Human Organ Systems

Question 1

know how to describe the digestive system’s main parts and each ones functions

Answer 1

1. The mouth - food is broken up by teeth mixed with saliva which contains amylase
2. Oesophagus - carries food from your mouth to your stomach
3. Stomach - produces hydrochloric acid and protease
4. Liver - to create bile (with enzymes)
5. Pancreas - to create protease, lipase and carbohydrase
6. Small Intestine (duodenum) - to absorb all digested food products
7. Large Intestine (ileum) - absorbs fluid
8. Rectum - stores the waste in our body
9. Anus - controls when waste leaves your body

Question 2

know the difference between physical and chemical digestion

Answer 2

Physical digestion - The food is physically broken down into smaller pieces
Chemical digestion - Specific enzymes ‘cut’ the large complex food molecules into new, simpler molecules

Question 3

what is an enzyme?

Answer 3

Enzymes are chemicals produced by the body to help with digestion.

Question 4

list and explain each stage of digestion

Answer 4

Ingestion - Placing food into the alimentary canal at the mouth
Digestion - The breakdown of complex food into their simple soluble absorbable subunits
Absorption - The passage of the products of digestion into the blood or lymph
Assimilation - Conversion of the absorbed nutrients into complex molecules for growth, repair and defence
Egestion - Expulsion of the undigested and unabsorbed material from the alimentary canal

Question 5

what are each of your different types of teeth and what are their functions

Answer 5

incisors - cut and gnaw pieces of food
canines - grip and position the food before you bite
premolars - tear, crush and grind food into smaller pieces
molars - grind and chew pieces of food

Question 6

know the layout of teeth

Answer 6

(only counting the left part of the top/bottom) - inside to outside

2 incisors (i)
1 canine (c)
2 premolars (p)
3 molars (m)

tooth order of one row (l->r)=
m|m|m|p|p|c|i|i|i|i|c|p|p|m|m|m

Question 7

how to care for your teeth

Answer 7

*Brush your teeth
*Floss regularly
*Eat a well balanced diet
*Don’t smoke (for a smaller chance for gum disease)

Question 8

what is peristalsis and how does fibre affect it

Answer 8

*a group of wave-like muscle contractions that move food inthe osophagus
*fibre affects it by stimulating it

Question 9

how are the villi in the small intestine adapted to their function

Answer 9

*specialised for absorption as they have walls that are only once cell thick

Question 10

what is the function of the skeletal system and structure of bones

Answer 10

*to protect our delicate organs (tough bones)
*to support our body (it has a rigid frame that allows our body to hang on)
*to aid the production of blood cells (bone marrow produced red blood cells)
*movement (muscles are attached to our bones)

Question 11

how do humans move using bones, muscles, tendons and ligaments

Answer 11

through tough bands called tendons, when a muscle contracts, it applies a force on the bone it is attached to which makes the bone move

Question 12

what are joints and how do they aid movement?

Answer 12

*where two bones meet
*strong ligaments (elastic bands of tissue) surround the joint to give support and limit its movement

Question 13

describe how an antagonistic pair of muscles cause movement. (Use the triceps and biceps as your example)

Answer 13

1. Antagonistic muscles are pairs of muscles that work against eachother
2. One muscle contracts while the other one relaxes and vice-versa.
3. They are attached to bones with tendons. This allows them to pull on the bone, which then acts like a lever.
4. One muscle pulls the bone in one direction and the other pulls it in the opposite direction - causing movement at the joint
5. The biceps and triceps are antagonistic muscles.

e.g. When you flex your hand, your biceps contract and your triceps relax

Question 14

describe the role of the veins and
arteries, and how blood circulates around the body

Answer 14

1. The heart pumps the blood into your arteries making it under high pressure and to withstand that pressure, you arteries are thick.
2. Your arteries bring your blood down and then the blood moves to the vein, which carry the blood up. At this point, the blood is under low pressure as some of it has been lost when it was transferred to your organs. Due to this, your veins are thinner and less muscular. As it is low pressure, there are one way valves so that the blood doesn’t flow back down.

The Human circulatory system is called a ‘figure of 8’ system

Question 15

know all the organs in the respiratory system and where they are located

Answer 15

1. Larynx - above the trachea
2. Trachea - the coiled-looking tube (the windpipe - leads from the mouth to the bronchi)
3. Bronchi - the smaller coiled-looking tube going from the trachea (tube leading from the trachea to a lung)
4. Lung - looks like a chicken wing (contains the gas exchange surface)

Below is inside the lung

5. Bronchioles - Pipe leading from the bronchi (smaller tubes in lungs leading from the bronchus to the alveoli
6. Alveoli - looks like coral (Tiny air sacs at the end of the bronchioles, site of gas exchange

Diaphragm - at the bottom (works with intercostal muscles to allow ventilation to happen)
Rib-cage - around the lung (provides a moveable cage to enclose and protect the lungs)
Intercostal muscles - in between the rib-cage (allow the ribcage to change in volume for ventilation to happen)

Question 16

describe the role of the lungs, diaphragm, and ribs in breathing

Answer 16

breathing in:
rib cage = up and out
diaphragm = contracts and flattens

breathing out:
rib cage = down and in
diaphragm = relaxes and becomes dome shaped

lung= inhales oxygen and exhales carbon dioxide

Question 17

how are the lungs and alveoli adapted to gaseous exchange

Answer 17

1. Moist lining of Alveoli
2. Alveoli has a large surface area
3. Alveoli are 1cm thick
4. Alveoli have a good blood supply

Question 18

what are the stages in human development from fertilised egg to death

Answer 18

1. Foetus
2. Baby
3. Childhood
4. Adolescence
5. Adulthood
6. Old age

Question 19

what are the 6 organs of the male reproductive system

Answer 19

1. Testes (produce sperm & make testosterone)
2. Scroutm (a bag of skin outside the body)
3. Epidiymis (a muscular, coiled tube where sperm are stored)
4. Sperm duct (transports sperm from testes to penis)
5. Prostate gland & Seminal Vesicle (add fluid to sperm to make semen)
6. Penis (passes semen into a woman)

Question 20

know and describe the difference between asexual and sexual reproduction

Answer 20

asexual = only one parent is required as only one parent is needed, it is a direct clone of that offspring
sexual = allows some of the genetic information from both parents to mix in, but are not direct clones of any of the parents & leads to a variety in the offspring

Question 21

define puberty

Answer 21

the time when a boy or girl experiences changes in their body as they mature

Question 22

describe changes in males in puberty

Answer 22

*Testicles produce sperm
*Penis grows longer and wider
*Testicles grow larger and fuller
*Wet dreams

Question 23

define and describe what adolescence is

Answer 23

the time between puberty and adulthood

Question 24

what are the stages of the menstrual cycle in a typical 28 day month

Answer 24

1-4 = Bleeding from the vagina begins as the lining of the uterus bleeds
5 = Blood stops and the uterus lining regrows and ovum start to mature in one of the two ovaries
13-15 = Ovulation occurs and the ovum travels through the oviduct towards the uterus
16-20 = The egg dies if unfertilised
28 = The lining of the uterus breaks down and then the cycle repeats

Question 25

know the fertilisation, implantation and development of the embryo

Answer 25

Fertilisation - the process in which the sperm’s nucleus fuses with an egg cell to produce a zygote which will grow into a human

Implantation - Once the fertilised egg reaches the uterus, the embryo attaches to the thick uterus lining to receive the placenta, umbilical cord, amnion and the amniotic fluid.

Development - An ovum divides to form a ball of cells called an embryo, which attaches to the uterus lining. After attaching, it develops into a foetus and then a baby. It takes a foetus 40 weeks to develop in the uterus (gestation)

Question 26

what is the function of the placenta and umbilical cord?

Answer 26

*The placenta lets the blood of the foetus and mother get very close to allow exchange of food, oxygen and wastes

*The umbilical cord attaches the baby to the placenta. It has an umbilical artery (carbon dioxide to mother) and an umbilical vein (oxygen and nutrients to baby)

Question 27

know all of the stages of pregnancy

Answer 27

*1 Month-embryo has brain, heart, eyes, ears, legs
*9 Weeks- body is completely formed, it is now called a foetus
*3 Months- looks much more like a baby
*5 Months- It kicks and its fingernails can be felt
*7 Months- The foetus is ‘Viable’ - it would have a decent chance of surviving if it was born then
*39 Weeks-It is fully developed and ready to be born

Question 28

know what happens at birth when a baby is coming out

Answer 28

1. The muscular uterus walls begin to contract.
2. The contractions becomes stronger and the cervix muscle starts to relax.
3. At some stage the amnion breaks and the fluid comes out of the vagina.
4. Once the cervix is 10cm dilated the strong contractions begin to push the baby out.
5. The baby comes out head first, the umbilical cord is tied and cut.
6. About half an hour after the baby is born the placenta breaks away and passes out of the vagina.

Question 29

what are the 6 organs of the female reproductive system

Answer 29

1. Fallopian Tube/Oviduct (where ovum/eggs pass through from the ovary)
2. Vulva (the outermost part of the reproductive system - where the penis enters)
3. Ovary - where unfertilised eggs are stored
4. Uterus/Womb - where the fertilised zygote develops
5. Vagina (a muscular tube that leads from the cervix to the outside of a woman’s body)
6. Cervix (a ring of muscle at the lower end of the uterus & keeps the baby in place when it develops)

Question 30

describe changes in females in puberty

Answer 30

*Ovaries start releasing eggs
*Periods start
*Breasts develop
*Hips get bigger

Question 31

describe changes in males and females in puberty

Answer 31

*Grow taller
*Spots appear on skin
*Pubic hair
*Weight gain
*Voice gets deeper
*Body and face shape changes

Question 32

what can remove the amount of oxygen in the lungs

Answer 32

asthma and emphysema

Question 33

what factors can change a babies health

Answer 33

what their mother eats/drinks/puts in her body