p.23
Physiological Responses to Temperature Extremes
How does age affect thermoregulation?
Older adults are less tolerant due to less effective sweat glands and reduced skin blood flow.
p.3
Role of Endocrine and Nervous Systems
Which systems regulate homeostasis?
The endocrine and nervous systems.
p.5
Set Point and Normal Range
Does body temperature remain constant at the ideal level?
No, it fluctuates within a normal range.
p.21
Control of Heat Production and Loss
What environmental factor influences vasodilation?
Environmental temperature.
p.1
Thermoregulation Processes
What role does thermoregulation play in homeostasis?
It helps maintain the body's temperature within a narrow range, which is essential for metabolic processes.
p.10
Concept of Homeostasis
What are the stages of parturition?
Labor, delivery, and afterbirth.
p.17
Control of Heat Production and Loss
What happens to heat production when the body is cold?
Heat production increases.
p.1
Concept of Homeostasis
Why is homeostasis important for organisms?
It allows organisms to maintain a stable internal environment, which is crucial for proper functioning and survival.
p.10
Concept of Homeostasis
What is parturition?
The process of giving birth.
p.3
Concept of Homeostasis
What is homeostasis?
A relatively stable condition of the internal environment.
p.19
Role of Endocrine and Nervous Systems
What are the two parts of a sweat gland?
Secretory portion and duct portion.
p.2
Concept of Homeostasis
What is homeostasis?
The process by which biological systems maintain stability while adjusting to conditions that are optimal for survival.
p.2
Set Point and Normal Range
What is a set point in homeostasis?
The ideal value or range that a physiological variable should maintain.
p.24
Set Point and Normal Range
What environmental temperature range can the body tolerate while maintaining core temperature?
Between 12.8 and 54.4 °C.
p.11
Role of Endocrine and Nervous Systems
What triggers the release of nerve impulses during breast suckling?
The act of suckling by the infant.
p.22
Role of Endocrine and Nervous Systems
What happens after skin thermoreceptors send signals to the brain?
The brain sends signals to effectors for responses like vasoconstriction and muscle shivering.
p.11
Role of Endocrine and Nervous Systems
What role does the posterior pituitary play in lactation?
It secretes oxytocin to aid in milk secretion.
p.18
Control of Heat Production and Loss
What role does sweat secretion play in heat loss?
It increases heat loss by evaporation.
p.22
Feedback Mechanisms in Homeostasis
What is feedforward regulation?
A process that is stimulated before the feedback system to minimize changes in a regulated variable.
p.24
Concept of Homeostasis
What is the core temperature range maintained during thermoregulation?
Between 36.1 and 37.8 °C.
p.2
Set Point and Normal Range
What is the normal range in homeostasis?
The range of values around the set point that is considered acceptable for physiological variables.
p.16
Thermoregulation Processes
What type of thermoreceptors are found in the skin?
Peripheral thermoreceptors.
p.22
Thermoregulation Processes
What is the purpose of muscle shivering in thermoregulation?
To generate heat in response to cold temperatures.
p.18
Control of Heat Production and Loss
What physiological changes occur in the skin when the body is hot?
Arterioles dilate and sweat secretion increases.
p.11
Role of Endocrine and Nervous Systems
Which gland secretes prolactin for milk production?
The anterior pituitary gland.
p.13
Heat Balance and Regulation
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.
p.13
Heat Balance and Regulation
What are the methods of heat gain?
Conduction and radiation.
p.26
Physiological Responses to Temperature Extremes
What triggers heat exhaustion?
More severe dehydration and low blood volume.
p.7
Feedback Mechanisms in Homeostasis
What is the function of the effector in negative feedback?
Responds to the stimulus.
p.21
Control of Heat Production and Loss
What triggers vasoconstriction?
The sympathetic nervous system.
p.22
Role of Endocrine and Nervous Systems
What role do skin thermoreceptors play in thermoregulation?
They detect temperature changes and send signals to the brain.
p.22
Thermoregulation Processes
What is vasoconstriction?
The narrowing of skin arterioles to reduce blood flow and conserve heat.
p.13
Heat Balance and Regulation
What is the formula for heat balance?
Heat balance = heat gain - heat loss.
p.9
Feedback Mechanisms in Homeostasis
How does the feedback cycle in blood clotting end?
When the wound is sealed by the clot.
p.12
Concept of Homeostasis
What is core temperature?
The temperature within the skull, thoracic, and abdominal cavities.
p.1
Thermoregulation Processes
What is thermoregulation?
The process by which an organism regulates its body temperature within certain boundaries, even when the surrounding temperature is different.
p.23
Physiological Responses to Temperature Extremes
What is a key difference in thermoregulation between genders?
Males have higher metabolic rates and sweat more than females.
p.23
Physiological Responses to Temperature Extremes
How does exercise influence thermoregulation?
Exercise improves tolerance to heat or cold.
p.20
Effects of Environmental Factors on Thermoregulation
What happens to sweat evaporation rates as humidity increases?
Evaporation efficiency decreases.
p.15
Feedback Mechanisms in Homeostasis
What happens when the room temperature drops?
The effector responds to raise body temperature.
p.17
Control of Heat Production and Loss
What effect does adrenaline have on metabolism?
It increases basal metabolism.
p.26
Physiological Responses to Temperature Extremes
What can untreated heat exhaustion lead to?
Heat stroke, which can break down thermoregulation mechanisms.
p.1
Concept of Homeostasis
What is homeostasis?
The process by which biological systems maintain stability while adjusting to conditions that are optimal for survival.
p.19
Role of Endocrine and Nervous Systems
What does the secretory portion of the sweat gland secrete?
Water, mainly sodium and chloride.
p.10
Role of Endocrine and Nervous Systems
What triggers the onset of parturition?
Hormonal changes and fetal signals.
p.9
Feedback Mechanisms in Homeostasis
What happens when platelets adhere to the wound site?
They release chemicals that attract more platelets.
p.8
Role of Endocrine and Nervous Systems
What type of nerve carries signals from the pancreas to the brain?
Sensory nerve (afferent nerve).
p.7
Feedback Mechanisms in Homeostasis
What are the components of negative feedback?
Receptor (or sensor), control center, and effector.
p.22
Feedback Mechanisms in Homeostasis
How does feedforward regulation respond to changes in core temperature?
It initiates responses before changes occur in core temperature.
p.19
Role of Endocrine and Nervous Systems
What is the function of the duct portion of the sweat gland?
To pass sweat to the skin surface and reabsorb sodium and chloride.
p.8
Role of Endocrine and Nervous Systems
What are the two main systems responsible for homeostatic control?
Nervous system and endocrine system.
p.16
Thermoregulation Processes
Where are central thermoreceptors located?
In abdominal organs and the hypothalamus.
p.26
Physiological Responses to Temperature Extremes
What characterizes heat exhaustion?
Muscle cramps, fatigue, pale moist skin, fainting, fever, dizziness, nausea, and vomiting.
p.13
Heat Balance and Regulation
What are the methods of heat loss?
Convection and evaporation.
p.7
Feedback Mechanisms in Homeostasis
What is the role of the receptor in negative feedback?
To monitor the environment.
p.16
Heat Balance and Regulation
What is the formula for heat balance?
Heat balance = Heat gain – Heat loss.
p.19
Role of Endocrine and Nervous Systems
What is the relationship between water loss and mineral loss in sweat secretion?
Water loss is greater than mineral loss.
p.15
Feedback Mechanisms in Homeostasis
What is the role of the control center in thermoregulation?
To process input from the receptor and send output to the effector.
p.26
Physiological Responses to Temperature Extremes
What is the core temperature that defines hyperthermia?
Core temperature greater than 40°C.
p.26
Physiological Responses to Temperature Extremes
What are the symptoms of heat cramps?
Painful muscle cramps, red moist skin, triggered by Na+ loss and dehydration.
p.15
Set Point and Normal Range
What is the set point in thermoregulation?
The desired temperature that the body aims to maintain.
p.12
Thermoregulation Processes
What is the thermoneutral zone?
A range of environmental temperature (25 – 30 ℃) where body temperature is regulated only by skin blood flow.
p.9
Feedback Mechanisms in Homeostasis
What initiates the feedback cycle in blood clotting?
A break or tear in a blood vessel.
p.20
Effects of Environmental Factors on Thermoregulation
What is the effect of high humidity on air's capacity to accommodate water vapor?
High humidity implies the air is overcrowded with water vapor, reducing its capacity to accommodate more.
p.8
Feedback Mechanisms in Homeostasis
What happens when blood glucose levels increase?
The pancreas secretes insulin.
p.7
Feedback Mechanisms in Homeostasis
What is the purpose of feedback mechanisms in homeostasis?
To help the body maintain different variables within normal ranges.
p.10
Concept of Homeostasis
How does the body prepare for parturition?
Through physical and hormonal changes.
p.18
Control of Heat Production and Loss
What physiological changes occur in the skin when the body is cold?
Arterioles constrict and sweat secretion stops.
p.12
Heat Balance and Regulation
How is body temperature regulated in the thermoneutral zone?
By controlling skin blood flow to manage heat loss.
p.24
Physiological Responses to Temperature Extremes
What can result from extreme environmental temperatures?
Hypothermia or hyperthermia.
p.18
Control of Heat Production and Loss
How does the body increase heat loss when hot?
By increasing blood flow through dilating skin arterioles and constricting shunt vessels.
p.10
Feedback Mechanisms in Homeostasis
What role do contractions play in parturition?
They help to push the baby through the birth canal.
p.20
Thermoregulation Processes
What is the relationship between body temperature and evaporation?
An increase in body temperature leads to an increase in evaporation, but this is not effective for thermoregulation.
p.20
Heat Balance and Regulation
What is the maximum sweat evaporation rate at 20% relative humidity with specific conditions?
The specific maximum rate is not provided, but it is influenced by environmental temperature and wind speed.
p.13
Heat Balance and Regulation
What is the role of radiation in heat gain?
It occurs via infra-red rays.
p.12
Concept of Homeostasis
What is shell temperature?
The temperature essentially at the skin surface.
p.7
Feedback Mechanisms in Homeostasis
What does the control center do in negative feedback?
Determines if the variable is kept within the normal range.
p.2
Feedback Mechanisms in Homeostasis
What is negative feedback?
A mechanism that counteracts a change, bringing the system back to its set point.
p.2
Feedback Mechanisms in Homeostasis
What is positive feedback?
A mechanism that amplifies a change, moving the system away from its set point.
p.2
Thermoregulation Processes
What is thermoregulation?
The process by which the body maintains its core internal temperature.
p.16
Control of Heat Production and Loss
What are the effectors involved in thermoregulation?
Skeletal muscle, skin arterioles, sweat glands, and adrenal medulla.
p.7
Feedback Mechanisms in Homeostasis
What are the two types of feedback mechanisms?
Negative feedback and positive feedback.
p.8
Role of Endocrine and Nervous Systems
What type of nerve carries signals from the brain to the pancreas?
Motor nerve (efferent nerve).
p.13
Heat Balance and Regulation
What process describes evaporation in heat loss?
The process of liquid water turning into water vapor.
p.24
Health Implications of Thermoregulation Failure
What happens to core temperature if environmental conditions are extreme?
It can lead to hypothermia or hyperthermia.
p.9
Feedback Mechanisms in Homeostasis
What is the result of the positive feedback cycle in blood clotting?
Clotting proceeds until the wound is sealed by a newly formed clot.
p.18
Control of Heat Production and Loss
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.
p.13
Heat Balance and Regulation
How does conduction occur in heat gain?
Via contact with body surface.
p.7
Feedback Mechanisms in Homeostasis
What does positive feedback do?
Enhances the stimulus or action.
p.12
Concept of Homeostasis
What is thermoregulation?
The process by which the body maintains its core temperature.
p.10
Concept of Homeostasis
What is the significance of the afterbirth stage?
It involves the expulsion of the placenta and membranes.
p.26
Physiological Responses to Temperature Extremes
What are the symptoms of heat stroke?
Muscle cramps, red/warm dry skin, rapid heart rate, and seizures.
