Human Anatomy BIOB33 Lecture notes.

BIOB33 Lecture Notes 

Lecture 1



(based on chapters 1 & 3)




Foundations: An Introduction to Anatomy

The study of external structures
The study of internal structures
The study of the relationship between body parts The careful observation of the human body
Physiology
The study of how the body functions The study of mechanisms in the body
Microscopic anatomy
The study of structures that cannot be seen without magnification Cytology—study of cells
Histology—study of tissues
Macroscopic anatomy
The study of structures that can be seen without magnification
Surface anatomy: refers to the superficial anatomical markings
Regional anatomy: refers to all structures in a specific area of the body, whether they are superficial or deep Systemic anatomy: The study of the organ systems of the body (digestive system, cardiovascular system, etc.)
Other Perspectives on Anatomy
Developmental anatomy: examines structural changes over time Embryology: the study of early developmental stages Comparative anatomy: - considers different types of animals
Levels of Organization
Chemical/Molecular (simple) Cell
Tissue
Organ

Organ system Organism (complex)
Levels of Organization
Chemical/Molecular

- over a dozen elements in the body
- four of them make up 99% of the body - hydrogen, oxygen, carbon, and nitrogen - major classes of compounds – water, carbohydrates, proteins, lipids, nucleic acid

Cell - the smallest living unit in the body
Tissue - many cells and some surrounding material
Organ - Combination of tissues
Organ System - Combination of various organs make up a specific system (example: the stomach, small intestine,
large intestine, liver, gallbladder, and pancreas make up the digestive system) Levels of Organization of Organ Systems - Humans are composed of 11 organ systems
Integumentary System Skeletal System Muscular System Nervous System Endocrine System Cardiovascular System

Lymphoid System Respiratory System Digestive System Urinary System Reproductive System
The Language of Anatomy
Superficial Anatomy
The terms are typically derived from Latin or Greek
Latin or Greek is used because they are descriptive languages
Anatomical position
The hands are at the side
The palms are facing forward
All discussion of the human body is in reference to the anatomical position Supine: lying down (face up) in the anatomical position
Prone: lying down (face down) in the anatomical position
Abdominopelvic quadrants and regions
Anatomists and clinicians use specialized regional terms to indicate a specific area of concern within the abdomen or the pelvic regions of the body.
The abdomen and pelvic regions can be subdivided into four regions (abdominopelvic quadrants): Right upper quadrant (RUQ)
Left upper quadrant (LUQ) Right lower quadrant (RLQ) Left lower quadrant (LLQ)
The abdomen and pelvic regions can be subdivided into nine regions (abdominopelvic regions): Epigastric
Right hypochondriac Left hypochondriac Umbilical
Right lumbar
Left lumbar Hypogastric Right inguinal Left inguinal
Anatomical directions
The most common directional terms used are: Superior
Inferior Anterior Posterior Medial Lateral Superficial Deep
See Table 1.2 Regional and Directional Terms
Sectional Anatomy
There are many different ways to dissect a piece of tissue for further study. These are referred to as dissectional cuts or dissectional planes.
Transverse cut: separating superior and inferior Sagittal cut: separating left and right Midsagittal: separating left and right equally Parasagittal: separating left and right unequally

Frontal cut: separating anterior and posterior Oblique cut: separating the tissue at an angle
Sectional Anatomy: Body cavities
If you remove an organ from the body, you will leave a cavity The body cavities are studied in this manner:
Posterior cavity
Cranial cavity: consists of the brain Spinal cavity: consists of the spinal cord
Anterior cavity
Thoracic cavity consists of:
Pleural cavity: lungs
Pericardial cavity: heart
Mediastinal cavity: space between the apex of the lungs
Abdominopelvic cavity consists of:
Abdominal cavity: stomach, intestines, spleen, liver, etc. (within peritoneal cavity) Pelvic cavity: urinary bladder
Each cavity consists of a double-layered membrane (parietal and visceral)
The membrane nearest the wall of the body (farthest from the organs) is the parietal membrane
- parietal pleura (lungs), parietal pericardium (heart), parietal peritoneum (abdomen)
The membrane farthest from the wall of the body (nearest the organs) is the visceral membrane
- visceral pleura (lungs), visceral pericardium (heart), visceral peritoneum (abdomen)
Between the double membranes (parietal and visceral) is a cavity filled with serous fluid which a very smooth non-
viscous fluid allowing very fluid easy movements of organs with no friction, in contrast to mucous fluid which is thick and sticky (very viscous)


From Chapter 3 - Foundations: Tissues
There are over 75 trillion cells in the body
All cells can be placed into one of the four tissue categories
Epithelial tissue Connective tissue Muscular tissue Neural tissue
Epithelial Tissue
Epithelial Tissue Characteristics
- Cells are bound close together
- No intercellular space - Arranged in sheets - Composed of one or more layers of cells
-Regeneration - Cells are continuously replaced via cell reproduction - Polarity -have an exposed apical surface
- have an attached basal surface
- Attachment - Basal layer is attached to the basal lamina
- Avascularity - Do not consist of blood vessels (no vascular connections)
Functions of Epithelial Tissue
Provides physical protection Controls permeability Provides sensation Produces secretions
Specialization of Epithelial Cells
Microvilli - For absorption and secretion
Stereocilia - Long microvilli, commonly found in the inner ear
Ciliated epithelium - Moves substances over the apical surfaces of the cells

Tissue

Classification of Epithelia
Simple - Epithelium has only one layer of cells Stratified - Epithelium has two or more layers of cells
Epithelial Tissue Cells
Squamous cells - Thin, flat cells / “squished” nuclei
Cuboidal cells - Cube-shaped cells / centered, round nucleus Columnar cells - Longer than they are wide / nucleus near the base Transitional cells - Mixture of cells / nuclei appear to be scattered
Simple Squamous Epithelium - Consists of very delicate cells Location - Lining body cavities, the heart, the blood vessels Function - Reduces friction
- Absorbs and secretes material
Stratified Squamous Epithelium
Location - Surface of skin
Lines: mouth, esophagus, anus, vagina Function - Protection
Simple Cuboidal Epithelium
Location - Thyroid gland, ducts, kidney tubules Function - Secretion, absorption
Stratified Cuboidal Epithelium
Location - Ducts of sweat glands Function - Secretion, absorption

Simple Columnar Epithelium
Location - Lining: stomach, intestines, uterine tubes Function - Secretion, absorption, protection
Stratified Columnar Epithelium
Location - Pharynx, epiglottis, mammary glands, salivary glands Function - Protection
Pseudostratified Ciliated Columnar Epithelium
Nucleus situated at different levels Location - Nasal cavity, trachea, bronchi Function - Protection, secretion
Transitional Epithelium
Consists of many layers
Consists of a combination of cuboidal and “odd” shaped cells Location - Urinary bladder
Function - Ability to stretch extensively