BIO 223 Exam 1

TMCC, Dr. C

Anatomy

Describes the structures of the body, what they are made of, where they are located, what other structures are associated with them

Physiology

Is the study of functions of anatomical structures, individuals and cooperative functions

True/False: Form and function are integrally linked

True

Levels of organization from smallest to largest

Atoms → Molecules → Cells → Tissue → Organs → Organ system → Organism

Chemical level: Atoms

Smallest stable units of matter

Chemical level: Molecules

Consist of groups of atoms

Cellular level: Cells

The smallest living units in the body composed of organized assemblages of molecules

Tissue level: Tissue

A group of cells working together

Organ level: Organ

Made of two or more tissues working together

Organ System level: Organ system

A group of interacting organs. Humans have 11 organ systems

Organism level: Organism

An individual life form

Main function of most organ system is to maintain

Homeostasis

Homeostasis

Stable internal environment. System responds to external and internal changes to keep variables within normal ranges (body temp, fluid balance)

Homeostatic Regulation

Adjustment of physiological systems to preserve homeostasis

Autoregulation

Automatic response in a cell, tissue, or organ to an environmental change

Example of autoregulation

Tissue releases vasodilators when oxygen levels are low

Extrinsic Regulation

Response controlled by nervous and endocrine system

Components of Homeostatic regulation

Receptor, Control center, and Effector

Negative Feedback

The response of the effector negates the stimulus. Body is brought back into homeostasis. Normal range is maintained

Positive Feedback

Initial stimulus produces a response that amplifies the original change in conditions. Body is moved away from homeostasis. Normal range is not maintained

Surface anatomy

Locating structures on or near the body surface

Sectional Anatomy

A section is a slice through a 3-dimensional object, used to visualize internal organization

Sectional plane

A single view along a 2D flat surface

Front (coronal) plane

Vertical plane that divides body into anterior and posterior portions

Sagittal Plane

Vertical plane dividing body into left and right portions

Midsagittal plane

Lies in the middle

Parasagittal plane

Offset from the middle

Transverse plane

Divides body into superior and inferior portions

Functions of body cavities

Protect organs from shock/impacts and permits significant changes in size and shape of internal organs

True body cavities are lined with a

Serous membrane (serosa)

Two layers of tissue that are continuous are

Parietal and visceral layers

Lines cavity

Parietal serosa

Covers organs

Visceral serosa

Cranial cavity

Within the skull; protects the brain

Vertebral (spinal) cavity

Within vertebral column; protects spinal cord.

Thoracic cavity

Above the diaphragm, Right and left pleural cavities.

Mediastinum

Upper portion filled with blood vessels, trachea, esophagus, and thymus. Lower portion contains pericardial cavity.

The heart is located within the

Pericardial cavity

Abdominal pelvic cavity

Peritoneal cavity, Abdominal cavity, and Pelvic cavity

Abdominal cavity

Is the space from the diaphragm to the top of the pelvic bones. Includes both the peritoneal cavity and the retroperitoneal space.

Peritoneum

A serous membrane that encloses the liver, stomach, spleen, small intestine, and most. of large intestine

Lines the internal body wall

Parietal peritoneum

Covers the organs

Visceral peritoneum

Retroperitoneal space

Area posterior to peritoneum and anterior to muscular body wall. Contains pancreas, kidneys, ureters, and parts of the digestive tract

Pelvic cavity

Inferior portion. Medial to pelvic bones. Contains reproductive organs, rectum and bladder

Histology

The study of tissues. Collections of specialized cells and cell products that perform specific functions. Tissues in combination form organs, such as the heart and liver

Four types of tissue

Epithelial, Connective, Muscle, and Nervous tissue

Epithelial tissue

Covers exposed surfaces. Lines internal passageways. Forms glands

Muscle tissue

Specialized for contractions. Skeletal muscle, heart muscle, and muscular walls of hollow organs

Connective tissue

Fills internal spaces. Supports other tissues. Transport materials. Stores energy

Nervous tissue

Carries electrical signals from one part of the body to another

Functions of Epithelial Tissue

Provide physical protection, control permeability, provide sensation, and produce specialized secretions

Characteristics of Epithelia

Polarity (apical/basal surfaces), Cellularity (little ground substance), Attachment (basement membrane), Avascular, Regeneration

Integrity of epithelia is maintained by

Intercellular connections, attachment to the basement membrane, and epithelia maintenance and repair

Polarity of Epithelial cells - Apical surface

Microvilli increase absorption or secretion. Cilia on a ciliated epithelium move fluids.

Intercellular Connections of epithelia

Cells in epithelia are firmly attached to each other. Large areas of opposing plasma membrane and cell junctions

Cells connected by large areas of opposing membrane are held together by

Cell adhesion molecules (CAMs)

Cell adhesion molecules (CAMs) are

Transmembrane proteins

Proteoglycans act as

Intercellular cement

Proteoglycans

Contains glycosaminoglycans such as hyaluronan (hyaluronic acid)

Intercellular Connections of epithelia - Cell junctions

Form bonds with other cells or extracellular material. Gaps junctions, Tight junctions and Desmosomes

Gap Junctions

Allow rapid communication. Cells held together by interlocking transmembrane protein (connexons). Allow small molecules and ions to pass.

Tight Junctions

Encircle apical portions of cells, Adhesion belt attaches to terminal web. Attaches to microfilaments within cells. Prevents passage of waters and solutes, Keeps enzymes, acids, and wastes in the lumen of the digestive tract

Desmosomes

Densely packed CAMs and proteoglycans line opposing plasma membranes

Spot Desmosomes

Tie cells together. Allow bending and twisting

Hemidesmosomes

Attach cells to the basement membrane

Attachment to basement membrane - Basal Lamina

Closest to the epithelium. Disorganized layer of extracellular matrix. Secreted by epithelium

Attachment to basement membrane - Reticular Lamina

Deeper portion of basement membrane. Mostly reticular fibers and ground substance. Secreted by underlying connective tissue. Provides strength

Epithelial Maintenance and Repair

Epithelial cells are replaced by continual division of stem cells. Located near basement membranes

Classification of Epithelia - Based on shape

Squamous (thin and flat), Cuboidal (square shaped), Columnar (tall, slender rectangles)

Classification of Epithelia - Based on Layers

Simple epithelium (single layer of cells) and Stratified epithelium (several layers of cells)

Simple squamous epithelium

Absorption and diffusion.

Mesothelium

Lines body cavities

Endothelium

Forms inner lining of heart and blood vessels

Stratified squamous epithelia

Protects against mechanical stress. Keratin adds strength and water resistance

Simple Cuboidal epithelia

Secretions and absorption. Glands and portions of kidney tubules

Stratified Cuboidal epithelia

Relatively rare. Ducts of sweat glands and mammary glands

Transitional epithelia

Tolerate repeated cycles of stretching without damage. Appearance of apical cells changes as stretching occurs. Cuboidal when relaxed, squamous when stretched, Found in urinary bladder

Simple columnar epithelia

Absorption and secretion. Found in the stomach, small intestine, and large intestine

Pseudostratified columnar epithelia

Typically have cilia. Cell nuclei exist at multiple levels, but each cell attaches to basement membrane. Found in nasal cavity, trachea and bronchi.

Stratified columnar epithelia

Relatively rare. Only superficial layers are columnar. Provide protection in pharynx, anus, and urethra

Glands

Collections of epithelial cells that produce secretions

Endocrine glands

Release hormones that enter bloodstream. No ducts

Exocrine glands

Produce exocrine secretions. Discharge secretion through ducts onto epithelial surfaces

Methods of secretion - Merocrine

Released by sensory vesicles (exocytosis).

Methods of secretion - Apocrine

Released by shedding apical portions of cytoplasm packed with secretory vesicles.

Methods of secretion - Holocrine

Released by cells bursting, killing gland cells. Gland cells replaced by stem cells.

Types of exocrine gland secretions - Serous glands

Watery secretions

Types of exocrine gland secretions - Mucous glands

Secrete mucins

Types of exocrine gland secretions - Mixed exocrine glands

Both serous and mucous

Components of connective tissue

Specialized cells, Extracellular protein fibers, Ground substance

Extracellular matrix

Extracellular protein fibers + ground substance. Majority of tissue volume and determines specialized functions

Functions of connective tissue

Establishing a structural framework for the body. Transporting fluids and dissolved materials. Protecting delicate organs. Supporting, surrounding, and interconnecting other types of tissues. Storing energy reserves, especially triglycerides. Defending the body from invading microorganism

Connective tissue proper

Connect and protect. Many cell types. Extracellular matrix is viscous with varying densities of protein fibers.

Fluid connective tissue

Transport. Water extracellular matrix

Supporting connective tissue

Structural strength. ECM is gel-like or rigid. Densely packed protein fibers

Fibroblast

The most abundant cell type. Found in all types of connective tissue proper. Secrete proteins and hyaluronic acid

Fibrocytes

Second most abundant cell type. Maintain connective tissue fibers

Adipocytes

Fat cells. Each cell stores a single, large fat droplet

Mesenchymal cells

Stem cells that respond to injury or infection. Differentiate into fibroblasts, macrophages, etc.