Co-ordination and response Flashcards
Homeostasis
Is the maintenance of a constant internal environment
Example of homeostasis
Body water content
Body temperature
Glands
A gland is an organ that releases or secretes a substance
Exocrine glands
They have a duct
Endocrine glands
They do not have a duct
Pituitary glands
Produced hormones like FSH, LH which are involved in the menstrual cycle and ADH a which controls water level in the body
Pancreas
Produces insulin and glucagon which are involved in the control of blood sugar
Adrenal glands
Produced adrenaline that prepares the body for action
Ovary
Produced estrogen (female sex hormone) and progesterone which is involved in menstrual cycle
Testis
Produces the testosterone (male sex hormone)
Hormones
Hormones are chemical molecules produced by endocrine gland and carried by the blood from endocrine to specific target organs glands to all parts of the body. They affect specific cells called target cells
Hormones & nervous control: hormones
Communication is by chemicals called hormones
Transmission is in the blood to all parts of the body. Only target organs respond
Slows transmission
Slow and long-lasting response
Response is widespread
Effect maybe be permanent and irreversible
Hormones & nervous control:
Communication is by nervous impulses.
Transmission is by neurones and travels to specific part of the body.
Fast transmission
Fast and short-lived response
Response is localised
Effect is temporary and reversible
Adrenaline
Adrenaline prepares you for action
Effect of adrenaline
Pupils dilate so more light enters for better vision.
Increased heart rate sends more blood to the muscles so they receive more glucose and oxygen in respiration.
Deeper and faster breathing as body takes up more oxygen into the body.
Blood is diverted from intestines to intestines so more glucose and oxygen is available for muscles.
Stored glycogen converted back to glucose so more glucose is readily available for respiration.
Insulin
Regulates blood sugar
Effect of insulin
After a meal when blood glucose level increases, insulin is released from pancreas to decrease it.
1. Increasing its uptake by liver cells
2. Increasing its uptake by muscle cells
Inside these cells, glucose is converted to glycogen and stored
Tropism
A tropism is a growth movement in response to directional stimulus. Plants grow towards or away from stimuli
Stimuli affecting plant
Light
Gravity
Water
Positive tropism
A growth movement towards a stimulus
Negative tropism
A growth movement away from a stimulus
Phototropism
Growth response to light from one direction
Geotropism
Growth response to the direction of gravity
Auxin
Stimulates growth
Components of a coordinated behavior
Stimulus to receptor to coordinator to effector to response
Stimulus
A stimulus is a change inside or outside the body that creates a response
Receptor
They detect the stimulus by changing its energy into electrical energy of nerve impulses
Coordinator
The receive and process Information from receptors. They are comprised of brain and spinal cord.
Nerves carry impulses to and from the coordinator
Effector
They bring about responses to return the body to optimum. They are comprised of muscles and glands
Response
The change brought in response to a stimuli
Nervous system
Central nervous system (CNS)
Pheripheral nervous system (PNS)
Nerve
Nerves are bundles of nerve fibres
Motor nerves
Carry impulses of motor neurones
Sensory nerves
Carry impulses of sensory neurones
Neurone
The biological name for a nerve cell is called a neurone. They are specialised for the rapid transmission of impulses throughout the organism
Types of neurone
Sensory neurone
Motor neurone
Relay neurone
Sensory neurone
Sensory neurones carry impulses from sense organs to the CNS (brain or spinal cord)
Relay neurone
Relay neurones are found inside the CNS and connect sensory and motor neurones
Motor neurone
Motor neurones carry impulses from the CNS to effector (muscles or glands)
Reflex actions
It is a rapid and automatic response to a stimulus by an organ or organs without conscious thought
Receptor cells
Are cells that detect stimuli
Effector
Is a muscle or gland that brings about a response
Coordination centre
Such as the brain or spinal cord receives and processes information from receptors and initiate responses
Effect of auxin
Stimulates cell elongation in plant shoots
.
Examples of hormone of endocrine glands
Ovaries
Testes
Pituitary gland
Pancreas
Adrenal gland
Central nervous system
Brain
Spinal cord
The eye when objects are close
Ciliary muscles contract
Suspensory ligaments slacken
Lens becomes fatter
The eye when the object is far away
Ciliary muscle relaxes
Suspensory ligaments pulled tight
Lens becomes thinner
The eye in a dark environment
Photoreceptors detect change in environment (dark)
Radial muscles contract
Circular muscles relax
Pupil dilates (diameter of pupil widens)
More light enters the eye
The eye in bright light
Photoreceptors detect change in environment (bright)
Radial muscles relax
Circular muscles contract
Pupils constricts (diameter of pupil narrows)
Less light enters the eye
Sensory receptors example
Eye
Ear
Skin
Nose
Tongue
Receptors
They detect the stimulus
Contain receptors sensitive to: ear
Sound
Contain receptors sensitive to: eye
Light
Contain receptors sensitive to: skin
Touch
Contain receptors sensitive to: nose
Smell
Contain receptors sensitive to: tongue
Taste
