seeley chapter 1

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Chapter 1The Human Organism

Cells of the Peritoneum

Characteristics of Living Things

Organization


Responsiveness


Growth and Differentiation


Reproduction


Movement


Metabolism and Excretion

Definitions

Anatomy – Study of structure

Physiology – Study of function

Anatomy and Physiology

• Anatomy is the study of the structures of the body

– Systemic anatomy is the study of the body by organ systems

– Regional anatomy is the study of the body by areas

– Surface anatomy uses superficial structures to locate deeper structures

• Physiology is the study of the processes and functions of the body

Studies in Anatomy

Microscopic Anatomy

1.Cytology – study of cells

2.Histology – study of tissues

Studies in Anatomy

Gross Anatomy1.Regional anatomy - the study of the body

by areas2.Systemic anatomy - the study of the body

by organ systems3.Surface anatomy - uses superficial

structures to locate deeper structures4.Developmental anatomy – study of

structure throughout the lifespan

Studies in Anatomy

Gross Anatomy

5.Embryology – study of structural development from fertilization to birth

6.Medical or pathological anatomy – study of anatomical changes caused by disease

Studies in Physiology

Cell physiology – study of the function of cells

Special physiology – study of the function of organs

System physiology – study of the function of organ systems

Pathological physiology – study of changes in function caused by disease

Structural and Functional Organization

• Six Levels of Organization

1. Chemical Level

2. Cell Level

3. Tissue Level

4. Organ Level

5. Organ System Level

6. Organism Level


1. Chemical Level Atoms (colored balls) combine to form molecules

2. Cell Level Molecules form organelles, such as the nucleus and mitochondria, which make up cells

3. Tissue Level Similar cells and surrounding materials make up tissues


4. Organ Level Different tissues combine to form organs, such as the urinary bladder

5. Organ System Level Organs such as the urinary bladder and kidneys make up an organ system

6. Organism Level Organ systems make up an organism

Fig. 1.3a

Organ systems of the human body and their associated organs

Fig. 1.3b

Organ systems of the human body and their associated organs

Homeostasis

• Existence and maintenance of a relatively constant internal environment– set point is the ideal normal value (body

temperature)• normal range is the fluctuation around set point

Homeostatic regulation

• Autoregulation – a cell, tissue or organ automatically adjusts to a change in the environment. Example: inflammation

Homeostatic regulation

• Extrinsic regulation: When the nervous or endocrine system controls or adjusts the activity of tissues, organs or organ systems in response to a change in the environment.

Homeostatic regulatory mechanism

• Stimulus – a change in an enviromental factor

• Receptor (sensor) – a sensor that is sensitive to the environmental change

• Control center (integration center) – receives and processes the stimulus. If needed send a message to the effector

Homeostatic regulatory mechanism

• Effector – usually a muscle or a gland. Proves the response to the stimulus.

• The action of the effector determines if the response will take place through negative feedback or positive feedback.

Homeostasis

• Homeostasis is maintained by negative and positive feedback mechanisms

– Negative feedback turns off or reverses the original stimulus

– Positive feedback enhances and up-regulates the initial stimulus (is usually harmful to the body)

Homeostatic imbalance

• A homeostatic imbalance is a disease

• Signs – characteristics of a disease that can be measured

• Symptoms – characteristics of a disease that cannot be measured

Terminology and Body Plane

• Body Positions– Anatomical position

• human standing erect with the face directed forward, the arms hanging to the sides, and the palms facing forward

– Supine – person laying face up– Prone – person laying face down

Terminology and Body Plane

• Directional terms– Always refer to anatomical position

• Right

• Left

• Superior

• Inferior

• Cephalic

• Caudal

• Anterior

• Posterior

• Ventral

• Dorsal

• Proximal

• Distal

• Lateral

• Medial

• Superficial

• Deep

Fig. 1.11

Body Parts and Regions

Fig. 1.12

Body Parts and Regions

Body Planes

• Sagittal plane: divides the body into left and right parts

• Transverse plane: divides the body into superior and inferior parts

• Frontal (coronal) plane: divides the body into anterior and posterior parts

Fig. 1.13

Organ Planes

• Longitudinal section: along its long axis

• Cross (transverse) section: right angle to the long axis

• Oblique section: across the long axis at an angle other than a right angle

Fig. 1.14

Body Cavities

• Thoracic cavity: bounded by the ribs and the diaphragm

• Abdominopelvic cavity: Contains two subdivisions

• Abdominal cavity: bounded by the diaphragm and the abdominal muscles

• Pelvic cavity: surrounded by the pelvic bones

Fig. 1.15

Serous Membranes

• Parietal membrane: lines the wall of the cavity

• Visceral membrane: is in contact with the internal organs

• Serous fluid: secreted by the serous membrane and protects organs against friction

Serous Membranes

• Pericardial cavity: has the pericardium that surrounds the heart

• Pleural cavities: has the pleura that surround the lungs

Serous Membranes

• Peritoneal cavity: has the peritoneum that surrounds certain abdominal and pelvic organs– Mesenteries hold the

abdominal organs in place and provide a passageway for blood vessels and nerves to organs

– Retroperitoneal organs are located “behind” the parietal peritoneum

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