Explain the steps of events that are involved in transmission across a cholinergic synapse
Compare and contrast the transmission across the neuromuscular junction and the cholinergic synapse
How do muscles act?
What are skeletal muscles made of?
What are myofibrils made of?
Compare and contrast slow-twitch vs. fast-twitch muscles
What is the sliding filament theory?
Explain the role of actin in myofibril contractions
What is the role of myosin in myofibril contraction?
How do calcium ions cause myofibril contractions?
What is the role of ATP in myofibril contractions?
What is the role of calcium ions in the cycle of actin-myosin bridge formation?
What is the role of tropomyosin in the cycle of actin-myosin bridge formation?
How do organisms increase their chance of survival?
Why does gravitropism and phototropism occur in plants?
What is gravitropism?
What is phototropism?
