Organization of the Human Body

Week 2

Anatomy

Branch of biology concerned with bodily structure of organisms

Physiology

Branch of biology concerned with normal functions of organisms

Levels of Structural Organization

Chemical, Cellular, Tissue, Organ, Organ Systems, Organism

Chemical

Atoms & Molecules

Cellular

Cells (specialized structures/functions)

Tissues

Groups of cells and materials that perform specific functions

Types of Tissues

Epithelial, Connective, Muscle, Nervous

Organ

Types of tissues joined together to perform specific functions, recognizable shape

Organ Systems

Related organs with a common purpose

Organism

Living individual, levels from chemical to systems working as one

Basic Life Processes

Metabolism, Responsiveness, Movement, Growth, Differentiation, Reproduction

Metabolism

Sum of all chemical processes that occur in the body

Anabolism

Buildup of substances (Glycogenesis or protein synthesis)

Catabolism

Breakdown of substances (Glycogenolysis or proteolysis)

Responsiveness

Ability to detect and respond to changes (Nerve cells generate electrical signals)

Movement

As a whole, individual organs, single cells, structures in cells

Growth

Size of organism, cells, # of cells

Differentiation

Unspecialized to specialized (stem cells, RBC)

Reproduction

Formation of new cells or organism

Homeostasis

State of balance in the body with respect to functions and composition of fluids and tissues

An organism is said to be in homeostasis when its internal
environment:

Optimal concentrations of nutrients, gases, ions and water, maintains optimal temperature, maintains optimal pressure for the health of the cells

Internal Feedback System (maintains homeostasis)

Circular sequence of events where info about the status of a situation is reported to a central control unit

Components of Feedback Loop

Receptor, Control Centre, Effector

Receptor

Senses the change in the variable

Control Centre

Compare value to reference point, provides response

Effector

Makes changes to the variable

Negative Feedback Loop

Response where the stimulus makes changes that reverse/reduce the stimulus

Examples of Negative Feedback Loop

Temperature receptors feel cold - stimulates shivering

High BP - stimulates vasodilation

Positive Feedback Loop

Stimulus causes an increase in the original stimulus. Does NOT maintain homeostasis

Examples of Positive Feedback Loop

Childbirth - hormones released during labour increase contractions

Clotting - Platelets gather and release an enzyme that promotes platelet aggression

Stress

Any stimulus that creates an imbalances in the internal environment. Can lead to dysfunction.

Supine

Prone

Lateral Recumbent (L/R)

Fowler’s

Trendelenburg

Regional Names

Head (cephalic), Neck (cervical), Trunk, Upper Extremities, Lower Extremities

Abdominopelvic Quadrants

RUQ, LUQ, RLQ, LLQ

Abdominopelvic Regions

Right & Left Hypochondriac, Epigastric, Right & Left Lumbar, Umbilical, Right & Left Inguinal (Iliac), Hypogastric (Pubic)

Anterior

Near the front of the body

Interior

Near the back of the body

Superior

Near the head

Inferior

Away from the head

Medial

Nearer to the midline

Lateral

Farther from the midline

Ipsilateral

On the same side of the body

Contralateral

On the opposite of the body

Intermediate

Between two structures

Proximal

Nearer to the origin of structure

Distal

Farther from the origin of structure

Superficial

Towards or on the surface of the body

Deep

Away from the surface of the body

Anatomical Position

Facing forwards, palms forwards

Midsagittal

Through the midline

Parasagittal

Slightly left or right from midsagittal

Frontal

Front & Back

Transverse

Top & Bottom

Oblique

Any angle

Body Cavities

Spaces within the body that protect and support internal structures (Cranial, Vertebral, Thoracic, Abdomino-Pelvic)

Cranial Cavity

Formed by cranial bones, contains brain

Vertebral Cavity

Formed by vertebral column, contains spinal cord and spinal nerves

Pleural Cavity

Fluid-filled space surrounding lungs and chest wall

Pericardial Cavity

Fluid-filled space surrounding heart

Mediastinum

Region surrounding heart between lungs

Abdominal Cavity

Contains digestive organs

Pelvic Cavity

Contains reproductive organs and rectum

Retroperitoneal Organs

Behind/outside peritoneum membrane, contains urinary organs

Serous Membrane

Double layered membrane with serous fluid

Visceral Layer

Attached to “viscera” (internal organs)

Parietal Layer

Attached to wall of the cavity

Pleural Membrane

Serous membrane of pleural cavity, lubricates lungs against wall of pleural cavity, air/blood can get trapped

Pericardium

Fibrous sac that encloses the heart, has outer fibrous layer and inner double layered serous membrane

Peritoreum

Serious membrane of abdominal cavity

Parts of Integumentary System

Skin, hair, nails, sweat/oil glands

Purpose of Integumentary System

Protection, temperature regulation, elimination of waste, makes vitamin D, sensory

Parts of Skeletal System

Bones, joints, cartilage

Purpose of Skeletal System

Protection, support, movement (muscles), produce RBC, stores minerals/lipids

Parts of Muscular System

Skeletal, smooth, cardiac muscle

Purpose of Muscular System

Produces movement, stabilizes body position, circulates blood/fluid, generates heat

Parts of Nervous System

Brain, spinal cord, nerves, sensory tissues

Purpose of Nervous System

Generates action potential, regulates body activities, feedback systems

Parts of Endocrine System

Hormone producing glands; pituitary, hypothalamus, adrenal, thyroid

Purpose of Endocrine System

Regulates body activities by releasing hormones (chemical messengers transported in the blood to targeted tissues)

Parts of Respiratory System

Lungs, trachea, bronchi, pharynx

Purpose of Respiratory System

Gas exchange between environment and blood cells CO2/O2, helps regulate acid base balance

Parts of Cardiovascular System

Heart, blood, vessels

Purpose of Cardiovascular System

Pumps blood to all tissues in the body, carries O2 and nutrients to cells, transports cellular waste for elimination, regulation of acid base, temperature and water content

Parts of Digestive/Gastrointestinal (GI) System

Esophagus, stomach, intestines, pancreas, gallbladder, salivary glands

Purpose of Digestive/Gastrointestinal (GI) System

Physical and chemical breakdown of food, absorbs nutrients, eliminates waste

Parts of Urinary/Renal System

Kidneys, ureters, bladder, urethra

Purpose of Urinary/Renal System

Produces, stores, eliminates waste, regulates blood volume, chemical composition, acid base balance, body mineral balance, production of blood cells

Parts of Lymphatic & Immune System

Lymphatic fluids, lymph vessels, lymph nodes, spleen, thymus, tonsils

Purpose of Lymphatic & Immune System

Returns proteins and fluids to blood, carries lipids from GI tract to blood, produces lymphocytes that protect against disease

Parts of Reproductive System

Gonads, testes, ovaries, uterus, vagina, penis

Purpose of Reproductive System

Production of sperm and eggs, reproduction of a new organism