Unit 8: Human BodyLevels of Organization

8.0 The cell is the smallest level of organization.

8.1 Tissue: is a group of similar cells that work together. Example: Muscle Tissue

8.2 Organ: is a group of two or more types of tissue that work together.

Examples: Brain, Lung, Heart

8.3 Organ System: is a group of organs that work together. Example: Digestive system includes mouth, stomach, and intestines to break down food.

8.4 The Body Systems: Skin, Skeletal, Muscular, Digestive, Respiratory, Circulatory, Excretory, Nervous, and Reproductive

8.5 Types of Animal Tissue

1. Epithelial Tissue: the skin that covers the outside of most animals.

2. Nerve Tissue: this tissue sends electrical signals through the body.

3. Muscle Tissue: this tissue lets animals move, run, jump, swim, and wiggle.

4. Connective Tissue: this tissue joins body parts together.

Examples: Tendons, Fat, Blood

The Skin System8.6 The Functions of the Skin System:

1. Protection from germs, water loss, bumps, U.V. rays

2. Cooling by evaporation3. Fat…food storage, insulation from cold.

8.7 Epidermis: New growth moves to the surface in 3 weeks. Old growth dies and sheds.

8.8 Sebaceous Glands: Secretes oil to waterproof skin and soften hair. Acne infections occur when too much oil is produced.

8.9 Melanin (Skin pigmentation): The more melanin..the darker your skin will become. Melanin protects your skin from the harmful effects of U.V. Rays which cause sunburn and skin cancer.

Label Skin Diagram

The Skeletal System

8.10 Skeletal System: is the framework of bones that supports the body, protects internal organs, and anchors all the body’s movement.

8.11 Functions of the Skeletal System:

1. Framework for support and muscle attachments.

2. Produces White Blood Cells (WBC) and Red Blood Cells (RBC)

3. Protection of the internal organs

8.12 Axial Skeleton: is the center part of the skeleton that includes the skull, spinal column, and the ribs. This part of the skeleton provides support and protection.

8.13 Appendicular Skeleton: includes the arms, legs, and other bones that work to let the body move.

8.14 Bones are made of living tissue made up of cells and minerals such as calcium.

8.15 Bones are not completely solid. They have spaces and have blood vessels inside of them.

8.16 Joints: is a place where 2 bones in the skeletal system meet. Joints let the body move.

8.17 Cartilage: is a tough but flexible connective tissue that connects bones together.

8.18 Most of the joints in your body move freely. The bones of movable joints are separated by a space that contains fluid. (Think: Cracking your fingers.)

8.19 Moveable joints move in different ways. Some examples are:

1. Hinge Joint - elbows and knees

2. Pivot Joint - neck and elbow

3. Ball-and-Socket Joint - shoulder / hip

8.20 Immovable Joints: lock bones together with no space and the bones do not move. Example: Cranium

Muscular System

8.21 Muscular System: is the system of all the muscles in your body. There are about 656 muscles in your body.

8.22 The Functions of the Muscular System:1. Movement2. Maintaining Body Temperature3. Maintaining Posture

Different Types of Muscles8.23 Skeletal Muscle: the muscle tissue that

is attached to bones in the body that controls movement.

8.24 Smooth Muscle: is a type of muscle that attaches to organs in your body and it works without your control.

Example: Stomach / Intestines - Smooth muscle pushes food.

8.25 Cardiac Muscle: is the muscle cells that contract together to make your heart beat and move without your control.

8.26 Ligaments: is a tissue that connects bones to bones.

8.27 Tendon: is a tissue that connects skeletal muscle to bone.

8.28 When a muscle contracts, it pulls on a tendon. The tendon then pulls on a bone and makes it move.

8.29 Muscles can only pull.

8.30 Exercise causes muscles to get bigger and stronger.

8.31 Muscle can become damaged. A muscle can be stretched too much or even torn. Over time the body will heal the damaged muscle.

Example: Pulled muscles can occur when a person doesn‘t stretch before sports.

8.32 Muscles normally occur in pairs.1. Flexor: Bends joints2. Extensors: Straightens Joints

Example: Biceps are a flexor and triceps are an extensor.

The Nervous System8.33 Neurons: nerve cells that send signals.8.34 Central Nervous System: Brain and

Spinal Cord8.35 Peripheral Nervous System: The rest

of the body’s nerves

The Brain8.36 Cerebrum: The thinking center of

the brain. (memory, planning, calculating, consciousness)

8.37 Cerebellum: The coordination center for muscles. (Balance, Sports)

8.38 Medulla: The autonomic (automatic) control center. (Breathing, heart beat, digestion)

Draw and Label the Brain.

How to have a Better Brain1. Have a daily sleep schedule (8 hours)2. Daily Exercise (jogging, walking, sports)3. Brain needs exercise. (puzzles, reading)4. Foods high in carbohydrates (rice, bread,

potatoes). These foods provide glucose, energy for the brain.

5. Eat Breakfast

6. Be careful of your caffeine intake. Caffeine causes your brain and body to fight with one another.

7. No Drugs and Alcohol. They kill brain cells and destroy memory.

8. Protect your brain when playing dangerous sports by wearing a helmet.

Circulatory System8.39 Circulatory System: a collection of organs

that transport blood throughout the body.

8.40 Heart: a muscular organ the size of your fist that pumps blood through blood vessels. (2,500 gallons each day)

Circulatory System8.41 Atrium: upper chamber of the heart

8.42 Ventricle: lower chamber of the heart

Circulatory System8.43 Valves: flaplike structures found between

the atria and ventricles; prevent blood from going backwards

Circulatory System

8.44 Artery: a blood vessel that carries blood away from the heart.

8.45 Vein: blood vessels that carries blood back to the heart with 1-way valves.

Circulatory System8.46 Capillary: tiny blood vessels that allows

exchanges between body cells and blood (Food, oxygen, CO2, Waste)

Circulatory System8.47 Blood: the fluid that carries gases,

nutrients, and wastes through the body and that is made of platelets, white blood cells, red blood cells, and plasma.

Circulatory System8.48 Blood Pressure: the force that blood exerts

on the walls of the arteries

Circulatory System8.49 Blood Plasma: the liquid part of the blood

(mostly water) that wastes and digested food.

Circulatory System8.50 Red Blood Cells (RBC): carries oxygen to all

cells

8.51 White Blood Cells (WBC): fights bacteria and viruses

Respiratory System8.52 Respiratory System: the

group of organs that take in oxygen and get rid of carbon dioxide

8.53 Respiration: process by which a body gains and uses oxygen and gets rid of carbon dioxide and water

Respiratory System8.54 Pharynx: the passage from

the mouth to the larynx and esophagus

8.55 Larynx: the area of the throat that contains the vocal cords and produces sound

8.56 Trachea: the tube that connects the larynx to the lungs

Respiratory System8.57 Bronchi: one of the tubes

that connect the lungs with the trachea

8.58 Alveoli: any of the tiny air sacs of the lungs where oxygen and carbon dioxide are exchanged

Human Digestive System

8.59 Mouth: digestion begins with chewing and saliva breaking down starches.

8.60 Stomach: muscular contractions with release of digestive juices and hydrochloric acid digest food.

8.61 Small Intestine: absorbs digested food through villi.

8.62 Large Intestine (Colon): absorbs water from wastes forming feces. Bacteria live off some of wastes.

8.63 Rectum: stores the fecal material before it leaves through the anus.

8.64 Liver: produces bile that is used to break down fats and filters body poisons (like alcohol).

8.65 Pancreas: produces digestive juices and insulin (controls blood sugar)

8.66 A meal takes about 15 hours to travel from the mouth to the rectum, stopping in the stomach for 3-5 hours.

8.67 A stomach can hold as much as 3 pints of food.

The Eye / Ear System

Questions: Facts:

The Ear8.68 Outer Ear: is the part of your

ear outside your skull, the ear canal, and the eardrum.

8.69 Middle Ear: is a space filled with air. It contains 3 tiny connected bones, vibrations move the bones.

8.70 Inner Ear: Contains the semicircular canals and cochlea that sense movement and send signals to your brain.

8.71 Eardrum: thin membrane that vibrates when sound waves strike it.

8.72 Eustacian Tube: equalizes pressure between the middle ear and the outside air.

8.73 Cochlea: a tube filled with fluid and lined with tiny hairs that pick up sound vibrations and send signals on to the brain.

8.74 Semi-circular canals: maintains balance

The Eye8.75 Cornea: clear window

that protects the eye.8.76 Pupil: opening that light

travels through to the inside of the eye.

8.77 Iris: controls the pupil opening. In bright light the iris closes, in dim light the iris opens.

8.78 Lens: Focuses light rays onto the retina. Muscles change the focus for seeing objects up close or far away.

8.79 Retina: Contains the photoreceptors (rods and cones)

8.80 Rods: Black and White (night vision)8.81 Cones: Color8.82 Optic Nerve: carries signals from the eye to the brain.