Chapter 1: The Human Organism

Question 1

What are the major organ systems?

Answer 1

1. integumentary
2. cardiovascular
3. digestive
4. urinary
5. skeletal
6. muscular
7. lymphatic
8. endocrine
9. nervous
10. female reproductive
11. male reproductive

Question 2

What are the essential characteristics?

Answer 2

1. organisation
2. metabolism
3. growth
4. responsiveness
5. reproduction
6. development

Question 3

What is the integumentary system? Explain its functions.

Answer 3

Consists of: skin, hair, nails and sweat glands 
Functions: 
1. regulate temperature 
2. produce vit. D precursors 
3. protection 
4. prevent water loss

Question 4

What is the skeletal system? Explain its functions.

Answer 4

Consists of: bone, cartilage, ligaments, joints
Functions: 
1. protection 
2. movement 
3. stores fats and minerals 
4. produce red blood cells

Question 5

What is the muscular system? Explain its functions.

Answer 5

Consists of: muscles attached to bones by tendons 
Functions: 
1. movement 
2. produce heat 
3. maintains posture

Question 6

What is the lymphatic system? Explain its functions.

Answer 6

Consists of: lymph nodes, lymph vessels, lymph organs 
Functions: 
1. removes foreign substances 
2. combats diseases 
3. maintains tissue fluid balance 
4. absorbs fats from GI

Question 7

What is the respiratory system? Explain its functions.

Answer 7

Consists of : lungs and other respiratory organs
Functions:
1. gas exchange
2. regulation of blood pH

Question 8

What is the digestive system? Explain its functions.

Answer 8

Consists of: mouth, oesophagus, stomach, intestines, rectum, anus
Functions:
1. mechanical and chemical digestion of foods
2. elimination of waste products
3. absorption of nutrients

Question 9

What is the nervous system? Explain its functions.

Answer 9

Consists of: nerves, sensory receptors, brain, spinal cord
Functions:
1. detects sensations
2. control movements

Question 10

What is the endocrine system? Explain its functions.

Answer 10

Consists of: glands
Functions:
1. hormone productions
2. regulate growth, metabolism and reproduction

Question 11

What is the cardiovascular system? Explain its functions.

Answer 11

Consists of: heart, blood vessels, blood
Functions:
1. Transports nutrients, wastes, gases, hormones
2. body temp regulation
3. immune system

Question 12

What is the urinary system? Explain its functions.

Answer 12

Consists of: kidneys, ureter, urinary bladder, urethra
Functions:
1. eliminate wastes
2. regulates blood pH, ion balance and water balance

Question 13

What is the female reproductive system? Explain its functions.

Answer 13

Consists of: ovaries, vagina, uterus, mammary glands
Functions:
1. produce oocytes
2. produce milk for fetus
3. site of fertilization, fetal development
44. produce hormone

Question 14

What is the integumentary system? Explain its functions.

Answer 14

Consists of: testes, penis, ducts 
Functions: 
1. produce sperm cells 
2. produce hormones 
3. transport of sperms from penis to vagina

Question 15

What is negative feedback?

Answer 15

When the deviation from the normal set point becomes lower and is maintained within the normal range.

The components of negative feedback mechanism:

1. receptors: monitors the value of variable
2. control center: establish a set point
3. effector: change the value fo variable

Question 16

Give an example of negative feedback mechanism.

Answer 16

Blood is moved from the heart to the tissues and all over the body. The blood supplies the tissues with oxygen and nutrients, while removing waste products. This regulates the blood pressure and keep it within the normal range.

Question 17

What is positive feedback?

Answer 17

The deviation from the normal set point is made higher than the normal range, thus, the system is not maintained. Positive feedback mechanisms are often lethal and could put big risks on the body.

Question 18

Give an example of positive feedback mechanism.

Answer 18

Contraction of muscles generates Blood Pressure which moves blood through vessels and to the tissues. Blood vessels on the wall of the heart supply blood to the cardiac muscles.

When there is blood loss, the BP decreases and there is an inadequate supply of blood to muscles. Thus, cardiac muscle homeostasis is interrupted and cardiac muscle does not function properly. The heart pumps less blood and the blood pressure drops. This drop in blood pressure means less pumping, and this process goes on till heart stops beating, and death results.

Question 19

Define anatomy, surface anatomy, anatomical imaging and physiology.

Answer 19

Anatomy: the study fo the structures of the body

Surface anatomy: usage of superficial structures to locate deeper structures

Anatomical imaging: a noninvasive method for examining deep structures

Physiology: the study of the processes and functions of the body

Question 20

What does the term homeostasis mean? If a deviation from homeostasis occurs, what kind of mechanism restores homeostasis?

Answer 20

Homeostasis: the condition in which body functions, fluids and other factors of the internal environment are maintained within a range of values suitable to support life

Negative - feedback mechanism occurs to restore homeostasis.

Question 21

Describe a negative - feedback mechanism in terms of receptor, control center, and effector. Give an example of a negative-feedback mechanism.

Answer 21

Blood pressure homeostasis is a negative-feedback mechanism. The blood pressure is closely monitored by the receptors which are located in the heart. When BP increases, the receptor detects and send it to control center in the brain. The control center informs the heart to decrease in HR which decreases the BP. This change is known as an effector.

Question 22

Define positive - feedback mechanism. Why are positive-feedback mechanisms generally harmful?

Answer 22

Positive - feedback mechanism makes deviations from normal even greater.

They are generally harmful because these deviations could often lead to death, if not medically treated.

Question 23

Give an example of a harmful positive-feedback mechanism.

Answer 23

Harmful:
Fever can cause a positive feedback within homeostasis that pushes the body temp continually higher. If the temp reaches 45 degrees centigrade cellular proteins denature bringing metabolism to a stop and death.

OR

Chronic hypertension can favor the process of atherosclerosis which causes the openings of blood vessels to narrow. This, in turn, will intensify the hypertension bring on more damage to the walls of blood vessels

Question 24

Give an example of a beneficial positive-feedback mechanism.

Answer 24

Childbirth is an example. Pressure caused by the baby’s head on the mothers uterus causes an increase in the production of the hormone, oxytocin.
Oxytocin causes more intense uterine contractions which in turns causes more pressure on the wall of the uterus. This leads to the release of even more oxytocin. This feedback loops continues until the child is born.

Question 25

What is the anatomic position? Why is it important to remember the anatomic position when using directional terms?

Answer 25

Anatomic position: A human standing erect with the face directed forward, upper limbs handing to the sides, and palms facing forward Understanding terminology ensures doctors and technicians have a shared method of communicating, which helps to avoid confusion when pinpointing structures and describing locations of lesions.

Question 26

# Define and give an example of the following directional terms: 1. Anterior : 2. Posterior : 3. Inferior : 4. Superior : 5. Dorsal : 6. Ventral : 7. Proximal : 8. Distal : 9. Lateral : 10. Medial : 11. Superficial : 12. Deep :

Answer 26

1. Anterior : front 2. Posterior : back 3. Inferior : lower (caudal) 4. Superior : higher (cephalic) 5. Dorsal : posterior 6. Ventral : anterior 7. Proximal : nearest 8. Distal : far 9. Lateral : near sides 10. Medial : near midline 11. Superficial : surface 12. Deep : deep

Question 27

List the subdivisions of the upper limbs.

Answer 27

``` UPPER LIMB: Anterior: - axillary (armpit) - brachial (arm) - antecubital (front of elbow) - antebrachial (forearm) - carpal (wrist) - palmar (palm) - digital (fingers) ``` Posterior: - acromial (point of shoulder) - olecranon (point of elbow) - dorsum (back of hand)

Question 28

List the subdivisions of the lower limbs.

Answer 28

``` LOWER LIMB: Anterior: - coxal (hip) - femoral (thigh) - patellar (kneecap) - crural (leg) - talus (ankle) - dorsum (top of foot) - digital (toes) ``` Posterior: - popliteal (hollow behind knee) - sural (calf) - plantar (sole) - calcaneal (heel)

Question 29

List the subdivisions of the trunk.

Answer 29

``` TRUNK: Anterior: - pectoral (chest) - sternal (breastbone) - mammary (breast) - abdominal (abdomen) - umbilical (navel) - pelvic (pelvis) - inguinal (groin) - pubic (genital) ``` Posterior: - scapular (shoulder blade) - vertebral (spinal column) - lumbar (loin) - sacral (between hips) - gluteal (buttock) - perineal (perineum)

Question 30

Define sagittal planes.

Answer 30

Sagittal: divides body into left and right

Question 31

Define midsagittal planes.

Answer 31

Midsagittal: a sagittal plane that perfectly divides the body down the midline.

Question 32

Define transverse planes.

Answer 32

Transverse: divides the body into superior and inferior parts

Question 33

Define frontal planes.

Answer 33

Frontal: divides the body into anterior and posterior

Question 34

Define longitudinal planes.

Answer 34

Longitudinal: divides an organ along its long axis

Question 35

Define transverse planes.

Answer 35

Transverse: cuts an organ at a right angle to the long axis

Question 36

Define oblique planes.

Answer 36

Oblique: cuts across the long axis at an angle other than a right angle

Question 37

Define the following cavities: thoracic cavities.

Answer 37

Thoracic: bounded by ribs and diaphragm and divided by mediastinum, contains heart, thymus, trachea, eosophagus, 2 lungs on 2 sides

Question 38

Define the following cavities: abdominal cavities.

Answer 38

Abdominal: bounded by diaphragm and abdominal muscles, | contains stomach, intestine, liver, spleen, pancreas, kidneys

Question 39

Define the following cavities: abdominopelvic cavities.

Answer 39

Abdominopelvic: a cavity of the abdominal and pelvic cavity

Question 40

What is mediastinum?

Answer 40

Divides thoracic cavity. | It consists of the esophagus, trachea, blood vessels, thymus and heart.

Question 41

What is the difference between the visceral and parietal layers of a serous membrane?

Answer 41

Visceral: covers the internal organs Parietal: lines the walls of the cavity

Question 42

What function do serous membranes perform?

Answer 42

Functions: 1. secrete fluid that fills the space between parietal and visceral membranes 2. protect organs from friction

Question 43

Name the serous membrane associated with the heart, lungs and abdominopelvic organs.

Answer 43

The serous membrane covering the heart and lining the mediastinum: pericardium The serous membrane lining the thoracic cavity and surrounding the lungs: pleura The serous membrane lining the abdominopelvic cavity and the viscera: peritoneum.

Question 44

Define mesentery. What does the term retroperitoneal mean? Give an example of a retroperitoneal organ.

Answer 44

Mesenteries are a part of the peritoneum that hold the abdominal organs in place and provide a passageway for blood vessels and organs. Retroperitoneal: covered by parietal peritoneum eg. kidneys, adrenal glands, pancreas, parts of intestines, urinary bladder

Question 45

Describe the pericardial cavity.

Answer 45

The inner (visceral) layer of the serous pericardium lines the outer surface of the heart itself. Between the two layers of the serous pericardium is the pericardial cavity, which contains pericardial fluid. It is this fluid that provides lubrication between the two layers, and allows the heart to expand and contract.

Question 46

Describe the pleural cavity.

Answer 46

The pleural cavity is a fluid filled space that surrounds the lungs. It is found in the thorax, separating the lungs from its surrounding structures such as the thoracic cage and intercostal spaces, the mediastinum and the diaphragm. The pleural cavity is bounded by a double layered serous membrane called pleura. The pleura includes two thin layers of tissue that protect and cushion the lungs. The inner layer (visceral pleura) wraps around the lungs and is stuck so tightly to the lungs that it cannot be peeled off. The outer layer (parietal pleura) lines the inside of the chest wall.

Question 47

Describe the abdominopelvic cavity.

Answer 47

The abdominopelvic cavity (inferior to diaphragm) contains various digestive and reproductive organs, and it can be divided into two sub-cavities: an upper (abdominal) portion and a lower (pelvic) portion: - The abdominal cavity (superior), which contains organs such as the liver, stomach, pancreas, spleen, gallbladder, intestines, and kidneys - The pelvic cavity (inferior), which contains the bladder, reproductive organs, and the distal portions of the large intestine (sigmoid colon and rectum)