Chapter 1 Anatomy

Serous Membranes form two layers:

-Parietal layer -Visceral layer

Coronal Plane

A coronal (kˉor′ˉo-n˘al; korone = crown) plane, also called a frontal plane, is a vertical plane that divides the body or organ into anterior (front) and posterior (back) parts. (Page 11).

Anterior

Anterior In front of; toward the front surface The stomach is anterior to the spinal cord. (Page 12).

Atoms

Atoms are the smallest units of matter that exhibit the characteristics of an element, such as carbon and hydrogen. (Page 6).

Caudal

Caudal At the rear or tail end The buttocks are caudal to the head. (Page 12).

Cranial

Cranial (cephalic) At the head end The shoulders are cranial to the feet. (Page 12).

In a negative feedback mechanism, which of the following events do NOT occur?

D. The effector stimulates or increases the stimulus so the cycle continues

Organismal Level

Highest Level of organization in the body. All body systems function interdependently in an organism, which is the living being. (Page 7).

The term _____ refers to the sum of all chemical reactions in the body

Metabolism

Adbominalpelvic Regions

Nine compartments, called abdominopelvic regions, are delineated by using two transverse planes and two sagittal planes. (Page 17).

The term used to describe an appendage structure that is closest to its point of attachment to the trunk is called:

Proximal

Proximal

Proximal Closer to point of attachment to trunk The elbow is proximal to the hand. (Page 12).

Rostral

Rostral Toward the nose or mouth The frontal lobe of the brain is rostral to the back of the head. (Page 12).

Cellular Level

Smallest living structures serve as the basic units of structure and function in organisms. (Page 6).

Superficial

Superficial On the outside The skin is superficial to the biceps brachii muscle. (Page 12).

Hypogastric Region

The hypogastric (hˉı-p ˉo-gas′trik; hypo = under) region lies inferior to the umbilical region. (Page 17).

Right and Left Hypochondriac Regions

The right and left hypochondriac (hˉı-pˉo-kon′drˉe-ak; chondr = cartilage) regions are inferior to the costal cartilages and lateral to the epigastric regions (Page 17).

Components of the homeostatic system

There are three components 1) Receptor 2)Control Center 3)Effector

Molecules

When two or more atoms combine they form a molecule. (Page 6). Example: sugar, water molecule, vitamin

Parietal Layer

a parietal (p˘a-rˉı′˘e-t˘al) layer that typically lines the internal surface of the body wall (Page 15).

Organ Level

composed of organs, which contain two or more tissue types that work together to perform specific, complex functions. The small intestine is an example of an organ that is composed of all four tissue types, which work together to process and absorb digested nutrients. (Page 7).

Nervous Tissue

conducts nerve impulses for communication

Tissue Level

consists of tissues groups of similar cells that perform common functions There are four major types of tissues.

Organ System Level

contains related organs that work together to coordinate activities and achieve a common function. For example, the organs of the digestive system (e.g., oral cavity, stomach, small and large intestine, and liver) work together to digest food particles, absorb nutrients, and expel the waste products. (Page 7).

Epithelial Tissue

covers exposed surfaces and lines body cavities. (Page 7).

Membrane

membrane is a continuous layer of cells, (Page 15).

Connective Tissue

protects, supports, and binds structures and organs. (Page 7).

A midsagittal plane separates the body into:

right and left halves

Visceral Layer

visceral (vis′er-˘al) layer that covers the external surface of the organs (collectively called the viscera) within that cavity. (Page 15).

Organelles

which are microscopic structures found within cells. (Page 6).

Levels of Organization in Humans

-Chemical Level -Cellular Level -Tissue Level -Organ Level -Organ System Level -Organismal Level

Three major anatomic planes of reference include

-coronal -transverse -mid-sagittal

Four Major Types of Tissues

1) Epithelial Tissue 2)Connective Tissue 3)Muscle Tissue 4)Nervous Tissue

The state of maintaining a constant internal environment within an organism is called

Homeostasis

Oblique Plane

In addition to these major planes, there are numerous minor planes called oblique (ob-lˉek′) planes that pass through a structure at an angle (Page 12).

Inferior

Inferior Closer to the feet The stomach is inferior to the heart. (Page 12).

Lateral

Lateral Away from the midline of the body The arms are lateral to the heart. (Page 12).

Muscle Tissue

Produces Movement

Quadrants of the stomach

Some health-care professionals prefer to partition the abdomen more simply into four quadrants, using the umbilicus as the central point and having imaginary transverse and midsagittal planes pass through the umbilicus (figure 1.10b). The quadrants are named right upper quadrant (RUQ), left upper quadrant (LUQ), right lower quadrant (RLQ), and left lower quadrant (LLQ). These quadrants, like the abdominopelvic regions, are used to accurately locate and describe various aches, pains, injuries, or other abnormalities. (Page 17).

Superior

Superior Closer to the head The chest is superior to the pelvis. (Page 12).

Ventral

Ventral At the belly side of the human body The umbilicus (navel, belly button) is on the ventral side of the body. (Page 12).

Diabetes

example of homeostatic imbalance

Chemical Level

simplest level. involves atoms and molecules

Positive feedback

A homeostatic system may also be controlled by positive feedback. The stimulus here is reinforced to continue in the same direction until a climactic event occurs (figure 1.14). Following the climactic event, the body again returns to homeostasis. Because their end result is to increase the activity (instead of initially returning the body to homeostasis), positive feedback mechanisms occur much less frequently than negative feedback mechanisms. body, when a mother breastfeeds her baby. The baby suckling at the breast is the initial stimulus detected by sensory receptors in the skin of the nipple region. The receptors transmit this input to the control center, which is the hypothalamus of the brain. The hypothalamus signals the posterior pituitary to release the hormone oxytocin into the blood. Oxytocin is the "output" that is sent to the effector, which is the glandular tissue of the breast. Oxytocin stimulates the mammary gland to eject the breast milk. The baby feeds and the cycle repeats as long as the baby suckles. Once the baby stops suckling (and thus the initial stimulus is removed), then the cycle will stop. Other examples of positive feedback mechanisms include the blood clotting cascade (see section 18.4) and uterine contractions involved in labor and childbirth (see section 29.6). (Page 22). (Page 22). (Page 22).

Midsagittal Plane

A midsagittal (mid-saj′˘ı-t˘al; sagitta = arrow) plane, or median plane, is a vertical plane and divides the body or organ into left and right halves. A midsagittal plane through the head will split it into a left half and a right half (each containing one eye, one ear, and half of the nose and mouth). (Page 12).

Sagittal Plane

A plane that is parallel to the midsagittal plane, but either to the left or right of the midsagittal plane, is termed a sagittal plane. A sagittal plane divides a structure into left and right portions that are not equal. Although there is only one midsagittal plane, an infinite number of sagittal planes are possible. (Page 12).

Transverse Plane

A transverse plane, also called a horizontal plane or crosssectional plane, divides the body or organ into superior (top) and inferior (bottom) parts. (Page 12).

Which body cavity is located inferior to the diaphragm and superior to a horizontal line drawn between the superior edges of the hip bones?

Abdominal Cavity

Metabolism

All organisms engage in metabolism (m˘e-tab′ˉo-lizm; metabole = change), which is defined as the sum of all of the chemical reactions that occur within the body. (Page 6).

Serous Cavity and Fluid

Between the parietal and visceral serous membrane layers is a potential space called the serous cavity. Serous membranes secrete a liquid called serous fluid within a serous cavity. Serous fluid has the consistency of oil and serves as a lubricant. In a living human, organs (e.g., heart, lungs, intestines) are moving and rubbing against each other and the body wall. Friction caused by this movement is reduced (Page 15).

Deep

Deep On the inside, internal to another structure The heart is deep to the rib cage. (Page 12).

Distal

Distal Farther away from point of attachment to trunk The wrist is distal to the elbow. (Page 12).

Dorsal

Dorsal At the back side of the human body The spinal cord is on the dorsal side of the body. (Page 12).

Medial

Medial Toward the midline of the body The lungs are medial to the shoulders. (Page 12).

Anabolism

Metabolism consists of both anabolism (˘a-nab′ˉo-lizm, anabole = a raising up), in which small molecules are joined to form larger molecules, (Page 6).

Macromolecules

More complex molecules are called macromolecules and include some proteins and the deoxyribonucleic acid (DNA) molecules. (Page 6). Macromolecules form specialized microscopic subunits in cells called organelles, (Page 6).

Negative Feedback

Most processes in the body are controlled by negative feedback If a homeostatic system is controlled by negative feedback, the resulting action will always be in the opposite direction of the stimulus. In this way, the variable is maintained within a normal level, or what is called its set point. (Page 19).

The ____ level of organization is composed of two or more tissue types that work together to preform a common function

Organ

The _____ region is the anterior part of the knee

Patellar

Anatomic Position

Point of common reference An individual in the anatomic position stands upright with the feet parallel and flat on the floor, the upper limbs are at the sides of the body, and the palms face anteriorly (toward the front); the head is level, and the eyes look forward toward the observer (Page 11).

Posterior

Posterior In back of; toward the back surface The heart is posterior to the sternum. (Page 12).

Examining the superficial anatomic markings and the internal body structures as they relate to the covering skin is called:

Surface Anatomy

Control Center

The control center is the structure that interprets input from the receptor and initiates changes through the effector. You can think of it as the "go between" for the other two components of a homeostatic system. The control center is generally a portion of the nervous system (brain or spinal cord) or an endocrine organ (such as the thyroid gland). A homeostatic system involving the nervous system provides a relatively quick means of responding to change. An example is regulating blood pressure when you rise from bed in the morning. In contrast, the endocrine system usually provides a means of a more sustained response over several hours or days through the release of hormones. An example is when the parathyroid hormone continuously regulates blood calcium levels, a process that is essential for the normal function of both muscles and nerves. Note that the control center is sometimes the same structure as the receptor because it both detects the stimulus and causes a response to regulate it. For example, the pancreas acts as a receptor because it detects an increase in blood glucose and also acts as a control center because it releases the hormone insulin in response. (Page 18).

Effector

The effector is the structure that brings about the change to alter the stimulus. Most body structures can serve as effectors. The most common effectors are muscles and glands. For example, smooth muscle in the walls of air passageways (bronchioles) regulate airflow into and out of the lungs. Glands, such as the pancreas, release hormones (e.g., insulin). (Page 19).

Epigastric Region

The epigastric (ep-ı-gas ˘ ′trik; epi = above, gaster = belly) region is the superior region above the umbilical region. (Page 17).

Mediastinum

The median space in the thoracic cavity is called the mediastinum (mˉe-dˉe-as-tˉı′n˘um; medius = middle) (figure 1.8b). It contains the heart, thymus, esophagus, trachea, and major blood vessels that connect to the heart. (Page 16).

Stomach

The peritoneum (per′i-toˉ-neˉ′um; periteino = to stretch over) is the two-layered serous membrane that lines the abdominopelvic cavity (figure 1.9d). The parietal peritoneum, the outer layer of this serous membrane, lines the internal walls of the abdominopelvic cavity. The visceral peritoneum is the inner layer of this serous membrane, and it covers the external surfaces of most abdominal and pelvic organs. The potential space between these serous membrane layers is the peritoneal cavity, which contains and is lubricated by serous fluid. (Page 17).

Posterior Aspect of Body

The posterior aspect of the body is different from the ventral cavity, in that the posterior aspect contains cavities that are completely encased in bone and are physically and developmentally different from the ventral cavity. The term dorsal body cavity has been used by others to describe this posterior aspect, but is not used here because of these differences between the ventral cavity and posterior aspect. (Page 15). (Page 14). (Posterior aspect cavities have no serous membranes.) (Page 15).

Receptor

The receptor is the body structure that detects changes in a variable, which is a substance or process that is regulated. A receptor typically consists of sensory neurons (nerve cells). These neurons may be in the skin, internal organs of the body, or specialized organs such as the eye, ear, tongue, or nose. A stimulus is a change in the variable (a physical or chemical factor), such as a change in light, temperature, chemicals (e.g., glucose or oxygen levels), or stretch in muscle. For example, the retina of the eye (receptor) detects a change in light (stimulus) entering the eye. (Page 18).

Right and LEFT Iliac Regions

The right and left iliac (il′ˉe-ak; eileo = to twist) regions are lateral to the hypogastric region. (Page 17).

Right and Left Lumbar Regions

The right and left lumbar regions are lateral to the umbilical region. (Page 17).

Lungs

The right and left sides of the thoracic cavity house the lungs, which are associated with a two-layered serous membrane called the pleura (plˉur′˘a; = a rib) (figure 1.9c). The parietal pleura is the outer layer of the serous membrane and lines the internal surface of the thoracic wall. The inner layer is the visceral pleura, which covers the external surface of each lung. The pleural cavity is the potential space between these parietal and visceral layers, and it contains serous fluid. (Page 16).

Homeostasis

The term homeostasis (homoios = similar, stasis = standing) refers to the ability of an organism to maintain consistent internal environment, or "steady state," in response to changing internal or external conditions. (Page 18).

Section

The term section implies an actual cut or slice to expose the internal anatomy, (Page 11).

Umbilical Region

The umbilical (u˘ m-bil′i-k˘al; = navel) region is the middle region and is named for the umbilicus, or navel (belly button) that lies in its center. (Page 17).

Anterior Aspect of the Body

The ventral cavity is the larger, anteriorly placed cavity in the body (figure 1.8). Unlike the posterior aspect, the ventral cavity and its subdivisions do not completely encase their organs in bone. The ventral cavity is partitioned by the diaphragm into a superior thoracic (thˉo-ras′ik) cavity and an inferior abdominopelvic (ab-dom′i-nˉo-pel′vik) cavity. (Page 15). the subdivisions of the ventral cavity are lined with thin serous membranes. (Page 15).

The _____ is he serous membrane layer that covers the surface of the lungs

Visceral Pleura

Heart

Within the mediastinum, the heart is enclosed by a two-layered serous membrane called the serous pericardium (per-˘ı-kar′d ˉe-˘um; peri = around, kardia = heart). The parietal pericardium is the outermost layer of the serous membrane and forms the sac around the heart, whereas the visceral pericardium forms the heart's external surface (figure 1.9b). The pericardial cavity is the potential space between the parietal and visceral layers of the pericardium, and it contains serous fluid. (Page 16).

Catabolism

catabolism (k˘a-tab′ˉo-lizm; katabole = a casting down), in which large molecules are broken down into smaller molecules. (Page 6).

Plane

the word plane implies an imaginary flat surface passing through the body. (Page 11).