Unit 1: Body Organization and Homeostasis

Unit 1: Body Organization and Homeostasis

Tamalpais High School

Honors Physiology

Hippocrates

Greek physician born in 460 BC “Hippocratic Oath” Today Hippocrates is known as the "Father

of Medicine"

What exactly will we study in physiology?

Anatomy vs. Physiology

STRUCTURE vs. FUNCTION

Human Body Orientation

Body directional planes Body cavities Body regions Why?

Body Directional Planes

Sagittal Midsagittal Frontal (aka Coronal) Transverse

Fig 1.21

Body Cavities

Fig. 1.9

Body Regions

Fig. 1.24

Human Body Orientation

Anatomical position Superior vs. Inferior Medial vs. Lateral Distal vs. Proximal Deep vs. Superficial Ipsilateral vs.

ContralateralFig. 1.20

Human Body Orientation

Anterior vs. Posterior Ventral vs. Dorsal

Homeostasis

The body’s ability to maintain a stable internal environment– examples: human

body temperature, water balance, salt/ion balance, oxygen/CO2 balance, blood pH, etc

Fig 1.7

A Homeostatic Mechanism

Fig 1.6

Example Example mechanismmechanism

Gross vs. Fine Anatomy

Gross anatomy

Fine anatomy– involves cells and

tissues – Histology = study of

tissues

Levels of Organization

Fig. 1.3

Histology & Pathology

Histology: The study of tissues

that compose the body

Pathology: the study of disease

Tissues

Cells organize into tissues– Tissue = Cells + extracellular matrix (EM)

Nonliving Made by the cells Fig. 5.24

4 Main Tissue Types

1. Epithelial tissue • Protective covering• One “free” side• Other side: basement membrane• Tightly packed, little EM• Classified according to shape and # of layer of cells

Fig. 5.6

4 Main Tissue Types

Epithelial cell # of layers:– Simple – one layer– Stratified – two or more layers

Epithelial cell shape:– Squamous - flat– Cuboidal – cube – Columnar – tall, elongated

What would simple cuboidal epithelial What would simple cuboidal epithelial

tissue look like?tissue look like?

Fig. 5.4

4 Main Tissue Types

2. Connective Tissue– Lots of EM– Binds structures, provides support and protection,

fills spaces, stores fat, produces blood cells, and protects against infections

Figs 5.21 & 5.24

4 Main Tissue Types

Types of Connective Tissue:– Loose CT– under most layers of epithelium– Adipose – stores fat– Dense CT – very strong but stretchy; tendons &

ligaments– Bone– Blood– Cartilage

Hyaline Elastic Fibrocartilage Figs 5.26 & 5.27

4 Main Tissue Types

Figs 5.28, 29, and 30

3. Muscle Tissue– Skeletal muscle

– Cardiac muscle

– Smooth muscle

4 Main Tissue Types

4. Nervous tissue– Communication– Example cells include neurons (nerve cells)

Fig. 5.31

Major Chemical Elements in the Body

65% Oxygen (O2) 18.5% Carbon (C ) 9.5% Hydrogen (H) 3.2% Nitrogen (N) Total O,C,H, & N =

approx 96% of the body by weight

Organic substances contain both C & H

The rest are inorganic substances

– electrolytes = inorganic substances that dissolve in water

Electrolytes

Electrolyte: any substance containing free ions that make the substance electrically conductive

Examples: Na+, Cl-, Ca2+, K+, Why are they important?

Trace Elements

A trace element – needed in very small ( i.e. “trace”…) amounts – crucial to human survival

Examples – iron (Fe) - part of hemoglobin molecule– zinc (Zn) – in several enzymes– copper (Cu) – bone and melanin development– iodine (I ) – synthesis of thyroid hormones

Iodized salt!

Human Body Systems

1. Circulatory (cardiovascular) 2. Immune

3. Nervous & Senses

4. Digestive

5. Muscular

6. Skeletal

7. Integumentary

8. Endocrine

9. Respiratory

10. Excretory

11. Reproductive