The Human Body: An Orientation Ch. 1a

Overview of Anatomy and Physiology

Principle of Complementarity Anatomy and physiology are inseparable.

Levels of Structural Organization Chemical: Cellular: Tissue: Organ: Organ system: Organismal:

Cardiovascular system Organelle Atoms Molecule Smooth muscle cell 2 Cellular level 1 Chemical level Smooth muscle tissue Cardiovascular system 3 Tissue level Tissues consist of similar types of cells. Heart Blood vessels Blood vessel (organ) Smooth muscle tissue Connective tissue Epithelial tissue 4 Organ level Organs are made up of different types of tissues. Organismal level The human organism is made up of many organ systems. 6 5 Organ system level Organ systems consist of different organs that work together closely. Figure 1.1

Integumentary System – Maintains boundaries: Cellular Membranes Skin Hair Skin Nails Integumentary System – Maintains boundaries: Cellular Membranes Skin Figure 1.3a

Protects and supports body organs Attachment site for muscles Bones Joint Skeletal System – Movement Protects and supports body organs Attachment site for muscles Mineral storage Blood cell formation Figure 1.3b

Locomotion, facial expression Maintains posture Produces heat. Skeletal muscles Muscular System Locomotion, facial expression Maintains posture Produces heat. Figure 1.3c

Fast-acting control system of the body Brain Nerves Spinal cord Nervous System Fast-acting control system of the body Responds to internal & external changes by activating appropriate muscles and glands. Figure 1.3d

Glands secrete hormones that regulate processes various processes Pineal gland Pituitary gland Thyroid gland Thymus Adrenal gland Pancreas Testis Ovary Endocrine System Glands secrete hormones that regulate processes various processes Figure 1.3e

Cardiovascular System Heart Blood vessels Cardiovascular System Blood vessels transport blood, which carries oxygen, carbon dioxide, nutrients, wastes, etc. The heart pumps blood. Figure 1.3f

(Lymphatic System/Immunity Picks up fluid leaked from blood vessels Red bone marrow Thymus Lymphatic vessels Thoracic duct Spleen Lymph nodes (Lymphatic System/Immunity Picks up fluid leaked from blood vessels and returns it to blood Disposes of debris in lymphatic stream Houses WBC’s involved in immunity. Figure 1.3g

Nasal cavity Pharynx Bronchus Larynx Trachea Lung Respiratory System Keeps blood constantly supplied with oxygen and removes carbon dioxide. Figure 1.3h

Breaks down food into absorbable units that enter blood Oral cavity Esophagus Liver Stomach Small intestine Large intestine Rectum Anus Digestive System Breaks down food into absorbable units that enter blood for distribution to body cells. Indigestible foodstuffs are eliminated as feces. Figure 1.3i

Eliminates nitrogenous wastes Regulates water, electrolyte and Kidney Ureter Urinary bladder Urethra Urinary System Eliminates nitrogenous wastes Regulates water, electrolyte and acid-base balance of the blood. Figure 1.3j

Overall function is production of offspring. Mammary glands (in breasts) Prostate gland Ovary Penis Testis Ductus deferens Scrotum Uterine tube Uterus Vagina Male Reproductive System (Female Reproductive System Overall function is production of offspring. Figure 1.3k-l

Figure 1.3 Digestive system Takes in nutrients, breaks them down, and eliminates unabsorbed matter (feces) Respiratory system Takes in oxygen and eliminates carbon dioxide Food O2 CO2 Cardiovascular system Via the blood, distributes oxygen and nutrients to all body cells and delivers wastes and carbon dioxide to disposal organs Blood CO2 O2 Urinary system Eliminates nitrogenous wastes and excess ions Heart Nutrients Interstitial fluid Nutrients and wastes pass between blood and cells via the interstitial fluid Integumentary system Protects the body as a whole from the external environment Feces Urine Figure 1.3

Survival Needs Nutrients Oxygen Water Normal body temperature Appropriate atmospheric pressure

Homeostasis Definition: A dynamic state of equilibrium

Components of a Homeostatic Control Mechanism Receptor (sensor) Control center Effector

Output: Information sent along efferent pathway to effector. 4 3 Input: Information sent along afferent pathway to control center. Control Center Afferent pathway Efferent pathway 2 Receptor Effector 5 Receptor detects change. Response of effector feeds back to reduce the effect of stimulus and returns variable to homeostatic level. 1 IMBALANCE Stimulus produces change in variable. BALANCE IMBALANCE Figure 1.4

The response reduces or shuts off the original stimulus Negative Feedback The response reduces or shuts off the original stimulus Example: Regulation of body temperature

Temperature-sensitive Temperature-sensitive Control Center (thermoregulatory center in brain) Information sent along the afferent pathway to control center Information sent along the efferent pathway to effectors Afferent pathway Efferent pathway Receptors Temperature-sensitive cells in skin and brain Effectors Sweat glands Sweat glands activated Response Evaporation of sweat Body temperature falls; stimulus ends Stimulus Body temperature rises BALANCE Stimulus Body temperature falls Response Body temperature rises; stimulus ends Receptors Temperature-sensitive cells in skin and brain Effectors Skeletal muscles Efferent pathway Afferent pathway Shivering begins Information sent along the efferent pathway to effectors Information sent along the afferent pathway to control center Control Center (thermoregulatory center in brain) Figure 1.5

The response enhances or exaggerates the original stimulus Positive Feedback The response enhances or exaggerates the original stimulus Rare in biological systems Example: Enhancement of labor contractions by oxytocin

1 3 2 4 Break or tear occurs in blood vessel wall. Positive feedback cycle is initiated. 3 Released chemicals attract more platelets. Platelets adhere to site and release chemicals. 2 Positive feedback loop Feedback cycle ends when plug is formed. 4 Platelet plug forms. Figure 1.6

Chapter 1b

Standard anatomical body position: Anatomical Position Standard anatomical body position: Body erect Feet slightly apart Palms facing forward

Regional Terms Regional Terms: designate specific areas/regions of the body.

Upper limb Acromial Orbital Brachial (arm) Nasal Antecubital Oral Antebrachial (forearm) Cervical Carpal (wrist) Thoracic Axillary Digital Sternal Abdominal Lower limb Umbilical Coxal (hip) Pelvic Femoral (thigh) Inguinal Patellar Crural (leg) Pubic Fibular Tarsal (ankle) Thorax Abdomen Back (Dorsum) (a) Anterior/Ventral Figure 1.5

Upper limb Cephalic Acromial Brachial (arm) Occipital (back of head) Olecranal Cervical Back (dorsal) Scapular Vertebral Digital Lumbar Sacral Femoral (thigh) Gluteal Popliteal Sural (calf) Fibular Calcaneal Plantar (b) Posterior/Dorsal Figure 1.5

Table 1.1

Table 1.1

Table 1.1

Table 1.1

Table 1.1

Body Planes and Sections Sagittal plane Midsagittal (median) plane Parasagittal plane Frontal (coronal) plane Transverse (horizontal) plane

Median (midsagittal) plane Frontal plane Median (midsagittal) plane Transverse plane (a) Frontal section (through torso) (b) Transverse section (through torso, inferior view) (c) Median section (midsagittal) Pancreas Aorta Spleen Left and right lungs Liver Heart Spleen Liver Spinal cord Rectum Intestines Body wall Stomach Arm Vertebral column Subcutaneous fat layer Figure 1.6

Body Cavities Two Large Cavities: Dorsal cavity Two subdivisions: Cranial cavity Vertebral cavity

Body Cavities Ventral cavity Two subdivisions (separated by diaphragm):

Cranial cavity Cranial cavity Dorsal body cavity Ventral body cavity Vertebral cavity Dorsal body cavity Thoracic Cavity Vertebral cavity Ventral body cavity (thoracic and abdominopelvic cavities) Diaphragm Abdominal cavity (contains digestive viscera) Abdomino- pelvic cavity Pelvic cavity (contains urinary bladder, reproductive organs, and rectum) (a) Lateral view (b) Anterior view Figure 1.7

Thoracic cavity subdivisions: Ventral Body Cavities Thoracic cavity subdivisions: Two pleural cavities Mediastinum Pericardial cavity

Abdominopelvic cavity subdivisions: Ventral Body Cavities Abdominopelvic cavity subdivisions: Abdominal cavity Pelvic cavity

Thoracic cavity Cranial cavity Vertebral cavity Cranial cavity Dorsal body cavity Ventral body cavity Vertebral cavity Thoracic cavity Dorsal body cavity Vertebral cavity Ventral body cavity Diaphragm Abdominal cavity Abdomino- pelvic cavity Pelvic cavity (a) Lateral view (b) Anterior view Figure 1.7

Abdominopelvic Regions Nine divisions used primarily by anatomists

Figure 1.12 Liver Diaphragm Right hypochondriac region Left Epigastric region Gallbladder Stomach Right lumbar region Left lumbar region Ascending colon of large intestine Transverse colon of large intestine Umbilical region Small intestine Descending colon of large intestine Cecum Right iliac (inguinal) region Hypogastric (pubic) region Left iliac (inguinal) region Initial part of sigmoid colon Appendix Urinary bladder (a) Nine regions delineated by four planes (b) Anterior view of the nine regions showing the superficial organs Figure 1.12

Abdominopelvic Quadrants Divisions used primarily by medical personnel

Right upper Left upper quadrant quadrant (RUQ) (LUQ) Right lower (RLQ) Left lower quadrant (LLQ) Figure 1.11