Introduction to the Human Body: From Cells to Organ Systems

The human body mainly consists of what?

Water

The study of the body’s structure

anatomy

The study of the body’s functioning

physiology

What does the body's hierarchy system start with at the top?

Atoms and molecules

What is at the bottom of the hierarchy of the human body?

Organisms

What is the order of the hierarchy of our bodies from the top to the bottom?

Atoms, water molecules, cellular level, tissue level, organ level, organ system level, and organismal level.

What is the basic unit of structure and function of all living things?

Cells

How many types of the cell does the human body contain

200

Describe the fundamental characteristics and specialized roles of human cells.

Each cell carries out basic life processes that allow the body to survive. In addition, most human cells are specialized in structure and function to carry out other specific roles.

Nerve Cells

Cells that have long projections sticking out from the body of the cell, which help carry electrical messages to other cells.

Tissue

A group of connected cells that have similar functions

What are the four basic types of human tissues?

Connective, Epithelial, Muscle, Nervous

Organ

A structure that contains two or more types of tissues that work together to do the same job. 

Examples of organs

heart, brain, lungs, skin and kidneys

What are human organs organized into?

Organ Systems

Organ Systems

A group of organs that work together to carry out complex functions overall, and each organ does part of the larger job.

What do all of the organ systems of the human body normally work like?

A well oiled machine

Integumentary System

Organ System - Consists of the hair, skin, and nails. Encloses internal body structures and is the site of many sensory receptors. 

Skeletal System

Organ System - Consists of the cartilage, bones, and joints. Supports the body and enables movement with the muscular system.

Muscular System

Organ System - Consists of the skeletal muscles and tendons. Enables movement with the skeletal system and helps maintain body temperature.

Nervous System

Organ System - Consists of the brain, spinal cord, and peripheral nerves. Detects and processes sensory information, while activating bodily responses.

Endocrine Syste,

Organ System - Consists of the pituitary gland, thyroid gland, pancreas, adrenal glands, testes, and ovaries. It secretes hormones and regulates bodily processes

Cardiovascular System

Organ Systems - Consists of the heart and blood vessels. Delivers oxygen and nutrients to tissues while equalizing the temperature in the body.

Lymphatic System

Organ System - consists of the nasal passage, trachea, and lungs. It removes carbon dioxide from the body and delivers oxygen to the blood.

Digestive System

Organ System - Consists of the stomach, liver, gall bladder, large intestines, and small intestines. Processes food for use by the body, and removes waste from undigested food.

Urinary System

Organ Systems - Consists of the kidneys and urinary bladder. Controls water balance in the body, while removing wastes from the blood and excreting them.

Male Reproductive System

Organ System - Consists of the epididymis and testes. They produce sex hormones and gametes, and delivers gametes to females.

Female Reproductive System

Organ System - Consists of mammary glands, ovaries, and uterus. Produces sex hormones and gametes while supporting the embryo and fetus until birth. Produces milk for infants.

controls virtually all body activities

Nervous System

secretes hormones that help to regulate these activities

Endocrine System

What do the organ systems do to function together?

They supply body cells with all the substances they need and eliminate their wastes. They also keep temperature, pH, and other conditions at just the right levels to support life.

How is the human body like a complex machine?

Organs and organ systems work together and are closely regulated by the nervous and endocrine systems. They carry out basic life functions together and maintain the body pH and tempreture

Describe the difference between human anatomy and human physiology.

Human anatomy is the study of the body’s structure, and human physiology is the study of the body’s function.

Relate cell structure to cell function, and give examples of specific cell types in the human body.

Different types of cells have different functions within the body. These cells have clear differences in their structures, which help them with their specific function.

Examples: Nerve Cells - they have long projections sticking out from the body of the cell, which help carry electrical messages to other cells.

Define tissue, and identify the four types of tissues that make up the human body.

A group of connected cells that have the same function. The four types are, epithelial, connective, muscle, and nervous

What is an organ? Give three examples of organs in the human body.

A structure that consists of two or more types of tissues that work together to do the same job. Examples are the brain, heart, lungs, skin, and kidneys.

Define organ systems. Name all examples in the human body.

A group of organs that work together to carry out the overall function, and each organ has a part in the overall job. Examples are the integumentary system, skeletal system, muscular system, nervous system, endocrine system, cardiovascular system, lymphatic system, respiratory system, digestive system, urinary system, and male and female reproductive systems.  

How is the human body regulated so all of its organs and organ systems work together?

The nervous and endocrine systems work together to maintain homeostasis. The nervous system coordinates organ functions, where the endocrine system is a network of glands that use chemical signals to regulate slower, long-term bodily processes like growth, metabolism, and reproduction

Are the cells in a tissue all the same?

No, all the cells in the tissue do not have to be the same; they just have to work together.

What is the Epithelial tissue made up of?

cells that line the inner and outer body surfaces, such as the skin and the inner surface of the digestive tract. 

Mucous Membrane

Epithelial tissue that lines the inner surfaces and body openings, and produces mucus

Mucus

A slimy substance that coats mucous membranes and traps pathogens, particles, and debris

What do epithelial tissues do?

Protects the body and its internal organs, secretes substances such as hormones and mucus, and absorbs substances such as nutrients.

Basement Membrane

Anchors the epithelial tissue to underlying cells

Keys features to identify epithelial tissues

it contains a free surface and a basement membrane

Free surface in the epithelial tissues

Not attached to any other cells and is either open to the outside of the body, or is open to the inside of a hollow organ or body tube

How is Epithelial tissue named and identified

by shape and layering

What are the three main shapes of epithelial tissue

squamous, cuboidal, and columnar

What are the differences between the three types of epithelial tissue?

They are specifically shaped, and depending on function can be layered in two ways: simple and stratified

Two ways that epithelial tissues can be layered depending on function

Simple and stratified

What do epithelial tissues form?

covering and linings 

What are epithelial tissues responsible for?

Range of functions such as diffusion, absorption, secretion and protection

What does the shape of an epithelial cell do?

It can maximize its ability to perform a certain function

It is easier for substances to move through it to carry out diffusion and/or absorption in this type of epithelial cell. 

Thinner epithelial cell

These epithelial cells have more room in their cytoplasm to be able to make products for secretion, and have the ability to produce more protection for underlying tissues.

Larger epithelial cells

Squamous-shaped epithelial cells 

pancaked shaped - flat and oval

Cuboidal shaped epithelial cells

cube shaped

columnar shaped epithelial cells

tall and rectangular

Would multiple layers of cells or a single layer of cells provide excellent protection, but would not be effective for diffusion? 

Multiple layers of cells

Would multiple layers of cells or a single layer of cells be effective for diffusion and not as much for protection?

single layer of cells

Location of simple squamous epithelium

The air sacs of lungs and the lining of the heart, blood vessels, and lymphatic vessels

Function of simple squamous epithelium

allows for material to pass through by diffusion and filtration, and secretes a lubricating substance. 

Location of simple cuboidal epithelium

In the ducts and secretory portions of small glands and in kidney tubules

Function of simple cuboidal epithelium

secretes and absorbs

Location of simple columnar epithelium

Ciliated tissues are in bronchi, uterine tubes, and uterus; smooth (non-ciliated tissues) are in the digestive tract, bladder

Function of simple columnar epithelium

Absorbs; it also secretes mucous and enzymes

Secrete

to form and release a substance from a cell or gland, such as hormones or sweat, or to hide or conceal something in a place out of sight

Location of Pseudo stratified columnar epithelium

ciliated tissue lines the trachea and much of the upper respiratory tract

Function  of pseudo-stratified columnar epithelium

secretes mucus; ciliated tissue moves mucus

Location of stratified squamous epithelium

lines the esophagus, mouth and vagina

Function of stratified squamous epithelium

protects against abrasion

Location of stratified cuboidal epithelium

Sweat glands, salivary galnds, and the mammary glands

Function of the stratified cuboidal epithelium

protective tissue

Location of Stratified columnar epithelium

the male urethra and the ducts of some glands

Function of stratified columnar epithelium

secretes and protects

location of transitional epithelium

lines the bladder, uretha, and the ureters

Function of transitional epithelium

allows the urinary organs to expand ands stretch

How cells communication with each other through direct contact, also known as intercellular junctions

Cell junctions

Animal cel contacts include:

tight junctions, gap junctions, and desmosomes

Tight Junctions

a water-tight seal between two adjacent animal cells, which are held tightly against each other by proteins

What creates tight junction adherence?

proteins

What does the tight adherence prevent in tight junctions?

prevents materials from leaking between the cells

Where are tight junctions typically found?

Epithelial tissues, which line internal organs and cavities, and comprise most of the skin.

What might the tight junctions of the epithelial cells lining your urinary bladder prevent?

urine from leaking into the extracellular space

Define desmosomes

act like spot welds between adjacent epithelial cells

What does a desmosome form

a strong spot weld between cells

What is a desmosome made of?

Through the linkage of cadherins and intermediate filaments

Define gap junctions

channels between adjacent cells that allow for the transport of ions, nutrients, and other substances that enable cells to communicate.

What do gap junctions allow to pass?

water and small molecules

Why are gap cells important in cardiac muscle?

the electrical signal for the muscle to contract is passed efficiently through gap junctions, allowing the heart muscles to contract in tandem.

Examples of connective tissue

bone, blood adipose tissue, cartilage

General definition for connective tissues

forms a framework and support structure for body tissue and organs

What are connective tissues made up of

extracellular matrix - solid or liquid

Extracellular matric

can be solid or liquid and are made up of living cells separated by non-living material.

What is the extracellular matrix of bone?

rigid mineral framework

What is the extracellular matrix of blood

liquid plasma

Key identifying feature of connective tissues

composed of scattering of cells in a non-cellular matrix

What are the two main categories of connective tissue based on the nature of the matrix?

fibrous and special

Location of Fibroblasts

within the fibrous connective tissue

What do fibroblasts produce?

fibers of collagen, elastin, or reticular fiber