C3.1 Integration of Body Systems Flashcards
[C3.1.1/ C3.1.2] Define system integration and emergent property by providing an example
System integration is the use multiple systems in coordination to collectively perform an overall function through effective communication between components.
Emergent properties is the result of effective system integration. For example, cheetah is an effective predator due to features such as flexible spine that allows them to be fast.
[C3.1.1/ C3.1.2] List the hierarchy of subsystems in a multicellular organism
- Cell
- Tissue: made up of cells that are specialised to perform the same type of function (but may contain more than 1 cell type like the epithelium of alveolar walls)
- Organ: group of tissues that carry out a specific function for life
(ex. Photosynthesis) - Organ system: group of organs that interact with one another to perform an overall function of life
- Organism: living individual made up of interconnected organ systems that are interdependent of each other - failure of a group of cells cause organism to die
[C3.1.3] Distinguish between the endocrine system and the nervous system
Type of signal: Chemical/ Electrical
Transmission of signal: In the bloodstream/ In neurons
Destination of signal: To all parts of he body that are supplied with blood, but only certain cells respond/ Highly focused - to one specific neuron or group of effector cells
Effectors: Target cells in any type of tissue/ Muscles or glands
Type of response:
- Growth
- Development, including puberty
- Reproduction, including gamete production and pregnancy
- Metabolic rate and heat generation
- Solute concentrations in blood, including glucose and salt levels
- Mood, including stress, thirst, sleep, wakefulness
/
Responses due to contraction of muscle:
- Striated muscle: locomotion
- Smooth muscle: peristalsis, sphincter opening and closing
- Cardiac muscle: heart rate
Response or secretion from a gland:
- Exocrine glands: sweat, saliva secretion
- Endocrine glands: epinephrine secretion
Speed of response: Slower/ Very rapid
Duration of response: Long - until the hormone is broken down/ Short - unless nerve impulses are sent repeatedly
[C3.1.3] Describe the role of the bloodstream in transporting materials
Materials and energy that are required for cell respiration such as glucose and oxygen are transported between organs by the circulatory system. Therefore, the bloodstream supplies both of these respiratory substrates, along with water and carbon compounds needed for growth and repair. It also removes waste products like carbon dioxide produced in respiration.
[C3.1.4/ C3.1.5] Describe the 2 organs in the CNS
The nervous system is made up of the Central Nervous System (CNS) and the nerves that connect CNS to all the other organs in the body. The 2 organs in the CNS are:
1. Brain: central integrating organ that receives information, processes it to make decisions, stores some as memory, and send instructions to all parts of the body to coordinate life processes
2. Spinal cord: located inside the backbone with 2 main tissues:
○ White matter containing myelinated axons and other nerve fibres that convey signals from sensory neurons to the brain, and from the brain, to the organs of the body - processes decision making
○ Grey matter containing the cell bodies of motor neurons and interneurons (relay neurons) with many synapses between these neurons
○ Only coordinates unconscious processes, such as reflexes, which allow responses to stimuli occur more quickly than if signals were conveyed to and from the brain.
[C3.1.4/ C3.1.5] Distinguish between unconscious and conscious processes
Performed when awake or asleep / Only performed when awake
Performed involuntarily - do not have to think about the actions and cannot prevent them through thought / Performed voluntarily - can think about the actions and decide whether or not to carry it out
Secretion by glands and contractions of smooth muscles are unconscious / Contraction of striated muscles can be done consciously
Coordinated by the brain and spinal cord / Coordinated by the cerebral hemispheres of the brain
Ex. Swallowing of food once it has entered the oesophagus / Ex. Initiation of swallowing when food is pushed from the mouth cavity into the pharynx
[C3.1.6/ C3.1.7] List the location and the roles of 5 different receptors
Changes in the external environment such as heat, touch and vision can act as stimuli for sensory receptors to detect. The different types of receptors include:
1. Mechanoreceptor: located on skin and eardrum to detect pain, pressure, vibration, touch and sound
2. Photoreceptor: located on eyes to detect light
3. Chemoreceptor: located on tongue, nose and blood to detect taste, smell and chemicals
4. Thermoreceptor: located on skin and brain to detect temperature
5. Baroreceptor: located on walls of arteries to detect blood pressure
[C3.1.6/ C3.1.7] Describe what happens after the recptors have detected a stimuli, providing and example of a response to the stimuli
These receptors are located in the skin and sense organs, and this information is conveyed to the CNS by sensory neurons. The signals are in the form of nerve impulses carried along the axon of neurons, and when it reaches the brain, they are received by specialised areas in the cerebral hemispheres. The cerebral hemispheres have a major role to control contractions of muscles and secretion from glands via motor neurons.
[C3.1.8] Describe a nerve
A nerve is a bundle of nerve fibres (usually both sensory and motor neurons) enclosed in a protective sheath. Nerves include myelinated and unmyelinated fibres.
[C3.1.9] Define a relfex action and describe the process of the pain reflex arc
A reflex action is rapid, involuntary response to a specific stimulus since the signals pass through the smallest number of neurons. Some reflex actions like the pain reflex arc is coordinated by the spinal cord.
1. Sensory receptors detect stimuli.
2. Sensory neuron receive signals from the receptors and pass on the signal to CNS (spinal cord).
3. Interneuron located inside the spinal cord process signals and make decisions as a response to stimuli
○ Very simple and rapid process since there is 1 interneuron connecting a specific sensory and motor neuron
4. Motor neuron receive signal through synapse with interneuron and pass on a response for effectors to carry out
5. Effectors receive signals from motor neuron and conduct a response.
[C3.1.10/ C3.1.11/ C3.1.13/ C3.1.14/ C3.1.15] Describe the role of melatonin in regulating sleep patterns
Pineal gland secretes melatonin - high levels at night, resulting in drowsiness, and low levels at dawn, allowing individuals to wake up. High level of melatonin decreases body temperature
Suprachiasmatic Nuclei (SCN) regulates circadian rhythm - 24 hour cycle for waking up and sleeping
[C3.1.10/ C3.1.11/ C3.1.13/ C3.1.14/ C3.1.15] Describe the individual roles of hypothalamus and pituitary gland, and how the 2 features work together to control osmoregulation and puberty
Hypothalamus: links nervous system and endocrine system via pituitary gland. It has specialised areas called nuclei, where each nucleus control a specific system using information from sensory organs and other parts of the brain
Pituitary gland: has 2 distinct parts - anterior pituitary lobe and posterior pituitary. Both secretes hormones into blood capillaries under the direction of nuclei in hypothalamus but operates in different ways. The hormones secreted by the anterior pituitary lobe (which makes hormones) are LH (luteinising hormone) and FSH (follicle stimulating hormone). The hormones secreted by the posterior pituitary lobe (which stores hormones) are ADH and oxytocin.
Hypothalamus and pituitary gland controls osmoregulation and puberty by:
- using osmoreceptors that monitor blood solute concentration and hypothalamus triggers ADH to be released by pituitary gland
- produces GnRH which triggers LH and FSH to be released by pituitary gland
[C3.1.10/ C3.1.11/ C3.1.13/ C3.1.14/ C3.1.15] Describe the negative feedback loop regulating ventilation rate
Brain stem controls unconscious preocesses such as ventilation rate (number of times inhale and exhale in a minute) bu signalling the diaphragm to contract for inhalation (lungs expand). This is detected by stretch receptors which allow brain stem to stop signalling for inhalation for exhalation.
Medulla oblongata: receive signals from sympathetic nerves to increase heartbeat and received signals from vagus nerves to decrease heartbeat. The cardiovascular centre in medulla oblongata receive sensory inputs from baroreceptors located in the walls of aorta to monitor blood pressure by negative feedback - if blood pressure is low, heart rate increases and vice versa.
The cardiovascular centre also receives sensory inputs from chemoreceptors in the aorta to monitor blood oxygen concentration and pH (which depends on carbon dioxide concentration) by negative feedback - if oxygen concentration or pH is low, heart rate increases and vice versa. These chemoreceptors also regulate ventilation rate as decrease in blood pH signal the respiratory centre in the brain stem to increase ventilation rate.
[C3.1.10/ C3.1.11/ C3.1.13/ C3.1.14/ C3.1.15] Describe the roles of Medulla oblongata and the cerebellum
Cerebellum: control muscle contraction and balance, allowing previse movement (ex. help with maintain posture)
[C3.1.12] Describe the effect of epinephrine on different body systems during vigorous activity
Epinephrine (or adrenaline) is a hormone that is released by the adrenal glands near the kidneys and prepares the body for vigorous physical activity. When epinephrine reaches tissues where it can affect, it binds to the epinephrine receptors on the plasma membrane, triggering a response that increase the supply of oxygen ang glucose to skeletal muscles, maximising production of ATP. The responses include muscles cells and liver cells breaking down glycogen into glucose, ventilation increasing due to smooth muscles of bronchi and bronchioles relaxing, and increase in blood flow due to widening of arterioles. As a result, skeletal muscles receive a greater volume of blood per minute that contain more glucose and oxygen.
