Chapter 19:Coordination In Humans Nervous Control

Question 1

Flashcard 1:
Q: What is the main coordinating system of the body responsible for detecting and responding to stimuli?

Answer 1

A: The nervous control system.

Question 2

Flashcard 2:
Q: How does the nervous control system coordinate the body?

Answer 2

A: By using electrical impulses through neurons (nerves).

Question 3

Flashcard 3:
Q: What components make up the nervous control system?

Answer 3

A: Receptors, neurons (nerves), effectors (peripheral system), the spinal cord, and the brain (central nervous system).

Question 4

Flashcard 4:
Q: Name the three types of neurons.

Answer 4

A: Sensory neurons, inter (relay/connector) neurons, and motor neurons.

Question 5

Flashcard 5:
Q: What is the function of sensory neurons?

Answer 5

A: Conduct electrical impulses from the receptors (sense organs) to the CNS (brain & spinal cord).

Question 6

Flashcard 6:
Q: What is the function of inter (relay/connector) neurons?

Answer 6

A: Conduct electrical impulses inside the CNS from sensory to motor neurons.

Question 7

Flashcard 7:
Q: What is the function of motor neurons?

Answer 7

A: Conduct electrical impulses from CNS to the effector (muscles and glands).

Question 8

Flashcard 8:
Q: What are effectors?

Answer 8

A: Muscles and glands that respond to stimuli.

Question 9

Flashcard 9:
Q: How do effectors receive impulses and respond?

Answer 9

A: They receive impulses via motor neurons from the CNS, causing muscles to contract and relax or glands to secrete hormones.

Question 10

Flashcard 10:
Q: What is a synapse?

Answer 10

A: A junction between two neurons or between a neuron and an effector.

Question 11

Flashcard 11:
Q: What are the components of a synapse?

Answer 11

A: Presynaptic neuron, synaptic gap, and postsynaptic neuron.

Question 12

Flashcard 12:
Q: Describe how nerve impulses are transmitted across a synapse.

Answer 12

A: 1. A nerve impulse arrives at the end of the presynaptic neuron at the presynaptic knob.
2. Calcium channels open and calcium ions enter the presynaptic neuron knob.
3. Vesicles containing neurotransmitter move towards and fuse with the presynaptic membrane.
4. The vesicles release the neurotransmitter into the synaptic cleft.
5. The neurotransmitter diffuses across the synaptic cleft to the postsynaptic membrane.
6. The neurotransmitter attaches to the receptor site on the postsynaptic membrane.
7. Sodium channels open, and sodium ions enter the postsynaptic neuron.

Question 13

Flashcard 13:
Q: How does alcohol affect the release of neurotransmitters?

Answer 13

A: Alcohol slows down the release of neurotransmitters, resulting in fewer impulses crossing the synapse and slower reaction or response times.

Question 14

Flashcard 14:
Q: What characterizes voluntary actions?

Answer 14

A: Voluntary actions can be controlled, involve a decision or thought process, and are made deliberately and consciously (e.g., kicking a ball).

Question 15

Flashcard 15:
Q: What characterizes involuntary actions?

Answer 15

A: Involuntary actions cannot be controlled, are automatic, and occur without conscious thought (e.g., heartbeat, blinking).

Question 16

Flashcard 16:
Q: What is a reflex arc?

Answer 16

A: The pathway a nerve impulse travels along from the receptor to the effector to bring about a correct reflex action.

Question 17

Flashcard 17:
Q: Describe the sequence of a reflex arc.

Answer 17

A:
1. A stimulus is received by a receptor.
2. The stimulus is converted into a nerve impulse.
3. An impulse is conducted along a sensory neuron to the CNS.
4. The impulse is conducted from the sensory neuron along the interneuron to the motor neuron.
5. The motor neuron conducts the impulse from the spinal cord to the effector.
6. The effector makes the correct response to the original stimulus.

Question 18

Flashcard 18:
Q: What is a reflex action?

Answer 18

A: A rapid, automatic, inborn response to a stimulus.

Question 19

Flashcard 19:
Q: Define sense organs.

Answer 19

A: Groups of receptor cells responding to specific stimuli: light, sound, touch, temperature, and chemicals.

Question 20

Flashcard 20:
Q: Match the sense organs with their corresponding stimuli.

Answer 20

A:
- Skin: Touch, heat, cold, pain, pressure
- Nose: Chemicals in the air (smell)
- Tongue: Chemicals in food (taste)
- Eye: Light, colors (sight)
- Ear: Sound vibrations, motion, gravity (hearing and balance)

Question 21

Flashcard 21:
Q: What is the function of the cornea?

Answer 21

A: To allow light to enter the interior of the eyeball and help refract light rays to cause them to converge.

Question 22

Flashcard 22:
Q: What is the function of the lens?

Answer 22

A: To focus light onto the retina at the back of the eye and help the eye focus on objects at various distances by changing shape.

Question 23

Flashcard 23:
Q: What is the function of the iris?

Answer 23

A: To control the amount of light entering the eye by changing the size of the pupil through the contraction and relaxation of radial and circular muscles.

Question 24

Flashcard 24:
Q: What is the function of the pupil?

Answer 24

A: To control the amount of light entering the eye.

Question 25

**Flashcard 25:** Q: What is the function of the retina?

Answer 25

A: The light-sensitive cells that release impulses when stimulated by light. Rods are concerned with black and white vision, and cones with color vision.

Question 26

**Flashcard 26:** Q: What is the function of the optic nerve?

Answer 26

A: To transmit impulses from the retina to the visual cortex where they are interpreted.

Question 27

**Flashcard 27:** Q: What is the function of the blind spot?

Answer 27

A: It is the point where blood vessels enter and leave the eye, and no image is formed.

Question 28

### Pupil Reflex and Antagonistic Muscles **Flashcard 28:** Q: What is the pupil reflex?

Answer 28

A: The changing of the size of the pupil in response to light intensity through the antagonistic action of circular and radial muscles in the iris.

Question 29

**Flashcard 29:** Q: Describe the pupil reflex in bright light.

Answer 29

A: - Circular muscles of the iris contract. - Radial muscles of the iris relax. - Pupil constricts (becomes smaller), allowing less light to enter the eye, preventing retina damage.

Question 30

**Flashcard 30:** Q: Describe the pupil reflex in dim light.

Answer 30

A: - Circular muscles of the iris relax. - Radial muscles of the iris contract. - Pupil dilates (becomes larger), allowing more light to enter the eye for better vision in dim light.

Question 31

**Flashcard 31:** Q: What are antagonistic muscles?

Answer 31

A: Muscles that work in pairs but in opposite directions, such as the radial and circular muscles in the iris.

Question 32

### Accommodation of the Eye **Flashcard 32:** Q: What is accommodation in the eye?

Answer 32

A: The change in the shape of the lens to focus light coming from different distances.

Question 33

**Flashcard 33:** Q: How does the eye accommodate to view near objects?

Answer 33

A: - Ciliary muscles contract. - Suspensory ligaments become slackened/loose. - Lens becomes rounder/fatter/more convex to refract light rays more.

Question 34

**Flashcard 34:** Q: How does the eye accommodate to view distant objects?

Answer 34

A: - Ciliary muscles relax. - Suspensory ligaments become taut/tight. - Lens becomes less convex/flatter/less round as light rays do not need much refraction.

Question 35

### Rods and Cones **Flashcard 35:** Q: What is the function of cones in the retina?

Answer 35

A: - Cones detect color (red, green, and blue). - Each cone is linked to one neuron, providing a sharp image. - Cones work in bright light and are more sensitive to light than rods.

Question 36

**Flashcard 36:** Q: Where are cones located in the retina?

Answer 36

A: Mainly in the fovea centralis (yellow spot), with no cones in the blind spot.

Question 37

**Flashcard 37:** Q: What is the function of rods in the retina?

Answer 37

A: - Rods do not detect color. - Groups of rods are linked to one neuron, providing less sharp images. - Rods work in dim light.

Question 38

**Flashcard 38:** Q: Where are rods located in the retina?

Answer 38

A: In the peripheral areas (edges) of the retina, with no rods in the blind spot.

Question 39

### Comparison of Nervous and Hormonal Control Systems **Flashcard 39:** Q: How are messages transmitted in the hormonal control system?

Answer 39

A: By hormones through the blood.

Question 40

**Flashcard 40:** Q: How are messages transmitted in the nervous control system?

Answer 40

A: By electrical impulses through neurons/nerves.

Question 41

**Flashcard 41:** Q: Compare the speed and response of hormonal and nervous control systems.

Answer 41

A: - Hormonal control: Hormones travel slowly, and the response is slow, usually lasting longer and may be permanent. - Nervous control: Impulses travel faster, and the response is very fast, usually short-lived and temporary.

Question 42

**Flashcard 42:** Q: Where do the responses originate in hormonal and nervous control systems?

Answer 42

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