Unit 5 P5 M2 D2 Evaluate homeostasis
P5
Explain the concept of homeostasis with reference to the control of heart rate, breathing
rate, body temperature and blood glucose levels
Homeostasis
Homeostasis is the entitlement provided to the process of observing a perpetual internal
environment regardless of external changes. Homeostasis is a combination of two words. ‘Homeo’
which represents body, and ‘stasis’ which represents the same. Homeostasis is the process of
keeping the body balanced. Examples of this could be;
If an individual is too hot, they may remove items of clothing, which is a voluntary response
and sweating may occur, which is an automatic response provided by the body in an attempt
to regulate the body temperature.
If the internal environment within the body was not maintained, enzymes and chemicals within the
body would be unable to function correctly.
Negative feedback as a form of regulation
Negative feedback takes place when a key variable (PH of blood and tissue fluid for example),
diverges from the established limits, initiating a response to invalidate the divergence. The liver
glycogen is transformed into glucose to maintain the energy levels within the body cells. The
nervous system and brain perform important roles in the regulation of homeostatic mechanisms and
to also aid in the expectancy of when key variables may diverge from established limits. Negative
feedback systems necessitate;
A command centre in order to receive information and process responses
Effectors in order to reverse changes and reproduce the original state
Receptors to distinguish change
Homeostatic mechanisms for regulation of heart rate
The heart is directed by the autonomic nervous system. The autonomic nervous system consists of
two branches; the parasympathetic nervous system and the sympathetic nervous system. The two
systems perform the role of the brake and acceleration on the heart. When the body is enduring
muscular activity, fear or stress, the sympathetic nervous system becomes active. This causes every
heartbeat to escalate in strength and also increase the heart rate. Oppositely, the parasympathetic
nervous system subsides the output of the heart, and is active during periods of rest and relaxation.
The primary parasympathetic nerve is entitled the vagus nerve, if this is functioned, the heart beats
quicker.
Roles of internal receptors
The function of baroreceptors are to identify anomalies in the blood pressure, they are sourced in
the aorta walls and a portion of the carotid arteries, transporting blood to the neck and head, they
are referred to as the aortic and carotid bodies. A minute increase in blood pressure within these
arteries often imply that additional blood has been transported out the ventricles, resultant of
additional blood being pumped into the heart through the venous side or the right side.
Baroreceptors identify anomalies and suspend information to the cardiac centre through nerve
impulses. Activity within the vagus nerve decelerates the heart rate and reduces blood pressure to
its original state. Receptors that are susceptible to temperature are referred to as the
thermoreceptors, which are current in the skin and deep within the body. Thermoreceptors transmit
information through the nerve impulses to the hypothalamus, triggering the appropriate response.
Effects of adrenaline on heart rate
When adrenaline circulates it accelerates the sinus node (natural pacemaker of the heart),
enhancing the effects of the sympathetic nervous system. Adrenaline (or epinephrine) is a hormone
that is released from the medulla of the adrenal glands when the body experiences stress, exertion
and fear.
Effect of increased body temperature on heart rate
Thermoreceptors that identify a raise in temperature within the body instigate the hypothalamus to
trigger the sympathetic nervous system, this then causes the heart rate to escalate.
P5
Explain the concept of homeostasis with reference to the control of heart rate, breathing
rate, body temperature and blood glucose levels
Homeostasis
Homeostasis is the entitlement provided to the process of observing a perpetual internal
environment regardless of external changes. Homeostasis is a combination of two words. ‘Homeo’
which represents body, and ‘stasis’ which represents the same. Homeostasis is the process of
keeping the body balanced. Examples of this could be;
If an individual is too hot, they may remove items of clothing, which is a voluntary response
and sweating may occur, which is an automatic response provided by the body in an attempt
to regulate the body temperature.
If the internal environment within the body was not maintained, enzymes and chemicals within the
body would be unable to function correctly.
Negative feedback as a form of regulation
Negative feedback takes place when a key variable (PH of blood and tissue fluid for example),
diverges from the established limits, initiating a response to invalidate the divergence. The liver
glycogen is transformed into glucose to maintain the energy levels within the body cells. The
nervous system and brain perform important roles in the regulation of homeostatic mechanisms and
to also aid in the expectancy of when key variables may diverge from established limits. Negative
feedback systems necessitate;
A command centre in order to receive information and process responses
Effectors in order to reverse changes and reproduce the original state
Receptors to distinguish change
Homeostatic mechanisms for regulation of heart rate
The heart is directed by the autonomic nervous system. The autonomic nervous system consists of
two branches; the parasympathetic nervous system and the sympathetic nervous system. The two
systems perform the role of the brake and acceleration on the heart. When the body is enduring
muscular activity, fear or stress, the sympathetic nervous system becomes active. This causes every
heartbeat to escalate in strength and also increase the heart rate. Oppositely, the parasympathetic
nervous system subsides the output of the heart, and is active during periods of rest and relaxation.
The primary parasympathetic nerve is entitled the vagus nerve, if this is functioned, the heart beats
quicker.
Roles of internal receptors
The function of baroreceptors are to identify anomalies in the blood pressure, they are sourced in
the aorta walls and a portion of the carotid arteries, transporting blood to the neck and head, they
are referred to as the aortic and carotid bodies. A minute increase in blood pressure within these
arteries often imply that additional blood has been transported out the ventricles, resultant of
additional blood being pumped into the heart through the venous side or the right side.
Baroreceptors identify anomalies and suspend information to the cardiac centre through nerve
impulses. Activity within the vagus nerve decelerates the heart rate and reduces blood pressure to
its original state. Receptors that are susceptible to temperature are referred to as the
thermoreceptors, which are current in the skin and deep within the body. Thermoreceptors transmit
information through the nerve impulses to the hypothalamus, triggering the appropriate response.
Effects of adrenaline on heart rate
When adrenaline circulates it accelerates the sinus node (natural pacemaker of the heart),
enhancing the effects of the sympathetic nervous system. Adrenaline (or epinephrine) is a hormone
that is released from the medulla of the adrenal glands when the body experiences stress, exertion
and fear.
Effect of increased body temperature on heart rate
Thermoreceptors that identify a raise in temperature within the body instigate the hypothalamus to
trigger the sympathetic nervous system, this then causes the heart rate to escalate.
