sl integration of body systems Flashcards
do peristalsis/baroreceptors/chemoreceptors (21 cards)
System integration
- This is a necessary process in living systems. Coordination is needed for component parts of a system to collectively perform an overall function.
Different systems in an organism need to effectively communicate with each other and interact in order to be functional.
Cells, tissues, organs and body systems as a hierarchy of subsystems that are integrated in a multicellular living organism
Students should appreciate that this integration is responsible for emergent properties. For example, a cheetah becomes an effective predator by integration of its body systems.
Define emergent properties.
- Cells, tissues, organs and body systems as a hierarchy of subsystems that are integrated in a multicellular living organism
- Emergent properties are those that exist when the sum of all the parts creates features that do not exist within the individual components.
Integration of organs in animal bodies by hormonal and nervous signalling and by transport of materials and energy
- Distinguish between the roles of the nervous system and endocrine system in sending messages.
- Using examples, emphasize the role of the blood system in transporting materials between organs = nutrients, gases, hormones, water, waste, etc. (gas exchange!)
Hormone signalling / Neural signalling
type of signal: chemical / electrical
medium of transmission: blood / neurons
Speed of signal: slower/quick
Duration of signal: long-lasting / short
Destination: target cells of any tissue / muscles or glands
Specifity of response: wide-spread / very focused, a neuron or group of cells
in the nervous system…
In the nervous system electrical impulses are used to send messages by cells called neurons which transmit and receive impulses. The responses occur quickly but are short lived.
in the endocrine system…
The endocrine system: Hormones are chemical substances that are produced and secreted from the cells of the ductless or endocrine glands.
In effect, hormones carry messages about the body – but in a totally different way from the nervous system – they travel in the bloodstream.
NOTE: NERVOUS SYSTEM AND ENDOCRINE SYSTEM ARE LINKED
The brain as a central information integration organ
- Limit to the role of the brain in processing information combined from several inputs and in learning and memory.
- where are learning and memory formed?
- what is responsible for balance and muscle memory?
Central information integration organ
Receives impulses from sensory receptors
Integrates information
Sends impulses to effector organs
Stores information and forms memory.
Coordinates conscious, voluntary functions.
Initiates impulses
Seat of personality and emotions
- the cerebrum
- the cerebellum
The spinal cord as an integrating centre for unconscious processes
- characteristics
- spinal cord is made of…
Integration system for unconscious processes.
Carries nerve impulses between the brain and the rest of the body.
Controls reflexes (e.g. pain reflex) without input from the brain.
Reflexes are unconcious, automatic and involuntary
- white matter has mylienated axon fibres, used to send electrical impulses
- grey matter has motor neurons/interneurons, used to process info.
The spinal cord as an integrating centre for unconscious processes
- how do electrical impulses travel through CNS?
- Students should understand the difference between conscious and unconscious processes. (2)
- Electrical impulses pass from receptors to the CNS along sensory neurons, synapse with interneurons which send electrical impulses along motor neurons to effectors.
Input to the spinal cord and cerebral hemispheres through sensory neurons
- Students should understand that sensory neurons convey messages from receptor cells to the central nervous system.
(n/a)
- Electrical impulses pass from receptors to the CNS along sensory neurons, synapse with interneurons which send electrical impulses along motor neurons to effectors.
- Sensory receptors or free nerve endings located in the skin and sense organs perceive changes in the environment. The stimulus is passed on to sensory neurons which convey it to the CNS in form of nerve impulses carried along the axons fibres.
Sensory inputs to the brain are received by specialized areas in the cerebral hemisphere.
examplesss
- The rod and cone cells in the retina of the eye receive light in form of electromagnetic waves as a stimulus. The signal is transmitted to the visual cortex in the cerebral hemisphere.
Tiny hair cells embeded within a fluid in the cochlea of the ear act as mechanoreceptors responding to soundwaves which are transported through the fluid. Processing of sound occurs in the auditory cortex.
- A number of different touch receptors in the skin respond to different stimuli such as pressure, pain or temperature.
- These chemoreceptors in form of free nerve endings receive airborne chemicals as a stimulus.
- Taste receptors embedded within the tissue of the tongue act as chemoreceptor, binding to food chemicals as a stimulus.
Output from the cerebral hemispheres to muscles through motor neurons
- Students should understand that muscles are stimulated to contract.
- The cerebral hemispheres of the brain are responsible for the control of striated muscles (used for locomotion = moving from one place to another) and glands.
- Muscles can be controlled voluntarily and consciously via motor neurons.
- impulse sent from primary motor cortex
Nerves as bundles of nerve fibres of both sensory and motor neurons
- Use a transverse section of a nerve to show the protective sheath, and myelinated and unmyelinated nerve fibres.
- A nerve is a bundle of nerve fibres enclosed by a protective sheet. They vary in size depending on the number of fibres, and depending on propoertion of them that are myelinated. Most nerves contain nerve fibres of both sensory and motor neurons.
Pain reflex arcs as an example of involuntary responses with skeletal muscle as the effector
- Use the example of a reflex arc with a single interneuron in the grey matter of the spinal cord and a free sensory nerve ending in a sensory neuron as a pain receptor in the hand.
Role of the cerebellum in coordinating skeletal muscle contraction and balance
- Limit to a general understanding of the role of the cerebellum in the overall control of movements of the body.
The cerebellum controls balance and muscle contraction. It fine-tunes and coordinates the timing of contractions.
The cerebellum helps us to keep balance, but also is involved in the formation of muscle memory.
Modulation of sleep patterns by melatonin secretion as a part of circadian rhythms
- Students should understand the diurnal pattern (every 24 hrs) of melatonin secretion by the pineal gland and how it helps to establish a cycle of sleeping and waking. (think LIGHT)
- Define
- What do circadian rhythms depend on?
- Explainnn
- Circadian rhythms describe the body’s normal physiological responses to the 24 hour day-night cycle which are controlled by a biological clock in the brain
The suprachiasmatic nuclei (SCN) are groups of cells in the hypothalamus of the brain which set a daily rhythm.
The SCN control the secretion of the hormone melatonin by the pineal gland. When the retina is stimulated through expose to light, the release of melatonin is inhibited.
Control of the endocrine system by the hypothalamus and pituitary gland
- Students should have a general understanding, but are not required to know differences between mechanisms used in the anterior and posterior pituitary.
- The hypothalamus is a small region in the brain linking the nervous system to the endocrine system via the pituitary gland. It directs the release of hormones into the blood.
- Specialized areas in the hypothalamus (nuclei) act as sensors for blood temperature, blood glucose concentration, osmolarity and concentration of various hormones.
- The pituitary gland responds to directives from the hypothalamus, releasing a range of different hormones.
just remember, there are only 2 hormones released by the anterior pituitary gland
oxytocin and ADH
Epinephrine (adrenaline) secretion by the adrenal glands to prepare the body for vigorous activity
- Consider the widespread effects of epinephrine in the body and how these effects facilitate intense muscle contraction. (ATP production - myosin head pulling actin, causes muscle contraction)
- what is epinephrine/where is it released?
- Epinephrine is a hormone released by the adrenal glands upon receiving stimulating messages from the pituitary gland.
- increases heart rate, increases cellular respiration, increases need for glucose (access storage!), increases ventilation rate
Feedback control of heart rate following sensory input from baroreceptors and chemoreceptors
- Include the location of baroreceptors and chemoreceptors.
- Baroreceptors monitor blood pressure.
- Students should understand the role of the medulla in coordinating responses and sending nerve impulses to the heart to change the heart’s stroke volume and heart rate.
Feedback control of ventilation rate following sensory input from chemoreceptors
- Students should understand the causes of pH changes in the blood. These changes are monitored by chemoreceptors in the brainstem and lead to the control of ventilation rate using signals to the diaphragm and intercostal muscles.
- Chemoreceptors monitor blood pH and concentrations of oxygen and carbon dioxide.
