Lecture 5 - Human Being & Homeostasis (2024) PDF

Integrated Lecture: Human Being & Homeostasis Denny Agustiningsih Neni Trilusiana Rahmawati/Janatin Hastuti Junaedy Yunus Learning Objectives 1. Understand the homo sapiens as human being and its variation 2. Understand...

Integrated Lecture: Human Being & Homeostasis Denny Agustiningsih Neni Trilusiana Rahmawati/Janatin Hastuti Junaedy Yunus Learning Objectives 1. Understand the homo sapiens as human being and its variation 2. Understand the basic structure and function of the human body, with basic embryology correlation 3. Understand the principle of homeostasis Case Scenario Freezing Office Rini is working as a secretary. Her office is so nice and comfortable, but it is freezing cold since her boss likes cold temperature. During her working hours, she usually urinates much and more often. Sometimes she is even shivering and having goosebumps. These are what she doesn’t like it being in the office. But the good side is that she doesn’t sweat much. Questions to be discussed: A. What organs are involved to maintain homeostasis of the body in this case? B. How is the mechanism of our body to maintain homeostasis in this case? C. How is the homeostasis setting in Rini’s body to maintain her core body temperature? Scenario Analysis Shivering Human Being and Variation Characteristic of Human Being  Adaptation Human Variation Differences between people and populations Differences among members of the same species By Saharauiak - Old man and his camel, CC BY-SA 2.0, https://commons.wikimedia.org/w/index.php?curid=1178 3523 Adaptation to altitude High environments have a lot of environmental stress. At high places the O2 concentration is low--- low pressure Mechanism Increases O2 and PO2 availability at the network level Response to growth Individual factors and tolerance for high places: Age Physical endurance Sex Tibet people By Arian Zwegers from Brussels, Belgium - Response --- lung capacity, heart rate, production of red blood cells, light sensitivity, memory Zhongdian festival, CC BY 2.0, down, hearing down, taste sensitivity, difficulty sleeping, headaches, digestion disturbed, weight loss, https://commons.wikimedia.org/w/index.php?cur id=27472089 sexual function, growth. High altitude habitation (>3000m) Rocky Mt, USA, Canada Atlas Mt, Morocco Sierra Madre Mexico Ethiopia Andes, South America (Nunoa, Huancayo) Kilimanjaro, East Africa Pyrenees, French, Espanola Basutoland, East Africa Tien Shan Mt, Russia (Aymara) Kilimanjaro Himalaya Mt (Sherpa, Lepcha) By Chris 73 / Wikimedia Commons, CC BY-SA 3.0, Alpen Mt https://commons.wikimedia.org/w/index.php?curid=179266 7  Adaptation to cold Biological response  heat production and conservation Heat production ---- shivering Conservation ----- vasoconstriction (narrowing of blood vessels) Environmental factors that influence cold stress: Wind velocity Humidity Duration Tribes Aboriginal (Australian) Siberian Eskimo Bushmen (Kalahari, Africa) https://en.wikipedia.org/wiki/File:Siberian- eskimo-Nabogatova-.PNG Eskimo Lapp (Norway)  Biological response to cold stress: Long-term: Evolution is clearer, denser body mass, relatively less surface area. Increases basal metabolic rate Important organs wrapped in fat Long-term changes in blood flow patterns Short-term: Vasoconstriction vasodilation (the Lewis Hunting Phenomenon) Shivering VARIATION IN BODY SIZE AND PROPORTIONS Bergmann’s rule The body with the same body shape, which is larger has a relatively smaller proportion of surface area  humans adapted to INUIT Eskimo cold have relatively larger bodies, https://upload.wikimedia.org/wikipedia/ but those who live in the tropics commons/8/8a/Inuit-Kleidung_1.jpg have smaller bodies. Allen’s rule Short extremities increase the ratio of body mass to body surface area and those who are cold-adapted have relatively short extremities. Maasai people, Tanzania https://upload.wikimedia.org/wikipedia/commons/9/9 9/Maasai_tribe.jpg Examples of adaptation to heat in some tribes:  Aboriginal (Australia)  Bushmen (Kalahari) Aka Pygmy Congo  Chamba (Sahara desert) https://upload.wikimedia.org/wikipedia/com mons/f/fb/Living_on_the_rainforest.jpg low sweat rate High surface area/BB ratio Sahara people Aborigin, Australia Adaptation to Sun Light and Skin Color Differences Solar radiation functions: 1) provide light and heat 2) synthesis of biochemical components such as vitamin D 3) affect hormonal and neural changes in skin pigmentation Adaptive significance of dark skin and light skin Dark skin is more adaptive to skin and melanoma cancer Light skin is more adaptive to vitamin D synthesis San People, Bushmen https://en.wikipedia.org/wiki/File: Namibian_Bushmen_Girls.JPG  Light skin can meet vitamin D needs with very little sunlight.  Blacks in northern latitudes are more susceptible to rickettsia than whites  reduction in adult pelvic size  affects reproduction.  Frostbite is important in the evolution of whites. In cold temperatures, tissue damage to colored skin is more.  References: Moran EF. (2022) Human Adaptability: An Introduction to Ecological Anthropology (4th Edition). New York: Routledge Muehlenbein MP. (2010) Human Evolutionary Biology. Cambridge: Cambridge University press. Basic Structure and Function of the Human Body 18 Structural Organization of the Human Body Chemical Cellular Smallest independently functioning unit of a living organism Tissue Organ Organ system Organism Organ Systems Integumentary system Lymphatic system Skeletal system Respiratory system Muscular system Digestive system Nervous system Urinary system Endocrine system Male reproductive system Cardiovascular system Female reproductive system Integumentary System Skin Skin appendages: Hairs Nail Skin glands Subcutaneous tissue Breast Scalp Skeletal System Bones: Axial skeleton Appendicular skeleton Cartilages: Hyaline Fibrocartilage Elastic Joints: Fibrous Cartilaginous Synovial Teeth Muscular System Muscles: Skeletal Cardiac Smooth Fascia Synovial bursae Tendon sheaths Nervous System CNS: Meninges Brain Spinal cord PNS: Cranial nerves Spinal nerves ANS: Sympathetic Parasympathetic Endocrine System Hypophysis Pineal gland Thyroid gland Parathyroid gland Suprarenal gland Pancreas Testes/ovaries Cardiovascular System Heart Vessels: Artery Vein Capillary Lymphatic System Lymphatic vessels Lymphoid organs: Primary: bone marrows, thymus Secondary: spleen, lymph nodes Respiratory System Nose Nasopharynx – oropharynx Larynx Tracheobronchial tree Lungs Digestive System Mouth Oropharynx – laryngopharynx Esophagus Stomach Small intestine Large intestine Anal canal Accessory glands: Salivary glands Liver, gallbladder Pancreas Urinary System Kidney Ureter Urinary bladder Urethra Male Reproductive System Testis Epididymis Vas deferens Ejaculatory duct Glands: Seminal gland Prostate Bulbourethral gland Penis Scrotum Female Reproductive System Ovary Uterine tube Uterus Vagina Vulva Clitoris Basic Embryology Developmental Periods Prenatal, postnatal Prenatal: Germinal: week 1-2 Embryonic: week 3-8 Fetal: week 9-birth Postnatal: Infancy--Neonate Childhood Puberty Adulthood Trimester: I (week 1-13), II (week 14-26), III (week 27-40) Descriptive Terms Cranial – caudal Ventral – dorsal Median-sagittal plane Transversal/axial plane Frontal/coronal plane Derivatives of the three germ layers Fetal Period Estimation of fetal age: CRL Biparietal diameter Head circumference Abdominal circumference Femur length Foot length Homeostasis EXPOSURE TO HUMAN BODY INTERNAL EXPOSURE TO HUMAN BODY Internal exposure internal stimuli Daily activity Set point deviation  HOMEOSTASIS The name for the processes which keep the condition and environment of the tissues (internal environment) in the proper condition to sustain life. self-regulating process by which an organism can maintain internal stability while adjusting to changing external condition The dynamic mechanisms that detect and respond to deviations in physiological variables from their “set point” values. Normal Ranges (SET POINTS) for Some Blood Values Arterial pH 7.35-7.45 The set point is the normal Bicarbonate 24-28 mEq/L parameter value in a person's Sodium 135-145 mEq/L body. Calcium 4.5-5.5 mEq/L The set point deviates when Oxygen content 17.2-22 ml/100ml there are external or internal Urea 12-35 mg/100 ml stimuli/exposures Amino acids 3.3-5.1 mg/100ml Set point deviation triggers Protein 6.5-8 g/100ml homeostatic mechanisms Total lipids 400-800 mg/100ml set point has a narrow range to make it easier to detect if there Glucose 75-110 mg/100ml is a deviation The main Internal components of homeostasis Concentration of pH of the Concentration of oxygen and internal nutrients and carbon dioxide environment waste products Concentration of Volume and salt and other pressure of electrolytes extracellular fluid Maintenance of Homeostasis Maintaining and keeping the set point back to the normal range is very important  ROLE OF BODY SYSTEMS IN HOMEOSTASIS body system function aims to maintain and restore the set point several body systems can work together to maintain a constant internal environment Physiology, as a discipline dedicated to understanding how the parts of the body work together to maintain health.  Autoregulation (local control) When cells, tissues, organs or Control systems automatically change in Mechanisms in response to signals within themselves. Homeostasis Extrinsic control Changes stimulated by signals from outside of the cell, organ, or system  Extrinsic control is mediated by Nervous brain & spinal cord electrical signals system response is rapid but short term. Endocrine glands produce hormones system response is slower but lasts longer Homeostatic Control Mechanisms responses made after change has been detected Feedback Types of feedback systems Negative Positive responses made in Feedforward anticipation of a change Components of Feedback Mechanisms Stimulus The change from ideal or resting conditions. Receptor The cells or tissue which detects the change due to the stimulus Relay The transmission of the message, via nerves or hormones or both Integrating center Effector The cells or tissue, usually a gland or muscles, which cause the response to happen.  E.G. Thermostat in brain hypothalamus (integrator) Set-points can Increase in set-point for core body temperature during fever be modified E.G. Acclimatization to environmental temperature, altitude (increase red blood cells) REFFERENCES