cells and body systems

cell

* cells make up organisms.
* They are the most basic and **smallest unit** of all living things.
* They are made up of **organelles**.

Organelle

* Found inside of a cell
* Each organelle has a special job.
* Animal and plant cells have some organelles that are the same and some that are different.

7 organelles found in cells

1. Cell membrane- gate
2. Nucleus- DNA
3. Mitochondria- Energy
4. Cytoplasm- jelly
5. Ribosome- protein
6. Chloroplast- only found in plants
7. Cell wall - only found in plants

***Cell membrane***

* ”Skin” of the cell, forming a barrier around the cell
* Acts like a gatekeeper, letting things in and out

***Cytoplasm***

* Jelly-like fluid that holds the organelles
* Contains nutrients and waste products

***Nucleus***

* Contains DNA (*deoxyribonucleic acid)*
* DNA contains the instructions for every job the cell needs to do
* It is passed down through generations
* Your DNA is from your parents, half from each

mitochondria

* Where energy is produced
* they release energy from food

chloroplast

* only found in plants
* the green part of plants
* plants make their own food from water and carbon dioxide using energy from the sun
* this is called photosynthesis and takes place in the chloroplast

ribosome

Microscopic factories that produce the proteins used by the body for growth and repair.

cell wall

Plants don’t have a skeleton, so they need something else to keep them upright and in shape

The cell wall is OUTSIDE the cell membrane

similarities and differences between animal and plant cells

Animal cells:

* Small vacuole
* Blob shape

Both:

* Nucleus
* Mitochondria
* Ribosome
* Cell membrane
* Cytoplasm
* Vacuole

Plant cells:

* Large vacuole
* cell wall
* Chloroplasts
* Rectangular shape

main parts of a microscope

* Ocular Lens (Eyepiece)
* Body Tube
* Arm
* Revolving

Nosepiece
* Objectives
* Stage
* Stage Clips
* Coarse

Adjustment

Knob
* Fine

Adjustment

Knob
* Diaphragm
* Light

Source
* base

setting up a microscope

1. place the slide on the stage, securing it with the stage clips
2. bring the stage as close as possible to the objective lens using the coarse focus knob
3. while looking through the ocular lens, adjust the stage, using the coarse focus knob
4. use the fine focus knob to make it clearer

Unicellular

Simple organisms made up of only one cell

Multicellular

* Made of more than one cell


* Cells work together, but do not have the same function - they are ***specialised***
* More complex organisms

Tissue

* Groups of similar cells that work together to perform a specific function.

Organ

* A group of tissues that work together to perform a particular function

Organ system

* Groups of two or more organs which work together to perform a specific function

8 Organ systems

Excretory system, Nervous system, Digestive System, Circulatory system, Reproductive System, Respiratory System, Muscle system, Skeletal system

How are cells, tissues and organs arranged to make organ systems?

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five vital organs

Brain, Heart, Lungs, Liver, Kidney

Brain

* controls all the body's functions
* Part of nervous system

Heart

* Collect blood from the lungs (high in oxygen) and pumps it out to the body
* Part of Circulatory system

Lungs

* to allow oxygen in the air to be taken into the body
* Part of Respiratory System

Liver

* cleans your blood, produces bile, stores energy in the form of a sugar called glycogen
* part of Excretory system

kidneys

* filters the blood and takes out all the waste in the blood
* sends the waste onto the bladder in the form of urine
* part of the Excretory system

Role of the organ systems that contain the 5 main organs

1. Nervous system
* Controls everything you do, including, breathing, walking, thinking and feeling
2. Circulatory system
* carries oxygen, nutrients, and hormones to cells, and removes waste products, like carbon dioxide
3. Respiratory System
* allows oxygen in the air to be taken into the body, while also letting the body get rid of carbon dioxide
4. Excretory system

* filters your blood to remove wastes that could be harmful to your body

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6 organs in the digestive system

1. oesophagus
2. stomach
3. large intestine
4. small intestine
5. rectum
6. anus

main function of the oesophagus

* transfers food from the mouth to the stomach.

main function of the stomach

* stores the food you've eaten.
* breaks down the food into a liquidy mixture.
* Slowly emptys that liquidy mixture into the small intestine.

main function of the small intestine

* absorbing almost all of the nutrients you get from foods into your bloodstream

main function of the large intestine

* to **absorb water and salts from the material that has not been digested as food**
* **get rid of any waste products left over**

main function of the rectum

* The rectum acts as a **storage facility** that stretches to hold **faeces** – the **undigested material**

main function of the anus

* When the rectum has stretched sufficiently, it moves the faeces out of the body through the **anus.**

5 organs in the excretory system

1. liver
2. lungs
3. skin
4. kidneys
5. urinary system- ureters, bladder and urethra

main function of the skin

* covers and protects everything inside your body
* The sweat glands help cool the body.
* Heat escapes through millions of pores on the skin’s surface.
* Perspiration (evaporative cooling) is 99% water, mineral salts, and urea.

main function of the Ureters

* connects the kidney to the bladder

main function of the bladder

* The ***bladder*** is a muscular sac that stores urine. It expands when it is filled.

main function of the Urethra

* a tube leading from the bladder allowing urine to be released from the body.

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