Overview of Human Biology

Human biology is the study of the human body, its functions, and its relationship to the environment.
It encompasses various fields including anatomy, physiology, genetics, and biochemistry.

Skeletal System
- Composed of bones, cartilage, and ligaments.
- Functions: supports the body, protects organs, enables movement, stores minerals, produces blood cells.
Muscular System
- Composed of skeletal, smooth, and cardiac muscles.
- Functions: facilitates movement, maintains posture, generates heat.
Nervous System
- Includes the brain, spinal cord, and nerves.
- Functions: controls body activities through electrical signals, processes sensory information, coordinates responses.
Circulatory System
- Composed of the heart, blood vessels, and blood.
- Functions: transports oxygen, nutrients, hormones, and waste products.
Respiratory System
- Comprises the lungs, trachea, and airway passages.
- Functions: facilitates gas exchange (oxygen and carbon dioxide).
Digestive System
- Includes mouth, esophagus, stomach, intestines, liver, and pancreas.
- Functions: breaks down food, absorbs nutrients, eliminates waste.
Endocrine System
- Composed of glands such as the thyroid, adrenal, and pancreas.
- Functions: regulates metabolism, growth, and development via hormones.
Immune System
- Network of cells and tissues including lymph nodes and spleen.
- Functions: defends against pathogens, removes foreign substances.
Reproductive System
- Involves male (testes, penis) and female (ovaries, uterus) structures.
- Functions: produces gametes, facilitates reproduction, supports fetal development.

The basic unit of life is the cell, which contains organelles such as:
- Nucleus: houses genetic material (DNA).
- Mitochondria: produces energy (ATP).
- Ribosomes: synthesizes proteins.
Cell types:
- Prokaryotic (bacteria) vs. Eukaryotic (animal, plant) cells.

Genes: units of heredity made of DNA that code for proteins.
Chromosomes: structures that organize DNA within cells.
Inheritance patterns:
- Dominant and recessive traits.
- Mendelian and non-Mendelian inheritance.

The body's ability to maintain a stable internal environment.
Involves feedback mechanisms (positive and negative) to regulate physiological processes.

Stages of human development:
1. Prenatal (fertilization to birth)
2. Infancy (birth to 2 years)
3. Childhood (2 to 12 years)
4. Adolescence (12 to 18 years)
5. Adulthood (18 years and older)
Aging: a complex process involving genetic, environmental, and lifestyle factors affecting homeostasis and body systems.

Interconnectedness of body systems: all systems work together to maintain health.
Importance of nutrition, exercise, and lifestyle choices on overall biology and health.
Ongoing research in human biology influences medical advancements and public health policies.

The study of the human body, its functions, and its interactions with the environment.
Encompasses fields such as anatomy, physiology, genetics, and biochemistry.

Skeletal System: Provides support, protects organs, enables movement, stores minerals, and produces blood cells.
Muscular System: Facilitates movement, maintains posture, and generates heat.
Nervous System: Controls body activities through electrical signals, processes sensory information, and coordinates responses, consisting of the brain, spinal cord, and nerves.
Circulatory System: Transports oxygen, nutrients, hormones, and waste products, consisting of the heart, blood vessels, and blood.
Respiratory System: Facilitates gas exchange (oxygen and carbon dioxide), consisting of the lungs, trachea, and airway passages.
Digestive System: Breaks down food, absorbs nutrients, and eliminates waste, consisting of the mouth, esophagus, stomach, intestines, liver, and pancreas.
Endocrine System: Regulates metabolism, growth, and development via hormones, consisting of glands such as the thyroid, adrenal, and pancreas.
Immune System: Defends against pathogens and removes foreign substances, consisting of cells and tissues like lymph nodes and the spleen.
Reproductive System: Produces gametes, facilitates reproduction, and supports fetal development, consisting of male (testes, penis) and female (ovaries, uterus) structures.

The basic unit of life is the cell, containing organelles such as:
- Nucleus: Houses genetic material (DNA).
- Mitochondria: Produces energy (ATP).
- Ribosomes: Synthesizes proteins.
Cell Types:
- **Prokaryotic cells **(bacteria) are simple cells without a nucleus or other membrane-bound organelles.
- Eukaryotic cells (animal, plant) are more complex cells with a nucleus and other membrane-bound organelles.

Genes: Units of heredity made of DNA that code for proteins.
Chromosomes: Structures that organize DNA within cells.
Inheritance Patterns:
- Dominant and recessive traits: Determine how traits are passed from parents to offspring.
- Mendelian and non-Mendelian inheritance: Describe the different ways traits are inherited.

The body's ability to maintain a stable internal environment despite external changes.
Involves feedback mechanisms (positive and negative) to regulate physiological processes.

Stages of Human Development:
- Prenatal (fertilization to birth)
- Infancy (birth to 2 years)
- Childhood (2 to 12 years)
- Adolescence (12 to 18 years)
- Adulthood (18 years and older)
Aging: A complex process influenced by genetic, environmental, and lifestyle factors impacting homeostasis and body systems.

Interconnectedness of body systems: All body systems work together to maintain health.
Importance of nutrition, exercise, and lifestyle choices: Directly impact overall biology and health.
Ongoing research in human biology: Influences medical advancements and public health policies.