Chapter 14+15-Nervous Co-ordination And Hormones

Question 1

What’s the difference between the exocrine system and the endocrine system?

Answer 1

-Endocrine •Produces hormones only •Secretes into blood •Ductless •Has a target organ -Exocrine •Produces a secretion •Secretes hormones into tubes •Ducts

Question 2

Name 3 places where hormones are made, the name of the hormones and what they do.

Answer 2

Any of the following.: •Thyroid, Thyroxin, Controls metabolism. •Adrenal Gland, Adrenalin, Fight-or-Flight action (sudden) •Testis, testosterone, develop and maintain secondary sexual characteristics in males. •Pituitary Gland, Various i.e. ADH/GH/, Controls water absorption in kidney/Controls growth/ •Islets of Langerhans, Insulin and Glucagon, Regulate Glucose levels. •Ovary, Various i.e. Oestrogen/Progesterone, regulate menstrual cycle and develop secondary sexual characteristics in females.

Question 3

What is the only organ that is both exocrine and endocrine?

Answer 3

Pancreas, because it had the Islets of Langerhans which make Glucagon and Insulin and the pancreas makes Pancreatic Juice.

Question 4

What is a hormone?

Answer 4

A chemical messenger produced by an endocrine gland and works in a target organ.

Question 5

Where are the Adrenal Glands, how does the hormone they produce prove beneficial for the body (5 points)?

Answer 5

•Lies above each kidney •Produces Adrenaline, a fight-or-flight hormone. •Prepares the body by: -Pupils dilate, more light enters and sharper images. -Airways dilate for increased air intake. -Liver converts more glycogen into glucose. -Faster heartbeat, increased supply of O₂ and glucose to muscle. -Rapid breathing, more O₂. -Vasodilation in brain. -Vasoconstriction in gut and other organs so blood is diverted to muscles.

Question 6

What is nervous co-ordination?

Answer 6

A process of sending stimuli, interpreting it and responding to it appropriately.

Question 7

What are the two nervous systems and what do they consist of?

Answer 7

•CNS (Central Nervous System)-Brain and Spinal Chord •PNS (Peripheral Nervous System)-All the nerves emerging from the CNS

Question 8

Name the 3 types of neurons and what do they do?

Answer 8

•Sensory Neuron: Found in sense organs and carries impulses from the sense organs (receptors) to the CNS. •Motor Neuron: Carries impulses from the CNS to the effector which maybe the muscle or the gland. •Connector Neuron: Neuron which joint the motor neuron to the sensory neuron.

Question 9

How does the nervous system work, describe the route under which it works?

Answer 9

Stimulus ▶️Receptor (Sense Organ) ▶️Sensory Neuron ▶️Interneuron ▶️CNS ▶️Motor Neuron ▶️Effector (Muscle/Gland) ▶️Response

Question 10

What’s the difference between Voluntary and Involuntary Actions?

Answer 10

Voluntary actions are controlled by persons will. Involuntary actions are automatic-there’s no control over them.

Question 11

Name the three layers of the eye and what their functions are.

Answer 11

•Sclera: Tough outer layer of eye which protects it against damage. •Choroid: Has a lot of blood vessels to supply food to retina and pigmented so as to destroy any excess light. •Retina: Contains light-sensitive cells, rods and cones.

Question 12

Name the parts of the eye (aside from the layers) and their functions.

Answer 12

1. Conjunctiva: Protects cornea.
2. Cornea: A transparent layer responsible for most of the refraction of light rays that enter the eye.
3. Aqueous Humor: Watery fluid which supports the cornea keeping it convex.
4. Iris: Coloured part of the eye, can expand and contract to control the amount og light that enters the eye.
5. Pupil: The opening which allows light rays to enter-appears black because choroid is visible.
6. Lens: Change the focal distance of the eye so it can focus on objects of different distances.
7. Suspnsory Ligaments: Suspend lens.
8. Cilliary Ligaments: Hold suspensory ligaments.
9. Yello Spot (Fovea/Macula): Highest density of cones and offers maximum sharpness, full efficiency in bright light.
10. Bind Spot: No light sensitive neurons, any light that falls here cannot be detected.
11. Vitreous Humor: Jelly-like substance which helps keep the shape of the eyeball, support lens and keeps retina in place, nourish inside of eye.
12. Orbital Muscle: Connects eyeball to scokets from sclera.

Question 13

How do we see? Describe the pathway.

Answer 13

Light travels towards eye ▶️Conjunctiva refracts it ▶️Cornea refracts ▶️Aqueous Humor ▶️Pupil ▶️Lens ▶️Vitreous Humor ▶️Retina (light receptor, fovea) ▶️Optic Nerve ▶️Visual Center in a Brain

Question 14

What is accommodation?

Answer 14

Is the adjustment of the lens for near and far vision.

Question 15

How does the eye accommodate for near vision?

Answer 15

1. Ciliary Muscle contracts 2. Loosens hold on suspension ligaments 3. Lens becomes rounder, bulges out.

Question 16

How does the eye accommodate for far vision?

Answer 16

1. Ciliary Muscle relaxes 2. Suspending Ligaments are taught 3. Lens becomes flattened

Question 17

How does the eye accomodate for bright light?

Answer 17

Question 18

What’s the difference between rods and cones?

Answer 18

1. Rods: Light sensitive, 120 million in the periphery of retina, only sense brightness of light.
2. Cones: Sensitive to one of three wavelength (red, blue, green or yell/orange), 6 million concentrated around fovea, focus on * *objects of interest.

Question 19

Name the hormone responsible for growth in plants.

Answer 19

Auxins.

Question 20

Define:

tropism.

Answer 20

A growth response carried out by a plant in response to the direction of a stimulus.

Question 21

Where are auxins produced?

Answer 21

The are produced on tips of shoots and tips of roots.

Question 22

State the 2 different tropisms and what they mean.

Answer 22

1. Phototropism: The bending growth movement of a plant away from the dark side and towards the light.
2. Geotropism: The bending growth of a plant towards gravity.