The Major Internal Organs (Brain, Heart, and Lungs)

​The Major Internal Organs

Heart, Brain, and Lungs​

Open Ended

Why do you need to wear a helmet when doing a dangerous activity?

Each organ has an important function.

Our organs are connected to form a system.

The systems work together to make the body function properly.

There are 78 main organs in the human body.

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​Organs of the Body

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The brain is the central control system of the human body.

It is the main organ of the nervous system.

The nervous system sends signals to the different parts of the body.

The central nervous system (CNS) includes the brain and the spinal cord.​

The peripheral nervous system (PNS) includes the nerves that connect to the central nervous system.

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​The Nervous System

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Multiple Choice

What forms the PNS that connects the central nervous system to the rest of the body?

• nerves

• brain

• spinal cord

The brain controls your actions or what the body should do.

It also controls your thoughts and feelings.

It is like a computer.

The skull protects the brain.

The brain is divided into - the cerebrum, cerebellum, diencephalon, and brain stem.​

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​The Brain

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It is the largest part of the brain.

It controls the voluntary actions of the human body.

It also controls emotions, personality, hearing and vision.

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​The Cerebrum

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Multiple Choice

What is NOT a part of the brain?

• cerebrum

• cerebellum

• cochlear nerve

The brain has a fissure called the longitudinal fissure.

It divides the brain in two hemispheres -

Right hemisphere - controls the left side of the body, vision, and spatial processing.

Left hemisphere - controls the right side of the body, language and speech.

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​Cerebral Hemispheres

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Each hemisphere is divided into four lobes.

Frontal lobe - where the higher functions of the brain occurs - planning, reasoning, problem solving, emotions.

Parietal lobe - integrates sensory information (temperature, touch, pressure, and pain).

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​Cerebral Lobes

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Occipital lobe - it is the major visual processing center.

Temporal lobe - processes sensory information for hearing, language, and forming memories.​

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​Cerebral Lobes

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Multiple Choice

Which cerebral lobe is the "major visual processing center" of the brain?

• frotal lobe

• parietal lobe

• occipital lobe

• temporal lobe

It is also known as the "little brain".

It is the brain's second largest part.

It controls posture and balance, coordination of movements, motor learning, and cognitive functions.

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​The Cerebellum

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The left and right hemispheres of the cerebellum are connected by the "vermis".

Their core is white matter while their surface is grey matter.

They are divided into three (3) lobes.

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​Cerebellar Hemispheres

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Anterior - regulates subconscious movement of the skeletal muscles. The input is from the spinal cord.

Posterior - also regulates the skeletal muscles. The input is from the brainstem and cerebral cortex.

Flocculonodular - ​controls spatial orientation and balance.

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​Anatomical Lobes

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Multiple Choice

Which function is NOT controlled by the cerebellum?

• emotions

• balance

• movements

It is centrally located within the brain.

It coordinates with the endocrine system to release hormones.

It regulates the sleep cycle, body temperature, appetite, and more.​

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​Diencepalon

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Thalamus - the relay station of impulses from the sensory receptors (senses and movement).

Subthalamus - contains the groups of nerves that connect to the brain. It is the control center for the peripheral nervous system.

It connects the endocrine system with nervous and limbic system.

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​Components of the Diencepalon

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Hypothalamus - it maintains homeostasis and regulates hormones.

Epithalamus ​- it is where the pineal gland is found. It secretes melatonin. It bridges the limbic system with the other parts of the brain.

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​Components of the Diencephalon

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Multiple Choice

Which part of the brain does not belong with the components of the diencephalon?

• thalamus

• subthalamus

• epithalamus

• cortex

Connects the diencephalon and the spinal cord.

Spinal cord - where many nerves originate.

It regulates alertness, consciousness, and some involuntary body functions.​

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​Brain Stem

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Midbrain - shortest part of the brainstem. It processes visual and auditory information. The nerves control eye and face movements.

Pons - connects medulla oblongata and the cerebellum. Manages sleep, pain, and works with other parts of the brain.

Medulla Oblongata - important part in transmitting signals. It also controls heartbeat and breathing.

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​Structures of the Brain Stem

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Multiple Choice

Which component of the brainstem manages sleep and pain?

• midbrain

• pons

• medulla oblongata

Open Ended

Which organ of the body does "love" come from?

Heart - the major organ of the circulatory system (aka cardiovascular system).

It circulates essential fluids and transports oxygen and nutrients to the cells of the body.

It also helps to fight disease.​

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​The Circulatory System

Pumps blood, hormones, and other vital substances

Pumps blood into lungs for oxygenation

To carry metabolic waste products for excretion

Maintains blood pressure​

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​Functions of the Heart

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Multiple Choice

Which important substance is carried by the blood to different parts of the body?

• plasma

• oxygen

• nerve cells

Arteries - carries oxygenated blood from the heart to the other tissues.

Three layers - intima, media, adventitia

Arteries are muscular and elastic tubes.​

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​Blood Vessels

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Veins - carries blood form the organs and tissues back to the heart.

Veins have thinner walls than arteries.

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​Blood Vessels

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Capillaries - the smallest vessels which carry blood towards the heart.

They are small enough that some molecules can pass through.​

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​Blood Vessels

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Multiple Choice

Which blood vessel carries deoxygenated, low-pressure blood from the tissues and organs?

• arteries

• capillaries

• veins

Right atrium - receives blood from veins, pumps into right ventricle.

Right ventricle - receives blood, pumps into lungs.

Left atrium - receives blood from lungs, pumps into left ventricle.

Left ventricle - pumps blood to the body.​ It creates blood pressure.

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​Chambers of the Heart

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Tricuspid valve - controls blood flow from the right atrium to the right ventricle.

Pulmonary valve - controls blood flow from the right ventricle to the pulmonary arteries.

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​Other Parts of the Heart

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Mitral valve - allows blood to flow from the left atrium to the left ventricle.

Aortic valve - allows blood to flow from the left ventricle to the aorta (largest artery).

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​Other Parts of the Heart

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Multiple Choice

Blood goes into the right atrium, and then the right ventricle. After that, where does it go?

• left atrium

• lungs

• left ventricle

Lungs - the main organ of the respiratory system.

They help humans to breathe and stay alive.

Respiratory system - supplies the body with oxygen that is needed by the cells. ​

It also gets rid of carbon dioxide.​

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​The Respiratory System

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Trachea - the windpipe connects the larynx to the bronchi of the lungs.

Bronchus - a tube that looks like an upside-down "Y"​. They branch out into smaller bronchioles.

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​Parts of the Lungs

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Alveoli - around 300 - 700 million tiny balloon-like structures inside the lungs.

Oxygen and carbon dioxide are exchanged within the alveoli.​

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​Parts of the Lungs

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Multiple Choice

What is the process of exchanging gases in the lungs?

• respiration

• digestion

• circulation