What can cause changes in the normal range of physiological parameters?
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Age.
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What can cause changes in the normal range of physiological parameters?
Age.
What happens when blood glucose levels increase?
The pancreas secretes insulin.
What is parturition?
The process of giving birth.
How does age affect thermoregulation?
Older adults are less tolerant due to less effective sweat glands and reduced skin blood flow.
What role do skin thermoreceptors play in thermoregulation?
They detect temperature changes and send signals to the brain.
What are the two types of feedback mechanisms?
Negative feedback and positive feedback.
What is a set point in homeostasis?
The ideal value or range that a physiological variable should maintain.
How does increased humidity affect sweat evaporation rates?
Increased humidity decreases evaporation efficiency.
How does the body prepare for parturition?
Through hormonal changes and physical adaptations.
What is the initial stimulus in the thermoregulation process?
Rising room temperature.
What is an example of negative feedback in thermoregulation?
The regulation of body temperature.
What is the maximum sweat evaporation rate at 20% relative humidity with specific conditions?
The maximum sweat evaporation rate is influenced by environmental temperature and wind speed.
What is the set point for blood pressure?
120/80 mmHg.
What is the effector in the thermoregulation process when the room temperature rises?
The heater.
What environmental temperature range can the body tolerate while maintaining core temperature?
Between 12.8 and 54.4 °C.
What happens to blood vessel diameter as environmental temperature increases?
Vasodilation occurs.
What happens to heat loss when the body is hot?
Heat loss increases through increased blood flow and more sweat secretion.
What is the effect of vasoconstriction on heat loss?
It reduces heat loss.
What is the normal range for blood pH?
7.3 – 7.5.
What are the two main systems responsible for homeostatic control?
The nervous system and the endocrine system.
Which systems regulate homeostasis?
The endocrine and nervous systems.
What role does insulin play in blood glucose regulation?
It promotes the uptake of glucose by the liver, lowering blood glucose levels.
What is homeostasis?
The process by which biological systems maintain stability while adjusting to conditions that are optimal for survival.
What type of nerve stimulation induces sweat secretion?
Sympathetic stimulation.
What role do hormones play in parturition?
Hormones like oxytocin stimulate contractions.
Why is homeostasis important for organisms?
It allows organisms to maintain a stable internal environment, which is crucial for proper functioning and survival.
What is the effect of vasoconstriction of skin arterioles?
It helps to conserve body heat by reducing blood flow to the skin.
What happens when platelets adhere to the wound site?
They release chemicals that attract more platelets.
What are the symptoms of heat cramps?
Painful muscle cramps, red moist skin, triggered by Na+ loss and dehydration.
What is positive feedback?
A mechanism that amplifies a change, moving the system away from its set point.
Which gland secretes prolactin for milk production?
The anterior pituitary gland.
What does the control center do in negative feedback?
Determines if the variable is kept within the normal range.
What is the core temperature range maintained during thermoregulation?
Between 36.1 and 37.8 °C.
What is the thermoneutral zone?
A range of environmental temperature (25 – 30 ℃) where body temperature is regulated only by skin blood flow.
How does the body regulate temperature within the thermoneutral zone?
By controlling skin blood flow to manage heat loss.
What is the function of prolactin in lactation?
To stimulate milk production.
How does the body increase heat loss when hot?
By dilating skin arterioles and constricting shunt vessels.
What happens to sweat secretion when the body is cold?
There is no sweat secretion.
What is the normal blood glucose level?
Approximately 90 mg/100 ml.
Where is the secretory portion of the sweat gland located?
Deeper in the skin.
What is the function of the duct portion of the sweat gland?
To pass sweat to the skin surface and reabsorb sodium and chloride.
What is the primary function of feedback mechanisms in homeostasis?
To help our body maintain different variables within normal ranges.
What is homeostasis?
The process by which biological systems maintain stability while adjusting to conditions that are optimal for survival.
What is the relationship between water loss and mineral loss in sweat secretion?
Water loss is greater than mineral loss.
What initiates the feedback cycle in blood clotting?
A break or tear in a blood vessel.
What role does thermoregulation play in homeostasis?
It helps maintain the optimal temperature for enzymatic and metabolic processes in the body.
What physiological response occurs in muscles during cold exposure?
Muscle shivering, which generates heat.
What is the result of the positive feedback in blood clotting?
Clotting proceeds until the wound is sealed by a newly formed clot.
What type of contraction is muscle shivering?
Involuntary contraction.
What triggers heat exhaustion?
More severe dehydration and low blood volume.
What triggers vasoconstriction?
The sympathetic nervous system.
What effect does adrenaline have on metabolism?
It increases basal metabolism.
What can untreated heat exhaustion lead to?
Heat stroke, which can result in coma or death.
What can result from extreme environmental temperatures?
Hypothermia or hyperthermia.
What happens to core temperature if exposed to extreme heat?
It can rise, leading to hyperthermia.
What happens to blood flow when the body is cold?
Blood flow decreases to reduce heat loss.
What are the two main parts of a sweat gland?
Secretory portion and duct portion.
What is the formula for heat balance?
Heat balance = heat gain – heat loss.
What factors influence heat gain or loss in the human body?
Heat gain or loss can be controlled by the human body and depends on the temperature difference between the external environment and the human body.
Which nerve pathways are involved in sensing and responding to blood glucose changes?
Sensory nerve (afferent nerve), spinal cord, and motor nerve (efferent nerve) to the brain.
What are the two types of thermoreceptors involved in thermal sensation?
Peripheral thermoreceptors in the skin and central thermoreceptors in abdominal organs & hypothalamus.
What are the methods of heat loss?
Convection (via wind/air flow) and evaporation (via the process of liquid water turning into water vapor).
How does exercise influence thermoregulation?
Exercise improves tolerance to heat or cold.
What are the effectors involved in heat production and loss?
Skeletal muscle, skin arterioles, sweat glands, and adrenal medulla.
What does positive feedback do?
Enhances the stimulus or action.
What is one method the body uses to increase heat production?
Muscle shivering.
What characterizes heat exhaustion?
Muscle cramps, fatigue, pale moist skin, fainting, fever, dizziness, nausea, and vomiting.
What is thermoregulation?
The process by which the body maintains its core internal temperature.
What is the normal range for systolic blood pressure?
90 – 139 mmHg.
What is the primary purpose of increasing basal metabolism in cold conditions?
To generate heat.
What is the set point in thermoregulation?
The desired temperature that the control center aims to maintain.
What happens to core temperature if exposed to extreme cold?
It can drop, leading to hypothermia.
What is the set point for blood pH?
7.4.
What is the effect of nerve impulses from the hypothalamus when the body is hot?
They cause skin arterioles to dilate and shunt vessels to constrict.
What is the core temperature threshold for hypothermia?
Less than 35.0 °C.
What is feedforward regulation?
A process that is stimulated before the feedback system to minimize changes in a regulated variable.
How does feedforward regulation respond to changes in core temperature?
It initiates a response before changes occur in core temperature.
What are the two methods of heat gain?
Conduction (via contact with body surface) and radiation (via infra-red rays).
What is a key difference in thermoregulation between genders?
Males have higher metabolic rates and sweat more than females.
What is the skin temperature at 100% relative humidity?
35 °C.
What is the role of negative feedback?
To suppress the stimulus.
What is the core temperature that defines hyperthermia?
Core temperature > 40 °C.
What is thermoregulation?
The process by which the body maintains its core temperature.
What triggers the release of nerve impulses during breast suckling?
The act of suckling by the infant.
What role do the released chemicals play in the clotting process?
They attract more platelets to the wound site.
What is the function of the thermostat in thermoregulation?
It serves as the control center that processes input from the receptor.
What is shell temperature?
The temperature essentially at the skin's surface.
What is the process called when milk is released from the mammary glands?
Milk letdown.
What is the normal range for diastolic blood pressure?
60 – 89 mmHg.
What is the set point for body temperature?
37 ℃.
What is the normal range for body temperature?
36.7 – 37.1 ℃.
What occurs in the skin when the body is cold?
Arterioles constrict and shunt vessels dilate.
What is homeostasis?
A relatively stable condition of the internal environment.
What is the ideal body temperature?
37 ℃.
Does body temperature remain constant at the ideal level?
No, it fluctuates within the normal range.
What are the stages of parturition?
Labor, delivery, and afterbirth.
What is thermoregulation?
The process by which an organism regulates its body temperature within certain boundaries, even when the surrounding temperature is different.
What signals are sent from the brain during thermoregulation?
Signals are sent to effectors for responses like vasoconstriction and muscle shivering.
What is the significance of contractions during parturition?
They help to push the baby through the birth canal.
What is the normal range in homeostasis?
The range of values around the set point that is considered acceptable for physiological function.
What happens to evaporation rates when body temperature increases?
Evaporation rates increase, but this is not effective for thermoregulation.
What are the components of negative feedback?
Receptor (or sensor), control center, and effector.
What role does the thermometer play in thermoregulation?
It acts as a receptor that detects temperature changes.
What is core temperature?
The temperature within the skull, thoracic, and abdominal cavities.
What hormone is secreted by the mammary gland to facilitate milk secretion?
Oxytocin.
What is the role of the effector in negative feedback?
Responds to the stimulus.
What happens when the room temperature drops?
The effector (heater) responds to raise body temperature.
How much can heat transfer change from fully constricted to fully dilated state?
An eight-fold change.
What is the set point for blood glucose?
85 mg/dL.
What does the secretory portion of the sweat gland secrete?
Water, mainly sodium and chloride.
How is homeostasis described in terms of its nature?
As a dynamic process.
What is the formula for heat balance?
Heat balance = Heat gain – Heat loss.
What are the times mentioned for body temperature fluctuations?
Noon and Midnight.
What type of feedback mechanism is blood clotting?
Positive feedback.
Which part of the brain acts as the control center for temperature regulation?
The hypothalamus.
Which method of heat loss is always occurring?
Convection and evaporation.
What happens to heat production when the body is cold?
Heat production increases.
What is negative feedback?
A mechanism that counteracts a change, bringing the system back to its set point.
What is the relationship between humidity and water vapor in the air?
Higher humidity means more water vapor, making it less likely for air to accommodate additional water vapor.
What is the function of the receptor in negative feedback?
To monitor the environment.
Which gland secretes adrenaline to increase heat production?
Adrenal medulla.
What are the symptoms of heat stroke?
Muscle cramps, red/warm dry skin, rapid heart rate, and seizures.
What environmental factor influences vasodilation?
Environmental temperature.
What role does the posterior pituitary play in lactation?
It secretes oxytocin to aid in milk secretion.
How does the effector respond to a drop in body temperature?
By activating the heater to increase the temperature.
What role does sweat play in heat loss?
Sweat secretion increases heat loss by evaporation.
What is the normal range for blood glucose?
75 – 95 mg/dL.
