Human Biology: Nervous System, Senses, and Reproduction
1. Organization of the Nervous System
1.1 Central Nervous System
- Brain:
- Cerebrum (Cerebral Cortex and Limbic System)
- Cerebellum
- Brainstem
- Hypothalamus
- Epithalamus
- Thalamus
- Spinal Cord
1.2 Peripheral Nervous System
- Autonomic Nervous System:
- Sympathetic
- Parasympathetic
- Somatic Nervous System:
- Sensory Nerves
- Motor Nerves
2. Nerve Impulse
2.1 Along a Neuron
The nerve impulse travels in the form of an electric current from the dendrite to the soma (cell body) to the axon.
2.2 Neuron to Neuron
Transmission occurs via connections
Read MoreDigestive & Respiratory Systems: Anatomy, Functions & Diseases
Digestive System
Gastrointestinal Tract
The gastrointestinal tract is a long tube that extends from the mouth to the anus. It’s responsible for the digestion and absorption of food.
Parts of the Digestive System:
Oral Cavity (Mouth)
- Salivation: Saliva contains amylase (breaks down complex carbohydrates), lysozyme (kills bacteria), and mucin (lubricates food).
- Chewing: Mechanically breaks down food into smaller pieces.
- Swallowing: Chewed food mixed with saliva (bolus) is pushed by the tongue to the pharynx
Complications of Liver Failure: A Case Study
Clinical Situation 4: Liver Failure Case Study
77-Year-Old Male with Aggravated Liver Failure
Background:
- Liver failure from cirrhosis of enolic origin.
- Upper gastrointestinal bleeding from esophageal varices 2 months ago.
- Poorly controlled type 2 diabetes mellitus.
Evolution (Day 2 of Admission):
- Drowsiness and confusion, disorientation in space and time, not recognizing family members.
- Prostrate, remains in bed all day but moves independently within the bed.
- Increased waist circumference (2.5 cm from admission)
Lipids, Cell Biology, and Immunology Overview
Lipids
Properties and Classification
Lipids are organic molecules composed of carbon, hydrogen, and oxygen. Some complex lipids also contain nitrogen, phosphorus, or sulfur. Key properties include insolubility in water, solubility in organic solvents, and low density.
Lipids are classified into:
- Fatty acids
- Saponifiable lipids:
- Simple: Triacylglycerols and waxes
- Complex: Phosphoglycerides and sphingolipids
- Non-saponifiable lipids:
- Steroids
- Terpenes
- Icosanoids
Cholesterol
Cholesterol, a sterol, is present in
Read MoreHip, Knee, and Ankle Anatomy and Function
Hip Joint
Articulation
The hip joint is a ball-and-socket joint (enarthrosis/spheroidal).
Joint Surfaces
- Femur
- Hip Bone
Muscles
Flexors
- Iliopsoas
- Rectus Femoris (Quadriceps)
- Sartorius
- Tensor Fascia Lata
- Pectineus
Extensors
- Hamstrings (Biceps Femoris, Semitendinosus, Semimembranosus)
- Gluteus Maximus, Medius, and Minimus
Adductors
- Adductor Brevis, Longus, and Magnus
- Gracilis
Internal Rotators
- Gluteus Medius and Minimus
External Rotators
- Gluteus Maximus
- Iliopsoas
- Pectineus
- Adductors (Brevis, Longus, Magnus)
- Sartorius
- Tensor
Peroxisomes: Structure, Function, and Associated Diseases
Peroxisomes. In 1954, Rhodin found small organelles in the proximal tubule of mouse kidneys, which he called “microbodies.” In 1962, Novikoff discovered microperoxisomes. These self-replicating organelles, bound by a single membrane, are present in all eukaryotic cells. They contain enzymes and are involved in:
- Control of lipid homeostasis by beta-oxidation
- Conversion of cholesterol into bile salts (liver only)
- Plasmalogen biosynthesis
- Cellular respiration
- In plants, seed peroxisomes convert fatty acids