Science Body System Overview

Question 1

How Do Body Systems Work Together?

Answer 1

Body systems work together to maintain homeostasis and support overall health.
They communicate via chemical signals (hormones) and electrical signals (nerve impulses).

Question 2

Endocrine System:

Answer 2

It uses hormones to send messages through the bloodstream.
Slower but longer-lasting effects.

Question 3

Nervous System:

Answer 3

Uses electrical impulses to send messages through neurons.
Fast but short-term effects.

Question 4

Diffusion

Answer 4

Process by which molecules move from an area of high concentration to an area of low concentration.
Important for the exchange of gases (O2 and CO2) in the lungs and tissues.

Question 5

Circulation

Answer 5

Transports nutrients, gases, and wastes.
Organs: Heart, blood vessels.

Question 6

Digestion

Answer 6

Breaks down food into nutrients.
Organs: Mouth, esophagus, stomach, intestines, liver, pancreas.

Question 7

Excretion

Answer 7

Removes waste products from the body.
Organs: Kidneys, liver, lungs, skin.

Question 8

Respiration

Answer 8

Exchanges gases (O2 and CO2) between the body and the environment.
Organs: Lungs, trachea, bronchi.

Question 9

Functions of the Liver

Answer 9

• Detoxifies chemicals and metabolizes drugs.
• Produces bile for digestion.
• Stores glucose as glycogen.
• Synthesizes blood-clotting proteins.

Question 10

Neurons: Parts and Functions

Answer 10

• Cell Body (Soma): Contains the nucleus.
• Dendrites: Receive signals.
• Axon: Sends signals away from the cell body.
• Myelin Sheath: Insulates the axon, speeds up signal transmission.
• Axon Terminals: Transmit signals to other cells

Question 11

3 Types of Neurons

Answer 11

• Sensory Neurons: Carry signals from receptors to the CNS. Located in sensory organs.
• Motor Neurons: Carry signals from the CNS to effectors (muscles, glands). Located in the CNS.
• Interneurons: Connect sensory and motor neurons. Located in the CNS.

Question 12

Receptors and Effectors

Answer 12

Receptors: Detect changes in the environment (stimuli).
Effectors: Carry out responses (muscles, glands).

Question 13

Synapse

Answer 13

• Junction between two neurons.
• Electrical signal triggers the release of neurotransmitters.
• Neurotransmitters cross the synaptic gap and bind to receptors on the next neuron.

Question 14

Brain: Parts and Functions

Answer 14

• Cerebrum: Controls voluntary activities, intelligence, memory.
• Cerebellum: Coordinates muscle movements, balance.
• Brainstem: Controls involuntary functions (breathing, heart rate).
• Hypothalamus: Regulates homeostasis, links nervous and endocrine systems.

Question 15

Endocrine System: Major Glands and Functions

Answer 15

• Hypothalamus: Regulates the pituitary gland.
• Pituitary Gland: Master gland, controls other endocrine glands.
• Thyroid: Regulates metabolism.
• Adrenals: Produce adrenaline, regulate stress response.
• Gonads (Testes and Ovaries): Produce sex hormones.
• Pancreas: Regulates blood sugar levels.

Question 16

Endocrine System: Hormones, Locations, Functions, Target Cells

Answer 16

• Hypothalamus: Produces hormones regulating the pituitary.
• Pituitary: Produces growth hormone, ADH, others.
• Thyroid: Produces thyroxine, regulates metabolism.
• Adrenals: Produce cortisol, adrenaline.
• Gonads: Produce testosterone, estrogen, progesterone.
• Pancreas: Produces insulin, glucagon.

Question 17

Enzymes: Function

Answer 17

Catalyze (speed up) chemical reactions.
Lower the activation energy required for reactions.

Question 18

Enzymes: Reactions

Answer 18

Substrate binds to the enzyme’s active site.
Enzyme-substrate complex forms.
Reaction occurs, products are released.

Question 19

Enzymes: Lock and Key Model

Answer 19

Enzyme’s active site is specific to the substrate, like a key fits a lock.

Question 20

Temperature Regulation

Answer 20

Maintained by sweating, shivering, blood flow adjustments.

Question 21

Homeostasis

Answer 21

Maintenance of a stable internal environment.

Question 22

Blood Glucose Levels

Answer 22

Insulin and glucagon regulate blood sugar levels.

Question 23

Differences to Stimulus-Response Models

Answer 23

• Reflex actions are automatic and quick.
• General stimulus-response involves conscious thought.

Question 24

Stimulus-Response Model

Answer 24

• Stimulus: External/internal change.
• Receptor: Detects stimulus.
• Sensory Neuron: Transmits signal to CNS.
  CNS: Processes information.
• Motor Neuron: Transmits response signal.
• Effector: Carries out response.