The Human Body: An Orientation Chapter 1

Three essential concepts that unify and Anatomy and Physiology: Complementarity of structure and function Hierarchy of structural organization Homeostasis

What is Anatomy? Structure of body parts Relationship of body parts Concrete subject

Structure of body parts

Relationship of body parts

Concrete subject

What is Physiology? Function of the machinery Processes of the body

Function of the machinery

Processes of the body

MUST know anatomy to understand physiology!!!

Topics of Anatomy Macroscopic Anatomy AKA “gross anatomy” Study of large body parts visible to the naked eye Dissection of animals Subdivisions include: Regional anatomy Systemic anatomy Surface anatomy Microscopic Anatomy Study of structures too small to be seen with the naked eye Subdivisions include: Cytology – cells Histology – tissues

Macroscopic Anatomy

AKA “gross anatomy”

Study of large body parts visible to the naked eye

Dissection of animals

Subdivisions include:

Regional anatomy

Systemic anatomy

Surface anatomy

Microscopic Anatomy

Study of structures too small to be seen with the naked eye

Subdivisions include:

Cytology – cells

Histology – tissues

Topics of Anatomy (con’t) Developmental Anatomy Traces structural changes that occur in the body throughout the life span Subdivisions include: Embryology – developmental changes before birth Pathological Anatomy Radiographic Anatomy Molecular Biology Anatomical Terminology

Developmental Anatomy

Traces structural changes that occur in the body throughout the life span

Subdivisions include:

Embryology – developmental changes before birth

Pathological Anatomy

Radiographic Anatomy

Molecular Biology

Anatomical Terminology

Some Topics of Physiology Renal physiology – kidney function and urine production Neurophysiology – workings of the nervous system Cardiovascular physiology – operation of heart and blood

Renal physiology – kidney function and urine production

Neurophysiology – workings of the nervous system

Cardiovascular physiology – operation of heart and blood

Complementarity of Structures and Functions Levels of Structural Organization Chemical Level Cellular Level Tissue Level Organ Level Organ System Level Organism Level

Maintaining Life

Necessary Life Functions Maintaining Boundaries Inside must be distinct from outside Movement Responsiveness AKA “irritability” Ability to sense changes in environment and respond Digestion Metabolism Chemical reactions within body cells Excretion Removes wastes from body and requires many organs Reproduction Growth

Maintaining Boundaries

Inside must be distinct from outside

Movement

Responsiveness

AKA “irritability”

Ability to sense changes in environment and respond

Digestion

Metabolism

Chemical reactions within body cells

Excretion

Removes wastes from body and requires many organs

Reproduction

Growth

Survival Needs Nutrients Taken in via diet Give energy and maintain cells Oxygen Water Obtained through diet Lose by evaporation from lungs, skin, and excretion 60 – 80% of body weight Normal body temperature Atmospheric pressure

Nutrients

Taken in via diet

Give energy and maintain cells

Oxygen

Water

Obtained through diet

Lose by evaporation from lungs, skin, and excretion

60 – 80% of body weight

Normal body temperature

Atmospheric pressure

Homeostasis Describes the ability to maintain relatively stable internal condition even though the outside world changes continuously. Indicates a dynamic state of equilibrium, or balance.

Homeostatic Control Mechanisms Communication in the body is accomplished chiefly by the nervous and endocrine systems. Variable – factor or event being regulated Receptor – sensor that monitors the environment and respond to changes Control center – analyzes the input it receives and then determines the appropriate response Effector – provides the response

Communication in the body is accomplished chiefly by the nervous and endocrine systems.

Variable – factor or event being regulated

Receptor – sensor that monitors the environment and respond to changes

Control center – analyzes the input it receives and then determines the appropriate response

Effector – provides the response

Negative Feedback Mechanism The output of the system shuts off the original stimulus or reduces its intensity. This mechanism causes the variable to change in a direction opposite to that of the initial change, returning it to its “ideal” value. All negative feedback systems have the same goal: to prevent sudden severe changes .

The output of the system shuts off the original stimulus or reduces its intensity.

This mechanism causes the variable to change in a direction opposite to that of the initial change, returning it to its “ideal” value.

All negative feedback systems have the same goal: to prevent sudden severe changes .

Positive Feedback Mechanism The result of response enhances or exaggerates the original stimulus so that the activity is accelerated. “ Positive” because the change occurs in the same direction as the initial disturbance, causing the variable to deviate further and further from the original value. Control infrequent events that don’t require continuous adjustments!!

The result of response enhances or exaggerates the original stimulus so that the activity is accelerated.

“ Positive” because the change occurs in the same direction as the initial disturbance, causing the variable to deviate further and further from the original value.

Control infrequent events that don’t require continuous adjustments!!

The Language of Anatomy

Anatomical Position Anatomical reference point Body is erect with feet slightly apart “ Standing at attention” pose Palms face forward and thumbs point away from body

Anatomical reference point

Body is erect with feet slightly apart

“ Standing at attention” pose

Palms face forward and thumbs point away from body

Directional Terms Allow us to explain exactly where one body structure is in relation to another.

Regional Terms Used to designate specific areas within the major body divisions. Two divisions: Axial part – head, neck, and trunk Appendicular part – limbs

Used to designate specific areas within the major body divisions.

Two divisions:

Axial part – head, neck, and trunk

Appendicular part – limbs

Body Planes Plane – flat surface Most frequent body planes: Sagittal Plane Vertical plane that divides body into right and left Midsagittal – exactly on midline Parasagittal – offset from midline Frontal Plane Divides body into anterior and posterior AKA “coronal” plane Transverse Plane Horizontal plane Divides into superior and inferior parts

Plane – flat surface

Most frequent body planes:

Sagittal Plane

Vertical plane that divides body into right and left

Midsagittal – exactly on midline

Parasagittal – offset from midline

Frontal Plane

Divides body into anterior and posterior

AKA “coronal” plane

Transverse Plane

Horizontal plane

Divides into superior and inferior parts

A section is a cut along a plane.

Body Cavities

Axial portion of the body: Dorsal Body Cavity Ventral Body Cavity

Dorsal Body Cavity Protects nervous system 2 Subdivisions: Cranial cavity – encases brain Vertebral cavity – encases spinal cord

Protects nervous system

2 Subdivisions:

Cranial cavity – encases brain

Vertebral cavity – encases spinal cord

Ventral Body Cavity 2 Subdivisions: Thoracic cavity Surrounds ribs and muscles Pleural cavity – houses lungs Pericardial cavity – houses hearts, esophagus and trachea Abdominopelvic cavity Separated from thoracic cavity by diaphragm Abdominal cavity – contains stomach, intestines, spleen, and liver Pelvic cavity – contains bladder, reproductive organs, and rectum

2 Subdivisions:

Thoracic cavity

Surrounds ribs and muscles

Pleural cavity – houses lungs

Pericardial cavity – houses hearts, esophagus and trachea

Abdominopelvic cavity

Separated from thoracic cavity by diaphragm

Abdominal cavity – contains stomach, intestines, spleen, and liver

Pelvic cavity – contains bladder, reproductive organs, and rectum

Membranes in the Ventral Body Cavity Serosa (serous membrane) Thin, double-layered membrane Parietal serosa – membrane lining cavity walls Visceral serosa – covers organs Serous fluid Separates serous membranes Allows sliding without friction

Serosa (serous membrane)

Thin, double-layered membrane

Parietal serosa – membrane lining cavity walls

Visceral serosa – covers organs

Serous fluid

Separates serous membranes

Allows sliding without friction

Other Body Cavities Oral and digestive Nasal Orbital Middle ear Synovial

Oral and digestive

Nasal

Orbital

Middle ear

Synovial

Abdominopelvic Regions and Quadrants Umbilical Epigastric Hypogastric (pubic) Right & Left iliac (inguinal) Right & Left lumbar Right & Left hypochondriac Quadrants are named according to subject’s pt. of view

Umbilical

Epigastric

Hypogastric (pubic)

Right & Left iliac (inguinal)

Right & Left lumbar

Right & Left hypochondriac

Quadrants are named according to subject’s pt. of view

Chemistry of the Human Body

Terms to know: Matter – anything that occupies space and has mass Kinetic energy – energy in action Potential energy – stored energy Chemical energy – energy stored in the bonds of a chemical substance Atom – building blocks of matter Element – unique substance that can’t be broken down

Matter – anything that occupies space and has mass

Kinetic energy – energy in action

Potential energy – stored energy

Chemical energy – energy stored in the bonds of a chemical substance

Atom – building blocks of matter

Element – unique substance that can’t be broken down

Terms (con’t): Molecule – combination of two or more atoms that are held together by a bond Compound – two or more kinds of atoms bind together Mixture - substance composed of two or more components Chemical reaction – occurs whenever chemical bonds are formed, rearranged, or broken

Molecule – combination of two or more atoms that are held together by a bond

Compound – two or more kinds of atoms bind together

Mixture - substance composed of two or more components

Chemical reaction – occurs whenever chemical bonds are formed, rearranged, or broken

Biochemistry The study of the chemical composition and reactions of living matter.

Compounds… Organic Contain carbon Covalently bonded (share electrons) Typically large Inorganic Include water, salts, and compounds needed for life Both are EQUALLY important!!!

Organic

Contain carbon

Covalently bonded (share electrons)

Typically large

Inorganic

Include water, salts, and compounds needed for life

Major Organic Compounds found in the body: Carbohydrates Sugars and starches Made of carbon, hydrogen, and oxygen Monosaccharide – simple sugars made of single chains/rings Disaccharide – double sugars made from two monosaccharides joined together Polysaccharides – long chains of simple sugars linked together; sometimes called polymers

Carbohydrates

Sugars and starches

Made of carbon, hydrogen, and oxygen

Monosaccharide – simple sugars made of single chains/rings

Disaccharide – double sugars made from two monosaccharides joined together

Polysaccharides – long chains of simple sugars linked together; sometimes called polymers

Lipids Fats Insoluble in water Contain carbon, hydrogen, and oxygen Triglycerides are an example of a lipid. Steroids are also fats! Cholesterol – an important steroid Essential for life!

Lipids

Fats

Insoluble in water

Contain carbon, hydrogen, and oxygen

Triglycerides are an example of a lipid.

Steroids are also fats!

Cholesterol – an important steroid

Essential for life!

Proteins Basic structural material of the body Also, aid in cell function Amino acids – building blocks of proteins Enzymes are proteins that act as catalysts for chemical reactions (kick-start or speed up the reaction). Proteins can be denatured (broken down), when they are exposed to high temperatures or high/low pH!! They won’t work!!

Proteins

Basic structural material of the body

Also, aid in cell function

Amino acids – building blocks of proteins

Enzymes are proteins that act as catalysts for chemical reactions (kick-start or speed up the reaction).

Proteins can be denatured (broken down), when they are exposed to high temperatures or high/low pH!! They won’t work!!

Nucleic Acids Made of structural units called nucleotides, which are made up of a sugar, phosphate, and a nitrogenous base DNA (deoxyribonucleic acid) is contains the sugar deoxyribose and is a double stranded molecule. RNA (ribonucleic acid) is contains the sugar ribose and is a single stranded molecule.

Nucleic Acids

Made of structural units called nucleotides, which are made up of a sugar, phosphate, and a nitrogenous base

DNA (deoxyribonucleic acid) is contains the sugar deoxyribose and is a double stranded molecule.

RNA (ribonucleic acid) is contains the sugar ribose and is a single stranded molecule.