BIO 1ST QT

bio gr 12 1st qt

Homeostasis

Homeostasis

The regulation and maintenance of the internal environment of the body to keep conditions within a narrow range.

Feedback mechanism

A process that compares current conditions to set ranges and allows the body to respond and maintain homeostasis.

Negative feedback loops

Necessary for homeostasis, these loops stop or reverse a change in order to maintain stable conditions.

Positive feedback loops

These loops promote growth and stimulate cell division, leading to an increase in change.

Respiratory system

The system responsible for the exchange of gases between the body and the external environment.

Exchange of gases

The process by which oxygen is taken in and carbon dioxide is released from the body.

Parts of the respiratory system

Nose, pharynx, larynx, trachea, lungs, bronchi, bronchioles, alveoli.

Muscular system

Responsible for movement, posture, and heat production in the body.

Types of muscles

Striated voluntary or skeletal muscle, smooth involuntary or visceral muscle, striated involuntary or cardiac muscle.

Muscle fiber contraction

The process by which muscles contract and generate movement.

Bursae

Small sacs lined with synovial fluid that act as cushions between moving parts in the body.

Tissues

Cells arranged together to perform specific functions in the body.

Epithelial tissues

Tissues that cover organs and line body surfaces, with functions including protection, absorption, sensation, and reproduction.

Types of epithelial tissues

Simple squamous, simple cuboidal, simple columnar, pseudostratified columnar, stratified squamous, stratified cuboidal.

Stratified Columnar Epithelium

This tissue consists of two to three layers of cuboidal cells lining the lumen of the mammary glands, sweat glands, salivary glands, and pancreas.

Transitional Epithelium

This tissue consists of several layers of cells and is found in the vas deferens, part of the male urethra, and parts of the pharynx. It is designed to distend and return to its normal size, as it does in the lining of the urinary bladder.

Glandular Epithelium

This tissue is made up of cells designed to produce and secrete substances into ducts or into body fluids. Glands that secrete products into ducts are exocrine; those that secrete into body fluids and blood are called endocrine.

Merocrine Glands

These glands release fluid products through exocytosis and are grouped as serous which produce a watery fluid or mucus which produce a thicker, protective substance.

Apocrine Glands

These glands lose portions of their cell bodies during secretion.

Holocrine Glands

These glands release entire cells.

Connective Tissues

These tissues bind, support, protect, serve as frameworks, fill spaces, store fat, produce blood cells, protect against infection, and repair tissue damage.

Extracellular Matrix

This is the non-living material found between cells in connective tissues, consisting of fibers and ground substance.

Fibroblast

This is a fixed, star-shaped cell in connective tissue that secretes fibers and is large in size.

Macrophage

These are wandering cells in connective tissue that function as scavengers and defend against infection.

Mast Cells

These cells are located near blood vessels in connective tissue and release heparin and histamine.

Adipocytes

These cells are found in adipose tissue and are responsible for storing fat.

Collagenous Fibers

These fibers, made of collagen, add strength for holding body parts together in connective tissue.

Elastic Fibers

These fibers, made of elastin, are stretchy and add flexibility to certain types of connective tissues.

Reticular Fibers

These are thin collagenous fibers that form supportive networks in a variety of tissues.

Loose Connective (Areolar) Tissue

This type of tissue forms delicate, thin membranes throughout the body that bind body parts together.

Adipose Tissue

This tissue is loose connective tissue designed to store fat.

Dense Connective Tissue

This tissue consists of densely packed collagenous fibers and is very strong but lacks a good blood supply.

Cartilage

This is a rigid connective tissue that provides a supportive framework for various structures.

Bone

This is the most rigid connective tissue, with deposits of mineral salts and collagen within the matrix. It is the site for blood cell formation.

Skeletal Muscle Tissue

This type of tissue is attached to bone and can be controlled by conscious effort. It is long and cylindrical, striated, and has many nuclei.

Smooth Muscle Tissue

This type of tissue lacks striations, is uni-nucleate, and consists of spindle-shaped cells.

Cardiac Muscle Tissue

This type of tissue is found only in the heart and consists of branching fibers that are connected to each other with intercalated disks. It has a single nucleus in each cell but appears striated.

Nervous Tissues

These tissues are found in the brain, spinal cord, and nerves. Neurons conduct nervous impulses, while neuroglia support and nourish the neurons.

Epithelial Membranes

These are composed of a layer of epithelial tissue and a layer of connective tissue. They cover body surfaces and line body cavities.

Serous Membranes

These line body cavities that lack openings to the outside and secrete serous fluid that acts as a lubricant.

Mucous Membranes

These line the cavities and openings that lead to the outside of the body and secrete mucus.

Synovial Membranes

These line the joint cavities and secrete lubricating synovial fluid.

Cutaneous Membrane

This consists of the skin and is the largest organ of the body.

Integumentary System

This system consists of the skin and its accessory structures, including the hair, nails, sebaceous glands, and sweat glands.

Epidermis

This is the outermost layer of the skin and is composed of epithelial tissue.

Hypodermis

This layer is composed of connective tissues and lies beneath the dermis.

Dermis

This layer is composed of connective tissues and contains blood vessels, nerves, glands, and hair follicles.

Papillary Layer

This layer is located in the dermis and forms ridges, such as fingerprints.

Reticular Layer

This layer is located beneath the papillary layer and consists of white fibrous tissue that supports the blood vessels.

Fascia

This is a thin, fibrous connective tissue found after the hypodermis and before the muscle.

Hair

This is an accessory structure of the integumentary system that develops in hair follicles.

Nails

These are accessory structures of the integumentary system that grow from the nail root and protect the fingertips.

Exocrine Glands

These glands secrete their products into ducts.

Sudoriferous Glands

These are sweat glands that secrete sweat for temperature regulation and excretion.

Sebaceous Glands

These glands secrete sebum for lubrication.

Ceruminous Glands

These modified apocrine glands produce cerumen or ear wax.

Mammary Glands

These modified apocrine glands produce milk.

Acne Vulgaris

This is a disorder of the sebaceous glands that results in the formation of blackheads, whiteheads, and pimples.

Stage 1

Mild - Definition:A stage of acne characterized by minor pimples, blackheads, milia, and comedonal (whiteheads) with no inflammation.

Stage 2

Moderate - Definition:A stage of acne characterized by greater blackheads/milia, papules/pustules, slight inflammation, and the potential for acne breakout to progress to other areas of the face.

Stage 3

Severe - Definition:A stage of acne characterized by significant inflammation, severe papules/pustules, cystic nodules, and a high risk for scarring and post-inflammatory hyperpigmentation.

Skin cancer

A condition that occurs when there are changes in the growth of skin cells, often caused by exposure to ultraviolet light. Symptoms may include new bumps or patches on the skin, or changes in the size, shape, or color of existing skin growths.

Basal Cell Carcinoma

The most common type of skin cancer that typically occurs on the head, neck, and arms.

Squamous Cell Carcinoma

The second most common type of skin cancer characterized by red bumps, scaly patches, or sores that do not heal.

Melanoma

The deadliest form of skin cancer that can spread quickly if not diagnosed early.

Psoriasis

An inflammatory, immune-related skin disease that is associated with various unsightly rashes.

Plaque Psoriasis

The most common type of psoriasis characterized by redness and scaling, often impacting the nails.

Guttate Psoriasis

A type of psoriasis often found in younger people, characterized by tear-drop-shaped red spots on the torso and limbs.

Inverse Psoriasis

A type of psoriasis that develops in skin folds such as the groin and armpits, characterized by smooth and shiny red patches.

Pustular Psoriasis

A rare type of psoriasis characterized by small pustules and blotchy redness on the palms and soles.

Burns

Tissue damage caused by heat, chemicals, electricity, or radiation.

First-degree (superficial) burn

The mildest type of burn that affects only the epidermis, characterized by redness, dryness, and no blisters.

Second-degree (partial thickness) burn

A burn that affects the epidermis and part of the dermis, characterized by redness, blistering, and swelling.

Third-degree (full thickness) burns

The most severe type of burn that destroys the epidermis, dermis, and may extend to underlying tissues such as bones, muscles, and tendons. It appears white, charred, and lacks sensation.

Circulatory System

The system responsible for providing communication between widely separated body parts and contributing to metabolic functions such as oxygen perfusion, water balance, immunity, enzymatic reactions, pH, and temperature regulation.

Blood

The transporting medium in the circulatory system, composed of plasma and blood cells (red blood cells, white blood cells, and platelets).

Erythrocytes or Red Blood Cells

Biconcave disc-shaped cells that carry oxygen to the tissues and are formed in the red marrow of bones.

Leucocytes or White Blood Cells

Cells that fight infections and are classified as granulocytes or polymorphonuclear leucocytes and mononuclear leucocytes.

Thrombocytes or Blood Platelets

Anucleate cellular fragments associated with hemostasis and blood coagulation.

Axial Division

The division of the skeletal system that includes the skull, hyoid bone, vertebral column, ribs, and sternum.

Appendicular Division

The division of the skeletal system that includes the pectoral girdle, upper extremity bones, pelvic girdle, and lower extremity bones.

Fractures

A break in a bone.

Simple fracture

Also known as a closed fracture, it is a clean break of a bone that does not penetrate the skin.

Greenstick fracture

A fracture where the bone breaks incompletely, often seen in children.

Compound fracture

Also known as an open fracture, it is a complete break of a bone where the bone ends protrude through the skin.

Comminuted fracture

A fracture where the bone breaks into many fragments.

Compression fracture

A fracture where the bone is crushed, commonly seen in porous bones.

Digestive System

The system responsible for the ingestion, digestion, absorption, and elimination of food.

Gastrointestinal Tract

The part of the digestive system that starts from the mouth and ends in the anus.

Digestive Glands

Glands responsible for secreting digestive juices containing enzymes for the digestion of food.

Mouth

The anterior opening of the digestive tube for the entrance of food, surrounded by lips, tongue, teeth, tonsils, hard and soft palate.

Oral Cavity

The cavity within the mouth that contains the tongue, teeth, and tonsils, and is involved in the initial digestion of food through mastication.

Cavity

The space immediately posterior to the mouth and bounded by the cheeks.

Teeth

The set of primary or deciduous teeth (20) and permanent teeth (32) that aid in chewing and breaking down food.

Pharynx

The posterior part of the oral cavity that serves as a passage for food and air.

Esophagus

A collapsible muscular tube that extends from the pharynx through an opening in the diaphragm to the stomach, facilitating the passage of food.

Stomach

A highly muscular pouch found in the abdominal cavity, where food is partially digested and stored before passing into the duodenum.

Gastrointestinal Tract

The pathway through which food travels, including the mouth, pharynx, esophagus, stomach, small intestine, large intestine, and anus.

Digestion

The process of physically and chemically converting food into simple absorbable forms, such as monosaccharides, amino acids, fatty acids, glycerol, and nucleotides.

Jejunum

The middle portion of the small intestine, characterized by its deep red color and rapid, vigorous peristaltic movements.