Animal Responses

Question 1

What is the central nervous system (CNS)?

Answer 1

The brain and spinal cord, responsible for processing and coordinating responses.

Question 2

What is the peripheral nervous system (PNS)?

Answer 2

Nerves outside the CNS that connect the CNS to the rest of the body.

Question 3

What are the two parts of the peripheral nervous system?

Answer 3

Somatic nervous system and autonomic nervous system.

Question 4

What is the role of the somatic nervous system?

Answer 4

Controls voluntary movements by carrying impulses to skeletal muscles.

Question 5

What is the autonomic nervous system responsible for?

Answer 5

Controls involuntary actions such as heart rate and digestion.

Question 6

What are the two divisions of the autonomic nervous system?

Answer 6

Sympathetic and parasympathetic nervous systems.

Question 7

What is the function of the sympathetic nervous system?

Answer 7

Prepares the body for ‘fight or flight’ responses by increasing heart rate, dilating pupils, etc.

Question 8

What is the function of the parasympathetic nervous system?

Answer 8

Promotes ‘rest and digest’ responses by slowing heart rate and increasing digestion.

Question 9

What are reflexes?

Answer 9

Rapid, automatic responses to stimuli that protect the body from harm.

Question 10

What is the pathway of a simple reflex arc?

Answer 10

Stimulus → receptor → sensory neuron → relay neuron → motor neuron → effector → response.

Question 11

What is the role of the cerebrum?

Answer 11

Controls voluntary actions, learning, memory, personality, and conscious thought.

Question 12

What is the role of the cerebellum?

Answer 12

Coordinates muscle movements, posture, and balance.

Question 13

What is the role of the medulla oblongata?

Answer 13

Controls involuntary processes like heart rate and breathing.

Question 14

What is the role of the hypothalamus?

Answer 14

Regulates homeostatic functions like body temperature and water balance.

Question 15

What is the pituitary gland?

Answer 15

An endocrine gland that secretes hormones and controls other endocrine glands.

Question 16

What is the fight or flight response?

Answer 16

A physiological response to perceived danger, preparing the body to confront or escape.

Question 17

What are the physiological effects of the fight or flight response?

Answer 17

Increased heart rate, pupil dilation, glucose release, and ventilation rate.

Question 18

What hormones are involved in the fight or flight response?

Answer 18

Adrenaline and noradrenaline released from the adrenal medulla.

Question 19

How is heart rate controlled by the medulla oblongata?

Answer 19

Via the sympathetic and parasympathetic nervous systems acting on the SAN.

Question 20

What is the role of baroreceptors?

Answer 20

Detect changes in blood pressure and send impulses to the medulla to adjust heart rate.

Question 21

What is the role of chemoreceptors?

Answer 21

Detect changes in blood pH (e.g., CO₂ levels) and influence ventilation and heart rate.

Question 22

What is the structure of skeletal muscle?

Answer 22

Composed of muscle fibres containing myofibrils, sarcomeres, and multiple nuclei.

Question 23

What is a neuromuscular junction?

Answer 23

The synapse between a motor neuron and a muscle fibre.

Question 24

What neurotransmitter is released at the neuromuscular junction?

Answer 24

Acetylcholine, which binds to receptors on the muscle membrane causing contraction.

Question 25

What are the three types of muscle tissue?

Answer 25

Skeletal, cardiac, and smooth muscle.

Question 26

What are antagonistic muscle pairs?

Answer 26

Muscles that work in opposition (e.g., biceps and triceps). One contracts while the other relaxes.

Question 27

How does skeletal muscle contract?

Answer 27

Via the sliding filament theory involving actin and myosin filaments.

Question 28

What is the sliding filament theory?

Answer 28

Myosin heads bind to actin, pull filaments, detach, and reattach using ATP, shortening the sarcomere.

Question 29

What role does calcium play in muscle contraction?

Answer 29

Calcium binds to troponin, causing tropomyosin to move and expose binding sites on actin.

Question 30

What is the role of ATP in muscle contraction?

Answer 30

Provides energy for myosin head movement and detachment from actin.

Question 31

What happens during muscle relaxation?

Answer 31

Calcium ions are pumped back into the sarcoplasmic reticulum, tropomyosin blocks actin sites.

Question 32

What is a sarcomere?

Answer 32

The contractile unit of a myofibril, bordered by Z lines.

Question 33

What are the key zones in a sarcomere?

Answer 33

A band (thick myosin), I band (thin actin), H zone (only myosin), Z lines (boundaries).

Question 34

What is the role of the sarcoplasmic reticulum?

Answer 34

Stores and releases calcium ions for muscle contraction.

Question 35

How is cardiac muscle different from skeletal muscle?

Answer 35

Cardiac muscle is involuntary, striated, branched, with intercalated discs for coordinated contraction.

Question 36

What is smooth muscle?

Answer 36

Involuntary, non-striated muscle found in organs like the gut and blood vessels.

Question 37

What are the main regions of the brain and their functions?

Answer 37

Cerebrum (conscious activity), cerebellum (coordination), medulla oblongata (autonomic control), hypothalamus (homeostasis), pituitary gland (hormones).

Question 38

What is the SAN and its function?

Answer 38

Sinoatrial node, the heart's natural pacemaker, initiates electrical impulses.

Question 39

What is the AVN and its function?

Answer 39

Atrioventricular node, delays impulse to allow atria to contract before ventricles.

Question 40

What is the Bundle of His and Purkyne fibres?

Answer 40

Conduct impulses from the AVN down the septum to the ventricles for coordinated contraction.

Question 41

What is an ECG (electrocardiogram)?

Answer 41

A recording of the electrical activity of the heart over time.

Question 42

What does the P wave represent on an ECG?

Answer 42

Atrial depolarisation (atria contracting).

Question 43

What does the QRS complex represent on an ECG?

Answer 43

Ventricular depolarisation (ventricles contracting).

Question 44

What does the T wave represent on an ECG?

Answer 44

Ventricular repolarisation (ventricles relaxing).

Question 45

What can an ECG be used to diagnose?

Answer 45

Arrhythmias, heart attacks, fibrillation, bradycardia, tachycardia.

Question 46

What is tachycardia?

Answer 46

Abnormally fast heart rate (over 100 bpm).

Question 47

What is bradycardia?

Answer 47

Abnormally slow heart rate (below 60 bpm).

Question 48

What is ectopic heartbeat?

Answer 48

An extra or early heartbeat out of rhythm.

Question 49

What is atrial fibrillation?

Answer 49

Irregular, uncoordinated contraction of the atria leading to poor blood flow.