The nose, diaphragm, and lungs are part of the system
circulatory
respiratory
nervous
excretory
your system consists of bones and the tissues connecting them
respiratory
digestive
skeletal
excretory cardiac muscles are located only in the
heart
stomach
lungs
diaphragm in saliva break down food
muscles
nerves
enzymes
blood vessels the spinal cord and the are main parts of the central nervous system
heart
brain
small
intestines
lungs

Q1. The answer is respiratory.

Some parts of the respiratory system are: nose, diaphragm, and lungs. Through the nose, air enters the lungs. In the lungs, oxygen is moved to the bloodstream and carbon dioxide is removed from the bloodstream and then removed from the lungs by exhaling it through the nose. Thanks to the contractions of the diaphragm, chest changes it volume and helps in process of breathing.

Q2. The answer is Skeletal.

The skeletal system consists of bones and connective tissues such as ligaments and tendons. The human skeleton is divided into the axial skeleton (the skull, the backbone, the sternum bone, and the ribs) and the appendicular skeleton (shoulder girdles, upper limbs (arms), pelvic girdle, and lower limbs (legs)).

Q3. The answer is heart.

As their name suggests, cardiac muscles or heart muscles can be found in the heart. They are involuntary and striated muscles. They are highly specialised and provide blood pumping through the body. The heart must pump blood all the time, hence these muscles must have high contractile strength and endurance. 


Q4. The answer is enzymes.
 

Saliva is watery substance secreted into the mouth by salivatory glands. It contains some enzymes involved in the food digestions. Some of them are amylase, responsible for the breakdown of the starch, and lipase, responsible for the breakdown of triglycerides. There are no enzymes in the saliva that break down proteins.

Q5. The answer is brain

The two main parts of the central nervous system are brain and spinal cord. The spinal cord receives information from the body and relays it to the brain, and vice versa, it receives information from the brain and relays it out to the effectors.

Ithink it’s around 500 million or something. kinda scary honestly but that’s just my opinion.