ANATOMY AND PHYSIOLOGY

Anatomy: studies the structure of the body parts and their relationships to one another.

Physiology: studies the function of the body parts.

Histology: studies the tissues.

Homeostasis: is a state of body equilibrium or stable internal environment of the body.

Negative Feedback: is a mechanism to maintain the homeostasis. Body systems respond in opposite direction to the perturbation.

Levels of Structural Organization

Chemical level: atoms (building blocks of matter) and molecules (form organelles)

Cellular level: cells (the smallest units of living things)

Tissue level: group of similar cells that have a common function. Bone cells, nerve cells, etc.

Organ level: complex functions. Heart, stomach, liver, etc.

Organ system level: Organs that work together to accomplish a common purpose.

Organismal Level: the sum total of all structural levels working together to keep us alive.

Organic Compounds: Macromolecules

Carbohydrates: Made of C, H, and O.

Glucose is source of energy. It can be broken down to release energy in animal cells. The most important cellular fuel but is not used directly to power cellular work.

ATP (adenosine triphosphate) is the primary energy-transferring molecule in cells that is immediately usable by all body cells.

Starch produce by plants. Large number of glucose units joined together.

Glycogen: is a multibranched polysaccharide of glucose stored in liver and skeletal muscle cells.

Lipids: Compose of C, H, O. Lipids are soluble in oil but not in water. Its primary function is nutrient storage

Triglycerides: are the main constituents of natural facts and oils, and high concentrations in the blood indicate an elevated risk of stroke.

Phospholipids are lipids containing a phosphate group in its molecule (cell membrane)

Steroids: Cholesterol. In high concentrations in the blood (mainly derived from animal fats in the diet) promote atherosclerosis.

Proteins or Polypeptide: Basic structural material of the body. Made of C, H, O, and N)

The building blocks of proteins are amino acids joined by peptide bonds.

They are essential to the structure of the red cells, enzyme and hormone regulation for growth and repair the body cells.

Enzymes: are proteins that act as biological catalysts speeding up the rate of biochemistry reactions by lowering the activation energy required for the reaction.

Nucleic Acids: Made of nucleotide units. C, H, O, N

DNA (deoxyribonucleic acid)

RNA (ribonucleic acid)

Nitrogenous Bases: Adenine, thymine, cytosine, guanine

CELLSCells are building block of living things. They are made of organelles with specialized functions.

Cell Theory:

A cell is a basic structural unit of living organisms

All living organisms are made up of one or more cells.

Cells are basic unit of reproduction.

DNA (in the nucleus) is the molecule that carries most of the genetic instructions used in the development, functioning and reproduction of all living organisms.

CELL Membranes

• Is a phospholipid bilayer• Mostly composed

of phospholipids • Also contains

Cholesterol , proteins, and carbohydrates

• Acts as a barrier• Regulates the

movement of substances across

Mutation: is a natural process that changes a DNA sequence and it is essential to evolution; they are the raw material of genetic variation.

Cancer: is the disease caused by an uncontrolled division of abnormal cells.

Anticancer Drugs: prevent the cell division of the cancer cells.

Cancer risk factor facts:

Tobacco smoke Pesticides UV radiation Chemicals Viruses Bacteria Family history cancer Alcohol Poor diet

CELL DIVISION. THE CELL CYCLE

Mitosis: a type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus, typical of ordinary tissue growth.

Tissues: Group of cells that have similar structure and perform a common function. Types of Tissues: Epithelial Tissue: is a sheet of cells that covers a body surface or lines a body

cavity

Connective Tissue: is everywhere in the body, the most abundant and widely distributed. Connect body parts; bind and support, protection, insulation, and transportation of substances.

Body membranes are composed by epithelial tissue and connective tissue.

Muscle Tissues: Highly cellular, well-vascularized tissue that is responsible for most type of body movements.

1.Skeletal muscles (muscle attached to bone)

2.Cardiac muscle (the heart)

3.Smooth muscle ( the walls of hollow organs)

Nervous Tissue: is the main component of the nervous system (brain, spinal cord, and nerves)

The Integumentary SystemThe bodily system consisting of the skin and associated structures such as the glands, hair, nails, scales, etc. Its functions include protection against thermal, chemical, abrasive injuries and pathogens, sensation, secretion, vitamin synthesis, insulation,

and thermoregulation.

The Skin: the thin layer of tissue forming the natural outer covering of the body of a person or animal. It is the largest organ in surface and weight.

Skin Layers

Epidermis: is the outermost layer of skin, provides a waterproof barrier and creates our skin tone.

It is a keratinized stratified squamous epithelium made up of

different four cells types and four types of layers

Dermis: is a strong, flexible connective tissue, hair follicles, and sweat glands.

Hypodermis: is made of fat and connective tissue. It acts as a shock absorber because the major part is adipose tissue (subcutaneous fatty tissue).

Skin functions:

Protection: As the first line of defense against the external environment, the epidermis is continuously replenishing and shedding tens of thousands of dead cells every minute to protect the body from:

1. Mechanical impact: Skin acts as the first physical barrier to withstand any pressure, stress or trauma

2. Fluids: Due to the tight packing of cells in the outermost layer of the epidermis (the stratum corneum layer), our skin helps us retain necessary body fluids and moisture

3. Radiation: If it weren’t for the skin, the ultraviolet light (UV light) radiating from sun would damage the underlying tissue in our bodies.

4. Infections: The top layer of skin is covered with a thin, oily coat of moisture that prevents most foreign substances or organisms (such as bacteria, viruses and fungi) from entering the skin.

Regulation: Temperature regulation is aided by the skin through the sweat glands and blood vessels in the dermis. Increased evaporation of the secreted sweat decreases the body temperature. 

Sensation: The skin dermis function is to detect the different sensations of heat, cold, pressure, contact and pain. Sensation is detected through the nerve endings in the dermis which are easily affected by wounds. This sensation in the skin plays a role in helping to protect us from burn wounds.

APPENDAGES OF THE SKIN

Glands: are specialized group of cells, or organs that removes materials from the blood, concentrates or alters them, and secretes them for further use in the body or for elimination from the body. Glands are located throughout various parts of the human body.

Endocrine, or ductless, glands (pituitary, thyroid, adrenal) secrete substances known as hormones directly into the bloodstream rather than through ducts.

Exocrine gland: A gland that secretes a substance out through a duct (holocrine glands). The exocrine glands include (salivary glands, sweat glands, and sebaceous glands). They are the "glands of external secretion."

Hairs (Pili): are flexible strands produced by hair follicle and consist largely of dead, keratinized cell. They are characteristic of mammals.

The functions of hair include protection, regulation of body temperature, and facilitation of evaporation of respiration; hairs also act as sense organs. Hairs develop in the fetus as epidermal down growths that invade the underlying dermis.

Types: Vellus hair: is pale and fine and cover the entire body. Terminal hair: is coarse, darker, longer. It is found in the eyebrows, face,

chest, scalp, axillary, and pubic regions.

Nail: It is a scale like modification of the epidermis. They contain hard keratin

Nail Function: Protect the fingertip and the surrounding soft tissue from injuries. It also serves to enhance precise delicate movements of the distal digits through counter-pressure exerted on the pulp of the finger.

THE SKELETAL TISSUES

The Human Skeleton is composed of bones, cartilages, joints, and ligaments. The Skeleton is divided into axial and appendicular portions.

• The Axial Skeleton: is segregated into three major regions: the skull, vertebral column, and thoracic cage.

It forms (1) the longitudinal axis of the body, (2) supports the head, neck, and trunk, (3) protects the brain, spinal cord, and the organs in the thorax

• The Appendicular Skeleton: is appended to the axial skeleton. It enables us to carry out the movements typical of our freewheeling and manipulate lifestyle.

It is form by (1) upper limbs attached to the pectoral girdles and (2) lower limbs attached to the pelvic girdle.