p.8
Feedback Mechanisms in Homeostasis
What happens when blood glucose levels increase?
The pancreas secretes insulin.
p.10
Concept of Homeostasis
What is parturition?
The process of giving birth.
p.23
Physiological Responses to Temperature Changes
How does age affect thermoregulation?
Older adults are less tolerant due to less effective sweat glands and reduced skin blood flow.
p.22
Physiological Responses to Temperature Changes
What role do skin thermoreceptors play in thermoregulation?
They detect temperature changes and send signals to the brain.
p.7
Feedback Mechanisms in Homeostasis
What are the two types of feedback mechanisms?
Negative feedback and positive feedback.
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.20
Effects of Environmental Factors on Thermoregulation
How does increased humidity affect sweat evaporation rates?
Increased humidity decreases evaporation efficiency.
p.10
Concept of Homeostasis
How does the body prepare for parturition?
Through hormonal changes and physical adaptations.
p.12
Feedback Mechanisms in Homeostasis
What is an example of negative feedback in thermoregulation?
The regulation of body temperature.
p.20
Heat Balance and Regulation
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.
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.18
Control of Heat Production and Loss
What happens to heat loss when the body is hot?
Heat loss increases through increased blood flow and more sweat secretion.
p.8
Role of Endocrine and Nervous Systems
What are the two main systems responsible for homeostatic control?
The nervous system and the endocrine system.
p.3
Role of Endocrine and Nervous Systems
Which systems regulate homeostasis?
The endocrine and nervous systems.
p.8
Feedback Mechanisms in Homeostasis
What role does insulin play in blood glucose regulation?
It promotes the uptake of glucose by the liver, lowering blood glucose levels.
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.10
Role of Endocrine and Nervous Systems
What role do hormones play in parturition?
Hormones like oxytocin stimulate contractions.
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.22
Thermoregulation Processes
What is the effect of vasoconstriction of skin arterioles?
It helps to conserve body heat by reducing blood flow to the skin.
p.9
Feedback Mechanisms in Homeostasis
What happens when platelets adhere to the wound site?
They release chemicals that attract more platelets.
p.26
Consequences of Extreme Temperatures: Hypothermia and Hyperthermia
What are the symptoms of heat cramps?
Painful muscle cramps, red moist skin, triggered by Na+ loss and dehydration.
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.11
Role of Endocrine and Nervous Systems
Which gland secretes prolactin for milk production?
The anterior pituitary gland.
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.24
Concept of Homeostasis
What is the core temperature range maintained during thermoregulation?
Between 36.1 and 37.8 °C.
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.12
Heat Balance and Regulation
How does the body regulate temperature within the thermoneutral zone?
By controlling skin blood flow to manage heat loss.
p.11
Role of Endocrine and Nervous Systems
What is the function of prolactin in lactation?
To stimulate milk production.
p.18
Control of Heat Production and Loss
How does the body increase heat loss when hot?
By dilating skin arterioles and constricting shunt vessels.
p.18
Control of Heat Production and Loss
What happens to sweat secretion when the body is cold?
There is no sweat secretion.
p.8
Set Point and Normal Range
What is the normal blood glucose level?
Approximately 90 mg/100 ml.
p.19
Physiological Responses to Temperature Changes
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.7
Feedback Mechanisms in Homeostasis
What is the primary function of feedback mechanisms in homeostasis?
To help our body maintain different variables within normal ranges.
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.19
Physiological Responses to Temperature Changes
What is the relationship between water loss and mineral loss in sweat secretion?
Water loss is greater than mineral loss.
p.9
Feedback Mechanisms in Homeostasis
What initiates the feedback cycle in blood clotting?
A break or tear in a blood vessel.
p.1
Thermoregulation Processes
What role does thermoregulation play in homeostasis?
It helps maintain the optimal temperature for enzymatic and metabolic processes in the body.
p.22
Thermoregulation Processes
What physiological response occurs in muscles during cold exposure?
Muscle shivering, which generates heat.
p.9
Feedback Mechanisms in Homeostasis
What is the result of the positive feedback in blood clotting?
Clotting proceeds until the wound is sealed by a newly formed clot.
p.26
Consequences of Extreme Temperatures: Hypothermia and Hyperthermia
What triggers heat exhaustion?
More severe dehydration and low blood volume.
p.21
Feedback Mechanisms in Homeostasis
What triggers vasoconstriction?
The sympathetic nervous system.
p.17
Control of Heat Production and Loss
What effect does adrenaline have on metabolism?
It increases basal metabolism.
p.26
Consequences of Extreme Temperatures: Hypothermia and Hyperthermia
What can untreated heat exhaustion lead to?
Heat stroke, which can result in coma or death.
p.24
Consequences of Extreme Temperatures: Hypothermia and Hyperthermia
What can result from extreme environmental temperatures?
Hypothermia or hyperthermia.
p.24
Consequences of Extreme Temperatures: Hypothermia and Hyperthermia
What happens to core temperature if exposed to extreme heat?
It can rise, leading to hyperthermia.
p.18
Control of Heat Production and Loss
What happens to blood flow when the body is cold?
Blood flow decreases to reduce heat loss.
p.19
Physiological Responses to Temperature Changes
What are the two main parts of a sweat gland?
Secretory portion and duct portion.
p.13
Heat Balance and Regulation
What is the formula for heat balance?
Heat balance = heat gain – heat loss.
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.8
Role of Endocrine and Nervous Systems
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.
p.16
Physiological Responses to Temperature Changes
What are the two types of thermoreceptors involved in thermal sensation?
Peripheral thermoreceptors in the skin and central thermoreceptors in abdominal organs & hypothalamus.
p.13
Heat Balance and Regulation
What are the methods of heat loss?
Convection (via wind/air flow) and evaporation (via the process of liquid water turning into water vapor).
p.23
Physiological Responses to Temperature Changes
How does exercise influence thermoregulation?
Exercise improves tolerance to heat or cold.
p.16
Feedback Mechanisms in Homeostasis
What are the effectors involved in heat production and loss?
Skeletal muscle, skin arterioles, sweat glands, and adrenal medulla.
p.7
Feedback Mechanisms in Homeostasis
What does positive feedback do?
Enhances the stimulus or action.
p.26
Consequences of Extreme Temperatures: Hypothermia and Hyperthermia
What characterizes heat exhaustion?
Muscle cramps, fatigue, pale moist skin, fainting, fever, dizziness, nausea, and vomiting.
p.2
Thermoregulation Processes
What is thermoregulation?
The process by which the body maintains its core internal temperature.
p.15
Set Point and Normal Range
What is the set point in thermoregulation?
The desired temperature that the control center aims to maintain.
p.24
Consequences of Extreme Temperatures: Hypothermia and Hyperthermia
What happens to core temperature if exposed to extreme cold?
It can drop, leading to hypothermia.
p.18
Role of Endocrine and Nervous Systems
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.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.22
Feedback Mechanisms in Homeostasis
How does feedforward regulation respond to changes in core temperature?
It initiates a response before changes occur in core temperature.
p.13
Heat Balance and Regulation
What are the two methods of heat gain?
Conduction (via contact with body surface) and radiation (via infra-red rays).
p.23
Physiological Responses to Temperature Changes
What is a key difference in thermoregulation between genders?
Males have higher metabolic rates and sweat more than females.
p.7
Feedback Mechanisms in Homeostasis
What is the role of negative feedback?
To suppress the stimulus.
p.26
Consequences of Extreme Temperatures: Hypothermia and Hyperthermia
What is the core temperature that defines hyperthermia?
Core temperature > 40 °C.
p.12
Concept of Homeostasis
What is thermoregulation?
The process by which the body maintains its core temperature.
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.9
Feedback Mechanisms in Homeostasis
What role do the released chemicals play in the clotting process?
They attract more platelets to the wound site.
p.15
Feedback Mechanisms in Homeostasis
What is the function of the thermostat in thermoregulation?
It serves as the control center that processes input from the receptor.
p.12
Concept of Homeostasis
What is shell temperature?
The temperature essentially at the skin's surface.
p.18
Control of Heat Production and Loss
What occurs in the skin when the body is cold?
Arterioles constrict and shunt vessels dilate.
p.3
Concept of Homeostasis
What is homeostasis?
A relatively stable condition of the internal environment.
p.5
Set Point and Normal Range
Does body temperature remain constant at the ideal level?
No, it fluctuates within the normal range.
p.10
Concept of Homeostasis
What are the stages of parturition?
Labor, delivery, and afterbirth.
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.22
Physiological Responses to Temperature Changes
What signals are sent from the brain during thermoregulation?
Signals are sent to effectors for responses like vasoconstriction and muscle shivering.
p.10
Feedback Mechanisms in Homeostasis
What is the significance of contractions during parturition?
They help to push the baby through the birth canal.
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 function.
p.20
Thermoregulation Processes
What happens to evaporation rates when body temperature increases?
Evaporation rates increase, but this is not effective for thermoregulation.
p.7
Feedback Mechanisms in Homeostasis
What are the components of negative feedback?
Receptor (or sensor), control center, and effector.
p.15
Feedback Mechanisms in Homeostasis
What role does the thermometer play in thermoregulation?
It acts as a receptor that detects temperature changes.
p.12
Concept of Homeostasis
What is core temperature?
The temperature within the skull, thoracic, and abdominal cavities.
p.7
Feedback Mechanisms in Homeostasis
What is the role of the effector in negative feedback?
Responds to the stimulus.
p.15
Feedback Mechanisms in Homeostasis
What happens when the room temperature drops?
The effector (heater) responds to raise body temperature.
p.19
Physiological Responses to Temperature Changes
What does the secretory portion of the sweat gland secrete?
Water, mainly sodium and chloride.
p.16
Heat Balance and Regulation
What is the formula for heat balance?
Heat balance = Heat gain – Heat loss.
p.13
Heat Balance and Regulation
Which method of heat loss is always occurring?
Convection and evaporation.
p.17
Control of Heat Production and Loss
What happens to heat production when the body is cold?
Heat production increases.
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.20
Effects of Environmental Factors on Thermoregulation
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.
p.7
Feedback Mechanisms in Homeostasis
What is the function of the receptor in negative feedback?
To monitor the environment.
p.26
Consequences of Extreme Temperatures: Hypothermia and Hyperthermia
What are the symptoms of heat stroke?
Muscle cramps, red/warm dry skin, rapid heart rate, and seizures.
p.21
Effects of Environmental Factors on Thermoregulation
What environmental factor influences vasodilation?
Environmental temperature.
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.15
Feedback Mechanisms in Homeostasis
How does the effector respond to a drop in body temperature?
By activating the heater to increase the temperature.
p.18
Control of Heat Production and Loss
What role does sweat play in heat loss?
Sweat secretion increases heat loss by evaporation.
