Human Function and Disease Yr9 Flashcards
What is the circulatory system?
The role of the circulatory system is to deliver oxygen and nutrients to the cells and takeaway waste.
What is the role of the digestive system?
The digestive system’s role is digestion and absorption The digestion is the breakdown of food into small molecules, which then absorb into the body.
What is the role of the endocrine system
The role of the endocrine system is to release hormones into the bloodstream. This allows the flow of hormones into other parts of the body.
What do the hormones from the endocrine system do?
The endocrine hormones help control mood, growth and development, the way our organs work and reproduction.
What is chemical control?
Hormones are chemical messengers. The interplay between the glands, hormones and other target organs are referred to as the endocrine system.
Muscular
- mobility
- circulation
- respiration
- stability
- posture
What is the role of the respiratory system?
provides cell with gases (oxygen)
What is the role of the excretory system?
removes cell wastes
What is the role of the nervous system?
Allows body to react to a stimulus, and monitors and controls almost every organ system.
What is homeostasis?
The process by which the body attempts to maintain a state of balance. It allows for there to be a constant internal environment by ensuring body systems are working together and correctly.
What systems control homeostasis?
Nervous: nervous control via brain, nervous and spinal cord.
Endocrine: chemical control through glands and hormones they produce.
What is the role of the immune system?
Defends body against infection
What is the stimulus response model?
Stimulus (eg. flame) -> receptor (eg. heat receptors in finger) -> effector (eg. motor neuron) -> response (eg. muscle contract, pulling finger from flame)
Body temp control feedback system
Normal body temperature:
body temp rises
blood vessels dilate, sweat, heart rate increase
heat lost to environment
Normal body temperature:
body temp decrease
blood vessels constrict, heart rate decrease, shivering muscles, goosebumps
heat is retained
Glucoregulation
Homeostasis stimulus: blood glucose level rise beta cells of pancreas release insulin liver takes up glucose to store as glycogen, and body cells take up more glucose blood glucose level decline
homeostasis stimulus: blood glucose level falls alpha cells of pancreas release glycogen liver breaks down glycogen and release glucose blood glucose level rise
What is the central nervous system?
Brain and spinal cord
Parts of the endocrine system
- Heart
- Thymus gland (between lungs (bronchi attached)
- parathyroid gland (four small dots at base of neck, on thyroid)
- thyroid (base of neck)
- pituitary gland (small knob under cerebrum in brain)
- pineal gland (further back knob than pituitary gland, in brain)
- adrenal gland (two on kidneys, kinda triangular shaped)
- pancreas (blob in front of stomach)
- ovaries
- testes (sacks inside scrotum)
- brain and spinal cord
- trachea and bronchus (attached to lungs)
- lungs
- stomach
- kidneys
- uterus + fallopian tubes
- scrotum
hormones produced by thyroid gland
iodine-based hormones that regulate physical and mental growth, oxidation, heart rate, blood pressure, temp, glucose absorption, and utilisation of glucose.
hormones produced by pancreas
insulin; level of sugar in blood
hormones produced by ovaries
estrogen: produces female characteristics and initiates female bodily functions
progesterone: affects endometrial lining of uterus
hormones produced by pituitary gland
hormones that influence other glands. Regulates skeletal growth, reproductive organs, secretions from ovaries and testes, mammary glands to provide milk, blood pressure, and adrenal cortex.
hormones produced by adrenal glands
cortisol: regulates metabolism and balance of salt and water levels
adrenaline: increases heart rate and stimulates liver and nervous system
hormones produced by testes
testosterone: controls growth of body hair, body size, and deepening of voice
What are the three main types of neurons?
sensory neurons: carry messages from receptors to central nervous system.
motor neurons: transmit messages from central nervous system to muscles (or glands)
interneurons: only in central nervous system, where they connect neuron to neuron.
Parts of a neuron
nucleus: dot in head
dendrite: roots coming off head (larger end)
body: larger end (head bit where nucleus is)
axon: singular rope bit from body to foot
Myelin sheath: shields along axon
Foot: end of neuron (smaller side opposite head)
Central nervous system components and functions
brain and spinal cord - controls functions of body and mind
peripheral nervous system components and functions
connects central nervous system to other parts of body, made up of sensory and motor neurons
What are reflex actions? Example?
A reflex arc is a simple nerve pathway which results in an effector organ responding to a stimulus. Its role is to prevent serious injury.
An example is nearing finger to flame. Heat receptors on finger transmit impulses to spinal cord, moto neuron stimulted and muscle sin hand contract, pulling finger away.
What is reaction time
length of time taken for body to respond to a given stimulus or event
Define health
State of complete physical, mental and social wellbeing and not merely the absence of disease or infirmity.
Define pathogen
A pathogen is a microorganism that can cause disease, and includes bacteria, viruses, parasites and fungi
Difference between infectious and non-infectious diseases
Infectious: - can spread from one person to another - caused by pathogens - (eg. chicken pox, hepatitis) Non-Infectious: - cannot be spread between people - are normally genetic, environmental or lifestyle - (eg. asthma, cancer)
What causes disease?
- pathogen
- genetic
- environmental
- lifestyle
Info on infectious (viral) disease - the flu
Disease: The flu Caused by: Influenza virus Transmission: -coughs (breathed in) -sneezes (breathed in) -direct contact -droplets Treatment: -rest -antiviral drug -drinking more fluids Symptoms: cough, fever, chills, muscle aches, congestion, runny nose, headache, fatigue Prevention: -vaccination -washing hands -cover mouth and nose
Info on non-infectious (genetic) disease - asthma
name: asthma treatment: -different relievers based on severity (immediate) -preventers base on severity (long-term) -medication
How are pathogens spread?
- direct contact
- droplet infection
- contaminated food and drink
- through break in skin
How does the immune system stop microbes entering the body?
First line of defence: - skin cells - waterproof barrier - slightly acidic skin - stops growth of microbes - saliva washes away microbes in mouth - urine washes out urinary tract - tears contain compounds to wash out eyeballs - stomach full of acid - hairs in nose and windpipe Second line: -Phagocytes (non specific - just stop everything) Third line: - B Lymphocytes - T Lymphocytes
Types of white blood cells
The main two are:
- Phagocytes
- Lymphocytes
What do Phagocytes do?
White blood cells that ingest foreign cells and other material and destroy it (known as phagocytosis)
What do Lymphocytes do?
White blood cells that can produce chemicals called antibodies.
What are antigens?
Chemical markers on pathogens
What is the process phagocytosis?
Phagocyte tracks foreign object and attaches itself to it.
Phagocyte flows around foreign object.
Foreign object taken in by phagocyte.
Chemicals are released that begin to break down foreign object.
What is the relationship between lymphocytes, antibodies and antigens?
Lymphocytes make chemicals called antibodies.
Pathogens have chemical ‘markers’ on their surfaces called antigens.
These markers are recognised by antibodies.
Antibodies stick to the surface antigen and destroy the pathogen.
Edward Jenner
Credited with creating term ‘vaccination’, although methods he used were also around for many years before his discoveries (eg. variolation - weakening virus through methods like freezing and steaming, before putting into someone’s skin).
Did the cow pox experiment.
Obesity causes, treatment and possible implications
Cause:
excess of body fat
Treatment:
change behaviour, including diet, exercise and sometimes even surgical procedures (eg. lap band surgery)
Implications:
Linked with other conditions, like heart disease, type 2 diabetes, high blood pressure, stroke and cholesterol problems.
What is the obesity level in Australia?
2 in 3 adults are considered obese.
Difference between epidemic and pandemic
Epidemic: widespread occurrence of an infectious disease in a community at a given time.
Pandemic: an epidemic occurring worldwide or over a large area, crossing international boundaries.
Ebola causes, symptoms, treatment and prevention
Cause:
- virus from Ebolavirus and Filoviridae family
- transmitted from animals to humans
Symptoms:
- fever, headache, muscle pain and chills
- later experiences internal bleeding (causes vomiting and coughing up blood)
Treatment:
- No treatment, except supportive hospital care
Prevention:
- don’t travel to infected areas
- avoid bodily fluids from others
- vaccination
How do vaccinations work?
- contain small amount of dead or weakened pathogens
- specific antigens are remembered by our cells of immune system
- when pathogen infects us, the body can produce and release correct antibodies.
What are some diseases that can be vaccinated against?
- rubella
- influenza
- measles
- polio
- mumps
- tetanus
- whooping cough
- HPV
What is the difference between a positive and negative feedback system?
Positive feedback systems bring the state of the body away from homeostasis (eg. uterine contractions)
Negative feedback systems bring the state of the body back to homeostasis (eg. glucoregulation and body temperature control)
Examples of hormones and what they do
Insulin: metabolism of glucose
Iodine-based hormones: increases metabolic rate, stimulates physical and mental growth
Adrenaline: activates the sympathetic nervous system
What is the role of the reproductive system?
To produce offspring and produce egg and sperm cells.
