Year 9 Science - Body Systems Flashcards (Video Notes)

A set of practice questions (Question and Answer style) drawn from the Year 9 Science notes on body systems, nervous system, brain lobes, eye anatomy, neurons, reflexes, endocrine system, and homeostasis.

Identify the sense associated with each organ listed in the notes.

Ear – hearing; Tongue – tasting; Nose – smelling; Eye – seeing; Skin – touch.

What is the function of the pupil in the eye?

An opening that allows light through to reach the lens.

What is the function of the lens in the eye?

Focuses light rays to form an image on the retina.

What is the function of the optic nerve?

Transmits visual information from the eye to the brain.

Identify the incorrect effect of adrenaline on the body

Expanded blood vessels allowing blood to flow smoothly.

How do sweat glands regulate body temperature?

They produce sweat which evaporates to cool the body.

How do body muscles regulate body temperature?

Muscle activity such as shivering generates heat to raise body temperature.

What is the Soma in a neuron?

The cell body of the neuron containing the nucleus.

What is the Axon in a neuron?

A long projection that transmits impulses away from the cell body.

What is the Nucleus in a neuron?

The organelle within the soma that contains the cell’s genetic material.

What is the Myelin sheath in a neuron?

A fatty layer around the axon that speeds up impulse transmission.

What is the Axon terminal (terminal buttons) in a neuron?

The endpoint of the axon where neurotransmitters are released.

Name the two main parts of the central nervous system (CNS).

Brain and spinal cord.

Which lobe is primarily responsible for vision?

Occipital lobe.

Which lobe processes touch, temperature, and spatial awareness?

Parietal lobe.

Which lobe is involved in decision making, planning, and higher thinking?

Frontal lobe.

Which lobe is linked to hearing and memory?

Temporal lobe.

Compare the CNS and PNS in one concise statement.

CNS = brain and spinal cord; processes information and coordinates; PNS = nerves outside CNS; transmits messages to and from CNS and the body.

Which statement correctly describes the relationship between the pituitary gland and the hypothalamus?

The hypothalamus produces releasing hormones that act on the pituitary gland.

Which reaction among the temperature-related responses is endocrine in origin?

Increased rate of metabolism caused by thyroxine.

Endocrine glands – Pancreas.

Produces insulin and glucagon controlling blood sugar levels.

Endocrine glands – Ovaries.

Produce oestrogen and progesterone.

Endocrine glands – Thyroid.

Produces thyroxine and regulates metabolic rate.

Endocrine glands – Adrenal.

Produces adrenaline in readiness of danger.

Endocrine glands – Testes.

Produce testosterone that controls male sexual development.

Endocrine glands – Pituitary gland.

Produces human growth hormone and stimulates other glands to release hormones.

What is meant by reflex actions being involuntary?

They are automatic, not under conscious control, and are mediated by the reflex arc.

Why are reflex actions beneficial when touching a hot object?

They cause a rapid withdrawal of the hand, protecting from burns without needing to think.

Higher thought processes for learning and memory occur mostly in which brain region?

Cerebrum.

In neuron diagrams, what is the structure labelled as the knob (synaptic knob)?

Axon terminal; it releases neurotransmitters into the synapse.

Which eye receptor detects colour?

Cones.

Which eye receptor detects darkness/lightness?

Rods.

Define a synapse and describe what happens there.

A synapse is the gap between neurons where neurotransmitters cross the gap and bind to receptors on the next neuron, converting electrical signals to chemical signals.

What is homeostasis in the context of blood glucose levels (BGL)?

Maintenance of stable BGL; glucose is regulated to stay within a narrow range.

What trend in BGL is described during vigorous exercise in the notes?

BGL can fall during exercise as muscles use glucose, then often recover with time.

Which statement about diabetes and glucose graphs is least likely to be true?

Chris is more likely to be a diabetic than Kelly.

Why could Yanni walk again after lower lumbar spinal injury?

The last thoracic nerves and the lumbar nerves above the damaged area could be used to move the muscles needed for walking.