Chapter 3 Organization of the Body

Levels of Organization Structural levels of organization: Cells Tissues Organs Systems Organism The body consists of structural levels of organization: Cells Tissues Organs Systems Organism

Levels of Organization—(cont.) The levels of organization in the body beginning with the cell and ending with the organism.

Cells Common elements: Cell membrane: allows certain substances in and out Nucleus: directs activities within cell Mitochondria: generates energy for the cell Cytoplasm: watery fluid that fills spaces outside the nucleus Cells The cell consists of various components but have common elements. Cell membrane—allows certain substances to pass in and out of the cell. Nucleus—directs activities within cell. Mitochondria—generates energy for the cell. Cytoplasm—watery fluid that fills spaces outside of the nucleus.

Tissues Cells make up tissue Similar cells working together to perform similar tasks Four types 1. Muscle 2. Connective 3. Nerve 4. Epithelial Tissues Tissues are composed of similar cells that work together to perform similar tasks. Four types of body tissues: Muscle Connective Nerve Epithelial

Organs Tissues with common functions form organs Structures that perform specialized functions Examples: brain, stomach, heart Organs Tissues with common functions come together to form the organs in the body. Organs are structures that perform specialized functions. Examples are brain, stomach, and heart.

Systems Group of organs forms systems Each system has own special purpose Systems A group of organs forms a system in the body. Each system has a common purpose to perform specialized functions.

Anatomic Position Body erect, facing forward Palms facing forward, arms at sides Left and right from subject’s perspective, not observer’s Anatomic Position The anatomic position: the body is erect and facing forward, and the arms are at the sides with the palms of the hands facing forward. Directional terms are language-specific and are specified relative to the anatomic position.

Directional Terms Superior (cranial; cephalic) Inferior (caudal) Anterior (ventral) Posterior (dorsal) Medial Lateral Proximal Distal Supine Prone Directional terms: Superior or cranial; cephalic—toward the head or above Inferior or caudal—toward the feet or below Anterior or ventral—relate to the front of the body Posterior or dorsal—relate to the back of the body Medial—toward the midline of the body Lateral—away from the midline or toward the side Ask: If one is standing in the correct anatomical position, is the thumb medial or lateral to the little finger? Ask: Is the hip superior or inferior to the knee?

Directional Terms—(cont.) Proximal- nearer to the body trunk or point of attachment to the body Distal- further from the body trunk or point of attachment Supine- position in which patient is lying face up Prone- patient is lying face down

Body Planes Body planes are imaginary surfaces within the body. Three planes: Frontal—divides the body into anterior and posterior Sagittal—divides the body into right and left Transverse—divides the body into superior and inferior portions

Body Cavities and Divisions Cranial cavity Spinal cavity Thoracic cavity Abdominopelvic cavity Body Cavities A body cavity is defined as a hollow space that contains body organs. Cranial cavity houses the brain. Spinal cavity houses the spinal cord. Thoracic cavity contains the lungs. Abdominopelvic cavity contains digestive and reproductive organs; abdominal cavity and inferior pelvic cavity.

Body Cavities and Divisions—(cont.) Divisions of the Abdomen The abdomen is divided into various sections which help to describe incisions, procedures, pain, etc. Two types of divisions: nine regions or four quadrants Nine regions: hypochondriac (2), epigastric, lumbar (2), umbilical, hypogastric, inguinal (2) Four quadrants: right upper quadrant (RUQ), left upper quadrant (LUQ), left lower quadrant (LLQ), right lower quadrant LRQ)

Body Cavities and Divisions—(cont.) Regions Hypochondriac Epigastric Lumbar Umbilical Hypogastric Inguinal

Regions of the Spinal Column Cervical Thoracic Lumbar Sacral Coccyx Divisions of the Back The back is divided into five sections that correspond to the spinal column. Cervical (7) Thoracic (12) Lumbar (5) Sacral (5 fused into 1) Coccyx (3-4 fused into 1)

Practice In the anatomic position, is the big toe medial or lateral to the little toe? Practice: In the anatomic position, is the big toe medial or lateral to the little toe?

Answer In the anatomic position, is the big toe medial or lateral to the little toe? Medial In the anatomic position, is the big toe medial or lateral to the little toe? Answer: Medial

Practice In the anatomic position, the elbow is _____ to the fingers. distal, proximal, lateral, medial

In the anatomic position, the elbow is proximal to the fingers. Answer In the anatomic position, the elbow is proximal to the fingers.

In the anatomic position, the knee is ____ to the hips. Practice In the anatomic position, the knee is ____ to the hips.

In the anatomic position, the knee is distal to the hips. Answer In the anatomic position, the knee is distal to the hips.

Practice Identify these word elements: Cerv/o Myel/o Inguin/o Chondr/o Cyt/o

Answer Identify these word elements: Cerv/o—neck Myel/o—spinal cord Inguin/o—groin Chondr/o—cartilage Cyt/o—cell

Practice Identify these word elements: Anter/o My/o Neur/o Proxim/o Poster/o

Answer Identify these word elements: Anter/o—front, anterior My/o—muscle Neur/o—nerve, neuron Proxim/o—near Poster/o—back, posterior

Practice Analyze this term: Hypogastric

Hypogastric = pertaining to below the stomach Answer Analyze this term: hypo gastr ic ↓ P R S below stomach pertaining to Hypogastric = pertaining to below the stomach

Practice Analyze this term: Myalgia

Answer Analyze this term: My algia ↓ R S muscle pain Myalgia = muscle pain

Practice Analyze this term: Hypochondriac

Answer Analyze this term: Hypo chondr iac ↓ P R S below cartilage pertaining to Hypochondriac—pertaining to below cartilage (this refers to the region below the rib cartilage)

Practice Analyze this term: Thoracic

Thoracic = pertaining to the chest Answer Analyze this term: thor acic ↓ R S chest pertaining to Thoracic = pertaining to the chest