A&P Chapter 1: The Human Body: An Orientation

Using the notes/slideshow created by Professor Voytek

Anatomy

Study of structure

Subdivisions of Anatomy

Gross (macroscopic) - easily observed

Microscopic - too small to be observed

Physiology

Study of function of the body

Subdivisions of Physiology

11 organ systems

Focuses on processes at a molecular level

Anatomy and Physiology are _____. ______ determines ________.

inseparable

structure determines function

Structural Organization (in order from smallest to largest)

Chemicals, Cellular, Tissue, Organ, Organ System, Organismal

Define Chemical

Atoms and molecules

Define Cellular

Cells — smallest unit of living things

Define Tissue

Groups of similar cells

Define Organ

Contains two or more tissue types

Organ System

Organs that work closely together

Organismal

All organ systems

Integumentary System Structures

External covering - skin

Deviates - sweat glands, oil glands, hair, and nails

Integumentary System Functions

Protects underlying structures

Synthesizes Vitamin D

Muscular System Structure

Muscles

Muscular System Functions

Movement

Maintains Posture

Produces Heat

Skeletal Systems Structures

Bones

Joints

Cartilage

Ligaments

Skeletal System Functions

Protects organs

Attachment site for muscles

Formation of blood cells

Stores minerals - calcium

Nervous System Structure

Brain

Spinal Cord

Nerves

Nervous System Function

Control center

Re

Cardiovascular System Structure

Heart

Blood Vessels

Cardiovascular System Function

Pumps blood

Transports oxygen, nutrients, waste, and carbon dioxide

Respiratory System Structure

Nasal Cavity

Pharynx, larynx

Trachea

Bronchi

Lungs

Respiratory System Function

Gas exchange

Oxygen delivered to blood

Carbon Dioxide removed from blood

Digestive System Structure

Oral Cavity

Esophagus

Stomach, small and large intestines, rectum, and anus

Accessory organs — liver, gallbladder, salivary glands, and pancreas

Digestive System Function

Breaks down food into absorbable parts

Eliminates waste

Urinary (renal) System Structure

Kidneys, Ureters, Bladder, Urethra

Urinary (renal) Systems Function

Eliminates nitrogenous waste

Regulates body water levels

Maintains blood electrolytes and acid-base balance

Male Reproductive System Structure

Scrotum, Testes, Ductus Deferens, Penis

Glands — prostate, Seminal Vesicles, Bulbo-urethral gland

Male Reproductive System Function

Reproduce offspring

Produce sperm and testosterone

Female Reproductive System Structure

Ovaries

Uterine (fallopian) tube

Uterus

Vagina

Mammary Glands

Female Reproductive System Function

Reproduce offspring

Ovaries produce egg, estrogen, and progesterone

Mammary glands produce milk

Endocrine System Structure

Glands — Pineal, Pituitary, Thyroid, Parathyroid, Thymus, Adrenal, Pancreas, Ovaries, Testes

Endocrine System Function

Secrete Hormones

Regulate growth and metabolism

Lymphatic System Structure

Thymus Gland

Lymphatic Vessels, Thoracic Duct, Lymph Nodes

Red Bone Marrow and Spleen

Lymphatic System Function

Recaptures lost fluids from blood

Involved in immunity

Organ systems do not function ______ of one another; instead they work ______ to perform functions that maintain life

independent, together

The number of necessary life functions

8

All 11 Organ Systems

Integumentary system, muscular system, skeletal system, endocrine system, female & male reproductive system, urinary system, digestive system, respiratory system, cardiovascular system, nervous system, lymphatic system

Eight Necessary Life Functions

Maintaining boundaries between internal and external environments, metabolism, movement, responsiveness, excretion, reproduction, digestion, and growth.

Maintaining boundaries between internal and external environments

Cell membranes

Skin

Metabolism

All chemical reactions that occur in body cells

Catabolism

Anabolism

Catabolism

break down large molecules into smaller parts

Anabolism

build up large molecules from smaller parts

Movement (muscle contractions)

Of body parts (skeletal muscle)

Of substances (cardiac and smooth muscle)

Excretion

Removal of wastes from metabolism and digestion

Urea, carbon dioxide, feces

Responsiveness

Ability to sense and respond to stimuli

Controlled by the nervous system

Reflexes

Reproduction

Cell division for growth or repair

Production of offspring

Digestion

Breakdown of ingested food

Absorption of simple molecules into blood

Growth

Increase in size of body part of organism

Hormones promote growth

5 Survival Needs

Nutrients, oxygen, water, normal temperature, appropriate atmospheric pressure

Nutrients

Chemicals for energy and cell building.

Carbs, fats, proteins, minerals, and vitamins

Oxygen

Required for the production of ATP

Water

Most abundant chemical in body

Provides the necessary environment for the body’s chemical reactions

Fluid base for secretions and excretions

Normal body temperature

37 C or 98.6 F

Affects the rate of chemical reactions

What happens to the body when its temperature falls below normal

chemical reactions will slow or even stop leading to loss of function or death

What happens to the body when its temperature rises above normal

Chemical reactions will proceed too fast and their products (proteins) will break down leading to loss of function or death

Appropriate atmospheric pressure

The force exerted on the body by the weight of air

Required for adequate breathing and gas exchange in lungs

Regions of high altitude (lower atmospheric pressure) causes gas exchange to be

slower; there will be less nutrients available for metabolic activities

Homeostasis

The body’s ability to maintain an internal dynamic state of equilibrium, despite changes in external environment

Homeostatic control mechanisms

Involve continuous monitoring and regulation of all factors that can change

Example of variables that can change when referring to homeostatic control mechanisms

body temperature or blood pressure

3 basic components of homeostatic control

Receptor

Control Center

Effector

What happens when an effector occurs

Response either reduces (negative feedback) or enhances stimulus (positive feedback)

Receptor

Takes in sensory information

Control Center

Determines the set point and regulates the body’s response

Variable

A factor in the body that can be modified by the effector

Effector

Carries our the body’s response

Feedback Mechanisms

Interactions among the components of a homeostatic control system to maintain stable internal conditions

Feedback Mechanism System (in order)

1. Stimulus

2. Receptor

3. Input

4. Output

5. Respond

Negative Feedback

Most feedback mechanisms in body are negative feedback

Response reduces or shuts off original stimulus

variable changes in opposite direction of initial change

Examples of negative feedback

regulation of body temperature

Positive feedback

Response increase the original stimulus

rare and infrequent mechanism

Examples of positive feedback

enhancement of labor contractions by oxytocin

Homeostatic imbalance

disturbance of homeostasis

What happens during homeostatic imbalance

increases risk of disease

contributes to changes associated with aging

negative feedback mechanisms may become overwhelmed

positive feedback mechanisms may take over

Anatomical position

body erect, upright

feet slightly apart

palms facing forward

thumbs point away from body

superior (cranial)

Toward the head end or upper part of a structure of the body

inferior (caudal)

away from the head end or toward the lower part of a structure of the body; below.

Ventral (anterior)

towards the front; in front of

Dorsal (posterior)

Toward or at the back of the body; behind

Medial

Toward or at the midline of the body; on the inner side of

Lateral

Away from the middle of the body; outer side of

Intermediate

Between a more medial and a more lateral structure

Proximal

Closer to the origin of the body part or the point of attachment

Distal

farther away from the origin of a body part of point of attachment

Superficial (external)

Toward or at the body surface

Deep (internal)

Away from the body surface; more internal

Body plane

flat surface along which body or structure may be cut for anatomical study

Sections

cuts or sections made along a body plane

3 most common body planes

Sagittal plane

Frontal (coronal) plane

Transverse (horizontal) plane

Sagittal plane

Divides the body into right and left parts

Midsagittal (median) plane

Lies on midline

Parasagittal plane

Not on midline

Frontal (coronal) plane

Divides body into anterior and posterior parts

Transverse (horiztonal) plane

Divides body into superior and inferior parts

Oblique section

Result of cuts at angle other than 90 degrees to vertical plane

Dorsal Body Cavity

Protects the Nervous System

What the cranial cavity encases

brain