Human Body Systems and Cell Types: Anatomy and Function

Nervous System

 fast control, communication, coordinates body. (brain, spinal cord)

Endocrine System

Hormones + long-term regulation

(Pituitary, thyroid)

Integumentary System

Protection, temperature, sensation (Skin, hair)

Skeletal System

Support, protection, blood formation (Bones, cartilage)

Muscular System

Movement, posture, heat (Skeletal muscle, heart muscle)

Cardiovascular System

Transport nutrients, gases, wastes (Heart, blood vessels)

Respiratory System

Brings O₂ in and CO₂ out for our body (lungs, trachea)

Digestive System

Break down food, absorb nutrients (Stomach, small intestine)

Urinary System

Remove waste, balance water & salts (kidneys, bladder)

Lymphatic/Immune System

Defend against disease, return fluids (Lymph nodes, spleen)

Reproductive System

Produce gametes, enable reproduction (ovaries/testes, uterus, penis)

Interdependency of Organ Systems

1. Respiratory + Cardiovascular: Lungs supply O₂ → heart pumps to tissues

2. Digestive + Circulatory: Nutrients absorbed → blood carries to cells

Cell

basic and smallest living unit of life

Function of Cells

carry out chemical activities needed to sustain life, and divide to form/repair tissues.

Importance of Cells

cells form tissues which allow for the division of labor among the body systems.

Cell Composition

carbon, oxygen, hydrogen, and nitrogen

4 Primary Tissue Types

epithelial, connective, nervous, and muscle tissues interweave to form the fabric of the body.

Epithelial Tissue (form, function, shapes, layers)

Form: cells are Packed together in sheets, one free surface, no blood vessels, heals easily

Function: Protect, absorb, filter, secrete

Shapes: Squamous (flat), Cuboidal (cube), Columnar (tall)

Layers: Simple = 1 layer, Stratified = many layers

( Skin, stomach lining, kidneys)

Connective Tissue (form, function, type)

Form: Made of Cells + extracellular matter, blood supply varies

Function: Support, protect, bind, transport

Types: Loose, Dense, Adipose, Cartilage, Bone, Blood

Muscle Tissue

Can contract, respond to signals, stretch, and go back to shape.

Skeletal = voluntary, striated, many nuclei

Cardiac = involuntary, striated, 1 nucleus, discs, mitochondria

Smooth = involuntary, spindle-shaped, no stripes, 1 nucleus

Nervous Tissue

Form: Neurons with long extensions, helper cells

Function: Send messages, controls all bodily functions -> signals are sent via electoral currents in order to communicate

(Brain, spinal cord, nerves)

Red Blood Cell

Small and concave with no nucleus in the center so RBC is thinner in the center and is more flexible which increases surface area for oxygen uptake and release. Therefore RBC can move more freely throug blood vessels and hemoglobin has more room to transport O2.

Cardiac Muscle

Cardiac muscle cells are striated with a central nucleus. They are connected by intercalated discs, which contain gap junctions that aren't too tight for rapid ion exchange and electrical signals between cells. These cells have many mitochondria to provide continuous energy for constant contractions so the heart is efficient and reliable (involuntary).