Introduction to Anatomy and Physiology Concepts

Anatomy

The study of the structure of the human body.

Physiology

The study of the function of body parts and systems.

Relationship between Anatomy and Physiology

Structure determines function; anatomy explains how physiology operates.

Gross Anatomy

The study of large body structures visible to the naked eye.

Histology

The study of microscopic body structures like tissues and cells.

Systemic Anatomy

Study of body systems like skeletal, muscular, cardiovascular, etc.

Regional Anatomy

Study of all structures in a particular body region.

Surface Anatomy

Study of external structures and their relation to deeper structures.

Anatomical Position

Standing upright, feet together, arms at sides, palms forward.

Frontal Plane

Divides the body into anterior (front) and posterior (back) parts.

Transverse Plane

Divides the body into superior (upper) and inferior (lower) parts.

Midsagittal Plane

Divides the body into equal left and right halves.

Superior

Toward the head or upper part of the body.

Inferior

Away from the head or toward the lower part of the body.

Anterior (Ventral)

Toward the front of the body.

Posterior (Dorsal)

Toward the back of the body.

Medial

Toward the midline of the body.

Lateral

Away from the midline of the body.

Proximal

Closer to the origin of a body part or point of attachment.

Distal

Farther from the origin of a body part or point of attachment.

Superficial

Toward or at the body surface.

Deep

Away from the body surface; more internal.

Major Body Cavities

Dorsal and ventral cavities.

Dorsal Cavity

Contains the brain and spinal cord (cranial and vertebral cavities).

Thoracic Cavity

Contains the heart and lungs.

Abdominal Cavity

Contains digestive organs like liver, stomach, intestines.

Pelvic Cavity

Contains bladder, reproductive organs, and rectum.

Epithelial Tissue

Covers and protects body surfaces and lines organs.

Connective Tissue

Supports, protects, and binds other tissues.

Muscle Tissue

Enables movement through contraction.

Nervous Tissue

Controls body functions by transmitting electrical signals.

Osteoblasts

Build new bone tissue.

Osteocytes

Maintain bone matrix.

Osteoclasts

Break down and resorb bone tissue.

Compact Bone

Dense bone tissue that forms the outer layer of bones.

Spongy Bone

Porous inner bone that contains trabeculae and marrow.

Intramembranous Ossification

Direct bone development from mesenchyme (e.g., skull).

Endochondral Ossification

Indirect bone formation from cartilage models.

Epiphyseal Plate

The growth plate where long bones grow in length.

Epiphyseal Line

What the epiphyseal plate becomes after puberty.

Stages of Bone Healing

Hematoma, fibrocartilaginous callus, bony callus, bone remodeling.

Growth Hormone

Stimulates growth plates.

Parathyroid Hormone (PTH)

Increases blood calcium by activating osteoclasts.

Calcitonin

Decreases blood calcium by inhibiting osteoclasts.

Osteoporosis

A condition characterized by weakened bones.

osteoporosis

A condition with decreased bone density and increased fracture risk.

rickets

Weak bones in children due to vitamin D or calcium deficiency.

osteomalacia

Soft bones in adults due to vitamin D deficiency.

osteosarcoma

A malignant bone tumor.

fibrous joints

Immovable joints connected by dense connective tissue.

cartilaginous joints

Joints connected by cartilage, slightly movable.

synovial joints

Freely movable joints with a joint cavity.

hinge joint

A joint that allows movement in one plane (e.g., elbow).

ball-and-socket joint

A joint allowing multiaxial movement (e.g., hip, shoulder).

pivot joint

A joint allowing rotation around a single axis (e.g., atlas/axis).

condylar joint

A biaxial joint allowing flexion-extension and abduction-adduction.

saddle joint

A biaxial joint allowing thumb opposition.

rheumatoid arthritis

Autoimmune joint inflammation affecting synovial membranes.

osteoarthritis

Degenerative joint disease due to cartilage wear.

gout

A joint condition caused by uric acid crystal buildup.

arteries

Carry blood away from the heart.

veins

Carry blood toward the heart.

capillaries

Allow exchange of gases, nutrients, and wastes between blood and tissues.

hydrostatic pressure

The pressure that pushes fluid out of capillaries.

oncotic pressure

Pressure that pulls fluid into capillaries due to plasma proteins.

lymphatic system

Returns excess interstitial fluid to the bloodstream and filters it.

muscle tissue types

Skeletal, cardiac, and smooth.

skeletal muscle

Voluntary muscle attached to bones for movement.

cardiac muscle

Involuntary muscle found only in the heart.

smooth muscle

Involuntary muscle found in walls of hollow organs.

motor unit

A single motor neuron and all the muscle fibers it controls.

fascicle

A bundle of skeletal muscle fibers.

nervous system parts

Central nervous system (CNS) and peripheral nervous system (PNS).

sensory (afferent) division

Brings signals from sensory receptors to the CNS.

motor (efferent) division

Sends commands from the CNS to muscles and glands.

interneurons

Neurons that connect sensory and motor pathways within the CNS.

reflex arc components

Receptor, sensory neuron, integration center, motor neuron, effector.

astrocytes

Support neurons, regulate the environment, and assist in learning and memory.

microglia

Act as immune cells in the CNS by phagocytosing debris and microbes.

ependymal cells

Line ventricles and circulate cerebrospinal fluid (CSF).

oligodendrocytes

Myelinate CNS axons.

Schwann cells

Myelinate axons in the PNS.

satellite cells

Support neuron cell bodies in PNS ganglia.

myelin

Increases the speed of nerve impulse conduction.

nerves

Bundles of axons in the PNS.

epineurium

Surrounds the entire nerve for protection.

neuromuscular junction

The site where a motor neuron communicates with a muscle fiber.

acetylcholine (ACh)

The neurotransmitter used at the neuromuscular junction.

motor end plate

The region of the muscle fiber membrane that receives neural signals.

Sympathetic

fight or flight

Parasympathetic

rest and digest