ssd Flashcards
(22 cards)
What is homeostasis?
The process of maintaining a stable internal environment in the body.
Which systems are responsible for homeostasis?
Nervous system (fast, short-term) and endocrine system (slow, long-lasting).
What is a feedback loop?
A loop of events that helps maintain homeostasis.
What is a negative feedback loop?
A loop that counteracts the original stimulus (e.g., blood sugar regulation).
What is a positive feedback loop?
A loop that enhances the original stimulus (e.g., childbirth).
What is the CNS?
Central Nervous System – includes brain and spinal cord.
What is the PNS?
Peripheral Nervous System – all nerves outside the CNS.
What is a neuron?
A specialised cell that transmits nerve impulses.
Name the parts of a motor neuron.
Dendrites, cell body, nucleus, axon, myelin sheath.
What is a synapse?
A junction between neurons where neurotransmitters pass the signal.
What are the three types of neurons?
Sensory, interneurons, and motor neurons.
What is a reflex arc?
A fast, involuntary response that bypasses the brain.
What are the five senses and their receptors?
Sight (photoreceptors), hearing/touch (mechanoreceptors), taste/smell (chemoreceptors), temperature (thermoreceptors), pain (nociceptors).
Name the key structures of the eye.
Cornea, sclera, iris, pupil, lens, aqueous humour, vitreous humour, retina, optic nerve.
What do rods and cones do?
Rods detect low light/motion; cones detect colour and detail.
How does the eye process images?
Light → Cornea → Pupil → Lens → Retina → Optic nerve → Brain.
What is the endocrine system?
A system that controls body functions using hormones via the bloodstream.
How do hormones work?
They travel through blood to target cells with specific receptors.
Name three endocrine glands and their hormones.
Pineal (melatonin), pancreas (insulin/glucagon), adrenal (adrenaline/cortisol).
What is insulin’s role?
Lowers blood glucose by helping cells absorb it.
What is glucagon’s role?
Raises blood glucose by releasing stored glucose.
What is diabetes?
A condition where blood glucose cannot be properly regulated.
