C3.1 Integration Of Body Systems Flashcards
Hierarchy of organization in a multicellular organism
Tissues, organs, body systems, organisms
Interactions between and within levels of organization result in…
Emergent properties
Hormonal signalling type of signal and route
Chemical, in the blood
Nervous signalling type of signal and route
Electrical, in neurons
Types of response to hormonal signalling
Growth, development, reproduction, changes to metabolic rate, mood etc.
Types of response to nervous signalling
Contraction of muscles, contraction of smooth muscle (e.g. gut), change to the rate of cardiac muscle contraction, secretion by glands
Speed of response of hormonal signalling
Slower
Speed of response of nervous signalling
Very rapid
Duration of response, hormonal vs nervous signalling
H: Long duration, until hormone has been broken down. N: short duration, unless nerve impulses are sent repeatedly
What is the brain (as an organ)
Integrating organ that receives information, processes it, stores some of it and sends instructions to coordinate life processes
What is the spinal cord, where is it and what does it do
Integrating centre for unconscious processes, grey matter inside the vertebral column (backbone), receives information from neurons and pattern of neurons and synapses determine what decisions are made (REFLEXES)
Features of unconscious processes
Can happen while asleep, involuntary, controlled by brain and spinal cord, (e.g. peristalsis in intestine, saliva secretion)
Features of conscious processes
Only happen when awake, voluntary, controlled by cerebral hemispheres of the brain, (e.g. putting food into the mouth, chewing)
Where are receptor cells and what do they do
In skin and sense organs, detect changes in the external environment –> pass the impulses to sensory neurons (some receptor cells are inside to detect e.g. blood pressure)
What are chemoreceptors
In the walls of blood vessels, monitor concentrations of oxygen, co2 and glucose
Signals from receptors and nerve endings are conveyed to __ by __
the central nervous system, sensory neurons
The brain receives all the signals from___ while the spinal cord receives signals__
The main sense organs located in the head – from other organs in the body including skin and muscles
What do the cerebral hemispheres (e.g. motor cortex) of the brain do?
CHs play a role in the conscious control of striated muscles, MC can send nerve impulses to any striated muscle in the body
What are striated muscles?
Attached to the bone, maintain posture and is used for locomotion
Motor neurons in the process of muscle contraction
Located in grey matter, MN dendrites receive signals from interneurons, one axon leads out of the brain and down the spinal cord –> forms a synapse with 2nd MN whose axon leads to striated muscle
A nerve is a__ enclosed in __. Most contain both __ and __ neurons
bundle of nerve fibres, a protective sheath. Sensory, motor.
Reflex action
Rapid, involuntary response to a specific stimulus. Simplest type of coordination by the nervous system as signals pass through the LEAST amount of neurons –> prevents harm to the body
5 stages of REFLEX
- Receptor cells (or nerve endings in pain and heat) 2. Sensory neurons deliver signals as nerve impulses via long axons 3. Interneurons in grey matter process and make decisions 4. Motor neurons receive signals via synapses with IN and pass it along axon out of CNS 5. Effectors carry out response to stimulus
Role of cerebellum
Important in control of skeletal muscle contraction and balance (fine-tunes timing), allows precise control of movements and helps with maintaining posture, helps with activities requiring motor memory (e.g. riding a bike)
Circadian rhythms
Rhythms in behaviour that fit humans’ 24h cycle, controlled by internal system
Circadian rhythms depend on __
two groups of cells in the hypothalamus called the suprachiasmatic nuclei (SCN) which set a daily rhythm – melatonin causes sleep-wake cycle
What is epinephrine and what does it do?
Adrenaline is secreted by adrenal glands and prepares body for physical activity.
Effect of adrenaline on target cells
Striated muscle fibres and liver convert stored glycogen to glucose, bronchioles dilate easing ventilation, gas exchange increased by cells in brainstem controlling intercostal muscles and diaphragm, pacemaker speeds up heart rate, atrioles dilate (more blood to muscles and less to gut etc.)
Hypothalamus
A small region in the brain that is important in integration of body systems. Links nervous system to endocrine system via PITUITARY GLAND
Pituitary gland parts
Anterior (growth, thyroid stimulating, prolactin hormones) and Posterior (antidiuretic (control of blood vessels) hormone and oxytocin)
Signals from the cardiovascular centre in the brain reach the SAN (pacemaker) TWO ways:
- Signals from the sympatetic nerve for increase of HR 2. Signals from vagus nerve to decrease HR
Ventilation rate followed by sensory output from chemoreceptors
Chemoreceptors monitor blood pH, o2 and co2 concentrations and alert respiratory centre to act
Peristalsis
is the wave of contraction and relaxation in the wall of the gut that moves food from mouth to anus, controlled by enteric nervous system (ENS)
Peristaltic muscle structure
Outer wall is longitudinal muscle, inner wall is circular muscle covered in lining (mucosa)
Two parts in the gut movements that are not involuntary
- swallowing 2. defecation (pooping)
