[BIO 137] Chapter 1: The Human Body: An Orientation

overview of chapter 1

Form

Anatomy

Function

Physiology

In what way does physiology depend on anatomy?

Function relies on form. The operation or function of a structure is promoted or prevented by its anatomy.

Levels of structural organization

Atom/element, molecules organelles, cells, tissue, organ, organ system, organism

Homeostasis

The body's ability to maintain a stable internal environment despite external changes.

Essential life processes

Boundaries, movement, responsiveness, digestion, metabolism, excretion, reproduction, growth, pathway

Boundaries

Essential for maintaining a distinct separation between internal and external environments. Ex: Integumentary system

Movement

The act of changing physical location or position, which is necessary for various life processes, including locomotion and the movement of substances within the body. Ex: Muscular system

Responsiveness

The ability of an organism to sense and respond to changes in its environment, crucial for survival. Ex: Nervous system.

Digestion

The process by which the body breaks down food into absorbable nutrients, essential for energy and growth. Ex: Digestive system.

Metabolism

The sum of all chemical reactions occurring within the body, enabling growth, reproduction, and energy production. Ex: Endocrine system

Excretion

The process of removing waste products from the body. Ex: Urinary system

Reproduction

Allows for the creation of offspring. Ex: Reproductive system

Growth

Allows for an organism to grow to its full potential and change.

Pathway

Allows for clear and easy movement of nutrients.

Integumentary system

The body’s main boundary from outside elements. Organs: Skin, hair, nails

Skeletal system

Provides support and structure for the body. Organs: Bones, joints

Muscular system

Allows manipulation, locomotion of the body and produces heat. Organs: Skeletal muscles

Nervous system

Main “control system” of the body, transmits sensory information to body using electricity. Organs: Brain, spinal cord, nerves

Endocrine system

Secretes hormones and chemicals to regulate and support metabolism and growth. Organs: Pineal gland, pituitary gland, thyroid gland, thymus, adrenal gland, pancreas, testis, ovary

Cardiovascular system

Supplies oxygen and nutrients for the body. Organs: Heart, blood vessels

Lymphatic/immune system

Attacks foreign substances in the body and drains fluids. Organs: Red bone marrow, thymus, lymphatic vessels, thoracic ducts, spleen, lymph nodes

Respiratory system

Supplies body with oxygen and removes carbon dioxide. Organs: Nasal cavity, pharynx, larynx, trachea, lung, bronchus

Digestive system

Breaks down food into nutrients to be absorbed by the body, also excretes waste. Organs: Oral cavity, esophagus, liver, stomach, small intestine, large intestine, rectum, anus

Urinary system

Removes nitrogenous waste and regulates water content in the body. Organs: Kidney, ureter, bladder, urethra

Reproductive system

Allows the body to produce offspring. Male organs: Prostate, penis, testis, scrotum, dectus deferens. Female organs: Mammary glands, ovary, uterine tube, uterus, vagina

Law of mass balance

The amount of a substance that the body takes in must be the same as the amount of that substance the body loses.

Homeostatic control system

1.) Receptor: detects stimulus

2.) Control center: determines set point in which the variable is to be changed

3.) Effector: Carries out control centers response to stimulus

Negative feedback mechanism

Cause the variable to change in a direction opposite to that of the initial change, returning it to its “ideal” value (the set point). Ex: Shivering in response to feeling cold.

Positive feedback mechanism

The initial response enhances the original stimulus so that further responses are even greater. Ex: Blood clotting

Feedforward (anticipatory) response

Maintains homeostasis by taking action in anticipation of a change to the internal environment. Ex: Salivating after smelling food

Superior

Above/toward head

Inferior

Below/toward feet

Anterior

Front of the body/toward chest

Posterior

Back of the body/toward glutes

Medial

Middle of the body/towards “midline”

Lateral

Away from middle of the body/away from “midline”

Intermediate

Between medial and lateral

Proximal

Point on limb closer to trunk

Distal

Point on limb farther from trunk

Superficial

Towards body’s surface

Deep

Towards body’s insides

Axial

“Axis” of body: Head, neck, trunk

Appendicular

Appendages, limbs

Saggital plane

Divides body into left/right sections
Midsaggital = Midline

Frontal/Coronal plane

Divides body into anterior/posterior sections

Traverse plane

Divides body into superior/inferior sections

Dorsal body cavity

Protects fragile nervous system organs. Subdivisions: Vertebral, cranial

Ventral body cavity

Protects viscera/organs. Subdivisions: Thoracic, abdominal, pelvic

Vertebral cavity

Part of the dorsal cavity. Protects spinal cord.

Cranial cavity

Part of the dorsal cavity. Protects brain.

Thoracic cavity

Part of the ventral cavity. Protects heart and lungs. Split into three sections: Superior mediastinum, pleural, pericardial

Abdominal cavity

Part of the ventral cavity. Protects digestive organs.

Pelvic cavity

Part of the ventral cavity. Protects urinary and reproductive system.

Serosa/serous membrane

Double-layered membrane that protects and lines the walls of the ventral cavity and outer surfaces of organs.

Parietal serosa

Layer of the serous membrane lining the cavity walls.

Visceral serosa

Layer of the serous membrane directly lining the organs.

Nine abdominopelvic regions

Four abdominopelvic quadrants

Surface body regions