Human Biology and Health Practice Flashcards

Comprehensive flashcards covering sense organs, homeostasis, the nervous and endocrine systems, respiratory and circulatory functions, digestion, excretion, infectious diseases, immunity, and reproductive strategies.

What are the five human sense organs listed in the transcript?

The eyes, ears, skin, tongue, and nose.

Identify the five types of receptors that respond to different stimuli.

Thermoreceptors, mechanoreceptors, chemoreceptors, photoreceptors, and pain receptors.

Define homeostasis.

Homeostasis is the constant maintenance of the internal body environment.

Which three variables specifically need to be kept within a particular range for body health?

Blood glucose, water, and carbon dioxide ($CO_2$).

What is the difference between negative and positive feedback?

Negative feedback occurs when the response is in an opposite direction to the stimulus; positive feedback occurs when the response is in the same direction as the change in stimulus.

What hormone is provided as an example of positive feedback during childbirth?

Oxytocin.

What are the components of the central nervous system (CNS)?

The brain and spinal cord.

Name the three types of neurons.

Sensory, interneuron, and motor neuron.

What is a synapse and what chemicals are released there?

A synapse is a gap between neurons where neurotransmitters are released.

List the three main parts of a neuron.

Dendrites, cell body, and axon.

What are the three main divisions of the brain and their components?

The forebrain (cerebrum, thalamus), the midbrain (reticular formation), and the hindbrain (medulla, pons, and cerebellum).

What is the function of the reticular formation?

It helps regulate alertness (from fully awake to deeply asleep), motivation, movement, and some reflexes.

How do hormones travel through the body in the endocrine system?

They are secreted into the bloodstream and travel via the circulatory system to act on target cells.

Which two hormones produced by the pancreas regulate blood glucose levels?

Insulin and glucagon.

Define paralysis and its cause in relation to the nervous system.

Paralysis is the loss of movement that can result from damage to the nervous system, particularly the spinal cord.

What is the main role of the respiratory system?

To take oxygen ($O_2$) into the body and carbon dioxide ($CO_2$) out.

Describe the composition of the lungs.

The lungs are made up of bronchi, bronchioles, and alveoli.

What happens during cellular respiration?

It is the breakdown of food in the presence of oxygen to produce energy in a form cells can use.

How is oxyhaemoglobin formed?

Oxygen moves from the alveoli into red blood cells and binds to haemoglobin.

Contrast the structure and function of arteries and veins.

Arteries transport oxygenated blood away from the heart and have thick, muscular, rigid walls; veins carry deoxygenated blood to the heart and have thin, collapsible walls containing valves.

Trace the path of oxygenated blood from the pulmonary vein to the body cells.

Pulmonary vein $\rightarrow$ left atrium $\rightarrow$ left ventricle $\rightarrow$ aorta $\rightarrow$ arterioles $\rightarrow$ capillary $\rightarrow$ body cells.

List the organs of the digestive system in order of food passage.

Mouth, oesophagus, stomach, small intestine, large intestine, rectum, and anus.

Name the three main types of enzymes and what they digest.

Amylase (carbohydrates), protease (protein), and lipase (fats/lipids).

What is the role of the kidneys in the excretory system?

They excrete unused waste products (such as urea) and excess chemicals (including water) to maintain blood balance.

Distinguish between infectious and non-infectious diseases.

Infectious diseases are contagious and caused by a pathogen; non-infectious diseases are not contagious and cannot be spread from person to person.

What are the three types of non-cellular pathogens?

Viruses, prions, and viroids.

What is an antigen?

Specific chemicals on pathogens recognized as non-self or foreign that trigger an immune response.

What are the physical and chemical barriers of the first line of defence?

Physical barriers include skin, coughing, sneezing, cilia, and nasal hairs; chemical barriers include saliva, tears, stomach acid, and acidic vaginal mucus.

How does the second line of defence function?

It involves inflammation and phagocytes that engulf and destroy pathogens through phagocytosis.

Explain the role of B lymphocytes and T lymphocytes in the third line of defence.

B lymphocytes differentiate into plasma cells to produce antibodies; T lymphocytes fight pathogens at a cellular level and attack damaged or cancerous cells.

Differentiate between active and passive immunity.

Active immunity is achieved by the body making its own antibodies; passive immunity is achieved by receiving antibodies from an outside source (e.g., mother's milk).

What virus causes poliomyelitis?

Picornaviridae virus.

Define the terms Epidemic and Pandemic.

An epidemic occurs when many people in a particular area have a disease in a short time; a pandemic is a disease that occurs worldwide.

Match the following influenza types to their subtypes: Spanish flu, Asian flu, Avian flu, Swine flu.

Spanish flu: $H_1N_1$; Asian flu: $H_2N_2$; Avian flu: $H_5N_1$; Swine flu: $H_1N_1$.

List five types of asexual reproduction.

Binary fission, budding, vegetative propagation, regeneration, and parthenogenesis.

How long is the typical human gestation period?

$38-40$ weeks, or nine months.