science revision

Question 1

Understand that body systems work in coordination to provide the requirements for life (e.g. oxygen, nutrients such as glucose, water and removal of waste).

Answer 1

Your circulatory system carries oxygen, water, and nutrients to cells throughout your body. Wastes from the cells are eliminated by your respiratory system, your excretory system, and your skin. Your nervous system controls all these activities with electrical impulses.

Question 2

metabolism

Answer 2

the chemical reactions in the body’s cells that change food into energy

Question 3

excretion

Answer 3

the process by which animals rid themselves of waste products and of the nitrogenous by-products of metabolism.

Question 4

homeostasis

Answer 4

A state of balance among all the body systems needed for the body to survive and function correctly.

Question 5

identify the location of sense receptors in the skin, eyes, ears, tongue and nose

Answer 5

chemoreceptors (chemical receptors) found in the mouth and nose, photoreceptors (light receptors) found in the eyes, and mechanoreceptors located in the ears.

Question 6

Consider the need for receptors inside the body as well as external sense receptors

Answer 6

to help us learn about the environment around us, or about the state of our internal environment.

Question 7

Understand the divisions of the nervous system including central nervous system and peripheral nervous system

Answer 7

The central nervous system is made up of the brain and spinal cord. The peripheral nervous system is made up of nerves that branch off from the spinal cord and extend to all parts of the body.

Question 8

Understand that the brain has different regions that carry out different functions

Answer 8

THE FRONTAL LOBE is for personality and emotions, higher thinking skills, like problem solving; and controlling movement.

Question 9

identify and recall the parts of the brain that are responsible for maintaining homeostasis

Answer 9

hypothalamus and brain stem.

Question 10

Understand the structure of a neuron and how this relates to its function

Answer 10

Their function is to send electrical impulses and chemical signals to and from the brain. Most neurons have three parts, including a cell body, which contains the nucleus and the cytoplasm, an axon, which transmits information away from the nucleus, and dendrites, which receive messages from other neurons.

Question 11

Classify neurons into three different types

Answer 11

Sensory neurons. …
Motor neurons. …
Interneurons.

Question 12

describe the differences between them in relation to structure and function

Answer 12

Structure refers to shape or arrangement whereas, function refers to the role.

Question 13

Describe the path a nervous impulse conducts from one neuron to the next

Answer 13

A neuron sending a signal (i.e., a presynaptic neuron) releases a chemical called a neurotransmitter, which binds to a receptor on the surface of the receiving (i.e., postsynaptic) neuron.

Question 14

Describe a stimulus-response model for a nerve pathway

Answer 14

usually a random, pseudo-random or natural sensory stimulus sequence presented under controlled conditions

Question 15

Describe a reflex arc pathway

Answer 15

In a reflex arc, the sensory neuron sends a signal to the interneuron and activates it. The interneuron then relays that signal to the next neuron, a motor neuron. Motor neurons connect with interneurons in the spinal cord. They send messages from the central nervous system to the body.

Question 16

Explain why reflex arcs are necessary

Answer 16

it provides a quick and automatic response to potentially harmful stimuli, allowing the body to quickly protect itself.

Question 17

Define the term hormone

Answer 17

chemical substances that act like messenger molecules in the body.

Question 18

Explain the roles of the hypothalamus and pituitary gland, outlining the coordinated response between the nervous and endocrine systems

Answer 18

The hypothalamus produces several releasing and inhibiting hormones that act on the pituitary gland, stimulating the release of pituitary hormones.

Question 19

Describe a simple model of how hormones work with respect to receptors on target tissues to affect an action inside a cell

Answer 19

The receptor will process the message by initiating other signaling events or cellular mechanisms that result in the target cell’s response.

Question 20

Contrast the endocrine and nervous systems

Answer 20

the endocrine system uses chemical signaling (hormones, produced by glands) while the nervous system uses electrical signaling (neural impulses).

Question 21

Describe the key parts of a negative feedback loop

Answer 21

stimulus, sensor, control center, and effector.

Question 22

Distinguish between a stimulus response model and a negative feedback loop

Answer 22

A stimulus response model does not have an affect on the stimulus itself.

Question 22

Apply negative feedback loops to body temperature homeostasis

Answer 22

if your body temperature is too high, a negative feedback loop will act to bring it back down towards the set point, or target value, of 98.6 ∘ F ‍ / 37.0 ∘ C ‍ .

Question 23

Explain how internal body temperature is controlled by the nervous system

Answer 23

process thermal afferent inputs from the skin and the body core to control the activity of thermoeffectors.

Question 24

Describe the link between eating and blood glucose levels

Answer 24

Carbohydrates are digested in the body to form glucose in the blood,

Question 25

Interpret negative feedback loops for controlling blood glucose concentrations

Answer 25

When blood sugar rises, receptors in the body sense a change. In turn, the control center (pancreas) secretes insulin into the blood effectively lowering blood sugar levels.

Question 26

Describe how a negative feedback loop maintains blood glucose

Answer 26

insulin sends a signal to the liver, muscles and other cells to store the excess glucose