topic 5 - homeostasis and response Flashcards
(298 cards)
1
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A
2
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What is homeostasis?
A
Homeostasis is the maintenance of a constant internal environment within an organism despite external changes. It ensures that optimal conditions are maintained for enzyme activity and overall cell functions.
3
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Why is homeostasis important for living organisms?
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Homeostasis is essential because it regulates vital variables such as blood glucose concentration body temperature and water levels allowing enzymes and cells to perform their functions optimally.
4
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What are the main variables that homeostasis controls in the human body?
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The main variables controlled by homeostasis in the human body are blood glucose concentration body temperature and water levels.
5
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What are the components of an automatic control system in homeostasis?
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An automatic control system in homeostasis consists of three main components: Receptors (which detect changes in stimuli) Coordination centres (which process the information received) and Effectors (which produce responses to restore balance).
6
Q
What role do receptors play in homeostasis?
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Receptors are specialized cells that detect changes (stimuli) in the environment such as temperature glucose levels and more. They relay this information to coordination centers.
7
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What is a coordination centre in the context of homeostasis?
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Coordination centres are organs or systems that process information from receptors. They include the brain spinal cord and pancreas which interpret the data and initiate appropriate responses.
8
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How do nervous and hormonal communications contribute to homeostasis?
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Nervous communication allows for rapid responses to changes in the environment through electrical impulses while hormonal communication involves chemical signals (hormones) that regulate longer-term changes and processes within the body.
9
Q
What happens to enzyme activity when homeostasis is disrupted?
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When homeostasis is disrupted conditions may fall outside the optimal range for enzyme activity which can lead to decreased efficiency denaturation of enzymes and potentially result in cell dysfunction or failure.
10
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What is the role of effectors in the homeostasis process?
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Effectors are the organs or cells that enact the response determined by the coordination centre to restore balance in the internal environment such as muscles or glands.
11
Q
Can you name an example of a receptor in human homeostasis?
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An example of a receptor in human homeostasis is the thermoreceptors in the skin and hypothalamus which detect changes in temperature and help regulate body temperature.
12
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What is an example of how the body maintains blood glucose levels?
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The body maintains blood glucose levels through the actions of hormones like insulin and glucagon. Insulin lowers blood glucose by facilitating cellular uptake while glucagon raises blood glucose by promoting glycogen breakdown.
13
Q
Explain the concept of negative feedback in homeostasis.
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Negative feedback is a mechanism that counteracts a change in a variable by initiating responses that restore the variable back to its normal level. For instance if body temperature rises mechanisms will activate to lower it and vice versa.
14
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Describe the importance of water levels in homeostasis.
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Maintaining water levels is crucial for normal cellular function as it affects osmosis nutrient transport and waste removal. Imbalance can lead to dehydration or overhydration both of which can disrupt physiological processes.
15
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What are the potential effects of prolonged disruption in homeostasis?
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Prolonged disruption in homeostasis can lead to serious health issues such as metabolic disorders heat stroke or kidney failure depending on which parameter (e.g. blood glucose temperature water levels) is affected.
16
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What are effectors in the human body?
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Effectors are components that bring about responses to restore conditions in the body to optimum levels. They can include muscles that contract or glands that secrete hormones.
17
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What is the primary function of the human nervous system?
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The primary function of the human nervous system is to allow organisms to react to their surroundings and coordinate actions in response to stimuli.
18
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What role do receptor cells play in the nervous system?
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Receptor cells convert a stimulus into an electrical impulse initiating the process of reaction to stimuli.
19
Q
How does an electrical impulse travel from sensory neurons to the CNS?
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After a stimulus is converted into an electrical impulse by receptor cells this impulse travels along sensory neurons to the central nervous system (CNS) for processing.
20
Q
What happens in the central nervous system (CNS) when it receives information from sensory neurons?
A
In the CNS the information is processed and an appropriate response is coordinated resulting in an electrical impulse being sent along motor neurons to the effectors.
21
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What are motor neurons responsible for in response to stimuli?
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Motor neurons are responsible for carrying the electrical impulse from the CNS to the effectors to execute the coordinated response.
22
Q
What actions do effectors perform in the body?
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Effectors can perform actions such as contracting muscles or secreting hormones from glands as part of the body’s response.
23
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What are reflexes and why are they important?
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Reflexes are automatic responses that occur before an individual has time to think. They are important as they prevent the individual from getting hurt by enabling quick vital reactions to stimuli.
24
Q
Describe the reflex arc. What is its function in the nervous system?
A
The reflex arc is a neural pathway that mediates a reflex action. It allows information to travel quickly from receptor to CNS and back to effector facilitating rapid responses to potentially harmful stimuli.
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What types of stimuli are receptor cells responsive to?
Receptor cells can respond to various stimuli including light sound temperature pressure and chemical changes converting these stimuli into electrical impulses.
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What are the two main types of neurons involved in the reflex arc?
The two main types of neurons involved in the reflex arc are sensory neurons that carry impulses toward the CNS and motor neurons that carry impulses away from the CNS to effectors.
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Can you provide examples of physiological effectors in the human body?
Physiological effectors in the human body include skeletal muscles (which contract to produce movement) and endocrine glands (which secrete hormones like adrenaline).
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What is the significance of automatic responses in the nervous system?
Automatic responses like reflexes are significant as they allow for rapid protective actions without the need for conscious thought ensuring the safety and integrity of the organism.
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What characterizes the reflex pathway compared to a regular response to stimuli?
The reflex pathway differs from the usual response to stimuli in that the impulse does not pass through the conscious areas of the brain.
30
List the steps involved in a reflex arc.
1. A stimulus is detected by receptors. 2. Impulses are sent along a sensory neuron. 3. In the CNS the impulse passes to a relay neuron. 4. Impulses are sent along a motor neuron. 5. The impulse reaches an effector resulting in the appropriate response.
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What is a stimulus in the context of a reflex arc?
A stimulus is any detectable change in the environment that is detected by receptors.
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What is the role of a sensory neuron in a reflex arc?
The sensory neuron carries the impulse from the receptor to the central nervous system (CNS).
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What is the function of the relay neuron in a reflex arc?
The relay neuron transmits the impulse from the sensory neuron to the motor neuron within the CNS.
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What does the motor neuron do in a reflex arc?
The motor neuron carries the impulse from the CNS to the effector which brings about the response.
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What is an effector in the context of a reflex arc?
An effector is a muscle or gland that responds to the impulse by producing a specific response.
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Provide examples of reflex actions.
Examples of reflex actions include pupils getting smaller to avoid damage from bright lights and moving your hand away from a hot surface to prevent injury.
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What are synapses?
Synapses are the gaps between two neurons where communication occurs.
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What happens when an impulse reaches the end of the first neuron at a synapse?
When the impulse reaches the end of the first neuron a chemical is released into the synapse.
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Describe the process that occurs at the synapse when the impulse reaches it.
The chemical released into the synapse diffuses across the gap and upon reaching the second neuron triggers the impulse to begin again in that neuron.
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What is reaction time?
Reaction time is the duration it takes for an individual to respond to a stimulus.
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How can reaction time be measured?
Reaction time can be measured using the ruler drop test where the time taken to catch a falling ruler is recorded.
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What is the central nervous system (CNS)?
The central nervous system (CNS) consists of the brain and spinal cord and it processes information and coordinates the body's responses.
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What is the significance of reflex actions in the human body?
Reflex actions are crucial for protecting the body from harmful stimuli and enabling quick reactions without requiring conscious thought.
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What is the primary function of the brain in the human body?
The brain controls complex behavior and is part of the central nervous system along with the spinal cord.
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What controls consciousness intelligence memory and language in the brain?
The cerebral cortex which is the outer part of the brain controls consciousness intelligence memory and language.
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Where is the cerebellum located and what is its main function?
The cerebellum rounded structure towards the bottom back of the brain controls fine movement of muscles.
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What functions does the medulla control and where is it located?
The medulla controls unconscious actions such as breathing and heart rate and is found in the brain stem in front of the cerebellum.
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Why is investigating brain function and treating brain damage and disease difficult?
It is difficult because the brain is complex and delicate easily damaged drugs cannot always reach the brain due to protective membranes and it is not fully understood which parts of the brain control specific functions.
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Who are neuroscientists and what do they study?
Neuroscientists are individuals who study the nervous system and can map out the regions of the brain using various methods.
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What is the relationship between the spinal cord and the brain?
The spinal cord is part of the central nervous system along with the brain and together they control the body's functions and responses.
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What are some methods neuroscientists might use to map out the brain's regions?
Neuroscientists might use imaging techniques such as MRI PET scans and electrophysiological methods to map out brain regions.
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What is the significance of the cerebral cortex in cognitive functions?
The cerebral cortex is crucial for high-level cognitive functions such as thinking reasoning and processing complex information.
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How does the structure of the cerebellum contribute to its function?
The rounded structure of the cerebellum allows for the coordination of muscle movements balance and fine motor skills.
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What role does the medulla play in autonomic functions?
The medulla regulates vital autonomic functions such as heart rate and respiratory rate ensuring the body's internal environment stays stable.
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What challenges do drugs face when trying to treat brain diseases?
Drugs face challenges in reaching the brain due to the blood-brain barrier and other membranes that protect the brain making treatment less effective.
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What advancements have been made in understanding which parts of the brain are responsible for specific functions?
Advancements in neuroimaging and electrophysiological recording techniques have improved understanding but many aspects of brain function remain not fully understood.
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What can be learned from observing patients with brain damage?
Observing the changes in an individual following damage to a certain area of the brain can provide insights into the role and function of that specific brain area.
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How can electrically stimulating different parts of the brain aid in understanding brain function?
Electrically stimulating different parts of the brain through the use of electrodes can result in observable mental or physical changes in the individual which helps researchers understand the role of those specific brain areas.
59
What is the purpose of MRI scanning techniques in studying the brain?
MRI scanning techniques are used to create detailed images of the brain allowing researchers to identify which parts are affected by tumors or which areas are active during specific tasks.
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What are the primary functions of the eye as a sense organ?
The eye is a sense organ that contains receptors sensitive to light intensity and color allowing it to perform the function of vision.
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What is the process by which the eye changes shape to focus on objects?
The process by which the eye changes shape to focus on near or distant objects is called accommodation.
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What different structures are found within the eye and what is their purpose?
The eye contains various structures including the cornea lens iris retina and pupil each adapted to perform specific functions related to focusing light and processing visual information.
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Describe the role of the cornea in the eye's function.
The cornea is the transparent front layer of the eye that helps to focus light onto the retina and protects the inner structures of the eye.
64
What role does the lens play in vision?
The lens of the eye adjusts its shape to help focus light onto the retina playing a crucial role in refining vision.
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What is the significance of the retina in the eye?
The retina contains photoreceptor cells (rods and cones) that convert light signals into electrical signals which are then transmitted to the brain for visual processing.
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How do rods and cones differ in the retina?
Rods are more sensitive to low light levels and are responsible for night vision while cones are responsible for color vision and function best in bright light.
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What is the role of the iris in the eye?
The iris controls the size of the pupil regulating the amount of light that enters the eye.
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Explain the function of the pupil in vision.
The pupil is the opening in the center of the iris that allows light to enter the eye adjusting its size in response to different light conditions.
69
What is accommodation in the context of the eye?
Accommodation refers to the eye's ability to change its focus from distant to near objects. This process is facilitated by the lens of the eye which changes shape to adjust focus.
70
What is the retina and its function in the eye?
The retina is a layer of light-sensitive cells located at the back of the eye. When light hits the retina the cells are stimulated and generate electrical impulses that are sent to the brain. The brain then interprets these impulses to create an image.
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What role does the optic nerve play in vision?
The optic nerve is a crucial nerve that exits the eye and connects to the brain. It transmits the impulses generated by the retina enabling the brain to create visual images based on the information received from the eye.
72
What is the sclera and its importance?
The sclera is the white outer layer of the eye. It provides structural support and protection to the internal components of the eye and its strength helps to prevent damage.
73
Describe the cornea and its function in the eye.
The cornea is the transparent front layer of the eye. It allows light to enter and has a curved surface that bends (refracts) and focuses incoming light onto the retina contributing to clear vision.
74
What is the iris and how does it control pupil size?
The iris is a muscular structure that encircles the pupil. It regulates the size of the pupil by contracting or relaxing. In bright light the circular muscles of the iris contract and the radial muscles relax causing the pupil to become smaller. In dim light the circular muscles relax and the radial muscles contract allowing the pupil to enlarge and let in more light.
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How do the muscles in the iris function in response to bright light?
In bright light the circular muscles of the iris contract and the radial muscles relax which results in constriction of the pupil. This response protects the retina from excessive light exposure.
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What happens to the iris muscles in dim light?
In dim light the circular muscles of the iris relax and the radial muscles contract causing the pupil to dilate allowing more light to enter the eye to improve vision under low light conditions.
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What are the functions of ciliary muscles and suspensory ligaments in the eye?
Ciliary muscles and suspensory ligaments hold the lens in place and control its shape.
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What is the process of accommodation in the eye?
The process of accommodation is how the eye focuses on near or distant objects by changing the shape of the lens.
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How does the lens change shape to focus on a near object?
To focus on a near object the ciliary muscles contract causing the suspensory ligaments to loosen. This makes the lens thicker and more curved increasing its refractive power.
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How does the lens change shape to focus on a distant object?
To focus on a distant object the ciliary muscles relax which tightens the suspensory ligaments. This causes the lens to become thinner reducing its refractive power.
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What is myopia and how does it affect vision?
Myopia or short sightedness occurs when the lens is too curved causing distant objects to appear blurry.
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What is hyperopia and how does it affect vision?
Hyperopia or long sightedness occurs when the lens is too flat and cannot refract light sufficiently making nearby objects appear blurry.
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What are the treatment options for myopia?
Myopia can be treated with spectacle lenses that are concave which spread out light to help focus it correctly on the retina.
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What are the treatment options for hyperopia?
Hyperopia can be treated with spectacle lenses that are convex which help to converge the light rays to improve focus on the retina.
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What are contact lenses and how do they function?
Contact lenses work similarly to glasses; concave lenses are used to treat myopia by spreading out light while convex lenses are used for hyperopia by converging light.
86
What occurs when light cannot focus on the retina?
When light cannot focus on the retina it leads to eye defects such as myopia or hyperopia.
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What are the different types of vision correction methods mentioned?
1. Glasses: Typically used for vision correction and allow for sports activities. 2. Contact lenses: Available in hard or soft varieties with differing durations of wear. 3. Laser eye surgery: Utilizes lasers to modify the cornea for the treatment of myopia or hyperopia. 4. Replacement lens: Involves replacing the lens with an artificial one or adding a plastic lens over the natural lens.
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How does laser eye surgery correct myopia and hyperopia?
1. Myopia (nearsightedness) is treated by reducing the thickness of the cornea which lowers its refractive power. 2. Hyperopia (farsightedness) is treated by changing the curvature of the cornea to increase its refractive power.
89
What are the risks associated with lens replacement surgery for hyperopia?
The risks include: 1. Damage to the retina. 2. Development of cataracts.
90
Where is the thermoregulatory center located in the human body?
The thermoregulatory center is located in the brain.
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What receptors are involved in the regulation of body temperature?
1. Blood temperature receptors: These monitor the temperature of the blood. 2. Skin receptors: These send impulses to the thermoregulatory center based on skin temperature.
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What is the average human body temperature?
The average human body temperature is approximately 37.5 degrees Celsius.
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What physiological response occurs when body temperature becomes too high?
When the body temperature rises too high sweat evaporates from the skin surface which results in increased energy transfer away from the body.
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What is myopia?
Myopia also known as nearsightedness is a vision condition where close objects can be seen clearly but distant objects appear blurry due to the eye being too long or the cornea being too curved.
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What is hyperopia?
Hyperopia or farsightedness is a vision condition where distant objects can be seen more clearly than close objects often due to a short eyeball or a flat cornea that leads to insufficient refractive power.
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What is the purpose of thermoregulation in the human body?
Thermoregulation helps maintain a stable internal body temperature which is essential for optimal physiological function and overall homeostasis.
97
What happens during sweat evaporation in hot conditions?
During hot conditions sweat on the skin surface evaporates which removes heat from the body and helps cool the skin thereby assisting in lowering body temperature.
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What is vasodilation and what effect does it have on the body?
Vasodilation is the widening of blood vessels which allows more blood to flow closer to the surface of the skin. This results in increased energy transfer from the body to the environment helping to cool down the body.
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What happens to sweating when vasodilation decreases too much?
When vasodilation decreases too much sweating stops. This occurs because the body is trying to retain heat when blood vessels constrict and blood flow to the skin is reduced.
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What is shivering and how does it help in thermoregulation?
Shivering is the rapid contraction of skeletal muscles. This process generates heat through increased respiration and metabolic activity helping to raise the body's temperature in response to cold.
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What is the purpose of hairs standing on end in cold conditions?
When hairs stand on end they create an insulating layer by trapping warm air close to the skin. This helps to reduce heat loss from the body.
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What is vasoconstriction and how does it affect heat loss?
Vasoconstriction is the narrowing of blood vessels which results in less blood flowing close to the surface of the skin. This reduces heat loss from the body and helps to retain warmth during cold conditions.
103
Describe the two main communication systems in the human body.
The human body has two main communication systems: the nervous system and the endocrine system. The nervous system uses electrical signals for quick responses while the endocrine system sends hormones which are chemical messengers throughout the body to produce slower longer-lasting responses.
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What is the role of hormones in the endocrine system?
Hormones are chemical messengers secreted by glands in the endocrine system. They travel through the bloodstream to target tissues where they produce specific responses essentially coordinating various functions in the body.
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What is the function of the pituitary gland?
The pituitary gland is often referred to as the master gland of the endocrine system. It secretes hormones into the bloodstream that regulate various bodily functions and control other glands in the endocrine system.
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How do the nervous and endocrine systems work together in the body?
The nervous system provides quick short-term responses to stimuli through electrical signals while the endocrine system provides longer-term regulation of bodily functions through hormones. Together they maintain homeostasis and coordinate responses to internal and external changes.
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Give an example of a hormone produced by the pituitary gland and its effect.
One example of a hormone produced by the pituitary gland is the growth hormone (GH). It stimulates growth cell reproduction and cell regeneration in the body playing a crucial role in development and metabolism.
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What is the function of the pancreas regarding hormones?
The pancreas secretes insulin which controls blood glucose levels.
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What hormone does the thyroid gland secrete and what is its primary role?
The thyroid gland secretes thyroxine which controls metabolic rate heart rate and body temperature.
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What hormone is secreted by the adrenal gland and what is its role?
The adrenal gland secretes adrenaline which is involved in the fight or flight response the body's response to stressful situations.
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What hormone do the ovaries secrete and what are its functions?
The ovaries secrete oestrogen which is involved in the menstrual cycle and the development of female secondary sexual characteristics.
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What is the primary hormone secreted by the testes and what is its significance?
The testes secrete testosterone which is involved in the production of sperm and the development of male secondary sexual characteristics.
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How does the hormonal system compare to the nervous system in terms of speed and duration of action?
The hormonal system is much slower than the nervous system but it acts for a longer duration.
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Why is the concentration of glucose in the blood important?
The concentration of glucose in the blood needs to be kept within a certain limit to maintain homeostasis and provide energy for bodily functions.
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What happens to hormones in the body after they are secreted?
After hormones are secreted they travel through the bloodstream to a target organ or tissue where they exert their effects.
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What are the roles of oestrogen in female development during puberty?
Oestrogen is involved in the menstrual cycle and the development of features that distinguish females from males during puberty.
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What is the fight or flight response and which hormone is associated with it?
The fight or flight response is the body’s reaction to stressful situations and it is associated with the hormone adrenaline.
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Why is insulin important for blood glucose regulation?
Insulin is important because it helps to control blood glucose levels preventing hyperglycemia (high blood sugar) or hypoglycemia (low blood sugar) both of which can be harmful.
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What is homeostasis and how do hormones contribute to it?
Homeostasis is the maintenance of a stable internal environment in the body and hormones contribute to this by regulating various physiological processes including metabolism and glucose levels.
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What are secondary sexual characteristics and which hormones are involved in their development?
Secondary sexual characteristics are features that develop during puberty that distinguish males from females; testosterone primarily influences male characteristics while oestrogen influences female characteristics.
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What is the primary function of glucose in the body?
Glucose is needed by cells for respiration which is the process through which cells convert glucose into energy.
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How is blood glucose level controlled in the body?
The blood glucose level is controlled by the pancreas which produces hormones that regulate glucose levels.
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What role do carbohydrates play in blood glucose levels?
Eating foods that contain carbohydrates increases the glucose levels in the blood as carbohydrates are broken down into glucose.
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What happens when blood glucose levels are too high?
When blood glucose levels are too high the pancreas produces the hormone insulin.
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Describe the function of insulin in regulating blood glucose levels.
Insulin binds to cells in target organs namely muscles and liver causing two main effects: 1) Glucose moves from the blood into muscle cells for respiration and 2) Excess glucose is converted into glycogen which is stored in the liver. This lowers blood glucose concentration.
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How does rigorous activity affect blood glucose levels?
Rigorous activity such as exercise uses glucose for respiration resulting in lower levels of glucose in the blood.
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What happens when blood glucose levels decrease?
When blood glucose levels decrease the pancreas produces the hormone glucagon.
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What is the role of glucagon in blood glucose regulation?
Glucagon binds to liver cells causing glycogen to be broken down into glucose which is then released into the blood increasing blood glucose concentration.
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How do insulin and glucagon work together to maintain blood glucose concentration?
Insulin and glucagon work in a feedback mechanism to keep blood glucose concentration constant; insulin decreases glucose levels when they are high while glucagon increases glucose levels when they are low.
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Where is excess glucose stored in the body?
Excess glucose is converted into glycogen and stored primarily in the liver.
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What are the target organs of insulin?
The target organs of insulin are primarily the muscles and the liver.
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What is the physiological role of glycogen in glucose regulation?
Glycogen serves as a storage form of glucose that can be rapidly mobilized to maintain blood glucose levels when needed.
133
Describe the relationship between exercise and glucose levels in the blood.
During exercise glucose is consumed for energy leading to a decrease in blood glucose levels.
134
Explain the term 'blood glucose concentration.'
Blood glucose concentration refers to the amount of glucose present in the blood which is maintained within a narrow range for proper metabolic function.
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What is a negative feedback loop in the context of blood glucose regulation?
A negative feedback loop is a physiological mechanism that opposes a change in a system to maintain homeostasis. In the context of blood glucose regulation when blood glucose levels increase hormones like insulin are secreted to lower the glucose concentration. Once a certain level is reached the secretion of insulin decreases and if blood glucose levels drop too low another hormone glucagon is secreted to increase glucose levels demonstrating the balance maintained by this feedback loop.
136
What happens to blood glucose levels in individuals with diabetes?
In individuals with diabetes the body cannot effectively regulate blood glucose levels. Type 1 diabetes occurs when the pancreas fails to produce adequate insulin leading to high blood glucose levels. In Type 2 diabetes the body's cells become resistant to insulin resulting in poor glucose uptake and high blood sugar.
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Describe the characteristics and consequences of Type 1 diabetes.
Type 1 diabetes is characterized by the pancreas's inability to produce sufficient insulin. This results in extremely high blood glucose levels which can reach fatal amounts. Patients experience excessive urination and increased thirst due to glucose being excreted in urine. Treatment typically involves insulin injections at mealtimes to help regulate blood glucose levels. Additionally it is advised to limit the intake of simple carbohydrates which can exacerbate the condition.
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What are the treatment options for Type 1 diabetes?
Treatment for Type 1 diabetes primarily involves insulin therapy where patients inject insulin at meal times to assist in glucose uptake from the bloodstream. Other treatment strategies may include limiting the intake of simple carbohydrates to manage glucose levels. Experimental approaches being investigated include pancreas and pancreatic cell transplants as well as genetically engineering pancreatic cells from mice to produce insulin.
139
What is Type 2 diabetes and how does it differ from Type 1 diabetes?
Type 2 diabetes is a condition where the body's cells are no longer responsive to insulin. This resistance leads to elevated blood glucose levels. Unlike Type 1 diabetes where there is an absolute deficiency of insulin Type 2 diabetes often involves an initial overproduction of insulin followed by eventual burnout of insulin production in the pancreas. Type 2 diabetes is often associated with obesity sedentary lifestyle and can sometimes be managed with lifestyle changes or oral medications.
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What are the potential complications of uncontrolled diabetes?
Uncontrolled diabetes can lead to serious and potentially life-threatening complications including cardiovascular diseases nerve damage (neuropathy) kidney damage (nephropathy) eye damage (retinopathy) foot complications (ulcers and infections) and skin conditions. Additionally individuals with diabetes are at increased risk of developing conditions like high blood pressure and high cholesterol.
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What lifestyle interventions are recommended for managing Type 2 diabetes?
Lifestyle interventions for managing Type 2 diabetes include maintaining a healthy diet low in sugars and refined carbohydrates regular physical activity weight management monitoring blood glucose levels and adherence to prescribed medications. These changes can improve insulin sensitivity and help maintain appropriate blood glucose levels.
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What are the potential consequences of excessively high blood glucose levels?
Excessively high blood glucose levels can rise to a fatal amount leading to serious health complications such as diabetic ketoacidosis hyperglycemic hyperosmolar state or organ failure.
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What is obesity and how does it relate to diabetes?
Obesity is a condition characterized by excessive body fat. It is a significant risk factor for type 2 diabetes as it can lead to insulin resistance which impairs the body's ability to use insulin effectively.
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What dietary changes can help in the treatment of diabetes?
Treatment for diabetes includes reducing the intake of simple carbohydrates which can cause rapid spikes in blood glucose levels. This dietary change aids in better overall blood sugar control.
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What lifestyle changes are recommended for diabetes management?
Recommended lifestyle changes for diabetes management include losing weight and increasing physical exercise both of which can improve insulin sensitivity and blood glucose control.
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What types of medications can assist in diabetes management?
There are various classes of drugs to assist in diabetes management including: 1. Insulin sensitizers which make insulin more effective on body cells. 2. Insulin secretagogues which help the pancreas produce more insulin. 3. Glucosidase inhibitors which reduce the absorption of glucose from the gut.
147
Define osmosis and its significance in the body.
Osmosis is the process by which water molecules move from an area of high water concentration to an area of low water concentration across a semi-permeable membrane. This process is crucial for maintaining cellular function and homeostasis within the body.
148
What happens to cells if the water concentration in the blood increases?
If the water concentration in the blood increases cells in the body will take up water due to the higher concentration of water in the bloodstream compared to the concentration in the cells. This can cause cells to swell and potentially burst if the influx of water continues.
149
Explain the relationship between blood water concentration and osmotic movement.
The movement of water across cell membranes is dictated by osmotic principles where water naturally moves from an area of higher concentration (in the blood) to an area of lower concentration (inside the cells) until equilibrium is reached.
150
What are the consequences of cells bursting due to excessive water intake?
If cells burst due to excessive water intake it can lead to cell death and tissue damage disrupting normal physiological functions and potentially leading to severe health complications.
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How does maintaining water and nitrogen balance play a role in overall health?
Maintaining water balance is essential for regulating blood pressure nutrient transport and temperature control in the body. Nitrogen balance linked to protein intake and metabolism is important for tissue repair muscle growth and the synthesis of hormones and enzymes.
152
What happens to body cells when the concentration of water in the bloodstream decreases?
When the concentration of water in the bloodstream decreases water moves out of the cells by osmosis because the concentration of water in the cells is higher than in the bloodstream. As a result the cells lose water and shrink.
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What is osmosis?
Osmosis is the movement of water molecules from an area of lower solute concentration to an area of higher solute concentration through a semi-permeable membrane.
154
What is the role of kidneys in the body?
The kidneys maintain the balance of water and other substances in the body by filtering waste products from the blood and selectively reabsorbing useful substances such as glucose ions and water.
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What substances do kidneys filter from the blood?
The kidneys filter out waste products such as water ions and urea from the blood.
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How do the kidneys help regulate water loss in the body?
The kidneys regulate water loss by adjusting the amount of water excreted in urine which depends on the concentration of water in the blood.
157
In addition to urine how else can water leave the body?
Water can also leave the body through exhalation at the lungs and from the skin as sweat.
158
What factors influence water loss from the skin?
Water loss from the skin as sweat occurs without control and depends on factors such as temperature physical activity and humidity.
159
What are ions and how do they enter the body?
Ions are charged particles that are essential for various bodily functions and they enter the body via the food we consume.
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What happens if the ion concentration in the body is not maintained?
If the ion concentration in the body is not maintained it can lead to imbalances that affect nerve and muscle function as well as overall homeostasis.
161
What is the significance of urine in relation to kidney function?
Urine is the product of the kidneys' filtration process that contains waste products and excess substances allowing the body to excrete unwanted materials and regulate fluid balance.
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What is selective reabsorption in the kidneys?
Selective reabsorption is the process by which the kidneys reabsorb useful substances like glucose and ions from the filtrate back into the bloodstream thus preventing their loss in urine.
163
What happens when there is an imbalance of water in body cells?
If there is too little or too much water it can lead to improper functioning of the cells. Too little water can cause cells to shrink (crenation) while too much water can cause cells to swell and potentially burst (lysis). This imbalance alters the water potential of the blood.
164
How is water lost from the body and why is it important to control this loss?
Water is primarily lost through sweat and this process lacks precise control which can lead to dehydration or overhydration. It is important to manage water loss to maintain homeostasis ensuring that cells have the appropriate internal environment for metabolic processes.
165
What role do kidneys play in maintaining blood concentration?
The kidneys filter the blood and reabsorb specific amounts of ions to maintain the osmotic balance and concentration in the blood. This process helps regulate hydration levels and electrolytes.
166
What are amino acids and how are they produced?
Amino acids are the building blocks of proteins and are produced from the digestion of proteins in the food we consume.
167
What occurs to amino acids in the liver?
In the liver amino acids undergo a process called deamination where they are converted into ammonia a toxic substance.
168
Why is ammonia converted to urea?
Ammonia is toxic to the body; therefore it is converted into urea through the urea cycle in the liver before being eliminated from the body.
169
How is urea eliminated from the body?
Urea is filtered out of the blood by the kidneys and excreted as a component of urine.
170
What is the role of anti-diuretic hormone (ADH) in water regulation?
ADH is a hormone that helps regulate water loss through urine. It is released by the pituitary gland when the brain detects that the blood is too concentrated promoting water reabsorption in the kidney tubules.
171
How does ADH affect the kidneys when blood concentration is high?
When blood concentration is high more ADH is secreted into the bloodstream which increases water reabsorption in the kidney tubules leading to more concentrated urine and conserving water.
172
What triggers the release of ADH from the pituitary gland?
The release of ADH from the pituitary gland is triggered by receptors in the brain that detect increased blood osmolarity or that the blood is too concentrated.
173
What happens to the permeability of tubules when ADH is increased?
The permeability of tubules increases to water allowing more water to move out of the tubule and back into the bloodstream.
174
What is the result of increased water reabsorption in terms of urine concentration?
Increased water reabsorption results in a smaller volume of more concentrated yellow urine.
175
How does the concentration of blood change when more water moves back into it?
The blood becomes less concentrated as more water moves into it.
176
What type of feedback loop is the process of ADH regulation on blood concentration?
This process is an example of a negative feedback loop.
177
What hormonal action occurs if the concentration of the blood increases?
If blood concentration increases more ADH (antidiuretic hormone) is secreted to reverse the change.
178
What is kidney failure?
Kidney failure is when the kidneys stop working leading to the buildup of waste products in the body which can be harmful and potentially fatal.
179
What are the two main treatments for kidney failure?
The two main treatments for kidney failure are dialysis and kidney transplantation.
180
What is dialysis and how does it work?
Dialysis is a treatment that performs the function of the kidneys using an artificial membrane. Blood moves between partially permeable membranes surrounded by dialysis fluid that matches the concentrations of ions and glucose in healthy blood.
181
What substances are retained and lost during dialysis?
During dialysis useful ions and glucose are retained in the blood while urea excess ions and water diffuse across the membrane and are lost.
182
How frequently is dialysis typically performed?
Dialysis needs to be performed three times a week.
183
What consequences arise from untreated kidney failure?
Untreated kidney failure leads to a build-up of waste products which can be harmful to the body and ultimately results in death.
184
What is the role of the kidneys in maintaining homeostasis?
The kidneys help maintain homeostasis by regulating fluid balance electrolyte levels and waste excretion.
185
Define 'negative feedback loop' in the context of blood concentration regulation.
A negative feedback loop in this context refers to a mechanism that counteracts changes in blood concentration by altering hormone secretion—specifically by increasing or decreasing ADH levels based on the concentration of blood.
186
What are the key components involved in dialysis?
Key components of dialysis include the patient's blood dialysis fluid and partially permeable membranes that separate them.
187
Why is it important for dialysis fluid to have the same concentrations of ions and glucose as healthy blood?
This is important to ensure that useful substances are not lost from the blood during the dialysis process.
188
What is urea and why is it significant in kidney functions?
Urea is a waste product formed from the breakdown of proteins; it is significant because it needs to be removed from the bloodstream by the kidneys.
189
What is dialysis and its purpose?
Dialysis is a medical procedure that acts as an artificial kidney filtering waste products and excess fluids from the blood to keep individuals alive while they wait for a kidney transplant.
190
How long does a typical dialysis session take?
A typical dialysis session takes three to four hours to complete.
191
What are the main problems associated with dialysis?
The main problems associated with dialysis include the possibility of blood clots forming the lengthy duration of sessions the necessity to follow a strict diet the unpleasant experience of undergoing the treatment and the buildup of waste products between sessions that can leave a patient feeling ill.
192
What is the only cure for kidney failure?
The only cure for kidney failure is a kidney transplant where a healthy kidney is provided to the individual.
193
From where are transplanted kidneys sourced?
Kidneys for transplantation can be sourced from deceased individuals who have died suddenly or from living donors as humans have two kidneys but only need one to survive.
194
What are the advantages of kidney transplants over dialysis?
Kidney transplants allow individuals to avoid frequent hospital visits associated with dialysis and are generally cheaper in the long run compared to the overall cost of undergoing dialysis.
195
What is the major risk associated with kidney transplants?
The major risk associated with kidney transplants is the possibility of the transplanted kidney being rejected by the recipient's body as the immune system may recognize the donor organ's antigens as foreign.
196
How does the experience of a kidney transplant compare to dialysis?
Compared to dialysis kidney transplant recipients typically have a significantly improved quality of life as they do not need to undergo regular treatments and can resume more normal activities.
197
What is the role of antigens in organ transplantation?
Antigens are molecules that can trigger an immune response; in the context of organ transplantation they can lead the recipient's immune system to reject the transplanted organ if it recognizes these antigens as foreign.
198
What is the effect of immunosuppressant drugs on patients who have undergone an organ transplant?
Immunosuppressant drugs reduce the chance of organ rejection after transplantation by suppressing the immune response. However this makes the patient vulnerable to other infections and diseases since their immune system is less able to fight off pathogens.
199
Do transplanted kidneys last indefinitely?
No transplanted kidneys do not last forever. They can function effectively for many years but eventually they may fail or require replacement due to a variety of factors including rejection damage or underlying health conditions.
200
During which life stage do reproductive hormones begin to be released in humans?
Reproductive hormones begin to be released during puberty.
201
What changes do reproductive hormones cause during puberty?
Reproductive hormones cause secondary sexual characteristics to develop in both men and women as well as the maturation of eggs in women.
202
What is the main male reproductive hormone and where is it produced?
The main male reproductive hormone is testosterone which is produced by the testes.
203
What are the effects of testosterone in males?
Testosterone stimulates sperm production and contributes to the development of male secondary sexual characteristics.
204
What is the main female reproductive hormone and where is it produced?
The main female reproductive hormone is oestrogen which is produced in the ovaries.
205
What role does oestrogen play in the female body?
Oestrogen produces physical changes during puberty and is involved in regulating the menstrual cycle.
206
Describe the menstrual cycle. What processes occur during this cycle?
The menstrual cycle is the monthly process the female body undergoes to prepare for a potential pregnancy. It starts with the breakdown of the uterine lining (menstruation) followed by the buildup of the lining. Ovulation occurs around day 14 when an egg is released from the ovary and travels to the uterus via the fallopian tube.
207
What happens during ovulation in the menstrual cycle?
During ovulation which occurs around day 14 of the menstrual cycle an egg is released from the ovary and moves to the uterus through the fallopian tube preparing for potential fertilization.
208
What is the significance of the uterine lining during the menstrual cycle?
The uterine lining thickens in preparation for a potential pregnancy providing a suitable environment for a fertilized egg to implant. If pregnancy does not occur the lining eventually breaks down and is shed during menstruation.
209
What happens to a fertilised egg if it has not embedded in the uterine lining after 28 days?
If a fertilised egg has not embedded in the uterine lining after 28 days it begins to break down and the menstrual cycle continues.
210
What role does Follicle Stimulating Hormone (FSH) play in the menstrual cycle?
Follicle Stimulating Hormone (FSH) causes the maturation of an egg in the ovary within a structure called a follicle. It is produced in the pituitary gland and stimulates the ovaries to produce oestrogen.
211
What is the source and effect of oestrogen in the menstrual cycle?
Oestrogen is produced in the ovaries as a result of the secretion of FSH. It causes the lining of the uterus to grow again stimulates the production of Luteinising Hormone (LH) and inhibits the secretion of more FSH.
212
What is Luteinising Hormone (LH) and what is its effect during ovulation?
Luteinising Hormone (LH) is produced in the pituitary gland as a result of the hormone oestrogen. Its release causes ovulation which is the release of a mature egg from the ovary.
213
What is the production source and function of progesterone in the menstrual cycle?
Progesterone is produced in the ovaries and secreted from the egg follicle. Its function is to maintain the lining of the uterus and support a pregnancy if the egg is fertilised. It also inhibits the release of both FSH and LH.
214
Describe how hormonal contraception works based on the hormones involved.
Hormonal contraception works primarily by using hormones such as oestrogen and progesterone to manipulate the menstrual cycle. They prevent ovulation by inhibiting the release of FSH and LH thicken cervical mucus to prevent sperm entry and thin the uterine lining to prevent implantation.
215
What happens if the contraceptive pill is not taken regularly?
If the contraceptive pill is not taken regularly the body's own hormones will be released which can lead to the maturation of an egg.
216
What are the main components of the mixed contraceptive pill?
The mixed contraceptive pill contains oestrogen and progesterone.
217
How does the high level of oestrogen in the mixed pill affect FSH levels?
The high levels of oestrogen in the mixed pill inhibit FSH (Follicle Stimulating Hormone) production preventing eggs from maturing.
218
What effect does the contraceptive pill have on the uterine lining?
The contraceptive pill stops the uterine lining from developing.
219
How does the contraceptive pill affect cervical mucus?
The contraceptive pill thickens the cervical mucus which hinders sperm movement.
220
List some possible side effects of the mixed contraceptive pill.
Some possible side effects of the mixed contraceptive pill include changes in mood mood swings depression breast pain or tenderness breast enlargement and increased blood pressure.
221
What is one advantage of the progesterone-only pill compared to the mixed pill?
The progesterone-only pill has fewer side effects compared to the mixed pill.
222
What is the purpose of the contraceptive patch and what components does it contain?
The contraceptive patch contains oestrogen and progesterone; it is a small adhesive patch that is applied to the skin.
223
How long does the contraceptive patch last?
The contraceptive patch lasts for one week.
224
What does the contraceptive implant do and how long does it last?
The contraceptive implant releases a continuous amount of progesterone preventing ovaries from releasing an egg thickening cervical mucus to block sperm and stopping fertilized eggs from embedding in the uterus; it lasts for three years.
225
What is the function of the contraceptive injection and how does it work?
The contraceptive injection provides hormonal contraception to prevent ovulation thickens cervical mucus and may inhibit implantation of fertilized eggs.
226
What is the mechanism of action of the progesterone-releasing intrauterine device (IUD)?
The progesterone-releasing IUD works by releasing progesterone which thickens the cervical mucus making it difficult for sperm to enter the uterus. It also may inhibit ovulation and thin the lining of the uterus to prevent implantation.
227
How long does the progesterone-releasing IUD last?
The progesterone-releasing IUD lasts for 2 to 3 months.
228
Describe the physical characteristics of the progesterone IUD.
The progesterone IUD is T-shaped and is inserted into the uterus for contraception.
229
What are non-hormonal methods of contraception?
Non-hormonal methods of contraception work by preventing sperm from fertilizing the egg. These methods include barrier methods and chemical methods such as spermicides.
230
What is the efficacy of chemical contraceptive methods like spermicides?
Chemical methods involving spermicides are 70 to 80% effective in preventing fertilization.
231
What are barrier methods of contraception?
Barrier methods of contraception include condoms and diaphragms which physically block sperm from reaching the egg.
232
How do condoms function as a contraceptive method?
Condoms are worn either over the penis or in the vagina to prevent sperm from entering the reproductive tract and also help to protect against sexually transmitted infections. However they can tear which poses a risk of pregnancy.
233
What is a diaphragm and how is it used?
A diaphragm is a plastic cup that is positioned over the cervix and is used in conjunction with spermicides to prevent sperm from entering the uterus.
234
Describe how the copper IUD works as a form of contraception.
The copper IUD works by killing sperm in the uterus and preventing any fertilized embryos from implanting into the uterine lining.
235
What does surgical sterilization involve?
Surgical methods of male and female sterilization involve cutting and tying the reproductive tracts to permanently prevent pregnancy.
236
What are the fallopian tubes and their function?
The fallopian tubes also known as oviducts or sperm ducts are tubes in the female reproductive system that connect the ovaries to the uterus. Their primary function is to transport the ovum (egg) from the ovary to the uterus and where fertilization by sperm typically occurs.
237
How long does the effect of abstaining from intercourse last in relation to fertilization?
Abstaining from intercourse ensures that an egg is not fertilized. This effect lasts indefinitely as long as intercourse is avoided.
238
What is the timing of abstaining during ovulation?
Some individuals may choose to only abstain from intercourse during ovulation to prevent fertilization therefore timing their abstinence based on ovulatory cycles.
239
What are fertility drugs and their primary purpose?
Fertility drugs are medications used to increase the likelihood of pregnancy in individuals facing infertility issues. They primarily aim to stimulate the ovaries to produce mature eggs.
240
Which hormones are mainly used in fertility treatments and why?
The main hormones used in fertility treatments are Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH) as they are crucial in stimulating the maturation and release of eggs from the ovaries.
241
What is In Vitro Fertilization (IVF) and its process?
In Vitro Fertilization (IVF) is a fertility treatment where hormones (FSH and LH) are administered to the mother to encourage the maturation of eggs. The eggs are then extracted from the mother fertilized in a laboratory using sperm and allowed to develop into embryos. One or two embryos are then implanted into the uterus.
242
What are the benefits of In Vitro Fertilization (IVF)?
The primary benefit of IVF is that it provides a potential option for infertile couples to conceive and have a child.
243
What are some challenges or stresses associated with IVF?
IVF can be physically stressful for women due to hormone reactions which may include feelings of sickness. Additionally it can be emotionally stressful as the procedure may not be successful with a typical success rate of only about 26%.
244
What are the potential emotional impacts of undergoing IVF treatment?
The emotional impacts of IVF can include anxiety disappointment and frustration due to the uncertainty of success and the emotional investment involved in the process.
245
What is the general success rate of IVF?
The general success rate of IVF is approximately 26% indicating that only about a quarter of attempted IVF cycles result in a pregnancy.
246
What is negative feedback in biological systems?
Negative feedback is a regulatory mechanism in which the body responds to an increase or decrease in a certain factor by returning it back to its original level. It helps maintain homeostasis.
247
How does thyroxine regulate metabolic rate?
Thyroxine regulates metabolic rate by controlling how quickly biochemical reactions occur in the body playing a crucial role in energy metabolism.
248
Where is thyroxine released from?
Thyroxine is released by the thyroid gland.
249
What stimulates the release of thyroxine?
The release of thyroxine is stimulated by the thyroid stimulating hormone (TSH).
250
How are the levels of thyroxine controlled?
The levels of thyroxine are controlled by negative feedback mechanisms. An increase in thyroxine levels is detected by receptors in the brain which inhibits the release of TSH thereby reducing thyroxine levels.
251
What happens when thyroxine levels increase in the body?
When thyroxine levels increase it is detected by receptors in the brain which inhibits the release of TSH subsequently leading to a decrease in thyroxine levels.
252
What is adrenaline and when is it produced?
Adrenaline is a hormone produced in times of stress specifically during the 'fight or flight' response.
253
Where is adrenaline produced?
Adrenaline is produced by the adrenal glands which are located on top of the kidneys.
254
What stimulates adrenaline release?
The release of adrenaline is stimulated by fear or stress which is detected in the brain.
255
What are the effects of adrenaline on the body?
The effects of adrenaline include increased heart rate and breathing rate which help deliver more oxygen and glucose to the brain and muscles for respiration.
256
What happens to glycogen stored in the liver in response to adrenaline?
In response to adrenaline glycogen stored in the liver is converted to glucose providing a quick energy source for the body during stress.
257
What physiological changes occur in response to respiration from the nervous system?
During respiration pupils dilate to allow more light in blood flow to muscles increases to enhance physical performance and blood flow to the digestive system decreases.
258
What is the role of hormones in plant growth and coordination?
Plant hormones are essential for coordinating and controlling growth in plants. They regulate processes such as tropisms which are growth responses to environmental stimuli.
259
Define phototropism and gravitropism. Provide examples.
Phototropism is the growth response of plants towards light. An example is a plant bending towards a sunlight source. Gravitropism (or geotropism) is the growth response of plants to gravity with roots growing downward and shoots growing upward.
260
How do plant hormones transport and respond to environmental stimuli?
Plant hormones move from their site of production to the area where their effects are needed coordinating growth responses in reaction to environmental stimuli.
261
What is the effect of auxin in phototropism?
Auxin is a plant hormone that moves to the shaded side of a shoot when exposed to light on one side. It stimulates cell elongation on that side resulting in the shoot bending towards the light.
262
What can be the outcomes of unexpected multiple births during pregnancy?
Unexpected multiple births can lead to increased risks for both the babies and mother potential complications and can be expensive if medical interventions or repeated processes are needed.
263
What is positive phototropism and how is it demonstrated in plants?
Positive phototropism is when plants grow towards their light source. It is demonstrated by the bending of shoots towards light a response facilitated by the uneven distribution of auxin.
264
What are the general functions of plant hormones besides auxin?
Other plant hormones include gibberellins (promote stem elongation and fruit growth) cytokinins (influence cell division) abscisic acid (involved in stress responses) and ethylene (regulates fruit ripening and flower wilting).
265
What is the significance of light absorption in relation to photosynthesis in plants?
Plants that receive more light can carry out photosynthesis at a faster rate increasing their growth and energy production.
266
What is negative gravitropism in plants?
Negative gravitropism is the growth of shoots away from gravity allowing them to grow upwards towards light.
267
How does Auxin affect the growth direction of plant shoots?
When a shoot is horizontal Auxin accumulates on the lower side causing cells on that side to grow more vigorously resulting in the shoot bending upwards away from the ground.
268
Why is it beneficial for shoots to grow away from gravity?
It is beneficial for shoots to grow away from gravity because higher light levels are typically found further from the ground optimizing photosynthesis.
269
What is positive gravitropism in plants?
Positive gravitropism is the growth of roots towards gravity helping them anchor the plant and search for water and nutrients.
270
How does Auxin affect the growth direction of plant roots?
When a root is horizontal Auxin accumulates on the lower side. This causes cells on the upper side to grow more making the root bend downwards into the soil.
271
Why is it advantageous for roots to grow downwards towards gravity?
Roots growing downwards is advantageous because they are more likely to encounter increased levels of water and nutrients essential for plant survival and stability.
272
What happens when Auxin distribution becomes equal on both sides of a plant stem or root?
When Auxin distribution becomes equal on both sides the plant stem or root grows straight in that direction without bending.
273
How can the effect of Auxin on plant growth direction be experimentally investigated?
The effect of Auxin can be investigated through experiments that manipulate light direction and observe resultant growth patterns or by applying specific concentrations of Auxin to various plant segments and measuring growth response.
274
What is the effect of light on newly germinated seedlings when placed in a cardboard box with light shining from one side?
When seedlings are placed in a cardboard box with light from one side they exhibit phototropism which is the growth response to light. The seedlings will grow towards the light source as they seek to optimize photosynthesis.
275
How does gravity affect newly germinated seedlings?
Gravity affects newly germinated seedlings through gravitropism. Roots will grow downward (positive gravitropism) while stems grow upward (negative gravitropism) allowing the plant to establish a stable growth orientation.
276
What are gibberellins and their role in plant growth?
Gibberellins are plant hormones that stimulate seed germination and promote growth elongation. They play a key role in breaking dormancy in seeds and initiating the growth process.
277
What is the importance of ethene in plants?
Ethene is a plant hormone involved in cell division ripening of fruits and many developmental processes. It is crucial for promoting the ripening of climacteric fruits such as bananas and tomatoes.
278
How do humans utilize plant hormones in agriculture and horticulture?
Humans use plant hormones to alter plant growth for various purposes including increasing yield achieving desirable plant features (such as size flavor or resistance to disease) and reducing production costs.
279
What is the function of auxins as weed killers?
Auxins synthesized as weed killers target broad-leaved plants. They cause excessive growth in these plants leading to their death while having little to no effect on narrow-leaved crops like grasses.
280
How do rooting powders utilize auxin for plant propagation?
Rooting powders contain auxins that promote root development in cuttings. This helps in cloning plants with desirable traits allowing for the production of uniform and genetically identical plants.
281
What is the impact of varying environmental conditions on the growth of seedlings?
Varying conditions such as light intensity gravity and the presence of nutrients can alter the growth patterns of seedlings. For example increased light can enhance photosynthesis and growth rate while inadequate water can inhibit development.
282
Explain the relationship between gibberellins and seed germination.
Gibberellins promote seed germination by stimulating the production of enzymes that break down stored food resources in seeds thereby providing energy and nutrients needed for growth.
283
What is the significance of ethene in fruit ripening?
Ethene triggers biochemical processes that lead to fruit ripening including softening of fruit tissues breakdown of starches into sugars and changes in color making it essential for the synchronization of ripening and market readiness.
284
Describe how auxins function in plant growth regulation.
Auxins regulate plant growth by promoting cell elongation and they play a crucial role in processes like phototropism and gravitropism ensuring that plants grow towards light and adjust their structure in response to gravity.
285
Can you list the three major plant hormones discussed and their primary functions?
The three major plant hormones discussed are: 1. Auxins - promote stem elongation and regulate plant responses to light and gravity. 2. Gibberellins - stimulate seed germination and growth. 3. Ethene - promotes fruit ripening and cell division.
286
What is one method for cloning a plant using cuttings?
One method for cloning a plant is to take a cutting from the original plant apply rooting powder containing auxin to it and place it in the ground. Roots will grow and a new plant begins to develop quickly.
287
What is the purpose of auxin in plant cuttings?
Auxin is a plant hormone that promotes root growth when applied to cuttings facilitating the cloning process.
288
How does tissue culture clone plants?
In tissue culture cells from the plant are taken and placed in a growth medium rich in nutrients. Hormones such as auxins are added to encourage the cells to form roots and shoots resulting in plant cloning.
289
What role does ethene play in fruit ripening?
Ethene is a plant hormone that controls ripening. It stimulates cell division and the production of enzymes that result in fruit ripening allowing fruits to mature properly for sale.
290
How does the food industry utilize ethene for fruit ripening?
In the food industry fruits are often picked when not fully ripened (when they are firm) to reduce bruising during transport. When ready to sell they are exposed to ethene and warmer temperatures to facilitate ripening.
291
What is the advantage of using ethene in fruit ripening for the food industry?
Using ethene helps reduce wastage as more fruit can ripen at the appropriate time making them suitable for sale and preventing premature ripening.
292
What is one use of gibberellins in agriculture?
Gibberellins are used to end seed dormancy allowing seeds to germinate and grow under favorable conditions.
293
In which industry are gibberellins utilized besides agriculture?
Gibberellins are also used in the brewing industry although the specific applications in brewing were not detailed in the provided text.
294
What is the role of gibberellins in barley seed germination?
Gibberellins increase the germination rate of barley seeds which is essential for the production of malt.
295
How do gibberellins promote flowering in plants?
Gibberellins enable plants to flower under various conditions by eliminating the need for longer days and low temperatures and they promote the development of larger flowers.
296
What effect do gibberellins have on fruit size?
Gibberellins produced by seeds in fruits lead to an increase in fruit size. Since seedless fruits do not produce gibberellins naturally they tend to be smaller unless treated with gibberellins.
297
Why do seedless fruits generally have a smaller size compared to fruit with seeds?
Seedless fruits are smaller because they lack the natural production of gibberellins which promotes growth and size in fruits containing seeds.
298
How can seedless fruits be treated to increase their size?
Seedless fruits can be sprayed with gibberellins to stimulate growth and increase their size.
