Anatomy and Physiology

Anatomy

The branch of science that deals with the structure of body parts, their forms, and organization.

Physiology

The branch of science that is concerned with the functions of body parts, what they do, and how they do it.

Levels of organization

The hierarchical organization of the body, from atoms and molecules to organ systems and the human organism.

atoms> molecule> macromolecule> organelle> cell> tissue> organ> organ system> organism

Atoms

Microscopic particles that are the building blocks of matter.

Molecules

Atoms joined together to form larger units.

Macromolecules

Molecules joined together to form even larger molecules.

Organelles

Small structures located inside a cell that are made up of macromolecules.

Cell

The basic unit of structure and function in living organisms.

Tissue

Cells that are organized into layers and perform a specific function.

Organs

A group of interacting tissues working together for a common goal.

Organ System

A group of organs that function closely together.

Organism

A group of organ systems working together to form a living being.

Movement

The self-initiated change in position or internal body parts.

Responsiveness

The ability to sense changes inside and outside of the body.

Growth

The increase in body size.

Reproduction

The process of making a new individual.

Respiration

The process of obtaining oxygen, using oxygen, and removing carbon dioxide.

Digestion

The process of breaking down food substances and using them for energy.

Absorption

The passage of digestive products into body fluids.

Circulation

The movement of substances from place to place within the body.

Assimilation

The process of chemically changing absorbed substances.

Excretion

The removal of wastes from the body.

Metabolism

The sum total of chemical reactions in the body that break down substances and build them up.

requirement of organism- Water

A requirement for metabolism, transportation of substances, and regulation of body temperature.

requirement of organism- Food

Provides the body with chemical energy and materials to build new matter.

requirement of organism- Oxygen

Used to release energy from food.

requirement of organism- Heat

The product of metabolic reactions, which affects the speed of metabolism.

requirement of organism- Pressure

Air pressure for breathing and blood pressure for circulation.

Homeostasis

The tendency to maintain a stable internal environment with narrow limits.

Shivering

Muscular contractions that produce heat in cold environments.

Sweating

The release of heat through the evaporation of sweat.

Body Cavities

Spaces where organs are found, such as the cranial, vertebral, thoracic, and abdominopelvic cavities.

cranial

brain and skull

vertebral

spinal cord

thoracic

between neck and diaphram

abdominopelvic

between diaphram and pelvis

abdominal

between diaphram and upper pelvic

pelvic

enclosed by hip bones

orbital

eyes

nasal

nose

oral

mouth

Organ Systems

Eleven different systems in the body that perform specific functions, such as body covering, support and movement, integration and coordination, transport, absorption and excretion, and reproduction.

body covering

integument (skin)

support and movement

skeletal and muscular

intergration and coordination

nervous and endocrine

transport

circulatory and lymphatic

absorption and excretion

digestion, respiratory, urinary

reproductive

reproductive

Anatomical position

The standard position of the body for anatomical reference, with the body standing erect, facing forward, and upper limbs at the sides with palms facing forward.

The difference in the cellular shape makes the functions

differ

A cell consists of three main parts

Nucleus, cytoplasm, and cell membrane

Cell Membrane

The thin, selectively permeable outer layer of a cell regulates the movement of substances in and out of the cell and helps cells adhere to other cells.

Characteristics:

1. The cell membrane is thin selectively permeable (choosy)

2. The surface is adapted to increase surface area (villi)

Structure: Consists of a double layer of phospholipids, with fatty acid tails turned inward, “sandwiched” in the middle

1. Heads are polar (like water)

2. Tails are nonpolar (dislikes water)

3. The double layer is also known as a “Fat Sandwich” or “Fluid Mosiac” model

Nucleus

The double-layered organelle in a cell that contains genetic material and controls cell activities.

Selectively permeable

Cytoplasm

The clear liquid that suspends the organelles within a cell.

Endoplasmic Reticulum (ER)

A network of thin membranes that act as a transport system inside the cell.

1. With Ribosomes, it is called Rough ER, and makes proteins

2. Without Ribosomes, it is called Smooth ER, and makes good fats

Ribosomes

Organelles are found with the ER and throughout the cytoplasm that make proteins. They contain RNA

Golgi Apparatus

Flattened sacs that package and deliver proteins within the cell.

1. Vesicles aid the Golgi by acting as a “Delivery service”, carrying chemicals throughout the cell 

Mitochondria

Organelles that are the powerhouses of the cell and produce energy.

Very active cells contain many mitochondria

Lysosomes

Organelles act as the "garbage disposals" of the cell, getting rid of waste materials.

Microfilaments and Microtubules are..

Thin structures that serve as the skeleton of the cell.

Centrosome

Made up of two hollow cylinders called centrioles, which separate chromosomes during cellular division.

Cilia and Flagella

Extensions from the cell that aid in movement

Cilia

short hair-like projections

propel substances on cell surfaces

found lining the respiratory tract

flagella

flagella is long tail-like projections

found on and provides motility to sperm

The Cell Membrane is

selectively permeable

1. Mechanisms of movement across the membrane may be:

   • Passive, requiring no energy from the cell (diffusion, facilitated diffusion, osmosis)

   • Active mechanisms, requiring cellular energy (active transport)

Nucleus

Is a double-layered organelle with pores and is also “selectively permeable”

Nucleolus

A structure within the nucleus that is composed of RNA and protein and is the site of ribosome production.

Chromatin

Loosely coiled fibers of DNA within the nucleus.

Passive mechanicisms - Diffusion

The random movement of molecules from an area of high concentration to an area of low concentration.

Passive mechanicisms - Facilitated Diffusion

The movement of large molecules across the cell membrane with the help

Mechanisms of movement across the membrane may be:

passive, active, diffusion, facilitated diffusion, osmosis

passive

 requiring no energy from the cell (diffusion, facilitated diffusion, osmosis)

Osmosis

3. – the diffusion of water 

4. Water moves from an area of greater water concentration to an area of lower water concentration

5. Water moves from a low solute area to a high solute area

hypertonic

Outside cell has higher solute concentration (water leaves the cell-osmosis and shrinks the cell)

hypotonic

• Higher solute inside the cell  (water enters the cell via osmosis and the cell expands / bursts.)

isotonic

concentrations of solute outside and inside the cell are equal

active transport

• Cell uses ATP to move molecules from areas of low concentration to areas of high concentration

  • Crossing the cell membrane

• Examples – sugars, amino acids, Na, K, Ca, and H ions as well as nutrients in the intestines

The Cell Cycle

1. The series of changes a cell undergoes from the time it is formed until it reproduces

2. The cell cycle consists of interphase, mitosis, cytokinesis, and differentiation 

3. The cell cycle is highly regulated – most cells do NOT divide continually

interphase

1. A period of growth in which the cell makes new products

2. The DNA of a cell is replicated in preparation for cell division

mitosis

1. One type of cell division, meiosis, four cells (sperm or egg) are produced, each of which contains half of the parents cell’s genetic information

2. Mitosis is a division of the nucleus that results in each daughter cell receiving and exact copy of the parent cells genetic information

prophase

3. the first stage of mitosis

   • DNA condenses into chromosomes

   • Nuclear membrane disappears 

metaphase

Chromosomes align in the middle of the cell

anaphase

Chromosomes are pulled apart to opposite sides of the cell and form halves called sister chromatids

telephase

6. the final stage of mitosis

   • Begins when chromosomes have completed their migration

   • Nuclear membrane reappears 

   • Chromosomes begin to unwind back into chromatin

cytokinesis

6. begins when the cytoplasm divides and a ring pinches the two cells apart

cell differentiation

New cells from mitosis develop into different types of cells with specialized functions

stem cell

• can divide to form two new stem cells

•  can divide to form a stem cell and a progenitor cell

•  totipotent – can give rise to any cell type

•  pluripotent – can give rise to a restricted number of cell types 

progenitor cell

• committed cell

•  can divide to become any of a restricted number of cells 

•  pluripotent