BIOL 231 Anatomy & Physiology I
Detailed Student Study Notes
Lectures: August 19, 21, 24, 26, and 28
CHAPTER 1: INTRODUCTION TO ANATOMY AND PHYSIOLOGY
Anatomy vs. Physiology
Anatomy
Anatomy is the study of structure (form). It focuses on what body parts look like and how those parts are organized. The term originally referred to dissection and examination of structures. Examples include studying the humerus, bones, muscles, organs, and tissues. [Aug 19 | Word]
Physiology
Physiology is the study of function. It examines how body structures work and perform their respective roles. For example:
Red bone marrow produces blood cells.
Muscles contract to create movement.
The heart pumps blood.
The lungs exchange gases.
The basic principle of A&P is:
Structure determines function.
Understanding anatomy helps explain physiology. [Aug 19 | Word]
TYPES OF ANATOMY
Developmental Anatomy
Studies how structures develop from embryo to adult.
Examples:
Embryology
Fetal development
Congenital abnormalities
Usually covered in more advanced courses. [Aug 19 | Word]
Microscopic Anatomy
Studies structures requiring magnification.
Examples:
Cells
Tissues
Histology
Although this course emphasizes gross anatomy, students will study tissues during the first test section. [Aug 19 | Word]
Gross Anatomy
The primary focus of this course.
Studies structures visible without magnification.
Examples:
Bones
Muscles
Organs
Organ systems
This represents most of what students learn during Anatomy & Physiology I. [Aug 19 | Word]
LEVELS OF STRUCTURAL ORGANIZATION
The human body is organized from simplest to most complex. [Aug 19 | Word]
1. Chemical Level
Includes:
Atoms
Molecules
Organic compounds
Examples:
Water
Proteins
Sugars
Lipids
2. Cellular Level
Cells are the basic units of life.
Examples:
Neurons
Muscle cells
Blood cells
3. Tissue Level
Groups of similar cells performing common functions.
Four tissue types:
Epithelial
Connective
Muscle
Nervous
4. Organ Level
Structures composed of multiple tissue types.
Examples:
Skin
Heart
Liver
5. Organ System Level
Groups of organs performing common functions.
Examples:
Skeletal system
Nervous system
Digestive system
6. Organismal Level
The entire human body.
HOMEOSTASIS
Definition
Homeostasis is the maintenance of a relatively stable internal environment despite changing external conditions.
Dr. Warren described it as:
Dynamic equilibrium
Dynamic = constantly changing
Equilibrium = remaining balanced
Living organisms continuously adjust internal conditions to maintain survival. [Aug 19 | Word]
FEEDBACK SYSTEMS
Negative Feedback
Most common homeostatic mechanism.
Characteristics
Reverses a change.
Maintains balance.
Returns a variable toward its normal range.
Example: Body Temperature
If body temperature rises:
Sweat glands activate.
Heat is lost.
If body temperature falls:
Shivering occurs.
Heat is produced.
This keeps temperature within a narrow survival range. [Aug 19 | Word]
Example: Blood Glucose
The pancreas regulates blood sugar.
High Blood Sugar
Pancreas releases:
Insulin
Result:
Blood glucose decreases.
Low Blood Sugar
Pancreas releases:
Glucagon
Result:
Blood glucose increases.
This is another classic negative feedback system. [Aug 19 | Word]
Positive Feedback
Amplifies a change rather than reversing it.
Characteristics
Enhances responses.
Continues until a specific endpoint is reached.
Example: Blood Clotting
When a blood vessel is damaged:
Platelets attach.
Platelets release chemicals.
More platelets are attracted.
Additional platelets attach.
The response grows stronger until bleeding stops. This process is called hemostasis. [Aug 19 | Word]
Example: Childbirth
Hormone involved:
Oxytocin
Process:
Uterine contractions begin.
Oxytocin release increases.
Contractions intensify.
More oxytocin is released.
Contractions continue strengthening until delivery occurs. [Aug 19 | Word]
BIOLOGICAL CLOCKS
Humans possess internal timing mechanisms.
Important concepts:
Humans are naturally diurnal.
Day/night cycles affect body function.
Disrupting biological rhythms causes problems.
Examples:
Night shift work
Sleep deprivation
Jet lag
These rhythms are essential components of normal physiology. [Aug 19 | Word]
ANATOMICAL POSITION
All anatomical descriptions use the anatomical position as a reference point. [Aug 21 | Word]
Characteristics:
Standing upright
Face forward
Arms at sides
Palms facing forward
Thumbs pointing laterally
Feet forward
Even if a body is lying down or upside down, structures are still described relative to anatomical position. [Aug 21 | Word]
DIRECTIONAL TERMS
Superior (Cranial)
Toward the head.
Examples:
Head is superior to the thorax.
Thorax is superior to abdomen.
Inferior (Caudal)
Toward the feet.
Examples:
Abdomen is inferior to thorax.
Pelvis is inferior to abdomen.
Anterior (Ventral)
Toward the front.
Examples:
Sternum is anterior to heart.
Heart is anterior to vertebral column.
Posterior (Dorsal)
Toward the back.
Examples:
Vertebral column is posterior to sternum.
Medial
Toward the midline.
Examples:
Nose is medial to eyes.
Heart is medial to lungs.
Lateral
Away from the midline.
Examples:
Arms are lateral to thorax.
Lungs are lateral to heart.
Proximal
Closer to:
Shoulder
Hip
Examples:
Elbow is proximal to wrist.
Knee is proximal to ankle.
Distal
Farther from:
Shoulder
Hip
Examples:
Fingers are distal to wrist.
Foot is distal to knee.
Superficial
Toward the body surface.
Examples:
Skin is superficial to muscle.
Deep
Farther from the surface.
Examples:
Bone is deep to muscle.
[Aug 21 | Word], [Aug 24 | Word]
REGIONAL ANATOMY TERMS
Students are expected to know the following regions. [Aug 21 | Word], [Aug 24 | Word]
Head and Neck
Cephalic = head
Frontal = forehead
Orbital = eye
Nasal = nose
Buccal = cheek
Oral = mouth
Mental = chin
Cervical = neck
Thorax and Abdomen
Thoracic = chest
Sternal = breastbone
Axillary = armpit
Mammary = breast
Umbilical = navel
Inguinal = groin
Pubic = genital region
Upper Limb
Acromial = shoulder
Brachial = arm
Antecubital = front of elbow
Olecranal = posterior elbow
Antebrachial = forearm
Carpal = wrist
Palmar = palm
Lower Limb
Coxal = hip
Femoral = thigh
Crural = leg
Sural = calf
Fibular (Peroneal) = lateral leg
Popliteal = back of knee
BODY PLANES
Frontal (Coronal) Plane
Divides body into:
Anterior
Posterior
[Aug 24 | Word]
Sagittal Plane
Divides body into:
Left
Right
Midsagittal
Equal left and right halves. [Aug 24 | Word]
Transverse Plane
Divides body into:
Superior
Inferior
Often seen in:
CT scans
MRI sections
[Aug 24 | Word]
BODY CAVITIES
Dorsal Body Cavity
Contains:
Cranial Cavity
Brain
Vertebral Cavity
Spinal cord
[Aug 24 | Word]
Ventral Body Cavity
Contains:
Thoracic Cavity
Contains:
Heart
Lungs
Abdominal Cavity
Contains:
Digestive organs
Pelvic Cavity
Contains:
Urinary bladder
Reproductive organs
[Aug 24 | Word]
SEROUS MEMBRANES
Students must know these three major membranes. [Aug 24 | Word]
Pleura
Surrounds lungs.
Pericardium
Surrounds heart.
Peritoneum
Surrounds abdominal digestive organs.
These structures become extremely important throughout the semester. [Aug 24 | Word]
ORGANIC MACROMOLECULES
Four major groups:
Carbohydrates
Lipids
Proteins
Nucleic Acids
[Aug 26 | Word]
CARBOHYDRATES
Important Sugars
Glucose
Most important six-carbon sugar.
Functions:
Major energy source
Essential for nervous system function
The brain relies heavily on glucose for energy. [Aug 26 | Word]
Ribose
Five-carbon sugar.
Found in:
RNA
Deoxyribose
Five-carbon sugar.
Found in:
DNA
[Aug 26 | Word], [Aug 28 | Word]
Glycogen
Storage form of glucose.
Found primarily in:
Liver
Skeletal muscle
Provides stored energy reserves. [Aug 26 | Word], [Aug 28 | Word]
LIPIDS (FATS)
Triglycerides
Major storage fats.
Contain:
Glycerol
Three fatty acid chains
Provide greater energy storage than carbohydrates. [Aug 26 | Word]
Saturated vs Unsaturated Fats
Saturated
Generally animal fats.
More hydrogen atoms
Associated with cardiovascular problems
Unsaturated
Generally plant fats.
Fewer hydrogen atoms
Healthier option
[Aug 26 | Word]
Phospholipids
Major component of cell membranes.
Functions:
Form membrane bilayer
Separate intracellular and extracellular fluid
Every cell membrane contains phospholipids. [Aug 26 | Word]
Steroids
Built from cholesterol.
Examples:
Testosterone
Estrogen
Progesterone
Cortisol
Characteristics:
Lipid-soluble
Powerful hormones
Cross cell membranes easily
[Aug 26 | Word]
PROTEINS
The most important macromolecule for anatomy and physiology.
Structural Functions
Examples:
Collagen
Elastin
Reticular fibers
These determine body structure. [Aug 26 | Word]
Functional Roles
Proteins act as:
Enzymes
Hormones
Receptors
Channels
Antibodies
Muscle proteins
Without proteins, neither anatomy nor physiology would exist. [Aug 26 | Word]
Amino Acids
Proteins are composed of amino acids linked together.
Protein synthesis involves:
DNA
RNA
Amino acids
Protein formation
[Aug 26 | Word], [Aug 28 | Word]
NUCLEIC ACIDS
DNA
Characteristics:
Contains deoxyribose
Stores genetic information
Located in nuclei
Exception:
Mature red blood cells do not contain nuclei and therefore do not contain DNA. [Aug 28 | Word]
DNA Bases
Students should memorize:
Adenine (A)
Thymine (T)
Cytosine (C)
Guanine (G)
Base pairing rules:
A pairs with T
C pairs with G
This is called complementary base pairing. [Aug 28 | Word]
CENTRAL DOGMA OF MOLECULAR BIOLOGY
The flow of information in cells:
DNA → RNA → Protein
Transcription
DNA is copied into RNA.
Translation
RNA is used to build proteins.
Genes contain instructions for making proteins. [Aug 28 | Word]
CODONS
A codon consists of:
Three nucleotides.
Each codon specifies one amino acid.
Proteins are produced according to the sequence of codons encoded within DNA. [Aug 28 | Word]
HIGH-YIELD EXAM REVIEW
Be able to:
✓ Define anatomy and physiology
✓ Explain levels of organization
✓ Define homeostasis
✓ Compare negative and positive feedback
✓ Explain insulin and glucagon
✓ Define anatomical position
✓ Use directional terms correctly
✓ Identify body planes
✓ Identify major body cavities
✓ Name pleura, pericardium, and peritoneum
✓ Describe glucose and glycogen
✓ Compare saturated vs unsaturated fats
✓ Explain phospholipid function
✓ Explain steroid structure and function
✓ Describe protein functions
✓ Explain DNA structure
✓ Memorize A-T and C-G base pairing
✓ Explain transcription and translation
✓ Define a gene
✓ Explain the central dogma: DNA → RNA → Protein
Detailed Study Notes: Tissues, Connective Tissues, Blood, Muscle, and Nervous Tissue
Based on Lectures: August 31, September 2, September 4, and September 9
THE FOUR BASIC TISSUES OF THE HUMAN BODY
Everything in the human body is composed of only four major tissue types:
Epithelial Tissue
Connective Tissue
Muscle Tissue
Nervous Tissue
If a section of the body is examined under a microscope, it will always be identified as one of these four tissue types. [Aug 31 | Word]
EPITHELIAL TISSUE
General Functions
Epithelial tissue performs two major functions:
Covering
Forms the external covering of the body.
Example:
Skin
Lining
Lines hollow spaces and organs.
Examples:
Respiratory tract
Digestive tract
Blood vessels
Urinary tract
Reproductive tract
The lumen (inside space) of every hollow organ is lined by epithelium. [Aug 31 | Word]
Classification of Epithelial Tissue
Epithelia are named according to:
Number of Layers
Simple
One cell layer thick
Stratified
Multiple cell layers thick
Cell Shape
Squamous
Flat cells
Cuboidal
Cube-shaped cells
Columnar
Tall, column-shaped cells
These categories combine to produce tissue names such as:
Simple squamous
Simple cuboidal
Simple columnar
Stratified squamous
[Aug 31 | Word]
SIMPLE SQUAMOUS EPITHELIUM
Structure
One layer
Flat cells
Extremely thin
Major Location
Alveoli of lungs
Function:
Gas exchange
The respiratory membrane consists of:
Alveolar simple squamous epithelium
Capillary simple squamous epithelium
This thin barrier allows oxygen and carbon dioxide to diffuse rapidly. [Aug 31 | Word]
Clinical Significance
Respiratory diseases such as emphysema damage this respiratory membrane, reducing gas exchange efficiency. [Aug 31 | Word]
SIMPLE CUBOIDAL EPITHELIUM
Structure
Single layer
Cube-shaped cells
Locations
Kidney tubules
Small bronchioles
Functions include:
Absorption
Secretion
Modification of fluids
[Aug 31 | Word]
SIMPLE COLUMNAR EPITHELIUM
Structure
Single layer
Tall cells
Digestive System
Non-ciliated simple columnar epithelium lines:
Stomach
Small intestine
Large intestine
Functions:
Absorption
Secretion
Microvilli
Microvilli are microscopic projections that:
Increase surface area
Contain digestive enzymes
Facilitate nutrient absorption
Microvilli DO NOT move. [Aug 31 | Word]
CILIA VS MICROVILLI
Students frequently confuse these structures.
Microvilli
Characteristics:
Non-motile
Increase surface area
Contain digestive enzymes
Location:
Small intestine
Function:
Nutrient absorption
Cilia
Characteristics:
Motile
Contain motor proteins
Move in coordinated waves
Locations:
Respiratory tract
Uterine tubes
Functions:
Move mucus in respiratory system
Move oocytes through uterine tubes
Without cilia in uterine tubes, fertilization could not occur normally. [Aug 31 | Word]
PSEUDOSTRATIFIED COLUMNAR EPITHELIUM
Characteristics
Appears multilayered
Actually one layer
All cells contact basement membrane
Location
Upper respiratory tract
Functions
Produces mucus
Moves mucus via cilia
Importance
Cilia move mucus containing:
Dust
Bacteria
Viruses
Debris
toward the digestive system for destruction. [Aug 31 | Word]
STRATIFIED SQUAMOUS EPITHELIUM
Function
Protection against friction and abrasion.
Non-Keratinized
Locations:
Mouth
Esophagus
Nasal cavities
Anal canal
Designed to withstand friction. [Aug 31 | Word], [Sept 2 | Word]
Keratinized
Location:
Skin
Contains:
Keratin protein
Functions:
Water resistance
Protection
Barrier formation
Keratin creates a protective barrier that prevents most substances from penetrating the skin. [Aug 31 | Word], [Sept 2 | Word]
HIGH MITOTIC ACTIVITY OF STRATIFIED SQUAMOUS EPITHELIUM
Epithelial tissues regularly replace damaged cells.
Examples:
Skin
Esophagus
Mouth
Skin cells are continuously shed and replaced approximately every month. [Sept 2 | Word]
CANCER AND EPITHELIAL TISSUES
Most cancers originate from epithelial tissues because these tissues divide frequently.
Examples:
Squamous Cell Carcinoma
Develops from stratified squamous epithelium.
Esophageal Cancer
Often associated with chronic gastric reflux.
Repeated exposure of stratified squamous epithelium to stomach acid can stimulate cellular damage and uncontrolled growth. [Sept 2 | Word]
CONNECTIVE TISSUE
General Functions
Connective tissue:
Binds
Supports
Protects
Connects structures
Examples:
Tendons
Ligaments
Cartilage
Bone
Blood
[Sept 2 | Word]
THREE CHARACTERISTICS OF CONNECTIVE TISSUE
All connective tissues possess:
1. Cells
Major connective tissue-producing cells:
Tissue
Cell
Connective tissue proper
Fibroblast
Cartilage
Chondroblast
Bone
Osteoblast
Blood
Hemocytoblast
[Sept 2 | Word]
Blast vs Cyte
Blast
Immature
Produces tissue
Developmental form
Examples:
Fibroblast
Chondroblast
Osteoblast
Cyte
Mature cell
Maintains tissue
Examples:
Fibrocyte
Chondrocyte
Osteocyte
[Sept 2 | Word]
2. Matrix (Ground Substance)
The matrix contains:
Glycosaminoglycans (GAGs)
Examples:
Hyaluronic acid
Chondroitin sulfate
Functions:
Hold water
Provide flexibility
Support tissues
These compounds account for many physical properties of connective tissues. [Sept 2 | Word]
3. Fibers
Collagen
Most important structural protein in the body.
Characteristics:
Extremely strong
Provides tensile strength
Major component of most connective tissues
Elastin
Provides elasticity and recoil.
Functions as biological rubber bands.
[Sept 2 | Word], [Sept 4 | Word]
CONNECTIVE TISSUE PROPER
Areolar Connective Tissue
Most common connective tissue.
Functions:
Packages organs
Supports tissues
Binds structures together
Found throughout the body. [Sept 2 | Word]
Adipose Tissue
Functions
Energy storage
Insulation
Cushioning
Hormonal regulation
Distribution is influenced by:
Hormones
Nervous system activity
Locations:
Under skin
Around organs
Bone marrow
[Sept 2 | Word]
Reticular Connective Tissue
Function:
Framework for blood cell production
Location:
Red Bone Marrow
Major sites include:
Epiphyses of long bones
Sternum
Ilium
Vertebrae
Skull
This tissue produces blood cells and is sampled during bone marrow biopsies. [Sept 2 | Word]
DENSE REGULAR CONNECTIVE TISSUE
Characteristics
Parallel collagen fibers
Extremely strong
Locations
Tendons
Connect:
Muscle to bone
Ligaments
Connect:
Bone to bone
Aponeurosis
A sheet-like tendon connecting:
Muscle to muscle or
Muscle to broad attachment areas
Example:
Epicranial aponeurosis
[Sept 2 | Word], [Sept 4 | Word]
DENSE IRREGULAR CONNECTIVE TISSUE
Characteristics
Collagen fibers arranged in many directions.
Location
Dermis of skin
Provides multidirectional strength to tissues. [Sept 4 | Word]
ELASTIC CONNECTIVE TISSUE
Primary Fiber
Elastin
Major Location
Aorta
Function
Allows arteries to:
Stretch
Recoil
Maintain blood pressure
Without elastic fibers, arteries could not withstand repetitive pressure generated by the heart. [Sept 4 | Word]
CARTILAGE
Key Characteristic
Cartilage is avascular.
Meaning:
No direct blood supply
Consequences:
Slow healing
Limited repair
[Sept 4 | Word]
HYALINE CARTILAGE
Locations
Articular surfaces
Growth plates
Costal cartilage
Trachea
Larynx
Bronchi
Functions
Structural support
Flexible framework
Smooth joint surfaces
All long bones begin as hyaline cartilage during development. [Sept 4 | Word]
ELASTIC CARTILAGE
Locations
External ear
Epiglottis
Function
Provides flexibility while maintaining shape.
The epiglottis is essential for preventing food from entering the airway during swallowing. [Sept 4 | Word]
FIBROCARTILAGE
Locations
Intervertebral Discs
Shock absorption
Vertebral stability
Pubic Symphysis
Connects pubic bones.
Menisci of Knee
Functions:
Cushioning
Stability
[Sept 4 | Word]
CLINICAL APPLICATIONS OF FIBROCARTILAGE
Meniscal Tears
Common knee injury.
Poor healing due to lack of blood supply.
Labral Tears
Locations:
Shoulder
Hip
Often occur in athletes.
Healing is limited because fibrocartilage is poorly vascularized. [Sept 4 | Word]
BONE TISSUE
Osteoblasts
Bone-forming cells.
Main Functions
Produce bone matrix
Promote mineralization
[Sept 4 | Word]
Types of Bone
Compact Bone
Characteristics:
Dense
Strong
Organized into osteons
Location:
Diaphysis of long bones
Spongy (Trabecular) Bone
Characteristics:
Porous
Contains trabeculae
Location:
Epiphyses
Interior of many bones
Contains red bone marrow. [Sept 4 | Word]
Bone Remodeling
Bone constantly responds to stress.
When muscles pull on bones:
Bone deposition increases
Bone becomes stronger
This principle forms the basis of Wolff's Law. [Sept 4 | Word]
BLOOD AS A CONNECTIVE TISSUE
Blood fits the connective tissue definition because it contains:
Cells
Erythrocytes
Leukocytes
Platelets
Matrix
Plasma
Contains:
Water
Electrolytes
Gases
Proteins
[Sept 9 | Word]
Fibers
Fibrin
Produced from fibrinogen during clotting.
Functions:
Forms blood clots
Prevents excessive blood loss
Blood is therefore classified as connective tissue. [Sept 9 | Word]
MUSCLE TISSUE
Three types:
Skeletal
Cardiac
Smooth
[Sept 9 | Word]
SKELETAL MUSCLE
Characteristics
Striated
Voluntary
Attached to skeleton
Proteins
Actin
Myosin
These proteins generate muscle contraction. [Sept 9 | Word]
SOMATIC NERVOUS SYSTEM
Controls:
Skeletal Muscle
Key concept:
Somatic = Voluntary Control
If you consciously move it, somatic motor neurons control it. [Sept 9 | Word]
CARDIAC MUSCLE
Characteristics
Striated
Involuntary
Found only in heart
Special Structure
Intercalated discs (gap junctions)
Functions:
Cell-to-cell communication
Coordinated heart contraction
[Sept 9 | Word]
SMOOTH MUSCLE
Characteristics
Non-striated
Involuntary
Spindle-shaped cells
Locations:
Blood vessels
Digestive tract
Respiratory tract
Urinary organs
Reproductive organs
Functions:
Control lumen size
Move substances through organs
[Sept 9 | Word]
AUTONOMIC NERVOUS SYSTEM
Controls:
Smooth muscle
Cardiac muscle
Glands
Two major divisions:
Sympathetic Division
Fight-or-Flight
Effects:
Heart:
Faster
Stronger contractions
Digestive system:
Slows activity
Airways:
Dilate
Blood flow:
Directed toward muscles and heart
[Sept 9 | Word]
Parasympathetic Division
Rest-and-Digest
Effects:
Heart:
Slows
Digestive tract:
Stimulates activity
Promotes:
Digestion
Absorption
Conservation of energy
[Sept 9 | Word]
NERVOUS TISSUE
Two major cell types:
Neurons
Function:
Communication
Signal transmission
Neurons carry information:
From brain to muscles
From receptors to CNS
Between regions of nervous system
[Sept 9 | Word]
Glial Cells (Neuroglia)
Function:
Support neurons
Protect neurons
Nourish neurons
Maintain nervous tissue
Examples to be studied later include:
Schwann cells
Oligodendrocytes
Microglia
Satellite cells
[Sept 9 | Word]
EXAM ESSENTIALS
You should be able to:
✓ Differentiate epithelial, connective, muscle, and nervous tissues
✓ Classify epithelial tissues by shape and layers
✓ Explain the respiratory epithelium sequence
✓ Distinguish cilia from microvilli
✓ Differentiate keratinized and nonkeratinized stratified squamous epithelium
✓ Explain why gastric reflux increases esophageal cancer risk
✓ Define fibroblast, chondroblast, osteoblast, and hemocytoblast
✓ Define blast vs cyte
✓ Explain the importance of collagen and elastin
✓ Identify areolar, adipose, reticular, dense regular, dense irregular, and elastic connective tissues
✓ Identify locations and functions of hyaline, elastic, and fibrocartilage
✓ Explain why cartilage heals poorly
✓ Differentiate compact and spongy bone
✓ Explain why blood is considered connective tissue
✓ Compare skeletal, cardiac, and smooth muscle
✓ Define somatic and autonomic nervous systems
✓ Compare sympathetic and parasympathetic divisions
✓ Explain the roles of neurons and glial cells
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