Control and co ordination Flashcards
Explain progesterone and oestrogen
oestrogen are the changes during puberty like voice, skin etc..
progesterone uterine changes during menstrual cycle , helps in pregnancy
What happens when insulin is not secreted in proper amounts
Insulin is secreted by pancreas
Sugar level rise - harmful effects for body
Why is it necessary for us to have iodised salt in our food
Necessary for thyroid to make thyroxin hormone - regulates metabolism, fats etc… helps in balanced growth
Synthesises thyroxin hormone
suffer from goitre if deficient - swollen neck
What happens in an emergency situation?
Adrenaline is secreted directly into the blood and carried to diff parts of body
mainly acts on heart which supplies more oxygen
The blood to the digestive system and skin is reduced to the contraction of muscles in small arteries
This diverts blood to skeletal muscles
Breathing rat increases due to contraction of diaphragm and rib muscles
All these responses help the animal to deal with a situation
Chemical signals are sent throughout the body by a hormone…
Adrenaline secreted by adrenal gland
Hormone for emergency
What are hormones
Hormones are minute, chemical messengers thrown into blood to act on target organs.
Other plant hormones?
Gibberellins - help in growth of stem
Cytokinins - cell division present in seeds fruits
Absicisic acid - inhibits growth, wilting of leaves
Explain auxin
Diff plant hormones help in coordinated growth, response etc…
These re synthesised away from where they act and are diffused at area of action
Auxin is a hormone in plant which helps plant growth by elongation this is synthesised at tip of cell
When is light is coming from one side auxin diffuses towards shady side and this helps the side of the shoot away from to light to grow longer - plant appears to bend towards light
Chemical communication
Working by stimulated cells - releases some chemicals/hormones - diffuses around original cell
if other cells have special molecules to detect compound it can receive info and even transmit it
Limitation to electrical impulse
Reaches cells only connected to nervous system
When an electrical impulse is generated it takes time to reset mechanism and generate new one
What is directional movement explain in detail
Environmental triggers such as light gravity etcc changes the dir of the plant in which it grows in. These movs can be towards stimulus or away
Phototropism - response towards ligh - shoot grows towards light, roots bends away
Geotropism - response to pull of earth or gravity - vice versa
Chemotropism - growth of pollen tubes towards ovules
Hydrotropism - response to stimulus of water
Why do plants appear as if its moving
Plants respond to stimuli slowly by growing in a particular direction. Since this growth is directional it appears to be moving
Explain growth in pea plant
A pea plant uses tendrils and these tendrils are sensitive to touch. When they come in contact with the object the part of the tendril in contact with the object does ot grow rapidly as compared to the part of the tendril away from he object and this causes the tendril to circle around the object and cling to it.
How do plants respond to stimuli?
How do plants and animals change shape differently?
The plants use electrical chemical means to convey information from cell to cell but there is no specialized tissue in plants for the conduction of information.
They also change shape by changing amt of water in them and this results in shrinking or swelling, unlike anils who have special proteins to change shape and arrangement in response to electrical impulse
How does the nervous tissue cause action?
When a nerve impulse reaches the muscle the muscle fibre must move. The muscle cells will move by changing their shape so that they shorten. Muscle cells have special proteins that change both their shape and their arrangement in the cell in response to nervous electrical impulses. When this happens new arrangements of these proteins give the muscle cells a shorter form.
Nervous system, nervous tissue, neurons and nerves
Nervous system is the organ system present in the animals to control and coordinate different activities of the body - brain spinal cord
Nervous tissue is made up of an organized network of nerve cells or neurons. It is specialized for conducting information via electrical impulses from one part of the body to another.
A neuron is the basic unit of the nervous system. Each neuron consists of three parts, namely, the cell body or cyton, branched projections called the dendrites, and the long process from the cell body, called the axon.
Nerve is a whitish fibre or bundle of fibres in the body made up of number of neuron cells that transmits impulses of sensation to the brain or spinal cord, and impulses from these to the muscles and organs.
Types of nerve cells or neurons:
Sensory nerves send messages from the sense organs to the brain or spinal cord. • Motor nerves carry messages back from the brain or spinal cord to all the muscles and glands in the body. • Interneuron or relay neuron connects neuron within specific regions of the central nervous system. These are neither motor nor sensory.
How are the tissues protected?
Human brain is protected by the thick bones of the skull and a fluid called cerebrospinal fluid which provides further shock absorption.
Vertebral column protects spinal cord
Explain hind brain
Involuntary actions like bp, vomiting etc controlled by medulla in hind brain
Activities are possible due to cerebellum in hind brain –> responsible for precision of voluntary actions and maintaining posture and balance of body
How are decisions made/ explain fore brain
The fore brain has regions which receive sensory impulses from receptors
Separate areas of association where the sensory information is interpreted by putting together info from other receptors and info already stored in brain
Based on this a decision is made on how to respond. This info is passed on to motor areas
What are motor areas
Motor areas control the mov of voluntary muscles
Which is the main coordinated centre of body…what are its 3 major parts
Brain
Fore Brain - Main thinking part of our brain, it has regions which receive sensory impulses from receptors, separate areas specialised for smell hearing etc…
Mid brain
Hind brain
2 ways in which nervous system communicates with muscles
The motor neurons release a chemical, which is picked up by the muscle fibre. This tells the muscle fibre to contract, which makes the muscles move. Neurons carry messages from the brain via the spinal cord. These messages are carried to the muscles which tell the muscle fibre to contract, which makes the muscles move.
Nervous action
Voluntary - action under our control
Reflex action - involuntary - immediate automatic
Involuntary - Action which not under our control
What is synapse
Narrow gaps bw axon terminal of one neuron and dendrite terminal of another neuron
Electrical impulses changes from electrical to chemical back to electrical
Delivery of impulses from neurons to other cells
Explain human nervous system
CNS
1. Brain
2. Spinal cord
Peripheral nervous system
1. connects brain and spinal cord to other organs of body
Explain reflex arc and its components
Process of detecting a signal or input and responding so output can be quicker
Formed at spinal cord
Input goes to brain
It is evolved in animals thinking f brain not fast enough even tho nerve networks are complex
Components - spinal cord, sensory nerve response, stimulus receptor organ to effector organ (organ getting effected)
Explain thinking tissue why does it take long to react
Made up of connected nerve cells which are intricately arranged
Acquires signals from nerves from all over our body
thinks about responding to them
Its a complex activity
Explain the working of a nerve
What are receptors give examples
All information is detected by specialised tips called receptors. These are located in our sense organs. Eg - gustatory ( taste , olfactory (smell)
This information is acquired at the end of the dendritic tip of nerve cell and sets of chemical reaction which creates an electrical impulse. This travels from dendrite - cell body - axon - nerve end
Axon sets off same more chemicals. These chemicals cross a gap or synapse. The synapse finally allows the delivery of impulses from neurons to other cells.
What is movement explain in brief (2m)
We associate movement with a change in environment of an organism
Also, a change in an env of an organism is taken for their advantage. Each change invokes a certain kind of movement or rather an event triggers it. These movements must be controlled and coordinated by specialised tissues
