Biology 2

Created by

MCK

Cards (166)

What is the primary function of the nervous system in humans?
To enable humans to react to their surroundings and coordinate behavior
How do receptors function in the nervous system?
They detect stimuli and pass information as electrical impulses to the CNS
What does CNS stand for?
Central Nervous System
What role do effectors play in the nervous system?
They carry out responses such as muscle contractions or hormone secretion
What is the sequence of events in the nervous system response to a stimulus?
Stimulus
Receptor
Coordinator (CNS)
Effector
Response
What is homeostasis?
The regulation of internal conditions to maintain optimum function
Why is homeostasis important for enzyme action?
It maintains optimal conditions for enzyme function
What are three key aspects controlled by homeostasis in the human body?
Blood glucose concentration
Body temperature
Water levels
What are the components of control systems in homeostasis?
Receptors that detect stimuli
Coordination centres (brain, spinal cord, pancreas)
Effectors (muscles or glands) that restore optimum levels
What are neurones?
Nerve cells that carry information as electrical signals
What are the three types of neurones?
Sensory, relay, and motor neurones
What is the function of sensory neurones?
They carry signals from receptors to the spinal cord and brain
What is the role of relay neurones?
They carry messages from one part of the CNS to another
What do motor neurones do?
They carry signals from the CNS to effectors
What is the myelin sheath?
A fatty layer that surrounds the axon of a neurone
What happens at a synapse?
Signals cross the gap using chemicals released by a neurone
What are the steps involved in signal transmission across a synapse?
Electrical impulse travels along an axon
Triggers release of neurotransmitters
Chemicals diffuse across the synapse
Bind with receptor molecules on the next neurone
What is a reflex action?
A rapid response that does not involve the brain
What are the steps in a reflex action?
Receptor detects a stimulus
Sensory neurone sends signal to relay neurone
Motor neurone sends signal to effector
Effector produces a response
What is the function of the pituitary gland?
It secretes several hormones in response to body conditions
What is the endocrine system?
A system composed of glands that secrete hormones into the bloodstream
How do hormones affect target organs?
They produce effects by binding to specific receptors in target organs
What hormone does the adrenal gland secrete?
Adrenalin
What is the effect of adrenalin on the body?
It increases heart rate and boosts oxygen and glucose delivery
What hormone is produced by the thyroid gland?
Thyroxine
What is the role of thyroxine?
It stimulates the basal metabolic rate and is important for growth
What hormone do ovaries produce?
Oestrogen
What is the function of oestrogen?
It controls puberty and the menstrual cycle in females
What hormone is responsible for maintaining the lining of the womb?
Progesterone
What is the role of insulin?
It controls blood sugar levels
What does ADH stand for?
Anti-diuretic hormone
What is the function of ADH?
It controls blood water levels by triggering water uptake in kidneys
What hormone triggers egg ripening in ovaries?
Follicle stimulating hormone (FSH)
What is the role of luteinising hormone (LH)?
It triggers egg release and progesterone production in ovaries
What hormone is produced by the testes?
Testosterone
What is the function of testosterone?
It controls puberty in males
How is blood glucose concentration controlled?
By the pancreas producing insulin and glucagon
What happens when blood glucose concentration is too high?
The pancreas produces insulin to move glucose into cells
What happens when blood glucose concentration is too low?
The pancreas produces glucagon to convert glycogen into glucose
What is Type 1 diabetes?
A disorder where the pancreas fails to produce sufficient insulin