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meriva
3 years ago
9

The human cardiovascular system is considered closed because __________.A.blood is continuously circulated in the body.B.blood p

rovides nutrients to organs.C.blood collects oxygen from the lungsD.there are no holes for blood to enter or leave the system
Biology
1 answer:
givi [52]3 years ago
5 0

Answer: Option D) there are no holes for blood to enter or leave the system

The human cardiovascular system is considered closed because there are no holes for blood to enter or leave the system

Explanation:

The closed circulatory system are made up of blood vessels called arteries from the heart that branch into small units called capillaries but eventually join up with other blood vessels called veins that are connected to the heart. So, blood is always confined to circulate within the blood vessels and the heart as there are no holes for blood to enter or leave the system

Thus, the human cardiovascular system is considered closed

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Describe 3 ways in which the organs of the circulatory system and respiratory system are protected
34kurt

Answer:

Explanation:

Three ways that the circulatory system and respiratory system are protected: The cutaneous system, the thoracic cage, and the immune system.

The cutaneous system:

The skin is the largest organ of the body and is the external interface with the external environment.

==> In its role of barrier, the skin ensures:

* physical and immune protection against external aggressions (microorganisms, foreign substances, traumas),

* protection against U.V. radiations,

* protection against liquid losses of organisms living in an open-air environment,

* protection against the cold (hypodermic fat layer and organized hairs in fur).

==> It participates in the thermoregulation of the body by:

evaporation mechanisms provided by eccrine sweat glands,

radiation mechanisms ensured by an organized vascular system in anastomotic plexuses supplemented with arteriovenous shunts.

Ribcage :

The rib cage has a protective role for internal organs: Due to its shape and constitution, the rib cage protects vital organs such as the heart and lungs, as well as certain abdominal organs.

It also has other roles:

Role of mobility. Its constitution, partly cartilaginous, gives it a flexible structure to follow the movements of the spine.

Role in breathing. The flexible structure of the cage, as well as the various articulations,  gives him large amplitudes of movements, participating in respiratory mechanics. Various breathing muscles also sit on the rib cage.

Immune system:

Set of cells whose role is to defend the body (including the circulatory and respiratory system) against infections.

The immune system's role is to defend the body against infections. When it is invaded by a foreign organism (virus, bacteria) or by foreign molecules (pollen, for example), the immune system reacts very quickly to get rid of it. Unlike other systems, the immune system consists of isolated cells that are not tissue.

The lungs represent the largest epithelial surface of the organism exposed to the external environment. During respiration, the airways and pulmonary alveoli are constantly in contact with a multitude of particles and microorganisms conveyed by the air flow and sometimes deposited on the surface of the tracheobronchial tree.

Unlike other epithelial surfaces such as the skin or the digestive tract, the cells are sterile.

This phenomenon results from a complex system of, particularly effective defenses. These are anatomical features of the respiratory tract and the defense system.

The blood in the circulatory system ensures the defense of the body (thanks to the cells of immunity) including the blood itself.

7 0
4 years ago
How does removing the "overburden" during coal extraction affect the environment?
Romashka [77]

Answer: Strip mining eliminates existing vegetation and alters the soil profile, or the natural soil layers.

Explanation:

Mining disturbs and may even destroy the beneficial micro-organisms in the topsoil. Soil also may be damaged if reclamation operations mix the topsoil with subsoils, diluting matter in the surface soil.

3 0
3 years ago
Damage to the enteric nervous system that innervates the digestive organs could affect:
Fudgin [204]
I think the damage to the enteric nervous system that innervates the digestive organs may affect the motility. The digestive motility or the gastro intestinal motility is defined by the movements of the digestive system, and the transits that contents within it. If the nerves or muscles in any position of the GI tract do not function with their normal strength and coordination, an individual develops symptoms related to motility problems.
7 0
3 years ago
What letter represents tRna
AleksAgata [21]

Answer:

F

Explanation:

tRNA are the RNA molecules that help decode the mRNA strand. On one end, They contain an anticodon which helps recognize the correct pairs in mRNA and on other end they contain amino acid. In this picture, letter F has both of these therefore it is tRNA.

7 0
3 years ago
Why are gymnosperms "naked seed" plants? they do not have ovaries. their seeds develop on the surface of sporophytes. their seed
Liula [17]
They don't have ovaries !!

so they don't turn into fruits and thus seeds are naked !!
3 0
3 years ago
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