Body Systems and Functions

Body Systems

• The body is made up of many different systems that work together to keep it functioning.
• The skeletal system provides support and structure to the body, and is made up of bones.
• Calcium is important for building and maintaining strong bones.
• The brain is the control center of the body and is part of the nervous system.
• The nervous system includes the brain, nerves, and spinal cord.

Nervous System

• The nervous system allows the body to respond to stimuli and control its functions.
• Neurons are thin threads of nerve cells that run throughout the body.
• Sensory nerves send messages to the brain from the body, while motor nerves carry messages from the brain to the muscles and glands.
• The spinal cord is a part of the nervous system that connects the brain to the rest of the body.

Muscular System

• The muscular system allows the body to move and is made up of muscles that are attached to bones.
• There are different types of muscles, including skeletal muscles, smooth muscles, and cardiac muscles.
• Tendons connect muscles to bones.

Circulatory System

• The circulatory system, also known as the cardiovascular system, moves nutrients, gases, and waste to and from cells.
• The heart is the main organ of the circulatory system and pumps blood throughout the body.
• The heart has four chambers: the right atrium, right ventricle, left atrium, and left ventricle.
• Blood vessels, including arteries, veins, and capillaries, transport blood throughout the body.
• The kidneys filter waste from the blood and regulate blood pressure.

Urinary System

• The urinary system removes waste from the blood and converts it to urine.
• The kidneys filter waste from the blood and combine it with water to produce urine.
• The urine then passes through the ureters to the bladder, where it is stored until it is eliminated from the body.
• The urethra is the tube that carries urine out of the body.

Respiratory System

• The respiratory system brings oxygen into the body and removes carbon dioxide.
• The diaphragm is a muscle that contracts to pull air into the lungs.
• The trachea, or windpipe, is a tube that connects the throat to the lungs.
• The bronchi are tubes that branch off from the trachea and lead to the lungs.
• The alveoli are tiny air sacs where oxygen is absorbed into the blood and carbon dioxide is removed.

Digestive System

• The digestive system breaks down food into nutrients that can be absorbed by the body.
• The mouth, esophagus, stomach, small intestine, and large intestine are the main parts of the digestive system.
• The stomach mixes food with gastric juices to break it down.
• The small intestine is where most nutrient absorption takes place.
• The large intestine absorbs water and electrolytes, and stores waste until it is eliminated.

Senses

• The five senses are sight, taste, smell, hearing, and touch.
• The eyes detect light and transmit it to the brain, where it is interpreted as vision.
• The tongue detects taste and smell, and sends messages to the brain.
• The ears detect sound waves and transmit them to the brain, where they are interpreted as sound.
• The skin detects touch, pressure, temperature, and pain, and sends messages to the brain.

Sense of Sight

• The eyes are the organs of sight.
• The cornea is the transparent layer on the front of the eye.
• The pupil is the opening in the center of the eye that lets in light.
• The lens changes shape to focus light on the retina.
• The retina is the layer of light-sensitive cells at the back of the eye.
• The optic nerve transmits visual information to the brain.

Sense of Taste

• The tongue detects taste.
• There are four main tastes: sweet, salty, sour, and bitter.
• Taste buds on the tongue contain receptors that detect taste molecules.

Sense of Smell

• The nose detects smell.
• Odor molecules in the air bind to receptors in the nose.
• The olfactory epithelium is the layer of cells in the nose that detects smell.
• The olfactory nerve transmits smell information to the brain.

Sense of Hearing

• The ears detect sound.
• Sound waves are transmitted through the air to the eardrum.
• The eardrum vibrates, and the vibrations are transmitted to the cochlea.
• The cochlea is a coiled tube that converts vibrations into sound signals.
• The auditory nerve transmits sound information to the brain.

Sense of Touch

• The skin detects touch, pressure, temperature, and pain.
• Receptors in the skin respond to different types of stimuli.
• The brain interprets touch information from the skin.### Nervous System
• Sensory nerves send messages to the brain
• There are two kinds of nerves: sensory and motor nerves

Muscular System

• Skeletal muscles help move the body and can be voluntary or involuntary
• Voluntary muscles are controlled by thinking
• Examples of involuntary muscles include:
  • Smooth muscles that move food in the stomach and intestines
  • Muscles that make blood vessels larger or smaller
  • Muscles in the iris of the eye
• Cardiac muscle is a type of involuntary muscle found only in the heart

Respiratory System

• The alveoli are the structures in the lungs where oxygen is exchanged for carbon dioxide
• The lungs take oxygen into the capillaries

Digestive System

• The order of food travel through the digestive system is: esophagus, stomach, small intestine, large intestine

Circulatory System

• The circulatory system transports nutrients, gases, and wastes to and from the cells in the body
• It includes the heart, blood, and blood vessels

Calcification and Bone Health

• Calcium is important for building and maintaining strong bones
• Foods rich in calcium, such as yogurt and Swiss cheese, can help repair broken bones

Body Systems

• The body is made up of several systems that work together to maintain its functions.

Skeletal System

• Provides support and structure to the body.
• Comprised of bones, which require calcium for strength and maintenance.

Nervous System

• Enables the body to respond to stimuli and control its functions.
• Comprised of the brain, nerves, and spinal cord.
• Neurons are thin threads of nerve cells that run throughout the body.
• Sensory nerves send messages to the brain from the body, while motor nerves carry messages from the brain to muscles and glands.

Muscular System

• Enables the body to move.
• Comprised of muscles attached to bones.
• Includes skeletal muscles, smooth muscles, and cardiac muscles.
• Tendons connect muscles to bones.

Circulatory System

• Moves nutrients, gases, and waste to and from cells.
• Comprised of the heart, which pumps blood throughout the body.
• Heart has four chambers: right atrium, right ventricle, left atrium, and left ventricle.
• Blood vessels, including arteries, veins, and capillaries, transport blood throughout the body.
• Kidneys filter waste from the blood and regulate blood pressure.

Urinary System

• Removes waste from the blood and converts it to urine.
• Kidneys filter waste from the blood and combine it with water to produce urine.
• Urine passes through ureters to the bladder, where it is stored until eliminated from the body.
• Urethra is the tube that carries urine out of the body.

Respiratory System

• Brings oxygen into the body and removes carbon dioxide.
• Diaphragm is a muscle that contracts to pull air into the lungs.
• Trachea, or windpipe, connects the throat to the lungs.
• Bronchi are tubes that branch off from the trachea and lead to the lungs.
• Alveoli are tiny air sacs where oxygen is absorbed into the blood and carbon dioxide is removed.

Digestive System

• Breaks down food into nutrients that can be absorbed by the body.
• Comprised of mouth, esophagus, stomach, small intestine, and large intestine.
• Stomach mixes food with gastric juices to break it down.
• Small intestine is where most nutrient absorption takes place.
• Large intestine absorbs water and electrolytes, and stores waste until it is eliminated.

Senses

• There are five senses: sight, taste, smell, hearing, and touch.

Sense of Sight

• Eyes are the organs of sight.
• Cornea is the transparent layer on the front of the eye.
• Pupil is the opening in the center of the eye that lets in light.
• Lens changes shape to focus light on the retina.
• Retina is the layer of light-sensitive cells at the back of the eye.
• Optic nerve transmits visual information to the brain.

Sense of Taste

• Tongue detects taste.
• There are four main tastes: sweet, salty, sour, and bitter.
• Taste buds on the tongue contain receptors that detect taste molecules.

Sense of Smell

• Nose detects smell.
• Odor molecules in the air bind to receptors in the nose.
• Olfactory epithelium is the layer of cells in the nose that detects smell.