Introduction to Anatomy & Physiology

Anatomy and Physiology Defined

Anatomy is the study of structure and the relationship among structures.

Anatomy and Physiology Defined

Physiology is the study of how body structures function.

Levels of Structural Organization

The human body consists of several levels of structural organization: chemical, cellular, tissue, organ, system, and organismic levels.

Structural Plan:

The human body has certain general characteristics.

Among the characteristics are a backbone, a tube within a tube organization, andbilateral symmetry.

Directional Terms: indicate the relationship of one part of the body to another.

1. superior (toward the head)2. inferior (away from the head)3. anterior (near front of the body)4. posterior (near back of the body)5. medial (near midline of the body)6. lateral (near side of the body)7. intermediate (between a

medial and lateral structure)8. ipsilateral (same side of the body)9. contralateral (opposite side of

body)

10. proximal (nearer the attachment of an extremity to the trunk or a structure)

11. distal (farther from the attachment of an extremity to the trunk or a structure)

12. superficial (on the surface of the body)

13. deep (away from the surface of the body)

14. parietal (outer wall of a cavity)

15. visceral covering of an organ).

Planes

Planes are imaginary flat surfaces that are used to divide the body or organs into definite areas.

A median plane is a vertical plane through the midline of the body that divides the body or organs into equal right and left sides

A sagittal plane is a plane parallel to the midsagittal plane that divides the body or organs into unequal right and left sides

A frontal/coronal plane is a plane at a right angle to a median (or sagittal) plane that divides the body or organs into anterior and posterior portions

A horizontal/transverse plane is a plane parallel to the ground and at a right angle to the median, sagittal, and frontal planes that divides the body or organs into superior and inferior portions.

Abdominopelvic Regions

To describe the location of organs easily, the abdominopelvic cavity may be divided into nine regions by drawing four imaginary lines.

The names of the nine abdominopelvic regions are epigastric, right hypochondriac, left hypochondriac, umbilical, right lumbar, left lumbar, hypogastric (pubic), right iliac (inguinal), and left iliac (inguinal).

Directional Terms

In the following activity you will practice labeling directional terms on a body.

Trace the outline of a group members body on butcher paper.

Label the following directional terms: superior, inferior, anterior, posterior, medial, lateral, intermediate, ipsilateral, contralateral, proximal, & distal.

You need to create a REFERENCE POINT for ipsilateral & contralateral (eye patch).

Make if LEGIBLE & colorful (if there is time)

Abdominopelvic Quadrants

The abdominopelvic cavity may be divided into four quadrants by passing imaginary horizontal and vertical lines through the umbilicus.

The names of the four abdominopelvic quadrants are right upper quadrant (RUQ), left upper quadrant (LUQ), right lower quadrant (RLQ). And left lower quadrant (LLQ).

Body Cavities Spaces in the body that contain internal organs are

called cavities. There are two major body cavities: Dorsal & Ventral

Cavity. The dorsal body cavity contains the brain and the spine.

It is subdivided into cranial (brain) and vertebral/spinal cavities (spinal cord)

Ventral body cavity is the space of the body’s trunk anterior to the vertebral column and posterior to the sternum and abdominal muscle wall.

Further divided into: The thoracic cavity (heart, lungs, trachea, etc) and the abdominopelvic cavity (liver, stomach, kidneys, etc).

 

BODY CAVITY MEMBRANES

The body cavities are lined with serous membranes that provide a smooth surface for the enclosed internal organs.

Abdominal cavity membrane: peritoneum.  Dorsal cavity membrane: Dura mater Thoracic cavity membrane: pleura Membranes are doubled layered with lubricant fluid between

them. The 2 layers:

Visceral layer: – the thin membranes that covers an organ in a cavity.

Parietal: actual wall of a body cavity or lining membrane that covers its surface.

Example: Parietal peritoneum: line abdominal cavity. Visceral peritoneum: lines abdominal organs

 

Descriptive Terms of the Body Region

Terms used for the body found on your handout.

Descriptive Terms of the Body Region

Body Types

Somatotype is a term used to describe a specific body build or physique.

There are three body types: Endomorph Mesomorph Ectomorph

Endomorph Heavy rounded physique

characterized by large accumulation of fat in trunk and thighs.

“Apple shaped” endomorphs have large waistlines & more health risks.

Pear shaped endomorphs have smaller waists and more fat in the hip, thighs, and buttock. Less health risks then apples.

Apple

Pear

Mesomorph

Muscular physique

Ectomorph

Thin, fragile physique characterized by little body fat.

Body Types In your journal, make a chart with the column below:

Looking through a magazine, find examples of the three body types.

Cut out the pictures and glue them on to your journal.

Point out the following body regions on your pictures: orbital, nasal, buccal, pectoral, deltoid, axillary, carpal, femoral, patellar, tarsal, lumbar, gluteal, & popliteal.

Mesomorph Endomorph Ectomorph

Homeostasis Homeostasis is a condition in which the

internal environment of the body remains relatively constant in terms of chemical composition, temperature, and pressure.

All body systems attempt to maintain homeostasis.

Homeostasis is controlled mainly by the nervous and endocrine systems.

Set point of range

The normal reading or range of a condition.

For example: set point of glucose/ml is between 80 and 100 mg.

Homeostasis attempts to keep reading within the set point of range.

Homeostatic control measures

Processes for maintaining homeostasis is called homeostatic control measures.

Feedback control loops are used to accomplish self regulation.

Information is transmitted by way of nerve impulses or chemical messengers called hormones.

Components of Control Mechanisms

1. Sensor mechanisms2. Integrating or control center3. Effector mechanism4. Feedback

Signals can be either Afferent (move toward a particular center) or Efferent (moves away from a particular center)

Sensory Mechanisms

Nerve cells or hormone producing glands act as homeostatic sensors.

They identify changes conditions (temp., blood glucose) that move it out of the set point of range.

If deviations from set point range occur, an afferent signal is sent to the integration or control center.

Nerve receptors on skin feel cold

Sends info

Integration/Control Center

Integration center receives signal. Information is analyzed. Efferent signal then travels from

the center to a effector mechanism, where an action is initiated.

Nerve receptors on skin feel cold.

Hypothalamus receive info

Sends info

Sends instructions

Effectors

Effectors are organs, such as muscles or glands, that directly influence the body’s physiology.

An effector can increase or decrease temperature, heart rate, blood pressure, etc.

Nerve receptors on skin feel cold.

Hypothalamus receive infoMuscle reacts by shivering.

Sends info

Sends instructions

Temperature increases.

Feedback Homeostatic controls can be labeled as

positive or negative. Most homeostatic controls are negative.

Positive feedback

Positive feedback mechanisms are designed to accelerate or enhance the output created by a stimulus that has already been activated.

Ex. Blood clotting increase the amount of platelets released.

Negative Feedback

Negative feedback mechanism consists of bringing a system back to its normal range of functioning.

Ex. Shivering brings low temperature back up.