Body coordination Flashcards
What are enzymes?
Proteins that help speed up chemical reactions but don’t get used up
What is a catabolic reaction?
A large molecule is split into smaller ones
What is an anabolic reaction?
A reaction where smaller molecules join to form a larger molecule
What is a substrate?
The substance that is altered during a chemical reaction
How to enzymes work?
They are specific to a particular type of substrate and attaches to it (lock and key model)
What do carbohydrates break down into during digestion?
Glucose
What do proteins break down to during digestion?
Amino acids
What do lipids break down to during digestion?
Fatty acids and glycerol
What is diffusion?
The movement of particles in a substance from a high concentration to a low concentration
What is the purpose of the respiratory system?
It takes oxygen into the body and removes waste carbon dioxide
What is the purpose of the circulatory system?
Carries materials to and from cells via arteries, capillaries and veins
What initiates the heart’s rhythm?
The pacemaker (SA node)
How does the pacemaker initiate the heartbeat rhythm?
It stimulates both atria to contract, the stimulus reaches the tissue between the atria and ventricles, the AV node stimulates both ventricles to contract
What is ventricular fibrillation?`
A condition in which the impulses in the ventricles become disorganised and the muscles twitch spasmodically
What is a defibrillator?
A machine that delivers an electric current to the heart, in attempt to restore the heart’s natural rhythm
What are hormones?
Chemicals that act as messengers in the body and are secreted from endocrine glands.
Which hormone is released under stress or fear and what is its effect on the heart?
Noradrenaline, it increases the rate at which it beats, the strength of the contractions and how much blood it pumps (up to 5x)
In what ways do vigorous exercise increase the heart rate?
Increased cellular respiration which causes more CO2 in blood, receptors send messages to brain. Increased muscular activity pumps more blood back to the right atrium, it stretchers, stretch receptors send messages to brain.
What are receptors?
Specialised cells that detect stimuli changes
What is the negative feedback when you stop exercising?
Receptors in the aorta and carotid artery send messages to the brain to slow down heart rate
What are mitochondria?
Organelles in which cellular respiration take place and that produce energy
What are ribosomes?
Chemical reactions to produce proteins from amino acids that the body can use
What are lysosomes?
Organelles that treat wastes within cells by digesting dying cells, damaged organelles and diseases that have invaded the cell
What are the functions of the liver?
Breaks down hormones, breaks down haemoglobin, breaks down and modifies toxic substances and medicines, converts ammonia to urea
Which two organs are involved in the excretory system?
Liver and kidneys
What is metabolism?
All of the chemical processes that maintain life
What are the 2 groups of metabolism?
Reactions that break down organic matter, reactions that build complex molecules from simpler substances
What is the nervous system?
A communication network that controls all other systems of the body
What are the 2 parts of the human nervous system?
central (CNS) and peripheral (PNS)
What is the central nervous system?
It is made up of the brain and spinal cord. Receives information from all over the body, processes the information and creates a response
What is the peripheral nervous system?
Made up of nerves that carry messages to and from the CNS and other parts of the body.
What are neurons?
Specialised cells that transmit electrical messages to and from parts of the body at a high speed.
What is a nerve impulse?
An electrical message transmitted by a nerve cell (neuron)
What is the purpose of the dendrites in a neuron?
They receive messages from other nerve cells and send them to the cell body.
What is the purpose of the axon terminals and the axon in a neuron?
The axon sends nerve impulses away from the cell body and the axon terminals pass the message to the next neuron
What are the 3 types of neurons and their functions?
Motor neurons: carry messages from CNS to effectors
Connector neurons: Transmit messages between neurons in the CNS
Sensory neurons: Carry messages to brain or spinal cord from sense organs
How are nerve impulses transferred from one neuron to the next?
When the nerve impulse reaches the axon terminals, a neurotransmitter is released into the synapse and it carries the message to the dendrites of the next neuron.
What is an effector?
A muscle or gland that translates messages into actions.
Whats a synapse?
The space between 2 nerve cells when a nerve impulse is being sent from one to another.
What is a myelin sheath?
An insulating layer on neurons that increases the speed of the nerve impulse.
What is the function of the brain?
To control and regulate body functions
What is the cerebrum?
The part of the brain that controls all conscious thought and the movement of body parts, receives sensory messages from body parts
Which cerebral hemisphere has more control over language and logical thinking?
Left.
What’s the cerebellum?
Located at the base of the cerebellum, where the skull curves inwards. It is responsible for coordination and balance.
What is the medulla or brain stem?
It is located where the spinal cord widens after passing into the skull, it controls the body’s vital (involuntary) functions.
What is the cranium?
A covering of bone that protects the brain
What are vertebrae?
Tiny bone structures that surround and protect the spinal cord?
What is a stimulus?
Any factor that stimulates a receptor and brings out a response.
What is a reflex action?
A very fast involuntary action as a response to a stimulus that can harm the body
What is a reflex arc?
The nerve pathway operating in a reflex action
What is the endocrine system?
A communication system that controls the internal environment of the body
What are hormones produced by?
Endocrine glands
What is the purpose of the pituitary gland?
It produces human growth hormone and antidiuretic hormone, it stimulates other endocrine glands
What is the purpose of the pancreas?
It produces insulin and glucagon which control blood glucose levels
What is the purpose of the adrenal glands?
They produce adrenalin in readiness for fight or flight
What is the purpose of the ovaries?
They produce oestrogen (women sexual development), and progesterone (pregnancy)
What is the purpose of the testes?
Produce testosterone, controls male sexual development and activity
What is the purpose of the thyroid?
Produces thyroxin, controls rate of chemical reactions in cells
What are target cells?
Cells that respond to particular hormones
What is the hypothalamus?
A portion of the brain that constantly checks the internal environment of the body
What is the main function of the hypothalamus?
It links the nervous system and endocrine system by secreting hormones that act on the pituitary gland
Why is the pituitary gland called the master gland?
It controls the activities of all the other endocrine glands
Explain how both the nervous and endocrine system are involved in times of stress
The endocrine system produces adrenalin and cortisol, the nervous system uses neurons, both increase heart rate, breathing rate and blood pressure
What s homeostasis?
The process of maintaining a constant internal environment
What is the feedback system?
The process in which a response is decided and carried out, according to a stimulus
Which endocrine gland is involved in maintaining a constant body temperature?
The thyroid gland
Explain the negative feedback system of a fall in body temperature
The hypothalamus detects a fall in temperature, stimulates pituitary gland to produce more thyroid stimulating hormone, thyroid produces more thyroxine, rate of metabolism increases
Explain how the nervous system controls a fall in body temperature
Nerve impulses sent to muscles, they shiver, increases activity of muscle cells which produces heat. Blood flow to skin slows by narrowing blood vessels.
Explain how the nervous system controls a rise in body temperature
Nerve messages sent to sweat glands and blood vessels. Blood vessels close to skin dilate. Sweat glands produce more sweat an the heat causes the sweat to evaporate.
